Effect of the age of the pupal holotissue on the nutritional quality of artificial diets for Trichogramma spp. (Hymenoptera: Trichogrammatidae)

Abstract

The nutritional quality of artificial diets composed of pupal holotissues of Diatraea saccharalis (Fabr.) (Lep.: Crambidae) from three different age classes (1-2, 3-4 and 5-6 days old) were tested for rearing Trichogramma galloi Zucchi and T. pretiosum Riley (Hym.: Trichogrammatidae) in vitro. Pupal holotissues were added to egg yolk, bovine fetal serum, lactoalbumine hydrolysate and preservatives, and offered to the parasitoids into artificial eggs. The quality of these diets in supporting the development of both parasitoids was evaluated by assessing the acceptance and parasitism of the artificial host eggs, larval and pupal survival, size, parasitism capacity and longevity of the in vitro-reared females, and the presence of deformed adults. Diets composed of 5-6 d old pupal holotissues did not support the larval development of both parasitoids as well as reduced the acceptance and/or parasitism of artificial eggs by T. galloi and T. pretiosum. The factors affecting the nutritional quality of pupal holotissues collected from different developmental stages are discussed.

The effect of host nutritional quality on multiple components ofTrichogramma brassicaefitness

“…Total amount of available protein during adulthood strongly affects reproduction (vitellogenins) (Fortes et al , 2011). Cônsoli & Parra (2000) showed that rearing Trichogramma galloi Zucchi and T. pretiosum Riley on artificial diets containing high amounts of protein led to an increased number of produced eggs. It seems that lower fecundity of low quality reared wasps may be due to less protein available during embryo growth and adulthood.…”

Egg laying and development of Neotropical trichogrammatid species in artificial eggs

“…Development of the three trichogrammatid species was tested on a standard diet, composed of D. saccharalis pupal holotissues (65%), egg yolk (18%), bovine fetal serum (8.5%), albumin hydrolysate (8.5%), and streptomycin sulfate (0.3%), which was developed for Trichogramma pretiosum Riley and Trichogramma galloi Zucchi (Cônsoli & Parra, 2000). Preparation and collection of the pupal holotissues of D. saccharalis , diet preparation, and artificial egg preparation followed Cônsoli & Parra (2000).…”

In Vitro Rearing of Egg Parasitoids

“…However, the quality of pupal holotissues as a component of artificial diets for Trichogramma was also dependent on the age at which the pupal tissues were collected. Older the pupae, lower the parasitoid development and survivorship (Cônsoli and Parra 2000). Although several Trichogramma species could be reared on diets containing hemolymph/holotissues of one of these insects, not all species or populations from a same species tested would properly parasitize artificial eggs filled with such diets, or complete their embryonic and/or larval development.…”

“…One of the major obstacles of producing parasitoids in the latter conditions is the fact that the artificial culture medium has to provide the adequate stimuli to allow for female oviposition and be a suitable rearing medium for parasitoid embryonic and larval development. Diets containing insect-derived components were good elicitors for most Trichogramma species reared on artificial diets, with a few exceptions depending on the host species used or the parasitoid tested (Cônsoli 1997, Cônsoli and Parra 2000.…”