Trip to Singapore: September 2006

"It just keeps getting better!"

This simple sentence, often found in many advertisements, sums up my third trip to Singapore in recent times. Although I had some personal matters to attend to, I also had lots of free time and spent nearly all of it outdoors. Although this visit was shorter than the past two (3 weeks, as opposed to 5 weeks), it was equally, if not more productive; I visited new places, made very unusual observations and saw lots of new species! The number of Vespa species I personally know of here now stands at 9! (as opposed to a recorded 3 or 4); the number of Polistes species at least 4; I also found some new Ropalidia, bringing the number of personally confirmed species to 5; Stenogastrine wasps were plentiful as usual and I saw three new species; two of them larger than the rest and attractively patterned. Large cavity-dwelling Pompillids which I have never seen before, bees that make mud nests which look exactly like potter wasp nests, a large swarm of Ropalidia in a crevice on a tree trunk; the list went on and on. Also, I finally caught a specimen of Vespa analis. The weather was truly unpleasant and suffocatingly hot this time, and the first few days seemed quite stale. However, I went on to observe and collect more and more new things, especially towards the end. I could not have asked for more!

Again I kept a journal of this trip, which was updated every night. Much of the text here is actually copied from my daily entries (only on days in which I was able to go out to watch wasps or observed something interesting; there is no need to bore the reader with details of my everyday life!) Warning: If you are busy or have a short attention span, please note that this is going to be very long!

Once again, the locations I described would be familiar to anyone from Singapore. For non-Singapore readers, it would be helpful to know that most of the locations I visited were quite well-vegetated, clean and unpolluted, but at the same time still not far from urban areas.

7/9/2006 - Thursday

As I usually do on my return here, I took a walk around my apartment block early the very first morning. There didn't seem to be many species around. I only saw the common Xylocopa latipes and a couple of Polistes sagittarius. Rather disappointing. From personal experience, September is one of the hottest months, but from what I have read, activity among insects and especially among hornets is unusually high during this period. This is the main reason why I planned my trip to coincide with this period. As a side note, there were more unusual birds than insects this morning. I saw several kingfishers and woodpeckers, all within 30 feet of my apartment block!

The weather is a lot hotter and more oppressive than on my past two trips (March-April 2006 was fairly pleasant by local standards, while May-July 2005 was hot as usual, but nothing like this.) I found myself sweating heavily even early in the morning. Later, I took another walk downstairs, just before lunch. At 11 a.m., the heat was almost intolerable and I felt slightly exhausted just by walking (which is rare for me!) Still, I managed to tolerate it for 15 minutes before deciding to find some shade. I found a lone Polistes sagittarius feeding on nectar from some flowers. She seemed in desperate need of nourishment, unable to fly properly but sucking voraciously at all the flowers she could find. Perhaps due to the heat?

I had other things to do later in the day, so I did not make any further observations. I fervently hoped my luck would improve, and that I wouldn't be braving the hot weather in vain!

8/9/2006 - Friday

Fortunately, I made lots of interesting observations, and there seemed to be more things around today. Even my morning walk near my place turned up more than usual.

I saw lots of Xylocopa confusa, this time not only around flowers but also at their nesting sites. I saw one female inspect a large tree branch very carefully before landing and starting to bite a hole in it. This species seems to like branches void of leaves but still firmly attached to the tree; this habit is in common with its larger relative Xylocopa latipes. It is interesting to note that although Xylocopa confusa is much smaller than Xylocopa latipes, its entrance hole is often about the same width! There are always lots of Xylocopa and Polistes sagittarius at a rather densely vegetated clearing behind my block. This stretch is very interesting. Just behind it is a busy highway. But the highway is lined with thick flowering shrubs such as bougainvillea! Behind this, there is a long stretch of various tall trees, providing lots of shade. It is an unusual sight but it makes the highway look very pleasant, compared to the stark concrete seen in many other places. This is one thing I love about Singapore. One can find vegetation at almost any part of the country.

Here is a view taken from my usual hunting ground; the expressway can be seen clearly, and also the beautiful flowering shrubs on the near side as well as an assortment of trees just in front of the apartment blocks opposite. This photo did not turn out well, so I did something different by editing it like this instead.

I walked slightly further this time, ending up in a wide open field just behind this stretch of forest. Here I saw several Vespa affinis foraging on the grass. I saw one dart at a butterfly and miss.

After breakfast, I visited an old friend at his home. Unlike many other Singaporeans, he lives in a three-storey semi-detached house near the Bedok district. There is a nest of the common honeybee (Apis cerana) in a crevice of his roof, which seemed to be quite active. And several Vespa affinis circled the area, making repeated attempts to capture the bees on their way out or back! Unlike Vespa velutina, Vespa affinis does not hover in front of the nest entrance, but instead circles the area slowly.

Later in the day, I visited Pasir Ris Park. I had once almost given up on this place once, but a succession of interesting sightings and good catches revived my faith in the place. I have long since realised that nothing is predictable; a place may be totally unproductive on one day, and extremely productive the next. I also realised that the "Pasir Ris Park" I frequented in younger days was merely the "main section" with the restaurants, fishing pond and other recreational facilities, merely one out of five large sections! There is still lots to be learned from this park alone! Today's visit to this park turned out to be better than ever!

While walking along the path, I spotted a worker of Vespa affinis heading purposefully in one direction. When wasps fly in this manner, instead of foraging in no particular order, they are usually either heading straight for a food source or returning to the nest! I broke into a quick run and was hot on her heels. I didn't intend to catch her, but to see where she would lead me to. I followed her all the way across an open field, then had to leap over a bench and duck under some flowering shrubs. And then I froze.

There were hundreds (yes, literally hundreds!) of Vespa affinis all around. For a moment, I was worried that I had accidentally disturbed a colony, and I crouched motionless among some bushes. However, the hornets didn't seem to mind my presence. Slowly, I moved out from my awkward position into an open space to get a better look.

