In vitro rearing of Eucelatoria bryani: improvements and evaluation of factors affecting efficiency

Abstract

In vitro rearing of Eucelatoria bryani Sabrosky (Diptera: Tachinidae) was made more efficient and economical. Absorbent cotton, used as a support to replace more expensive agar in an artificial medium, produced yields of adults equal to those reared on the agar‐based medium. The weights of pupae from the cotton‐supported medium were about 16% lighter than were the weights of pupae from the agar‐based medium. Evaluation of diet volumes (100, 200 and 250 μl) for individually reared flies revealed that highest adult yields (46.3%) were obtained when 200 μl per maggot of agar‐based diet were used in each well of microtiter plates; this is equivalent to 2,315 adults per liter of diet. The tachinids were small and the sizes were equal to those obtained when 10–15 maggots parasitize a single host. Costs could not be reduced by deleting free amino acids from the medium fed to older maggots because free amino acids are essential dietary ingredients for third instars of E. bryani.

In vitro rearing of Exorista larvarum on tissue culture‐based diets

“…The occasional lighter coloured halo-like ring noted round this hole is probably caused by the release of enzymes by the maggots, which have well developed salivary glands. A similar phenomenon was reported in E. bryani (Bratti & Nettles, 1992) and in Exeristes roborator (Fabr.) (Thompson, 1975a).…”

“…The most important include: (i) many eggs can be collected from a single host larva, a fact linked both to superparasitism and the fact that the eggs are readily detachable in the first hours after oviposition on the cuticle; (ii) unlike other tachinids (Nettles et al, 1980;Bratti & Benini, 1991), E. larvarum can develop in vitro without feeding initially in the host; (iii) the fact that its maggots fully penetrate the artificial diet and remain inside it enables them to eat more than those species that feed on the surface of the food; and (iv) its gregariousness allows numerous specimens to be reared in the same container and, hence, lower costs are involved. Except for some species of the genus Trichogramma, and until research was begun on E. larvarum, E. bryani had been the most successful example of in vitro rearing of an economically important parasitoid (Nettles, 1986;Bratti & Nettles, 1992). However, compared to E. larvarum, it has a major drawback: for, unlike the latter, high yields are dependent on its being able to feed on the host for one day after the first instar is larviposited in the host (Nettles et al, 1980).…”

Fecundity and oviposition of Eucelatoria bryani, a gregarious parasitoid of Helicoverpa zea and Heliothis virescens

“…Given that the size of laboratory-reared flies can be manipulated by the number of maggots per host (Ziser et al, 1977) or by the amount of artificial media available per maggot (Bratti & Nettles, 1992), understanding individual variation in fecundity and progeny allocation will assist in determining the most efficient method for rearing E. bryani for inundative releases. In addition, these results indicating that E. bryani can exploit a wide range of H. zea and H. virescens stages and sizes and is not dependent on a particular host size or stage will assist in assessing the impact of E. bryani on populations of H. zea and H. virescens (Knipling, 1992).…”

Parasitoides larva-pupa de Hylesia metabus Cramer (Lepidoptera: Saturniidae) en la región nororiental de Venezuela: un caso de control Biológico Natural

“…Cabe mencionar que se ha logrado la reproducción de S. lambens sobre una dieta artifi cial hasta la generación F1, bajo condiciones de laboratorio (Díaz & Osborn datos no publicados). Por otra parte, varias especies de Tachinidae, como por ejemplo Exorista larvarum L. y Eucelatoria bryani Sabrosky han sido criadas sobre diferentes dietas artifi ciales (Bratti & Nettles 1992, Dindo et al 2003. Esto evidencia que si conocemos la biología y reproducción de estas especies, podemos contar con una herramienta de control biológico natural.…”