Parapolybia, sometimes known as the lesser paper wasps, are similar to Polistes on first glance, but are noticeably more slender in body and the abdomen is joined to the thorax by a long, slightly curved petiole. Species of Parapolybia can be quite difficult to differentiate and show great geographical variance in different localities. Fortunately, Hong Kong's three species (Parapolybia indica, Parapolybia nodosa and Parapolybia varia) are distinct from each other in appearance and thus easier to identify.
In Hong Kong, Parapolybia nodosa and Parapolybia varia are the most common social wasps, among with Vespa bicolor, and can be found in virtually anywhere. Parapolybia indica is also common but tends to appear mostly in parks and rural areas.
Parapolybia nests start small, but can grow to magnificent sizes if the location and weather are favourable and the colony strong. They generally have a more vertical orientation than nests of Polistes. Some large nests can take on rather unique shapes. At its peak, such a nest can contain hundreds of individuals. However, most nests are usually smaller.
Parapolybia are extremely adaptable species. They are very common in urban areas and frequently build nests outside apartment windows, hanging from air-conditioning units, and sometimes even indoors. In more natural surroundings, they build nests in bushes, often not very high, and are common in urban parks. Not surprisingly, gardeners are often stung by them.
Parapolybia are not choosy over choice of prey. Usually I see them catching winged breeder termites, small flies, small caterpillars and other similar insects. They are also quite fond of carrion, and will scrape out the meat from dead insects or even snails; unlike most hornets, they will take meat or carcasses which have been exposed and are starting to rot. They will also attempt to collect our food, and even hang around garbage.
Parapolybia generally tolerate people moving around their nests, and are easy to approach. I have positioned my lens merely inches from the nest while photographing them, and they were not even alarmed. And when disturbed, they seldom fly out in an attacking swarm, as hornets or honeybees do. Usually only around four or five workers rush to attack. However, these wasps pursue intruders with a vengeance unmatched by any other! I recall, many years ago, accidentally disturbing a nest that had been built on a fence which I was leaning against. Five workers flew forward, and I took off immediately, running for my life. Four of them lost interest, but one of them just would not let me off; I ran over a distance of almost three football fields, and when I stopped, panting hard and out of breath, a tiny missile crashed into my forehead and stung me hard just above my eyebrow! It is amusing to recall the vengeance of this little wasp. She pursued me over such a great distance, just to land one good , proper sting. The sting of these wasps can be quite painful.
The three species described here are variously distributed across Japan, Taiwan, China (including Hong Kong), India and elsewhere in Asia. Parapolybia varia is even found in Papua New Guinea. I also once saw a Parapolybia in Singapore, but it flew off before I could catch it for a close look.