I wondered if it was swarm-founding in progress (Vespa affinis is known to show swarm-founding in the tropics). However, the hornets did not seem to be working together, they were simply foraging. They were feeding on nectar from flowers, and attempting to capture honeybees at the same time. But the sheer numbers shocked me. In Hong Kong, I have sometimes seen more than 20 Parapolybia varia or Parapolybia nodosa come to a food source, and that already seemed like a lot. The most wasps I have ever seen in a single place had to be some years back, when numerous Vespa bicolor "gatecrashed" a barbecue outing I attended; there had to be almost 50 of them. But this was ridiculous! Looking at the vast numbers in front of me, I felt certain that I could easily remove a hundred from this area and not even put a dent in the population. In the end, I collected ten specimens, since some of my contacts had requested that I collect some specimens during my stay here.

For the first time, I also saw Vespa affinis scavenging on prawns used as bait by anglers near a bridge, and also on scraps left behind at a barbecue site! I have never personally observed this, although I have read that Vespa affinis does this on occasion. I have never seen this in Hong Kong. I later saw an individual trying to land on food scraps on the grass; she was prevented from doing so by a weaver ant (Oecophylla smaragdina). It is always fascinating to see how hornets can overpower and "terrorize" all kinds of insects, but can almost never gain the upper hand from the much smaller ants!

I then walked close to the path again when I saw an unusually large hornet at a distance. Judging from its size, it couldn't be Vespa affinis or even Vespa tropica. I whipped my net out and sprinted after it. An exhausting chase followed; I pursued it over fields, around trees and finally had to weave in and out of some large bushes to keep it in sight. And finally, I saw what it was. All black, with only the last segment of its abdomen orange. Vespa analis! But it was really of extraordinary size - easily as big as a good-sized Vespa soror queen! It seemed to be searching through the bushes. Finally, I lined my net just next to it, and then swept. I missed it by a mere inch, which scared it away! I was too exhausted to chase it again, and anyway it shot straight up into the air this time. I knew I was fortunate just to have seen such a creature, but I wished I had been able to capture it and measure it. Most papers on local hornets mention that Vespa tropica is the largest local hornet. In my experience, all Vespa analis I have sighted so far equal or even exceed Vespa tropica in size! Unfortunately it is one of the rarest local hornets today.

I was too tired to hunt further by this time, and anyway it was already late, so I headed off for dinner.

"Catch of the day".

9/9/2006 - Saturday

My first visit to the Botanic Gardens on this trip. Upon reaching around 3 p.m., there were lots of Xylocopa latipes, but little else. I walked past the place where I found the extremely large Vespa tropica nest several months back, but it was no longer there. I then walked around the flowers where I could usually find many Ropalidia species and Stenogastrines, but there were none around today! Even the stingless bees seemed few in number.

However, towards the evening, the wasps started to return! I saw three different Stenogastrines and two species of Ropalidia. At 6 p.m., they were so numerous, feeding among the Heliconia flowers! I realised that they probably visited flowers in the evening, much later than usual, during this particularly hot period. I also managed to photograph Apis dorsata for the first time; there were several of them feeding on flowers.

11/9/2006 - Monday

On an early morning walk, I found quite a number of Xylocopa latipes nests on the trunk of a small tree, one of the many just behind the expressway! And here's something even stranger. A previous statement that the nest entrance of Xylocopa latipes is the same size as that of Xylocopa latipes was not entirely correct. The diameter of nest entrances of this species varies considerably! In addition, the size of the entrance hole seems linked to the area and structure the nest is built in. For instance, in open locations such as wooden poles used to support small trees or basketball posts, the hole usually leads straight into the nest, and the diameter is quite small for such a large bee (1 cm). However, in shady, wooded areas, these bees make far larger entrance holes which lead into the tree branch at an angle; these holes may be 2 cm in diameter! Furthermore, a nest on such a tree trunk may have 2 or 3 entrances, instead of just one! I found a branch with 3 separate nests; there were 9 entrance holes, 3 to each! It is quite fascinating. I watched one bee just starting to bite a new nest hole; when I came back in the afternoon, she had made little progress. I returned the next morning to see her still biting; the hole was only half done!

Above: A female looks out of her nest entrance.
Below: A new nest just being started; the female can take days to finish. Note that the strange lines running around the nest entrances in both photos are mud tunnels made by ants.

In the afternoon, I visited the Changi Boardwalk area. Much of this area is undergoing renovation, but there are still quite a number of insects around. Besides the ever-present Vespa affinis, the large black Sphex species and the Bembix sp. are still around.

Fortunately, the notoriously unpredictable weather did not ruin my afternoon hunt. The sky was blue and the sun blazing hot, but loud claps of thunder sounded repeatedly, keeping me on edge! Still, I was intent on photographing the large black Sphex, which turned out very difficult as I couldn't approach it closely enough. I initially thought I had some good photos, but made a very careless mistake; I had set the ISO on my camera way too high (because of some night photography the night before), thus the photos were badly overexposed. However, I observed something fascinating. On my last trip, I noted how many solitary wasps fly away when disturbed in the middle of building their nests, and only return when the disturbance moves away. I wondered if they were watching from somewhere. This time, I observed this large black Sphex flying off to a branch on a tree, and resting there. She seemed to be watching my direction the whole time I stayed at the foot of the burrow she was digging! I sat there for ten minutes, and she stayed where she was. Then I moved away. Immediately, she returned! Later, I disturbed another individual, which flew to a patch of grass nearby and kept an eye on me in the same way. Again, she returned when I moved away. They do indeed watch from somewhere!

12/9/2006 - Tuesday

I returned to Pasir Ris Park in the afternoon. I caught sight of Vespa analis once again, but the wasp shot high up into the air the minute I approached. There were also lots of Apis dorsata; the workers were collecting water from the ground, presumably to cool the nest. This is the first time that I managed to get so close to such large numbers of these giant honeybees. I managed to take quite a number of photographs, and also collected three specimens. I also collected a small Stenogastrine wasp.

I found yet another strange Polistes today; it resembled Polistes sagittarius at first glance, but for some reason, the yellow banding looked different, and this wasp was much larger than the latter (which is already of considerable size)! It passed by slowly enough for me to get a good look, and flew sharply upwards, disappearing into a tall tree, just as I reached for my net.

