INTERSPECIFIC COMPETITION BETWEEN NATIVE AND EXOTIC FRUIT FLY PARASITOIDSIN MIXED ORCHARDS IN MACEIO, ALAGOAS, BRAZIL

ABSTRACT The objective of this work was to assess the effects of the release and establishment of the exotic parasitoid Diachasmimorpha longicaudata (Ashmead, 1905) (Hymenoptera: Braconidae) and its interspecific competitive relationship with native fruit fly parasitoids in organic and conventional orchards in Maceio, State of Alagoas, Brazil. The exotic parasitoids were reared in the Radio-Entomology Laboratory of the Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, São Paulo, and released (112,350 individuals between five and eight days old) in orchards from June 8 to July12, 2013.Fruit samples were collected randomly every week during one year to assess the D. longicaudata recaptured from plants and fallen fruits on the ground, which were taken to the Entomology Laboratory of the CECA-UFAL, classified and individually placed in plastic containers, containing a layer of 1 cm of sand for pupation of the host larvae. The pupae, obtained after 10 days, were placed in Petri dishes with a layer of sand until the emergence of adults, which were then kept in plastic microtubes, containing ethanol 70%. The release of exotic parasitoids did not displace native species. The same species were found before and after the release in both cultures: Doryctobracon areolatus, Asobara anastrephae, Utetes anastrephae and Opius bellus (Braconidae), Aganaspis pelleranoi (Figitidae) and individuals of the Pteromalidae family. One year after the last release, 44 individuals of the exotic parasitoid were found, showing its establishment in the studied areas.

摘要 本研究旨在评估外来寄生蜂长柄茧蜂（Diachasmimorpha longicaudata，Ashmead, 1905）（膜翅目：茧蜂科）的释放定殖效果，以及其与巴西阿拉戈斯州马塞约市有机与常规果园内本土实蝇寄生蜂的种间竞争关系。该外来寄生蜂于巴西圣保罗州皮拉西卡巴市圣保罗大学农业核能中心放射昆虫学实验室繁育，并于2013年6月8日至7月12日在果园内释放，共释放112350头5~8日龄的成虫。研究期间连续一年每周随机采集果实样本，以检测从植株及地面落果中重捕到的长柄茧蜂种群；采集的样本被送至CECA-UFAL昆虫学实验室，经分类后单独放入铺有1cm厚细沙的塑料容器中，以供寄主幼虫化蛹。饲养10天后获得的蛹被转移至铺有细沙的培养皿中，等待成虫羽化；羽化后的成虫被转移至装有70%乙醇的塑料微量离心管中保存。外来寄生蜂的释放并未导致本土寄生蜂物种被取代。两种种植模式下的果园在释放前后均检测到以下类群：网状钻茧蜂（Doryctobracon areolatus）、按实蝇异索茧蜂（Asobara anastrephae）、按实蝇优茧蜂（Utetes anastrephae）、美丽奥普茧蜂（Opius bellus，茧蜂科），佩兰诺阿加纳小蜂（Aganaspis pelleranoi，广肩小蜂科Figitidae），以及金小蜂科（Pteromalidae）昆虫。末次释放一年后，共重捕到44头该外来寄生蜂个体，证实其已在研究区域成功定殖。