Irradiation ofAnastrepha fraterculus(Diptera: Tephritidae) Eggs to Inhibit Fly Emergence in the Mass-Rearing ofDiachasmimorpha longicaudata(Hymenoptera: Braconidae)

Abstract

As the incidence of Anastrepha fraterculus (Wiedemann) has increased in Southern Brazil in the past 3 yr, an initiative to release sterile flies and parasitoids has started. In order to make feasible the mass-rearing of the parasitoid Diachasmimorpha longicaudata (Ashmed), this study investigated the suitability of A. fraterculus larvae derived from irradiated eggs as host for D. longicaudata. Two different ages of A. fraterculus eggs (24 and 48 h old) were analyzed for hatchability after the exposure to a range of radiation doses. The hatchability of 48-h-old eggs was not affected by radiation, and no fly emerged at doses higher than 27.5 Gy. The larvae derived from irradiated eggs proved to be suitable hosts for the parasitoid development, with observed parasitism rates higher than 70% and sex ratio values above 0.6. The parasitism capability and longevity of D. longicaudata reared on larvae derived from irradiated eggs were also assessed. During the 10 d of parasitism evaluated, D. longicaudata from the treatments were able to parasitize nonirradiated larvae similarly as the parasitoids from controls and the laboratory colony. The longevity of D. longicaudata from the treatments was not affected either, with survival rates higher than 80% after 20 d of evaluation. The age of 48 h and a dose of 30 Gy could be considered the best age and dose for A. fraterculus eggs to be used in the mass-rearing of D. longicaudata. The results of this study will decrease the costs of mass-rearing D. longicaudata on A. fraterculus.

Effects of temperature on the activity of antioxidant enzymes in larvae of Bactrocera dorsalis (Diptera: Tephritidae) parasitized by Diachasmimorpha longicaudata (Hymenoptera: Braconidae): Optimizing the mass rearing of this braconid by varying the temperature

“…D. longicaudata can become established in various environments and is amenable to mass rearing in the larvae of several species of the genus Bactrocera (Wharton & Gilstrap, 1983;Baranowski et al, 1993;Chinajariyawong et al, 2000). The role of D. longicaudata in biological pest control programmes has stimulated research into various aspects of its biology, such as conditions for mass rearing and release, molecular biology and physiology, in order to improve its use in agriculture pest management (Constanza et al, 2016;Costa et al, 2016;Ndlela et al, 2016;Simmonds et al, 2016;Julsirikul et al, 2017).…”

Optimization of the sterilizing doses and overflooding ratios for the South American fruit fly

“…With the eradication of the codling moth, Cydia pomonella (Linnaeus), achieved in 2014 after a 17-year campaign in Brazil [ 4 ], researchers and growers decided to create the MOSCASUL center at Vacaria, Rio Grande do Sul, Brazil. The main goal of this center is to suppress the wild populations of the South American Fruit Fly, Anastrepha fraterculus (Wiedemann), from temperate fruit production areas of southern Brazil through the application of sterile insects and parasitoids [ 5 ]. Before scaling up the rearing colonies and the release of sterile A .…”

Irradiation of early immature Anastrepha ludens stages for the rearing of Doryctobracon areolatus (Hymenoptera: Braconidae), a fruit fly parasitoid

“…Our results indicate that it is possible to use second instar larvae (irradiated as eggs or as first instar larvae) for rearing D. areolatus. According to Costa et al (2016) and Cai et al (2017), the use of such early stages offers the advantage of simplifying the irradiation procedure. However, it is important to highlight that young developmental stages of the insects are also more susceptible to the negative effects of radiation (Benschoter and Telich, 1964) since the organisms experience several important metabolic changes during these stages (Hallman and Worley, 1999;Han et al, 2006;Mastrangelo and Walder, 2011).…”

“…Preliminary studies show that the use of A. ludens as a host for the rearing of D. areolatus represents a better option than Anastrepha obliqua Macquart (Pérez, 2019), since it is possible to obtain higher parasitism and a sex ratio more biased towards females. Although there is information about the use of irradiated early stages of fruit flies for rearing parasitoids (Palenchar et al, 2009;Cancino et al, 2012;Costa et al, 2016), the possibility of using this method to rear D. areolatus under laboratory conditions remains unexplored. The objectives of this study were therefore to: (1) determine the effect of different radiation doses on the development of A. ludens eggs and first and second instar larvae, and (2) evaluate the viability of these irradiated hosts for the development of the parasitoid D. areolatus under laboratory rearing conditions.…”