I spent the rest of the evening at the Night Safari with relatives. This is a special attraction of the Singapore Zoo, which opens at night and enables visitors to observe and see nocturnal animals. While waiting for the place to open, I sat on a bench and suddenly noticed a swarm of stingless bees going in and out into a small hole on one of the bench legs! This is probably one of the smallest local species, with a brown abdomen. I managed to get some photos of this swarm. They didn't seem to like my presence, and swarmed around me whenever I got too close. Despite not being able to sting, some stingless bees are known to bite ferociously and even to spray chemicals into the wound, so I was glad that their attacks were all bluff.

13/9/2006 - Wednesday

I revisited the Changi area, this time spending more time and covering more places in the vicinity. I explored the Changi Beach Park for the first time. Here, I found a fairly large Scoliid wasp - nowhere as big as the one I failed to catch on my previous trip in March, but still a considerable 20+ mm in length. It was digging in the sand when I found it.

In this area, I also found lots of Vespa affinis. Large Xylocopa latipes were also buzzing around flowers high on treetops. However, I did not see much else, so I walked to the Boardwalk and went back to my familiar hunting ground. There are several bungalows and chalets around, and I explored the surrounding area which was well vegetated (I did not dare to directly explore the buildings themselves even though I suspected that it might be productive, for fear of trespassing!). I saw a large Vespa tropica but she disappeared the minute I approached.

Later, I saw a beautiful yellow wasp flying around some ornamental flowers. I whipped out my net and captured it; it turned out to be a Delta sp. (potter wasp, probably Delta campaniforme). As I attempted to transfer her into a plastic container, I felt a sharp pain in my right index finger. I had been stung through my net! This is the second time in less than two weeks; I got stung just over a week ago by a Megachiliid (leaf-cutter bee), also through the net. I have to be careful in future. Unfortunately, the surprise from the sting gave the wasp just that split second she needed to crawl under the edge of the net and escape.

There wasn't much else worth mentioning for the day, except for an incident I found quite amusing. A group of tourists seemed greatly fascinated with one of the large black Sphex sp., and attempted to photograph it!

14/9/2006 - Thursday

I had something on in the morning, and planned to go back to Pasir Ris Park in the afternoon to stake out the area where I saw Vespa analis. However, it started raining, quite unexpectedly, almost immediately after my lunch. Therefore I decided that it would be pointless to go hunting, and I took a taxi to Chinatown instead, intending to treat myself to a nice dinner, followed by some shopping. Upon reaching, the clouds had thinned, the rain completely stopped and the sun shone again. Just behind part of Chinatown, I saw a grassy hill with stairs leading upwards; a prominent sign said "Pearl Hill City Park". The word “Park” always has a strong effect on me! I couldn't resist the urge to do some exploring. It was a beautiful park, to say the least. Although called a "city park", the landscaping was a lot more natural than urban parks in Hong Kong, man-made objects (apart from stairs, railings, paths and rubbish bins) were kept to a minimum and giant trees gave me the feeling of being in a rainforest! I did not manage to spot much on this trip, but I shall return some day. If even my modern apartment estate can turn up so many interesting finds, I don't see why this place wouldn't be productive as well!

16/9/2006 - Saturday

It rained the whole day yesterday (Friday), and I spent the whole afternoon and evening in a shopping centre. Eager to get out into a park and do some hunting, I decided to go back to Pasir Ris Park. I spent some time photographing the numerous Apis dorsata which were busy collecting water.

I believed there had to be a nest nearby, as the bees seemed to be coming from the same direction, and heading back in that direction as well. I tried to look in that direction, but it led to numerous tall trees far away, and I couldn't see any nest from such a distance. Just then, a large Vespa analis (not as large as the first one I saw on this trip, but still about the size of an average local Vespa tropica) flew past. I was not prepared, having only my camera in hand. By the time I bent to retrieve my net, the hornet had disappeared into the bushes.

A loud clap of thunder interrupted my hunt. The sky was now completely dark grey, and I had just enough time to find a small wooden shelter. The rain came in torrents, and even under the shelter, I was drenched as gusts of wind blew sheets of rain at me! As soon as the rain lightened, I ran all the way to the nearby Downtown East. This is a popular local entertainment venue, with eateries, video and computer arcades, sports facilities and other such features. By the time I finished my dinner, the rain had stopped. I walked over to look at a water feature with ornamental fish. Suddenly, an individual of Vespa affinis flew down and landed on a nearby plant! Not being ready with my net, I quickly took out an empty plastic bottle and shoved the wasp in immediately with my fingers.

17/9/2006 - Sunday

I returned to Marina South, where some exciting time spent there on my last trip was cut short by the weather. It was cloudy at first, and I feared that my trip would be cut short yet again. But the sun soon reappeared and thankfully, there was not a drop of rain.

I had a pleasant brisk walk across the whole park (the photo above shows part of it). There were lots of Vespa affinis. However, I did not see anything else this time. Since it was still early, I took a taxi to East Coast Park. Although now revamped and highly urbanized, lots of Vespa affinis flew around. I continued walking briskly till I reached a "long grass area" (yes, there is actually a sign stating that this place is designated as such!) There are several of these areas around this place, and although there are paths through them, they are mainly meant to act as bird sanctuaries. I saw a single Vespa tropica and several Polistes sagittarius here. There were lots of people jogging today; maybe that was the reason why there weren't many insects around.

Actually, I think there would have been a lot more to find in these two places. But I was not as alert and sharp as usual. Shortly after reaching Marina South, I sneezed seven times in a row, and had considerable discomfort in my nose for the rest of the time (I get bad nose allergies in Singapore quite frequently, despite the clean, warm air; I still don't know why this happens here and not in relatively polluted Hong Kong!) Therefore, I felt lethargic and was not able to spot things as easily, and also didn't bother bending to look under crevices or the undersides of leaves as I often do.

18/9/2006 - Monday

It rained the whole morning, and it seemed as if the rain would never stop. I decided that I would probably not be able to go outdoors today. But surprisingly, the rain stopped in the afternoon. I thus headed back to Pasir Ris Park, intending to search for Vespa analis. I have narrowed down a certain area in which I have seen them here, and walked several rounds in an attempt to spot one. Finally, I spotted an individual flying across a field. I gave chase, and just as I caught up with the hornet, she flew sharply upwards and evaded my net. This incident bore an uncanny resemblance to my first sighting and chase of Vespa analis back in March!

