Evaluation of sequential exposure of irradiated hosts to maximize the mass rearing of fruit fly parasitoids

Abstract

A series of evaluations were carried out to assess the feasibility of sequentially exposing tephritid hosts to a primary and a secondary parasitoid to ascertain if the larvae not parasitized by the primary parasitoid could be attacked by the secondary parasitoid in the pupal stage, thus optimizing the mass production of two or more species of parasitoids. Larvae or pupae of Anastrepha ludens (Loew) were exposed either to no parasitoids, the larval parasitoid Diachasmimorpha longicaudata (Ashmead) (primary parasitoid), the pupal parasitoids Coptera haywardi (Oglobin), Dirhinus sp., and Eurytoma sivinskii (Gates & Grissell) (secondary parasitoids), or sequentially to combinations of both the larval and pupal parasitoids. As part of all evaluations, host larvae were either irradiated or unirradiated. Typically, host larvae are irradiated under parasitoid mass rearing to avoid fly emergence from unparasitized hosts. Results show that a second host exposure did not increase parasitoid production mainly due to a high incidence of mortality caused by multiparasitism. With the exception of pupae exposed to C. haywardi obtained from irradiated larvae previously exposed to D. longicaudata, multiparasitism was around 50%. This resulted in a reduction in emergence of both parasitoids. To some extent, pupal parasitoids discriminated among pupae, preferring to oviposit in pupae that were not superparasitized previously by D. longicaudata. Notably, pupae resulting from irradiated larvae were not appropriate for the development of C. haywardi. In contrast, in the cases of Dirhinus sp. and E. sivinskii, adult parasitoids did emerge from pupae resulting from irradiated larvae, although emergence was significantly lower than when pupae from unirradiated larvae were used. Our findings offer critical insights for fine-tuning the possible use of sequential host exposure to maximize parasitoid mass production.

Best Host Age of Anastrepha obliqua (Diptera: Tephritidae) for Multiplication of Four Native Parasitoids from the Americas

“…We evaluated the native third-instar larval parasitoids U. anastrephae and O. anastrephae, and the pupal parasitoids C. haywardi and Dirhinus sp., which were obtained from the Biological Control Laboratory of the Moscafrut Program and reared according to Cancino et al (2009b) and Aluja et al (2009) . The molecular identification of Dirhinus sp.…”

“…Based on the preliminary results (i.e., percentages of parasitism, Tables 1 and 2 ), U. anastrephae and C. haywardi were selected as the species with the best potential for use in mass rearing the larvae and pupae of A. obliqua , respectively. In the second phase of the study, the fitness of the emerged parasitoids was assessed through the quality- control parameters of flight ability and survival without water and food, as in Cancino et al (2009b) and Poncio et al (2016) .…”

IsAnastrepha obliqua(Diptera: Tephritidae) a natural host of the Neotropical parasitoidsDoryctobracon crawfordiandOpius hirtus?

“…The native parasitoids D. crawfordi and O. hirtus were provided by the Biological Control Laboratory, where they are reared on A. ludens larvae for more than 100 generations following the protocols reported by Cancino et al . ().…”

“…; Cancino et al . ). These findings highlight the necessity of performing more detailed studies on the parasitoid–host relationship that each of these parasitoid species has established with the fruit fly species with which it coexists under natural conditions.…”

Application of Nuclear Techniques to Improve the Mass Production and Management of Fruit Fly Parasitoids

“…Previous research into post-harvest phytosanitary treatments using radiation helped with calculations to determine the different doses needed to suppress egg, larval and pupal development of various Tephritidae [ 37 ]. Within this general framework it is possible to apply radiation not only to larval tephritids, but also to other host stages such as eggs and pupae, with adequate results regarding parasitoid emergence and effectiveness [ 19 , 38 , 39 , 40 , 41 ].…”