Observations on a nest of a paper wasp(Polistes sp.)infested by a pyralid moth, Hypsopygia mauritialis (Boisduval, 1833).

A nest of a paper wasp, Polistes(Gyrostoma)sp., infested by the pyralid Hypsopygia mauritialis was dissected and examined in detail. The nest was found in Kagoshima, southern Japan, and collected in mid-September, 2021. Cell walls of the nest comb had many holes, and no brood or meconia remained, probably because of destruction from the feeding activities of the larval moths. The nest had a strange structure(fecal dangler)suspended from the nest comb: the fecal dangler was about 10 cm long and mainly comprised fecal grains of the moth mixed with pupal exuviae of the moth and fragments of wasp cocoons woven together with silk. The nest comb and fecal dangler contained 43 live moth larvae(only 13 of which were vigorous)and 8 live pupae. A total of at least 123 pupal exuviae were present. The feeding behavior and the function of the fecal dangler are discussed, and compared with other cases of Polistes nests infested by Hypsopygia species previously reported. [ABSTRACT FROM AUTHOR]