I then walked towards some wooden shelters, and crawled under these to see if anything nested below them. To my surprise, I found two nests of Stenogastrine wasps. Surprisingly, these nests seemed to be attached to strands of spiderweb! (I later learned that many Stenogastrine wasps produced these long thread-like things from which they attach their nests; I forgot if they are made of collected fibres or actually secreted by the wasps.) Unfortunately I found all the photos I took somewhat poor and not worth uploading.

19/9/2006 - Tuesday

For the first time in many years, I revisited Pulau Ubin. This island is a ten-minute boat ride from Changi Point on mainland Singapore, and is one of the few remaining rural settlements in Singapore. The island is heavily forested, and used to be one of my favourite places in my snake-hunting days. But this is the very first time hunting wasps on this island. I visited with my family and an old friend this time.

Upon reaching, I picked up a brochure, and immediately, my eyes fell on a special section at the bottom, telling people to beware of hornets and wild bees and to report the location so the nest can be destroyed! The photo showed an elongated, conical Vespa analis nest (one worker is visible at the bottom)! "Not to worry," my friend told me. "These nests are everywhere!" I was, of course, excited after hearing this, and would have liked to begin the hunt immediately. But it was lunch time, and so we hired a van (there are many vans which one can hire for single trips or for the whole day) and proceeded to a resort roughly 10 minutes’ drive away. The resort was surrounded by more greenery than I had seen in a long time, but the inside was mainly sand and neatly sculpted wooden structures, although there were still quite a number of trees around.

After lunch, my friend and I wandered around the resort compound. Very quickly, I caught a potter wasp (Delta sp.) and some Vespa affinis. I was hot on the heels of yet another Vespa affinis when I heard my friend's shocked "what... what's that?" I turned to look and immediately let out a loud, involuntary exclamation of pure surprise. I saw the biggest hornet I have ever seen in my whole life - it cruised round my friend's leg and then flew past me. I certainly did not intend to repeat my old mistake of letting something rare slip away while trying to photograph it (I decided that any new species would be captured first, and then photographed under controlled conditions later), and I leapt after it with my net. I must have cleared more than six feet in a single leap, and unfortunately got my foot stuck in mud concealed by the grass! I only just managed to stop myself from falling flat, and was able to free myself quickly, but the hornet had disappeared by then.

Words cannot describe the mixed feelings I experienced at that moment. Frustration at the hidden mud and at myself boiled up; although I had not hesitated this time, I truly wished I had not decided to leap in this manner; a normal, stealthy approach would have worked as well, since this insect was not flying fast. On the other hand, I felt truly fortunate to have seen this unbelievably magnificent creature. I would be lucky even to get a mere glimpse of it; managing to get a good look at its structure and colour as it flew slowly past was a blessing! Judging by the structure of its head and thorax, it is clearly a Vespa sp. (hornet). I estimate it to have been anywhere between 50 and 59mm. It is certainly not a Polistes sp. (paper wasp), and definitely not a solitary wasp such as a Scoliid or Sphecid. It is certainly larger than anything I have ever seen, even bigger than my Vespa mandarinia and Vespa soror queen specimens! However, it did not appear to have the enlarged head of these two species, although it was very powerfully built (quite expected for such a big wasp). It was someone reminiscent of Vespa tropica instead. The ground colour was completely black, and the first and third abdominal segments were mainly white!

Of course, I did not get a photograph of it, but this illustration shows the colour pattern and roughly what it looked like.

I only hope I will have a chance to see this wonderful wasp again, and if possible, to capture it and send it for expert identification. I have several references which are good keys to all species of Vespa, but I do not remember a description of this species. I decided right then that Pulau Ubin is one truly rich area which I have to visit again in future.

Later, I found yet another mystery hornet, this time, a rather small one (between 15 and 19mm in length). It flew fast and at first, appeared to be a beetle or fly. However, I got a good look once it landed on a plant; it was brown with extensive yellow markings. Could this be Vespa multimaculata? So far, all descriptions of this species state it as a small species with yellow markings. Quickly I whipped my net across the plant, but the wasp disappeared.

Despite these two disappointments, I enjoyed this outing thoroughly. Later, we ended up at an orchid farm. The elderly owner has long stopped growing orchids and now sells canned drinks instead. We stayed around to talk to him; he had lots of interesting experiences and stories from the past. He is also extremely knowledgeable about all the wildlife on the island. He even brought us to a crude self-constructed "jetty" (his farm lies at the edge of a mangrove swamp area!) and pointed out a medium-sized hornet nest on a distant tree. He claimed the nest belonged to Vespa affinis, which were flying around the farm in great numbers. The nest structure indeed fits Vespa affinis and also Vespa analis. I then asked if there were any other nests nearby, to which he replied, "Of course not! They've been either burnt by NParks (Singapore's National Parks Board) or eaten by myself!" Laughing at our stunned expressions, he told us of how fire on the end of a stick (like a torch, lit by wrapping a cloth around the end of a pole, soaking in kerosene and lighting it) could be used to drive the hornets from their nest. The nest could then be taken down and the larvae and pupae fried in oil. "Very fragrant, and very nutritious!" Apparently, countless other such nests had been destroyed by the National Parks Board just weeks ago! I was a little late.

This is also the first time I have heard of people eating hornets or their larvae/pupae in Singapore. Hornets are apparently quite commonly eaten in various forms in Japan, Taiwan and Mainland China, as well as other parts of Southeast Asia such as Thailand and Myanmar, but I have never heard of this in Singapore till now.

He then went to tell us of how Apis dorsata (giant honeybee) nests, sometimes 3 to 5 feet tall and wide, could be found on trees. The villagers often harvested the honey from these nests, although it had to be done with care because Apis dorsata can be vicious and dangerous when provoked (apparently they are said to be more dangerous than any of the hornets). At night, they would light a large fire at the base of the tree. Then, they would hit the tree hard or throw something into the canopy to provoke the bees. The whole swarm would then charge down and attack the fire, since it would be the only visible and moving thing. They would be burnt to death, and after some time, someone would climb up and take down the single-combed nest. One nest could fill two or three buckets with honey! And according to him, "all the expensive, specialty gourmet honey one can find in the high-grade supermarkets today is nothing compared to this honey. Once you have tasted it, you won't settle for anything less!"

