Egg Load and Body Size of Lab-cultured Cotesia marginiventris

Abstract

The egg load of lab-cultured Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae), a solitary koinobiont endoparasitoid of noctuid caterpillars, was determined in this study. Information on egg load may provide clues to more efficient in vivo rearing of C. marginiventris. I tested the hypothesis that egg load, defined as the number of mature oo¨cytes (i.e., fully chorionated eggs) found in adult females, was related to body size. Cotesia marginiventris females possessed two ovaries and two ovarioles per ovary; mature eggs were found in ovaries and oviducts. Newly-emerged females held an average of 149 mature eggs. Immature eggs were slightly visible in the distal portions of the ovarioles; they were not counted. Egg load was marginally related to body size (i.e., hind tibia length). The results of this study suggest that (1) body size can sometimes predict egg load or potential fecundity of lab-cultured C. marginiventris and (2) an efficient rearing system that exploits the potential fecundity of C. marginiventris might involve using young females and allowing them to oviposit in new hosts, each day, for up to a week.

Influence of honey and maternal age on egg load of lab-cultured Cotesia marginiventris

“…The average egg load at emergence was 149 mature eggs (Riddick 2006). If the maximum egg load of 4 day-old females (in this study) is used as an estimate of lifetime potential fecundity, the ovigeny index is 0.52 (i.e., 149/287) or 52%.…”

Parasitism and developmental parameters of the parasitoid Diadegma majale (Gravenhorst) in control of Plutella xylostella (L.) on selected cultivars of canola

“…Body size, a measure of the resources available to the developing parasitoid larvae, is an important fitness correlate because it often affects reproductive success through variations in fecundity, longevity, searching efficiency, and host handling strategies (Visser 1994;Kazmer and Luck 1995;Ebon et al 2000). Body size is usually measured in terms of the width or length of certain body parts such as wing, hind tibia, and thorax (Nicol and Mackauer 1999;Jervis 2005;Riddick 2006;Sarfraz et al 2008). Body masses are also measured as fitness parameters (Sarfraz et al 2008).…”

Parasitism Performance and Fitness of Cotesia vestalis (Hymenoptera: Braconidae) Infected with Nosema sp. (Microsporidia: Nosematidae): Implications in Integrated Pest Management Strategy

“…The length of the hind tibia has been used as an indicator of the body size of other parasitoids [43]. Ten F1 individuals (males and females) from the infected and uninfected groups were deep-frozen on the day of emergence and placed on microscope slides within a droplet of saline solution.…”