Association of the Female Flight Ability of Asian Spongy Moths (Lymantria dispar asiatica) with Locality, Age and Mating: A Case Study from China

Abstract

The spongy moth (formerly known as a gypsy moth), Lymantria dispar L. (Lepidoptera: Erebidae), is a polyphagous pest that defoliates various species of trees in the genera Populus, Salix, Quercus, Acer and Pinus. Egg masses of Asian spongy moths (Lymantria dispar asiatica) were obtained from five geographically distinct locations in China (Chengdu, Xifeng, Heilongjiang, Kuduer and Longhua regions) and were carried to the lab for incubation and rearing larvae up to adult emergence. The aim was to see how locality, age and mating status influenced the flying activity of female Asian spongy moths. The findings demonstrate that age significantly affects L. dispar asiatica flying activity, with flight period and distance decreasing dramatically as age increases. Locality also significantly impacts flight ability, and mating status does not affect the L. dispar asiatica female flight ability (p > 0.05). The maximum speed was observed for females from Xifeng (7.19 ± 0.34 km/h). The females from Heilongjiang were recorded as having the maximum average speed (2.35 ± 0.08 km/h). Females from Xifeng exhibited the maximum flight duration and distance (0.94 ± 0.04 h and 1.87 ± 0.18 km). Morphological features, i.e., thorax width (cm) and wing loading, significantly influenced the L. dispar asiatica flight ability (R2 = 0.93 and R2 = −0.98). The overall pattern observed for female L. dispar asiatica flight duration was Xifeng > Kuder > Chengdu > Heilongjiang > Longhua, and for flight distance, it was Xifeng > Longhua > Heilongjiang > Kuder > Chengdu. This research offers detailed information on the dispersion rate of Spongy moths in a known or newly introduced habitat, which can help us limit the spread of this polyphagous pest.