On the way back, I caught several of the large black Sphex species which I often see at the Changi Boardwalk area. They are even more abundant here than at Changi! Later, I saw something similar on one of the jungle paths back, and netted it without thinking. I was glad I did so, for this turned out to be a Pompillid (spider-hunting wasp)! It has two weird projections on the thorax, and appears to be a male. It looks black at first glance but has beautiful patches of metallic blue on its abdomen under the light.

A nice end to a most remarkable day! I look forward to returning to this beautiful island, although I may not have enough time for another visit on this trip.

20/9/2006 - Wednesday

My first visit to Fort Canning this time. I found quite a number of Vespa tropica here! I managed to net a medium-sized one quite easily; apparently my "jinx" with this species from the last trip has been lifted, and transferred to Vespa analis instead!

The weather today was extremely hot; it is easily the hottest day I have experienced in almost five years! Even though the official forecast was for a maximum of 33 degrees Celsius, several thermometers I saw in various places registered close to 37, and they were in shaded locations. This was ridiculous. I don't know what the exact temperature was, but it affected my concentration badly. I did not find anything because I did not look hard enough. Finally, I had to leave and head for the nearest shopping centre to buy a few bottles of water - I had finished all I brought!

I then headed back to the Botanic Gardens. This time, I entered from the main entrance at Tanglin Core. I intended to walk through the Central Core to the Bukit Timah Core, but I had to abandon this idea as the heat had really drained me. So I sat under the shade of creeping plants over a trellis near the old main entrance, watching the Xylocopa latipes buzzing around the flowers. Later, I managed to capture some Ropalidia species. I also managed to take another shot of the most beautiful local Stenogastrine wasps, which one of my professional contacts identified as a Liostenogaster sp. An earlier shot is shown here along with the one from today.

Just before leaving, I caught what I thought was a small Vespa tropica at first, due to it having a band only on the second abdominal segment. However, it appears to be Vespa affinis upon close examination! I remember reading that in parts of Southeast Asia exists an aberrant form with the orange band on the first segment reduced or absent. This seems to be such a case.

21/9/2006 - Thursday

Since I have only less than a week left, I went on my first visit to Sentosa. The stifling September heat was still strong, and greatly sapped my strength. Fortunately, it was much cooler in the rainforest trails, due to the shade from the trees.

As I walked along, I saw the shadow of a hornet on the ground, and looked up to see a large Vespa analis flying away. Yet again, I sprinted after it, but couldn't catch up.

I found yet another strange hornet in the forest trail. There was a signboard explaining local wildlife; the last sentence read, "beware of the big black Bees and orange Hornets. They may hurt you, but only if offended." I found this rather humourous. The signboard did not give any advice on how to avoid "offending" them! The big black bees were most likely Xylocopa sp. (large carpenter bees). I was more puzzled about the "orange hornets". I assumed that this referred to Vespa affinis or Vespa tropica, although these only have an orange band on black! So imagine my surprise when an orange hornet really flew by! I couldn't actually determine if it was a Vespa sp. or a type of Polistes, although from its body structure and flight I believe it was a hornet. Furthermore, it was quite large, about the size of Vespa tropica or Vespa analis. Its ground colour was almost completely orange, although I couldn't see what pattern or markings it had since it was still quite far. The orange ground colour was not the flashy or bright type, but instead rather muted. Nevertheless, I have never seen something like that. I will have to do some reading once I get back to narrow down what it might have been. Unfortunately it was too deep in for me to catch.

Coming out of the forest trail and near the seaside, I again spotted the "giant Polistes sagittarius" I had seen at Pasir Ris Park. I gave chase but lost it when it disappeared high up a tall tree. I then came across several nests of small stingless bees built inside tiny holes in lamp posts! I spent quite a bit of time photographing them. The workers guarding the nest entrance can be seen below. The entrance is in fact merely a couple of millimetres in width!

One of the nests seemed to have been disturbed; the bees were flying round agitatedly in vast numbers. I was surprised to find that it was, in fact, under attack by Vespa affinis! Three or four workers were circling, and trying to force their way inside the nest; they didn't attempt to catch the bees, which wasn't surprising since these were of one of the smallest species! I have never seen this before. The hornets were not successful in entering the nest because the entrance hole was too small! However, they had managed to work the bees into a frenzy.

Walking on, I found a new Stenogastrine wasp I have never seen before. It was a lot bigger than any of the other local species I have seen so far; I guess it was around 25mm in length! It was marked abundantly with yellow and looked most attractive. I caught it in the act of stealing food from a spider's web. This is common among most social wasps, and the Stenogastrines seem quite specialised to do this. I tried to capture it, but failed. These wasps can be very alert and elusive; their silent, hovering flight also makes them hard to track.

Later, I took a rest at the cafeteria just outside the well-known "Underwater World". Suddenly, I noticed a hornet flying around the roof. I ran over, and stopped in surprise. It was Vespa analis! After so many futile chases outdoors, here one was, trapped and ready for me. My heart was in my mouth and I was shaking like a leaf, mainly because I knew I only had one chance to bring this wasp down. Thank God for my new net which comes with a long extension pole. I fixed the pole and extended it to its full length, then raised it. I was aware of many people watching me, which made things worse actually; I found it hard to concentrate. But after a couple of futile sweeps, I finally brought it all the way down. And it turned out to be a male! I brought it home and photographed it before fixing it as a specimen. Finally! I fervently hoped that the "jinx" would be broken, just as happened with Vespa tropica on my last trip. And now I have got three of the confirmed hornets in Singapore. I shall now have to try to collect the several unconfirmed mystery hornets I saw on this trip and on previous trips, although I think I may not have the time since I will be leaving soon.

At long last!

