Characteristics of Wasps
Yellowjacket or yellow-jacket is the common name in North America for predatory wasps of the genera Vespula and Dolichovespula. Members of these genera are known simply as “wasps” in other English-speaking countries. Most of these are black-and-yellow, some are black-and-white (such as the bald-faced hornet, Dolichovespula maculata), while others may have the abdomen background color red instead of black. Wasps are carnivorous that they consume insects such as caterpillar and worm. But they also consume nectar and sap.
They develop with complete metamorphosis: egg, larva, pupa and adult. The adult wasps are of three forms: male, female and worker. The males and females are reproductive with the females (or queens) founding the nests and laying eggs. The workers are sterile females. Each female and worker wasp is armed with a sting used for defense against predators. However the male is unarmed.
Almost all types of wasps will pose threats against human, there are 75,000 known types of wasps, and there are 30 common types in Hong Kong.
Wasps may live solitary in ground holes, clay pots, or bamboo stem cavities. Species that cause nuisance, however, are social insects and live in papery nests hanging from trees or building surfaces. The most commonly found species are: (a) Vespa bicolor (b) Vespa affinis (c) Polistes olivaceous. They may fly 2-3 km to search for food. Large aggregation of wasps is usually caused by food attraction.