Host Egg Age of <I>Leptoglossus occidentalis</I> (Heteroptera, Coreidae) and Parasitism by <I>Gryon pennsylvanicum</I> (Hymenoptera, Platygastridae)

Abstract

Leptoglossus occidentalis Heidemann (Heteroptera, Coreidae) is native to Western North America and is a serious pest for seed production of conifers. The pest was accidentally introduced into Europe in the 1990s. Since then, seed loss has been recorded in Pinus pinea (L.) forests, with a negative impact on the commercial production of pine nuts. Classical biological control of this pest in P. pinea stands is an attractive proposition. Previous work showed that the egg-parasitoid Gryon pennsylvanicum (Ashmead) (Hymenoptera, Platygastridae) had promising life history traits in laboratory studies using L. occidentalis eggs as host. In the present work, the effect of host egg age on parasitization rate was evaluated in the laboratory, using choice and no-choice tests. Host eggs ranged in age from < 24 h to within a day of hatching. Results showed that parasitization rate, juvenile survival rate, sex ratio, and longevity of female G. pennsylvanicum were not significantly affected by the age of the host eggs. However, egg-parasitoid development time was longer in older host eggs, and females were smaller than those that developed in younger host eggs. Parasitization behaviors (drumming, oviposition, and marking) were not affected by the age of the host. G. pennsylvanicum females tended to parasitize all available host eggs within a cluster before moving to a new cluster, without displaying a preferences for host egg age. The ability to exploit host eggs of any age class improves the prospect of successful classical biological control using this egg-parasitoid.

A new substitute host and its effects on some biological properties ofOoencyrtus kuvanae

“…(Hymenoptera: Pteromalidae) (Islam, 1994), Brachymeria lasus (Walker) (Hymenoptera: Chalcididae) (Husni et al, 2001) and Diadromus collaris (Hymenoptera: Ichneumonidae) (Wang & Liu, 2002). Peverieri et al (2013) reported that the development time of the egg parasitoid Gryon pennsylvanicum (Hymenoptera: Platygastridae) is longer in older eggs of Leptoglossus occidentalis Heidemann (Heteroptera, Coreidae), and Da Rocha et al (2006) had the same result for Gryon gallardoi (Brethes) (Hymenoptera: Scelionidae). Crossman (1925) and Kamay (1976) reported that the development time of O. kuvanae was 21 days at 25°C and 14 days at 30°C.…”

Development of Cleruchoides noackae, an egg-parasitoid of Thaumastocoris peregrinus, in eggs laid on different substrates, with different ages and post-cold storage

“…Adequate egg age can improve parasitoid colonization and establishment, resulting in greater pest suppression as reported for Lobesia botrana Denis and Schiffermüller (Lepidoptera: Tortricidae) (Pizzol et al 2012), Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) (Peverieri et al 2013) and Chilo suppressalis Walker (Lepidoptera: Pyralidae) ). The quality of the nutritive resources decreases with host embryo development.…”

Pine Pitch Canker and Insects: Regional Risks, Environmental Regulation, and Practical Management Options

“…Leptoglossus occidentalis is another species for which there are biological pest control programs, such as the use of the parasitoid Gryon pennsylvanicum (Ashmead, 1893) (Hymenoptera: Scelionidae) [289]. Yet, laboratory tests have not yielded positive results on the eggs of L. occidentalis [290]. On the contrary, Barta [291] managed to inoculate artificially in the laboratory the fungi M. anisopliae and Isaria fumosoresea (Wize) Brown y Smith, obtaining good results in adults.…”