22/9/2006 - Friday

"Catching wasps in Orchard Road? You’re "siao" (Singapore slang for crazy)!" My friend exclaimed in a mix of shock and disbelief. I couldn't blame him. Anyone who has been in Singapore long enough will know that the Orchard Road district is probably THE most modern, high-end shopping district, with some of the biggest shopping centres. A large percentage of high-end housing areas and destinations popular with tourists are located here too. But what many people don't realise is that there are patches of secondary forest, trees and shrubs behind the concrete jungle. And in Singapore, trees and greenery are everywhere. It may not be the original vegetation, but it still provides a home for wildlife such as insects and even some birds. Step out of any of the shopping centres on a hot afternoon and you will hear cicadas high in the roadside trees! And honeybees often forage for water by the roadside greenery, especially after they are watered.

I didn't originally intend to hunt at Orchard Road. I had lunch with relatives at one of the restaurants there, and intended to move on to other places after that. But since I had my net and full kit with me, I decided to try some of the numerous patches of greenery on a slope just behind the shopping centres. I was not disappointed; I caught an unusually greenish blue-banded bee (Amegilla sp.) and a very large Delta sp. (potter wasp). I also saw a male Xylocopa confusa hovering around some plants. I decided to leave early only for two reasons; there were too many people around, making it hard to concentrate, and the afternoon heat was unbearable. Still, it was remarkable in a way.

I then took a taxi to Mount Faber. This is a small hill, from which one can get a spectacular view of part of Singapore and also of Sentosa. One can also take a cable car ride down to the Harbourfront area or to Sentosa. Although recently redeveloped, much of this hill is still heavily forested. I was not disappointed. I enjoyed a nice, slow walk down the stairs and around some of the smaller paths, and found some interesting creatures, such as brightly coloured spiders and a mantis which looked like a twig. I also saw a large male Xylocopa latipes. He was perched on a leaf, aggressively defending his territory by chasing some butterflies and dragonflies which flew nearby. He also attempted to mate with a female which came into the area.

The highlight of this afternoon was soon to come. Walking down the stairs, which were lined with thick shrubs and forest, a small yellow shape came darting around. Parapolybia varia! I quickly netted it. This specimen is similar to the one I got on my previous trip. Parapolybia varia in Singapore seem smaller and more extensively patterned with yellow than those I often see in Hong Kong. In the same area, I saw another three individuals, so I believe a nest was near. I did not catch these but attempted to follow them in an attempt to find the nest. This was not successful, mainly because the forest and undergrowth were impenetrable. Some day, I shall return. Finding a local Parapolybia nest remains one of my important goals for the future. I still wonder why they are so elusive and rare here, only being found near forested areas. The urban estates seem like perfect habitat for them too, with all the ornamental greenery and low bushes they love to nest in. Parapolybia are the most common urban wasps in Hong Kong, and are highly successful partly because they are adaptable wasps which also love scavenging near human dwellings and rubbish bins. But they are never found in urban estates in Singapore.

23/9/2006 - Saturday

Since my friend was free and I had also not planned anything for the day, we decided to visit Pulau Ubin once again. We started slightly earlier than the previous trip; since it was just the two of us, we didn't bother going to the resort for lunch. I simply brought some bread (my staple when out in the wild - I seldom eat anything else for fear of suddenly needing a toilet at the worst possible moment!) and we started walking straight away.

It was another really enjoyable outing. Although bees and wasps are my passion, I also greatly appreciate all sorts of wildlife. This time, we saw, among others, some hornbills, some really interesting bark scorpions (the small dark Liocheles sp. and a slender orangish one which was probably Isometrus maculatus) and the water monitor lizard.

However, at least for me, the highlight of this trip was in the remarkable variety of stinging insects I saw and interesting observations I made.

While walking on the trail, I saw a strange bee. It was medium-sized, much larger than a honeybee at about 15mm long, was very robust and rotund in build and completely covered with orange hairs! It looked very furry, and resembled a Bombus sp. (bumblebee), although it was probably something else because bumblebees are not known from lowland tropical regions. It flew very quickly from flower to flower, collecting pollen, and flew away before I could collect it.

I found a female of the large black Pompillid (spider-hunting wasp) I found on the previous trip. It was only slightly smaller than the male. However, since these wasps can vary greatly in size and males are usually smaller than females, I believe this was a particularly small female, and there are larger females around! I caught her in the process of dragging a spider into a cavity on a tree trunk. When I looked inside, I saw that she had three cells made of mud! These were tube-shaped and quite wide in diameter. Although most Pompillids either dig burrows or simply use existing crevices, a small number of species make mud cells and even return to them and guard them! This is apparently one. The spider she captured was a large, brightly marked huntsman spider. I did not manage to catch this female, but I didn't mind. She could probably go on to make even more nest cells and raise more young. I will check this crevice the next time I return.

We returned to the orchid farm, and spent some memorable time there. The owner of the place, elderly but still fit and sprightly, rowed a small sampan (wooden rowboat) out into the small "lagoon" and towards the mangrove trees at the other side, to allow us to approach the Vespa affinis nest. I managed to get some photos of it. Strangely, this nest seems to have been attacked by something. There seems to have been forced entry at the entrance hole, and no more activity! (On the previous trip, I could see wasps leaving and returning even at a distance). We then took shelter inside the owner's house as a sudden thunderstorm appeared out of nowhere, pouring rain down and creating a deafening sound when raindrops fell on the zinc roof, and then cleared in five minutes! At that moment, a large long-legged wasp appeared and started biting the wooden sign which said "Cold drinks available"! Polistes sagittarius, I thought. However, as I approached, I realised that the head and the last two abdominal segments were red and the distribution of the yellow band was different; it was the mystery "giant Polistes sagittarius" I had seen at Pasir Ris Park and Sentosa! This was a much smaller individual than the ones I had seen previously, but is still rather large. I quickly netted it, and indeed it looked strange. I wondered if it could be an aberrant form of Polistes sagittarius, but tentatively I believe it is in fact a different species, since there are significant differences in head and thorax structure, which are more important in determining species than differences in colour. Unfortunately, it was almost dead when I got home, so I couldn't photograph it alive. If this is indeed a distinct species from Polistes sagittarius, it is probably a new record for Singapore, since only Polistes sagittarius, Polistes stigma and Polistes olivaceus have been recorded. Actually, I believe that there are far more species than recorded locally, as I have found with the hornets in particular. I suspect that the small number of locally recorded species is purely due to the fact that few bother to research these insects here.

