Oviposition site selection by Japanese gypsy moth (Lymatria dispar japonica) in a warm-temperate secondary forest in western Japan

Abstract

The larvae of Japanese gypsy moth (JGM, Lymantria dispar japonica) are highly polyphagous and considered a serious pest that cause significant ecological and economic losses in forests. Monitoring of egg masses is important to prevent large outbreaks of JGM from occurring in their native range. To investigate oviposition site selection by JGM, we analyzed the occurrence and spatial distribution of egg masses across various evergreen tree species within a secondary forest dominated by evergreen broad-leaved trees in western Japan, following a large outbreak. Egg masses were concentrated on the abaxial surfaces of the leaves of a few evergreen tree species. There was a strong preference for Camellia japonica L., on which more than 75% of the egg masses were found. Egg masses were only found on evergreen tree species with large leaves (leaf area >10 cm 2 and leaf dry mass >0.1 g). The spatial distribution of egg masses were clustered at scales around 1-2 m. For effective monitoring of JGM egg masses in warm-temperate evergreen broad-leaved forests of Japan, the abaxial surfaces of the most abundant evergreen broadleaved trees with large leaves should be checked. If egg masses are found, it is likely that nearby trees of the same species will also have egg masses. Large trees should be checked thoroughly for occurrence of multiple egg masses.

Range expansion ofLymantria dispar dispar(L.) (Lepidoptera: Erebidae) along its north‐western margin in North America despite low predicted climatic suitability

“…Likewise, ovipositional behaviour within moth populations is under selective pressure with several potential trade-offs (Higashiura, 1989). Ovipositional site selection varies among species and subspecies of Lymantria, including L. dispar (Higashiura, 1989;Pogue & Shafer, 2007;Sasaki, Jikumaru, Azuma, Kuroda, & Ishii, 2016). Eggs laid high in a tree canopy facilitate dispersal of ballooning of first instar larvae to proximate food sources, but increase the risk of avian predation (Higashiura, 1989).…”

Comparing the Expression of Olfaction-Related Genes in Gypsy Moth (Lymantria dispar) Adult Females and Larvae from One Flightless and Two Flight-Capable Populations

“…The extent to which flight capable females are involved in host-plant choices is not yet fully understood, but evidence suggests that both AGM and JGM actively disperse and display oviposition preferences under field conditions (Baranchikov, 1989;Sasaki et al, 2016).…”