Mortality by Parasitization in the Association between &amp;lt;i&amp;gt;Diachasmimorpha tryoni&amp;lt;/i&amp;gt; (Hymenoptera: Braconidae) and &amp;lt;i&amp;gt;Ceratitis capitata&amp;lt;/i&amp;gt; (Diptera: Tephritidae) under Field-Cage Conditions

Patricia Albornoz Medina,Claudia Fidelis-Marinho,Sergio Marcelo Ovruski,Laura Patricia Bezdjian,Pablo Schliserman

doi:10.4236/ns.2014.617116

Abstract

Ceratitis capitata (Wiedemann) is one of the major pests currently affecting world fruit production. In Argentina’s northern Citrus-producing regions, C. capitata is actively multiplying in large exotic host fruits, such as Citrus paradisi Macfadyen (grapefruit), Citrus aurantium L. (sour orange) and Citrus sinensis L. (Osbeck) (sweet orange). Faced with this situation, the use of parasitoids as biocontrol agents is currently receiving renewed attention as a new biological tool for controlling pestiferous fruit flies within the Argentinean National Fruit Fly Control and Eradication Program (ProCEM). Consequently, a viable approach to controlling C. capitata involves the use of exotic parasitoids such as Diachasmimorpha tryoni (Cameron). In this study, the effectiveness of D. tryoni females to find and successfully parasitize C. capitata larvae infesting all Citrus species mentioned earlier was assessed. Parasitoids were allowed to forage for 8 h on grapefruits and oranges artificially infested with laboratory-reared C. capitata larvae under natural environmental conditions (field cage). Parasitoid emergence, parasitism, overall effectiveness, and sex ratio of parasitoid offspring were estimated as response variables. The higher effectiveness of D. tryoni females recorded from C. sinensis would be mainly a result of both increased host density per unit of fruit surface area and fruit physical features. The study provides evidence that D. tryoni contributed to C. capitata mortality in all Citrus species assessed. However, the mortality values recorded from C. sinensis, C. aurantium, and C. paradisi did not exceed 10%, 1.5%, and 1.7%, respectively. Nonetheless, D. tryoni might be selected to forage under both high and low host density conditions.

Highlights

The Mediterranean fruit fly (Medfly), Ceratitis capitata (Wiedemann), is one of the major pests of commercial fruit crops in Argentina
The mortality values recorded from C. sinensis, C. aurantium, and C. paradisi did not exceed 10%, 1.5%, and 1.7%, respectively
In Argentina’s northern Citrus-producing regions, C. capitata is actively multiplying in large exotic host fruits, such as Citrus paradisi Macfadyen, Citrus aurantium L. and Citrus sinensis L. (Osbeck) (Rutaceae), all originated in Southeast Asia [2]

Summary

Introduction

The Mediterranean fruit fly (Medfly), Ceratitis capitata (Wiedemann), is one of the major pests of commercial fruit crops in Argentina. (Osbeck) (sweet orange) (Rutaceae), all originated in Southeast Asia [2] These Citrus species are commonly found in abandoned crop fields or in disturbed wild vegetation areas [3]. Two Indo-Pacific parasitoid species, Diachasmimorpha longicaudata (Ashmead) and D. tryoni (Cameron), were introduced in Argentina via Mexico for augmentative releases against C. capitata [6]. Both braconid species are solitary, koinobiont endoparasitoids, which attack late instar larvae of several fruit-infesting tephritid flies [7]. D. tryoni was successfully colonized at the laboratory on larvae of C. capitata, it was reared on a small scale and was not released [6]

Objectives

Methods

Results

Discussion

Conclusion