Body size variation in Gryon gallardoi related to age and size of the host

Abstract

This study aimed to evaluate the influence of Spartocera dentiventris (Berg) (Hemiptera: Coreidae) egg quality (regarding age, size and superparasitism) on male and female body size of Gryon gallardoi Bre`thes (Hymenoptera: Scelionidae). It was also analysed host size influence on offspring sex choice and female oviposition order (within egg groups). Groups of 12 eggs, 2, 3, 4, 5, 6, 7, 8, and 12 days old were individually exposed to a female parasitoid for 2 h, and the order of each egg parasitisation was recorded. Size of adult parasitoids (head width and tibia length of the second leg pair), and parasitised and superparasitised host eggs were measured. Sexual dimorphism related to size (SDs), was estimated through a model II linear regression. Females have a larger head width but a smaller tibia length. Parasitoid adult size is significantly related to host age and size. Within an egg group, females did not exhibit preference for any egg size category either to start oviposition or to oviposit male or female eggs. The body size of both sexes diminished with host aging. There was a positive response in both sexes to host size increasing. Estimated SDs diminished with host aging and increased with host volume augmentation. The results suggest that adult body size of G. gallardoi, as well as size differences between males and females, are strongly associated to host quality.

Extreme natural size variation in both sexes of a sexually cannibalistic mantidfly

“…Additionally, the body size variation documented here may follow similar patterns seen in some other animals whose body size is similarly constrained by resources during development (e.g. parasitoid insects; [59,60]). However, the mantidfly system is exceptionally unique due to extreme consequences of size differences in a mating context.…”

Taxonomic study of Baeosega and its allies, with description of a new species of Nipponosega (Hymenoptera, Chrysididae, Amiseginae)

“… humida and N. yamanei , the body proportions of females can vary within a species. Although only a few records on the host of Amiseginae are available, the adult body size of egg parasitoids is usually affected by the host, for example, the size and age of the host egg ( Da Rocha et al 2007 ). Additionally, discontinuous differences can be observed in egg parasitoids if they attack different host eggs, as is known in Scelionidae ( Arakawa et al 2004 ; Abram et al 2016 ; Botch and Delfosse 2018 ).…”

Leaf-Footed Bugs (Coreidae)

“…Reported parasitoids of both S. dentiventris and S. lativentris include the eurytomid wasp Neorileya ashmeadi Crawford and the platygastrid Gryon gallardoi (Brèthes) (Becker and Prato 1982 ;Santos et al 2001 ). Extensive studies have been conducted on the behavior of G. gallardoi as a potential biological control agent for S. dentiventris (da Rocha et al 2007(da Rocha et al , 2008.…”