Reproduction and immature development of Hyssopus pallidus (Hymenoptera: Eulophidae), an ectoparasitoid of the codling moth

Abstract

Abstract. Hyssopus pallidus (Askew) (Hymenoptera: Eulophidae) is a gregarious ectoparasitoid of late larvae of the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae). In the present work reproduction and the development and morphology of the immature stages were studied. Five larval instars were differentiated by the shape and size of the mandibles. The larvae are hymenopteriform with a weakly sclerotized head and 13 segments. The first instar has four pairs of spiracles, while the other four instars have nine pairs. Under laboratory conditions of 22-24°C and 60-80% RH the egg stage lasted 1.5 days, the larval instars 6.3 days, and the pupal stage 7.9 days in females and 7.2 days in males. The duration of each of the five larval instars (L1-L5) is approximately 1, 0.5, 0.75, 0.75 and 3.5 days, respectively. Male and female development time does not differ significantly in the egg and larval stages, but differences are highly significant in the pupal stage. Male and female pupae can be differentiated by their sexual rudiments. Copulation takes place immediately upon emergence of the females between siblings, adult males appearing before the females. Females in culture with access to an energy source can survive for more than 60 days. They are synovigenic: they emerge with no mature eggs in their ovaries and take the first two days after emergence to mature the full set of around 24-30 eggs. They continue paralyzing hosts, ovipositing and maturing eggs for as long as they live. After an oviposition a female needs two to three days to mature a new full set of eggs. Age and feeding influence egg load. Oosorption is significant in starved females, but also occurs in older fed females with no host contact.

Superparasitism in gregarious hymenopteran parasitoids: ecological, behavioural and physiological perspectives

“…A first parasitoid wasp that enters an infested fruit through the calyx or the tunnel made by the caterpillar faces a mortality risk of 25% (Mattiacci et al ., 1999, 2000), which is considered to be largely due to the herbivore’s mechanical defense reaction. However, successful first comer wasps fully paralyse their host caterpillar (Tschudi‐Rein & Dorn, 2001; Gandolfi et al ., 2003), of which second comers could benefit because conspecific superparasitism occurs in this parasitoid species irrespective of the brood guarding by the first female (Zaviezo & Mills, 1999).…”

How two different host species influence the performance of a gregarious parasitoid: host size is not equal to host quality

“…Parasitoids used in these experiments derived from the CM and the CP strain. Upon successful oviposition, eggs were counted and the female wasp was kept with the brood for an additional 2 days for brood guarding (Zaviezo & Mills 1999) and to allow the maturation of a new set of eggs (Tschudi-Rein & Dorn 2001). Thereafter, the female was removed and offered a new host caterpillar.…”

Cold stored ectoparasitoid of Cydia fruit moths released under different temperature regimes

“…This parasitoid is relatively specialized (Zaviezo and Mills 2000), with the codling moth Cydia pomonella (L.) and the Oriental fruit moth C. molesta (Busck) being its only known hosts in Europe, as first (Askew 1964) and recent (Tschudi-Rein et al 2004) field samplings document. Similar to other Eulophidae (Brown 1996), this species has a rapid preimaginal development, a high lifetime fecundity and a female biased sex ratio (Zaviezo and Mills 1999;Tschudi-Rein and Dorn 2001;Häckermann et al 2007), rendering it particularly suitable for mass production. Female parasitoids use plant as well as host derived cues to locate their host (Mattiacci et al 2000).…”