Relationships between Body Size and Parasitic Fitness and Offspring Performance of Sclerodermus pupariae Yang et Yao (Hymenoptera: Bethylidae)

Abstract

The relationship between body size and fitness in parasitoid wasps has several effects on parasitic ability, reproductive behavior in female wasps, and progeny fitness. Female wasps with various body sizes were obtained by mass–rearing a gregarious ectoparasitoid, Sclerodermus pupariae, which is one of the excellent parasites to control the larvae and pupae of Buprestidae and Cerambycidae. We investigated the effects of body size of adult females introduced on Thyestilla gebleri (Coleoptera: Cerambycidae) larvae on their paralysis time, pre–oviposition period, oviposition period and fecundity, and the related fitness of their offspring. Results showed that small female wasps needed more time to paralyze a host and had a higher mortality rate than large female wasps. More offspring were produced by large female wasps than by small female wasps, and the percentage and body size of female offspring was not affected by maternal body size. The duration of the egg stage was not affected by foundress size, nor was that of the pupal stage, but the duration of the larval stage and generation time of small female wasps was longer than that of large females. Our findings suggest that the parasitic fitness and offspring performance are affected by maternal size, and there is need to choose reasonable body size of female wasps, to optimally utilize mass rearing and to control target pests with the lowest mortality cost.

Acceptability and suitability of Spodoptera exigua (Hübner) for Cotesia icipe Fernandez‐Triana & Fiaboe on amaranth

“…Gao et al. () reported that when the parasitoid Sclerodermus pupariae Yang & Yao (Hymenoptera: Bethylidae) encountered bigger or more active hosts, large females had greater advantages to subdue host larvae than the smaller sized females. Moreover, the same authors found that generally, large female parasitoids have greater reproductive potential because of larger volume of the spermatheca than small females.…”

“…The fitness of a female parasitoid positively influences the success of host parasitism. Gao et al (2016) reported that when the parasitoid Sclerodermus pupariae…”

Parasitoid wasps as effective biological control agents

“…These transcripts encode neurohormones, that is, proteins with functions in biosynthesis of ecdysone, metabolism of juvenile hormone, or chitin metabolism. They also found that two teratocyte proteins shared similarities with venom components, and two defensins exhibit anti-microbial activity which probably provide immune protection in the host-parasitoid system (Gao F et al 2016).…”

“…Sclerodermus pupariae Yang et Yao (Hymenoptera: Bethylidae) is a newly discovered native gregarious idiobiont ectoparasitoid of the emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), and an excellent parasitoid of larval and pupal Buprestidae and Cerambycidae (Yang et al 2012;Gao S et al 2016). The control efficiency of the bethylid parasitoids in suppression of wood-borers has been investigated in several wasp-host systems, especially S. pupariae (Gao S et al 2016;Gao S K et al 2016;Wang et al 2016;Wei et al 2016Wei et al , 2017. Parasitism and emergence rate in laboratory can be as high as 100% when the ratio of parasitoid-to-host is 1:1 while the rate in the field was 13% (Wei et al 2016).…”

“…Unlike the extensive functional studies of PDVs and venoms in parasitism, the roles of teratocytes are less understood with only two transcriptome data sets reported and a small number of studies reporting on the function of specific teratocyte genes. Gao F et al (2016) identified many transcripts with potential functions in host immune defenses, growth or metabolism in C. vestalis teratocytes. These transcripts encode neurohormones, that is, proteins with functions in biosynthesis of ecdysone, metabolism of juvenile hormone, or chitin metabolism.…”