PARASITISM OF FRUIT FLIES (TEPHRITIDAE) IN FIELD, AFTER THE RELEASES OF Diachasmimorpha longicaudata (ASHMEAD) (HYMENOPTERA: BRACONIDAE) IN RIO GRANDE DO SUL

Abstract

ABSTRACT-Diachasmimorpha longicaudata (ashmead) (hymenoptera: Braconidae) was introduced in 1994, in Northeastern Brazil, to evaluate its use in biological control programs of fruit flies. However, the effects of this specie on parasitism rates on the population of native parasitoids and fruit flies in Southern Brazil conditions are unknown. The objective of this study was to evaluate the impact of releases of D. longicaudata on the parasitism rates on loquats, peach trees, strawberry guava trees, and persimmons in an experimental area in the city of Eldorado do Sul, Rio Grande do Sul, in southern Brazil. In the first year of the study, fruits were collected and stored in the laboratory to obtain pupae. The flies or parasitoids that emerged were counted and identified. In the second year, adults of D. longicaudata were reared in the laboratory on Anastrepha fraterculus (Wied.) and larvae were released in the field (1.700 insects/ha) at each harvest time and the parasitism was evaluated in the same manner as in the first year. In the third year, the procedure was the same as the first year, without any releases. A significant increase in the rates of parasitism was recorded in the second year except in the persimmon, in which no parasitoid was recovered in any year. In the second year the number of emerged fruit flies was also lower. In the third year, no D. longicaudata were recorded and parasitism rates of parasitism were statistically similar to those found in the first year. The native parasitoids collected were Aganaspis pelleranoi (Brèthes), Doryctobracon areolatus (szépligeti), Doryctobracon brasiliensis (szépligeti) and Utetes anastrephae (Viereck). These species were found in at least one kind of fruit even in the years after the introduction of the exotic parasitoid, indicating that it was not harmful to these species. We conclude that D. longicaudata can help to reduce the population of fruit flies in Eldorado do Sul region, in Rio Grande do Sul.Index terms -biological control, Anastrepha fraterculus, Aganaspis pelleranoi, Doryctobracon, Utetes anastrephae. PARASITISMO DE MOSCASA-DAS-FRUTAS(TEPHRITIDAE) EM CAMPO, APÓS LIBERAÇÕES DE

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

“…In relation to the emergence of parasitoids and mortality, however, both had similar means, except for third instar larvae of A. fraterculus, with a higher mean number of unviable pupae and lower number of emerged parasitoids. Although C. capitata has been used for a long time in rearing of D. longicaudata in several places of the world, A. fraterculus has already been used, showing a good performance as a host (Messing et al, 1993;, Meirelles et al, 2016Harbi et al, 2018), and our study confirms this data. This aspect is important in mass rearing since studies such as those by Segura et al (2007) and Tognon et al (2013) have demonstrated that parasitoids that are reared in a given host are easier to recognize through chemical tracks, obtained by memory or learning, which would provide greater efficiency in the control of the target pest (Mattiacci & Dicke, 1995;Eben et al, 2000).…”

“…As an oviposition substrate for C. capitata, a 250 ml yellow plastic tube with small perforations (FAO/IAEA/ USDA, 2003) was used. For A. fraterculus, the substrate used was a blue tissue bag covered with silicone, as described in Meirelles et al (2016). The eggs were collected daily and placed on polystyrene trays (23.5 x 18 x 1 cm), with an artificial diet based on organic carrot, beer yeast, corn flour, sugar, distilled water, sodium benzoate (Dinâmica ® ), nipagin (Synth ® ) and citric acid (Synth ® ) (modified from Terán, 1977).…”

“…However, evaluations carried out a few years after their release showed that there were alterations in the presence of native parasitoid species and suggested the existence of interspecific competition in oviposition sites (Carvalho, 2005a). On the other hand, Meirelles et al (2016), after release D. longicaudata in Rio Grande do Sul field, did not detect a negative impact on native parasitoid populations. Despite parasitizing preferentially third instar larvae (Montoya et al, 2018), we affirm that D. longicaudata is able of parasitizing and succeeding in any instar, differing from that generally described.…”

Plasticidade da aprendizagem de Diachasmimorpha longicaudata (Hymenoptera: Braconidae) associada a voláteis de frutos e óleos essenciais

“…Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae), tem sido o agente mais utilizado em programas de controle de moscas-das-frutas (González et al, 2007;López et al, 2009;Meirelles et al, 2016;Vargas et al, 2016). Este inseto é um endoparasitoide coinobionte que oviposita no último ínstar larval de tefritídeos e completa o desenvolvimento no estágio pupal do hospedeiro (Carvalho & Nascimento, 2002).…”

“…A essência de baunilha foi utilizada por este odor não fazer parte do contexto ecológico do parasitoide e serviu como "odor modelo" também utilizado por outros autores (Takasu & Lewis, 1996;Tognon et al, 2013;Gregório et al, 2015). O óleo de laranja foi escolhido por apresentar ação repelente para outros insetos inclusive D. longicaudata (bioensaios piloto), objetivando observar uma possível reversão de comportamento para este parasitoide Meirelles et al (2016). Diariamente os ovos eram retirados e colocados sobre voile azul (3 cm²), em placas de Petri (9 × 2 cm), contendo papel filtro umedecido no fundo, acondicionadas durante 48 h em câmara climatizada.…”