I also caught another two specimens of Vespa affinis with only the second abdominal segment banded in orange, causing them to somewhat resemble Vespa tropica.

24/9/2006 - Sunday

My third (and probably last) visit to the Botanic Gardens, and the most fruitful to date. While at the Bukit Timah core, I saw Vespa analis on three separate occasions, each time simply catching a glimpse of the black body and gleaming orange tip of the abdomen disappearing into thick shrubs. Apparently it is more common than I initially thought; it is just that this species seems shy and often sticks close to bushes and shrubs; also, it seldom lands or visits flowers as the other hornets do. I did not manage to catch any of them.

Later, I found an individual of Vespa velutina, attempting to capture flies which were swarming around a dead frog! The subspecies or colour form here has a more contrasting black and orange-red pattern on the abdomen than those I am used to in Hong Kong, and with more red or orange markings on the thorax. The legs are still yellow. I could also recognise that swift, hovering flight and the way it attempts to catch flies; in fact, I knew even before I had a close look that it was Vespa velutina. I ran up and tried to catch it, but it evaded three sweeps of my net, flew around so fast I could hardly see it and then flew high up and away. Vespa velutina should not be found here; it is mainly a mountain-dwelling species in the tropics. However, I have found it to be surprisingly common, and yet I have never been able to catch one simply because they always seem to appear when I am not ready.

I then went back to the Central Core to catch Ropalidia. I caught one which appears to be a new species! It is black with yellow bands on the abdomen. Unfortunately, it bit a hole out of the plastic bag I held it in! I cursed myself for not putting an additional plastic bag over it. I never expected such a small wasp to be able to bite through a plastic bag. And just my luck that I was out of plastic containers.

Later, just before dinner, I noticed some activity around a large hole on the trunk of a palm tree. On a closer examination, I found lots of the large black and red Ropalidia species in the crevice! So my initial speculation that this is one of the swarm-founding or cavity dwelling species is correct! The cavity angled upwards sharply. I did not have a torch, but I bent to look up into the crevice and used my camera flash to illuminate the inside. Rows and rows of wasps were clustered around! It was a pity I could not photograph this. It was already difficult to examine the visible part of the cavity and to photograph these wasps, because some of the wasps would fly out and make darts at me every now and then! I did not see a nest. Either the nest is too high up inside the crevice, or they are starting a new nest. Unfortunately, I will not be around to watch the progress of this colony.

25/9/2006 - Monday

It rained in the morning, but was hot again in the afternoon. I spent most of the day doing some last minute shopping, then had dinner with family; I did not have time to do much else today. However, I took a walk around East Coast Park just before dinner. In the "Long Grass Area", I collected a beautiful female Phimenes flavopictus! I also saw Vespa affinis and a single Vespa analis, which was unfortunately too high for me to reach.

26/9/2006 - Tuesday

Unexpectedly, I found I had some free time. So even though this is my last day in Singapore, I headed off to the Botanic Gardens, hoping to observe the Ropalidia in the tree trunk. There were just as many individuals, if not more, in the crevice, although I did not see any leave the nest, or return with prey. As I got nearer to try to get a closeup shot, one flew out and charged at me. I backed away hurriedly and then started to run, but the determined little creature flew after me for almost 30 feet, and attempted to sting me on my arm! In fact, she failed only possibly because my arm was too slippery with sweat for her to latch on! I guess it would not be wise to provoke this whole colony; I do not know how many hundreds or thousands more would emerge if that happened, and do not dare to imagine how they would punish me.

I then went to Marine Parade to collect something from my friend. Suddenly, I saw a female of the beautiful yellow potter wasp (probably Delta campaniforme) land on the pavement, scraping up mud from between a gap in the concrete! I was of course delighted to find such a wasp in such an urban environment (Marine Parade Central is a mass of housing estates and shopping areas).

Finally, I went back to Pasir Ris Park. I headed straight back for the shelter and managed to photograph one of the Stenogastrine nests under the wooden shelter. I even managed to photograph one just as it was about to hatch out! This was not easy as I was lying flat under the structure in an awkward position, and found it hard to hold the camera at a right angle there. In the first photo, apart from the two at the top which appear to be females, the rest seem to be males (note the difference in the banding on their abdomens).

I managed to get a few last specimens of Vespa affinis. I saw another specimen of the “giant Polistes sagittarius”, noticeably bigger than the one I caught. I ran after it, but it flew high into the canopy of a tall tree. This species does not seem too rare! I should be able to find out more about its biology and habits in future. A beautiful end to this trip, I thought. However, that night, while transferring the Vespa affinis specimens, one of them stung me on the thumb (probably due to my carelessness – it’s always our fault when we get attacked by wild creatures, not the other way around!) It hurt quite badly, but I used a “venom extractor” I bought recently, and I can say this device is quite useful. The pain was alleviated, and the swelling was much less than usual for a hornet sting; the effects only lasted a few hours as compared to a couple of days. I was thankful; I did not like the idea of having to handle my luggage at the airport with a swollen, sore hand!

Results and reflection on this trip

Although this trip was slightly shorter than the previous two, it was just as productive, if not more. I returned with a surprising number of specimens (apart from Vespa affinis, most were species I had few or none of), and a great wealth of new observations.

The number of Vespa species I have personally seen now stands at a shocking 9! There are only 3 species described in all available literature from Singapore : Vespa affinis, Vespa analis, and Vespa tropica. Apart from these, I have so far seen Vespa velutina, a very large black species with a greatly enlarged yellow/orange head, a medium-sized wholly brown one, a muted orange species, a small species with extensive markings and a truly gigantic hornet, black with the first and third abdominal segments mainly white! This is unbelievable and incredible for such a small country, especially one which is largely urbanized! I only hope I can catch some specimens of any of them on future trips.

