Parasitism of Diachasmimorpha longicaudata (Ashmead) on two fruit fly species

Abstract

The aim of the present study was to investigate the parasitism of two fruit fly species by different Diachasmimorpha longicaudata strains. Females of two parasitoid strains were reared on Ceratitis capitata or Anastrepha fraterculus that were conditioned in adapted containers. Individual parasitoids were offered 20 larvae for 1 h, using no-choice (20 C. capitata or 20 A. fraterculus) or free-choice (10 of each species) assays. Parasitism was verified by counting scars, and the pupae were classified as non-parasitized (no scars), parasitized (one scar), or superparasitized (multiple scars). Parasitism intensity was compared by evaluating the proportions of non-parasitized, parasitized, and superparasitized larvae. Parasitism intensity and scar frequency were analyzed as functions of host species and parasitoid strain, using chi-square tests. In the non-choice tests, females of both parasitoid strains parasitized the larvae, regardless of host species. However, when the parasitoids had a choice, they preferred to superparasitize A. fraterculus larvae, which are larger than C. capitata larvae. In addition, the female parasitoids parasitized most of the host larvae, regardless of parasitoid strain or host species. However, the frequency of non-parasitized pupae was higher when the offered host species was different from the one in which the parasitoid was reared, and the frequency of superparasitized pupae was higher when the offered host species was the same as the one in which the parasitoid was reared.

Does Diachasmimorpha longicaudata (Hymenoptera: Braconidae) have a preferential instar to parasitize Tephritidae (Diptera)?

“…The interaction between D. longicaudata and A. fraterculus can be considered as a "new association", as they do not share an intense history of coevolution, a factor that may influence the parasitoid-host relationship (Hokkanen & Pimentel, 1989), and even change the parasitoid's preferences for the parasite. The fact that A. fraterculus larvae are larger than C. capitata (Meirelles et al, 2013;Oliveira et al, 2014;Sá et al, 2018) or those of many Bactrocera species (Mau & Kessing, 1992;Thomas et al, 2001;Singh et al, 2010), their original hosts, may cause the D. longicaudata to parasitize also the first instars of the South American fruit fly, recognizing the youngest larvae as appropriate for their development, with sufficient nutritional quality and quantity to meet their needs, opposing previous studies (López et al, 2009;Harvey et al, 2012).…”

Processo de domesticação do parasitoide nativo de moscas-das-frutas Doryctobracon areolatus (Szépligeti) em laboratório

“…As vespas parasitoides estão incluídas no grupo dos insetos Hymenoptera que, usualmente, têm o sistema de determinação do sexo por haplodiploidia, o que permite a seleção do sexo dos ovos pelo controle do acesso do esperma (GODFRAY, 1994). Um dos motivos para essa seleção é o tamanho da larva hospedeira, sugerindo que larvas menores impulsionam as fêmeas a colocar ovos que originarão machos, ao passo que larvas maiores estimulam a oviposição de ovos que originarão fêmeas (OLIVEIRA et al, 2014;SÁ et al, 2018).…”