Liostenogaster vechti is a type of eusocial hover wasp within the family Vespidae. They are typically brown and yellow in color and are considered a passive aggressive species. Their stings are less painful to humans than other social wasps, and they engage in associative nest foundation. They are mostly found on the Malaysian peninsula and are known for living in large clusters of small ring-shaped nests.
Taxonomy and phylogeny
Liostenogaster vechti was first classified by Stefano Turillazzi in 1988. These wasps are part of the subfamily Stenogastrinae and are often referred to as hover wasps due to their manner of flying. Stenogastrinae has many other groups that are distributed across the Oriental region, but the species most closely associated with L. vechti is L. flavolineata due to similar coloring, behavioral patterns, and the similar locations of the two species.
Description and identification
The adult females are 14 to 16 mm in length with dark brown coloring and yellow markings all over the body. The abdomen has brown and yellow stripes with the tip being mostly dark brown, and the legs are typically lighter at the bottom and browner near the top. Their mandibles are also yellow and each have three teeth (tridentate) which are not yellow. The antennae are partially dark brown and the eyes are dark brown and hairless unlike the hairy eyes of L. flavolineata. The top of the thorax is usually dark brown with the rest of the thorax having yellow and brown intermediate patches, and the petiole (slender stalk connecting the abdomen to the thorax) is usually a reddish brown. They also have two sets of wings, two posterior and anterior.
The adult males look very similar to the females. They have about the same body length, and the main differences include their antennae being completely dark brown, and having hair on the broad yellow plate (clypeus) at the front of their heads. They have more hair in other places as well. Also, their upper hind limbs (femora) on their median legs are brown with a thin, long, yellow stripe. Lastly, the aedeagus (reproductive organ which is used to secrete sperm) is flattened and inflated at the apex.
Habitat and distribution
Along with most other members of the Stenogastrinae, L. vechti are only located in Southeast Asian rainforests. These wasps along with L. flavolineata are mostly distributed in the Malaysian peninsula. Their nests are located in large clusters and are usually found on flat, vertical, or horizontal substrates.
Colony cycle
Colonies are often founded by a group of L. vechti females using what is known as associative foundation. They begin by constructing small nests in the center, and eventually other wasps join the colony and build nests around the initial central one. The nests last for multiple years, and colonies grow and contain up to 600 nests or more. Temperature does not play a serious limiting factor in the lives of these wasps, and there is no particular season during which the colonies of these wasps are not present and active. However, brood rearing and reproduction is more likely to occur during the dry season, and the population of the nest tends to increase during that time as well, although brood rearing and reproduction also occurs during the wet season.
Nests are sometimes destroyed by predators or by other environmental factors such as floods and earth slides, but new nests are continually built around the old nests. Each nest usually contains relatively few individuals (usually no more than 10) and there are usually more females than males. There is typically one dominant reproductive female per nest, and after her daughters mature, they stay with their mother in her nest for a short while and engage in nest defense, brood care, or foraging activities. After this period ends, daughters often leave and join other colonies. Occasionally, dominant females are usurped by other visiting dominants. A new reproductive female may arrive, fight the current dominant female, and take over the nest if she (the newcomer) wins.