Upon my return, the mysterious “giant Polistes sagittarius” was confirmed by Dr. Junichi Kojima (Ibaraki University, Japan) to be, in fact, Polistes tenebricosus. I had all along expected this species to be found in Singapore, since it has quite a wide distribution over much of Malaysia and Indonesia. However, what I didn’t expect was the colour and pattern of the ones I have seen. I have specimens of Polistes tenebricosus from Indonesia, and these are a dull brown! And I have also seen photos of this species in Taiwan; it is mainly reddish brown as well.

Getting this mysterious wasp identified suddenly reminded me of a nest I found at Sentosa. It was in an old wooden shelter at an old attraction called the Asian Village, which has since closed down. I never bothered taking photos of the old abandoned Polistes nest on previous trips, assuming it to have belonged to Polistes sagittarius. How foolish I had been! The nest of Polistes sagittarius is usually dark brown or gray, and has an excentric petiole (the petiole is the “stem” which connects the nest and the surface it is built on; A centric petiole is one built roughly from the middle of the nest, while an excentric one is obviously positioned to one side as the nest expands). However, this nest was deep and with a centric petiole, and was very light gray, almost white. Looking back, the cells were also too large even for Polistes sagittarius. A guidebook to Taiwan species shows such a nest; it belongs to Polistes tenebricosus! This gives it quite a wide range locally; I have found a nest in Sentosa, and actually seen specimens in Pasir Ris, Sentosa and Pulau Ubin, and it doesn’t seem that rare. I expect that that shelter and nest will no longer be there by the time I return (the area is being demolished to make way for new attractions), but hopefully I will find more specimens and perhaps even live colonies.

The number of Polistes species I now know of in Singapore stands at 4. Polistes sagittarius, Polistes tenebricosus, Polistes stigma (which exists in 3 colour forms!) and a fourth species which is smaller than Polistes sagittarius but bigger than Polistes stigma (I haven’t seen this but I am guessing based on a nest I found during my trip in March 2006). If Polistes olivaceus, which has been recorded from Singapore, indeed does exist there, that brings the number to 5. I also wonder if the “brown phase” of Polistes sagittarius I found on my last trip is simply a colour form, or if it could instead be a different species. The number of Ropalidia species I now know of also stands at 6 (five of which I have seen before, and an unidentified species I saw on a local photographer’s gallery). And I now know of at least 5 or 6 species of Stenogastrine wasps! Finally, I found Parapolybia varia again; although I only collected one specimen, I found a few others. I shall search that area for nests in future.

I have always suspected the common black and red Ropalidia species to be swarm founding, meaning that instead of a single queen (or small group of queens) starting a small nest from scratch, a whole swarm moves into a new location and immediately starts building. I had never been able to prove this, but I have seen photos of similar species in Thailand nesting in large groups. And a couple of friends have mentioned seeing this species in very large nests too. My chance discovery of a colony in a hole in the trunk of a palm tree proves this; there were so many of them inside, and I wished I could see the structure of the nest itself, which was probably quite deep inside.

Having now familiarized myself with the various habitats and locations and having a rough idea of the nesting habits of various species, I hope to do more in future trips. One thing I hope to slowly work on over the next few trips will be to establish a distribution map of the various species of social wasps. I have already noted some interesting facts. Even though Singapore is a very small country with a relatively unvarying environment, there seems to be clear-cut distribution patterns for certain species. For instance, Vespa affinis, though the most common local species which can be found in quite a variety of places, seems most abundant around coastal regions and beaches; the numbers seem considerably fewer inland. In contrast, Vespa tropica seems fairly common towards more inland locations. Although I have seen only a few specimens around places near the sea, I see this species far more regularly in inland areas. And the red and yellow form of Polistes stigma seems to be present mainly in mangrove areas, while the black form is found in inland areas, particularly grassy fields and secondary forest. I hope to get a clear picture of the distribution of various species.

I also noticed for the first time a different colour form of Vespa affinis. Instead of having the first abdominal segment partly or almost fully orange, it is almost fully black, with a thin orange line at most; only the second segment is orange. It is thus easy to mistake it for Vespa tropica at first glance; only a detailed comparison of structural features allows for correct identification. I am not sure if this form is merely an aberrant in which such individuals for some reason develop this pattern in a colony of normal individuals, or if it is actually a separate form or subspecies which breeds true to its type. Time will tell, I suppose. However, I have noticed that the flight pattern of Vespa affinis and Vespa tropica is quite different; the former often flies close to the ground, catching flies or other small insects in the grass, or ambushing bees from flowers, while Vespa tropica usually flies around the canopy of shrubs and trees, seemingly searching for its usual prey (nests of paper wasps). After so much time spent watching them in the wild, I can now rely somewhat on their flight patterns and behaviour to distinguish them even before I get a good look.

I also hope to get a chance to relocate some colonies locally, if they are built in areas where people feel threatened by them. Ever since starting on these relocations, I have had tremendous success and learned more than I could ever learn simply from reading by doing so. In the summer of 2006, I relocated too many colonies to recall, using many new and refined techniques with far more skill than the year before (and receiving fewer stings in the process!). But none of these have been performed in Singapore. I foresee several challenges; for one thing, foliage on most bushes, shrubs and trees is generally far denser than that in Hong Kong. Also, for some reason, many species of wasps in Singapore are far more aggressive than their counterparts in Hong Kong (a good example is Vespa tropica, which tolerates its nest being approached to 2 feet in Hong Kong but already had several workers flying out to inspect me at 10 feet from the nest in Singapore). The nests are often far larger, and the colony size far greater. But still, I would like to try. Polistes sagittarius often nests in the area around my aunt’s condominium estate, and colonies are often unfortunately wiped out by fumigation. In fact, I suspect there are nests in the vicinity of my estate as well, since I see both females and males all the time. It is in such urban areas that people are most likely to come across nests, and I therefore intend to move any nests I find here to somewhere undisturbed.

Unfortunately I have been quite busy and am unable to take the planned trip to Taiwan this year. I still hope to visit Taiwan (or possibly Thailand or Japan) some time in the near future, but it is impossible to say just when at the moment. In the meantime, I have yet another trip back to Singapore planned for March, since I will be taking a one-month course there. I believe there’s more to come, and that I will find many more interesting things in the future.