A Nest of a Social Wasp, Vespa Affinis, in Thailand (Hymenoptera: Vespidae)

The nests of the tropical Vespa species are very poorly known. Van der Vecht (1957) reviewed what little was known as of the early 1950’s, and since then only a few additional reports have appeared (Sakagami and Fukushima 1957, van der Vecht 1967, Matsuura 1971a, b, 1973, Matsuura and Sakagami 1973, Yamane 1977, Yamane and Makino 1977, Makino and Yamane 1980, Kojima and Yamane 1980). We now report observations made on a Vespa affinis nest in Thailand. We found the nest in a residential area in Bang Khen, a district on the northern outskirts of Bangkok. The nest hung in a mango tree (Mangifera indica) where it was thoroughly shaded and concealed by the tree’s thick foliage. The nest bottom was 1.4 rn off the ground. We first observed the nest on 13 October 1979, at which time the nest was occupied by an evidently strong colony of wasps. During the daytime about 30 wasps, apparently guards, were scattered over the nest’s outer surface and there was strong flight to and from the nest. Several wasps were collected and have been placed as voucher specimens in the entomology collection of the Peabody Museum, Yale University. When we reexamined the nest on 21 October 1979 the wasps were gone. The people in whose yard the nest was built said the wasps had left earlier that day. We do not know why the wasps abandoned their nest. Many small ants (species undetermined) were scavenging on pupae left in the nest, but we do not know whether these ants had previously been attacking the wasp colony and so perhaps caused its absconding, or whether the ants had invaded the nest only after the wasps abandoned it. The owners of the nest reported that during the wasps’ approximately 9-month residence in their yard the wasps had not been disturbed by humans.