Parasitism Behavior of Three Species of Eucoilinae (Hymenoptera: Cynipoidea: Figitidae) Fruit Fly Parasitoids (Diptera) in Brazil
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March - April 2004 217 BIOLOGICAL CONTROL Parasitism Behavior of Three Species of Eucoilinae (Hymenoptera: Cynipoidea: Figitidae) Fruit Fly Parasitoids (Diptera) in Brazil JORGE A. GUIMARÃES1 AND ROBERTO A. ZUCCHI2 1EMBRAPA/CNPAT, Rua Sara Mesquita, 2270, C. postal 3761, 60511-110, Fortaleza, CE e-mail: [email protected] 2Depto. Entomologia, Fitopalogia e Zoologia Agrícola, ESALQ/USP, Av. Pádua Dias, 11, C. postal 9, 13418-900 Piracicaba, SP, e-mail: [email protected] Neotropical Entomology 33(2):217-224 (2004) Comportamento de Parasitismo de Três Espécies de Eucoilinae (Hymenoptera: Cynipoidea: Figitidae) Parasitóides de Moscas-das-Frutas (Diptera) RESUMO - Os eucoilíneos são endoparasitóides larvais de dípteros ciclorrafos. Várias espécies têm sido associadas a larvas de moscas frugívoras (Tephritidae, Lonchaeidae e Drosophilidae). Algumas espécies desses dípteros causam danos aos frutos cultivados. Para minimizar as perdas, tem-se utilizado o Manejo Integrado de Pragas (MIP), onde o controle biológico com himenópteros parasitóides tem papel fundamental. O conhecimento a respeito do comportamento de parasitismo pode auxiliar na maximização do uso de parasitóides em programas de controle biológico aplicado. Dessa forma, este trabalho teve como objetivos: (1) estudar a resposta olfativa de Aganaspis pelleranoi (Brèthes) e Dicerataspis grenadensis Ashmead aos voláteis emitidos de goiaba infestada com larvas de moscas- das-frutas em olfatômetro de quatro vias, com fluxo de ar e (2) verificar a seqüência comportamental de localização e avaliação do hospedeiro por A. pelleranoi, D. grenadensis e Odontosema albinerve Kieffer, em goiabas infestadas com larvas frugívoras em laboratório e em campo. Nos experimentos com olfatômetro de quatro vias, A. pelleranoi e D. grenadensis foram mais atraídos pelos voláteis dos frutos infestados por larvas frugívoras. Ao estudar a seqüência comportamental dos eucoilíneos, em polpa de goiaba madura infestada com larvas de moscas, verificou-se que A. pelleranoi e O. albinerve, ao chegarem nos frutos por meio dos voláteis, localizam as larvas hospedeiras nos frutos por meio de vibrotaxia e que D. grenadensis localiza as larvas hospedeiras nos frutos com o ovipositor. Foi estabelecida a especificidade de D. grenadensis às larvas da família Drosophilidae em goiaba podre. PALAVRAS-CHAVE: Odontosema albinerve, Dicerataspis grenadensis, Aganaspis pelleranoi, olfatômetro, semioquímico ABSTRACT - Eucoilinae are larval endoparasitoids of cyclorrhaphous dipterous. Several species have been associated with frugivorous larvae (Tephritidae, Lonchaeidae and Drosophilidae). Some species of these dipterous cause serious damage to fruit crops. In order to minimize their damage, Integrated Pest Management (IPM) using biological control with hymenopteran parasitoids has been used. Studies on parasitism behavior can maximize the use of parasitoids in biological control programs. Thus, this paper had as objectives (1) to study the olfactory response of Aganaspis pelleranoi (Brèthes) and Dicerataspis grenadensis Ashmead to the volatile emitted by guava infested with fruit fly larvae and (2) to verify the behavioral sequence of location and evaluation of hosts by A. pelleranoi, D. grenadensis and Odontosema albinerve Kieffer in laboratory and in field conditions. Experiments in a four-armed airflow olfactometer showed that A. pelleranoi and D. grenadensis were more attracted to volatiles of fruits infested with frugivorous larvae. The behavioral sequence of Eucoilinae, in ripe guava pulp infested by frugivorous larvae, showed that A. pelleranoi and O. albinerve located the host larvae by vibrotaxis and D. grenadensis found the host larvae with the ovipositor. These results established that D. grenadensis showed specificity to larvae of the family Drosophilidae in rotting guava. KEY WORDS: Odontosema albinerve, Dicerataspis grenadensis, Aganaspis pelleranoi, olfactometer, semiochemical 218 Parasitism Behavior of Three Species of Eucoilinae (Hymenoptera: Cynipoidea: Figitidae)... Guimarães & Zucchi The Eucoilinae are the largest group of Cynipoidea, Material and Methods consisting of approximately 1,000 species in 82 genera distributed throughout the world. It is the most diversified Olfactory Response to Volatiles in an Olfactometer. The subfamily of Figitidae in Brazil, with 55 species in 29 genera Eucoilinae olfactory response to the volatiles released from (Ronquist 1995, Diaz 1998). They are koinobiont the association of frugivorous larvae and host fruits was endoparasitoids of cyclorrhaphous dipterous that parasite observed in a four-armed airflow olfactometer (Vet et al. 1983). preferentially the last larva instars, emerging from the fly pupa The apparatus consisted of a star-shaped central arena with (Diaz 1998). Some Eucoilinae species only parasite the larvae four exits (Fig. 1A-B). The central arena consisted of four acrylic of flies of the Tephritoidea superfamily, making them potential semi-circles (arc 90o, 135 mm radius) placed on a 3-mm thick biological control agents for use in fruit fly integrated acrylic sheet. There was a 5-mm diameter hole at each end of management programs (Ovruski et al. 2000). Recently seven the arena to attach the hose of the side tubes containing the Eucoilinae species were detected associated with fruit-eating test sample. In the center of the arena there was a 5 mm hole to flies (Anastrepha spp., Ceratitis capitata Wied and attach the vacuum hose. The arena roof is a 3-mm thick acrylic Lonchaeidae) in 34 species of fruit trees belonging to 15 sheet. Complete sealing of the system was ensured with the botanical families. The Myrtaceae fruit are the most attractive use of vaseline to join the base (central arena) to the roof. Each for these parasitoids, indicating a strong tritrophic arm of the chamber was connected to a series of three glass relationship among these organisms (Guimarães et al. 1999, tubes (50 ml). The tube closest the chamber was to capture the 2000, 2003). insect that responded positively to the tested odor, the sample The Eucoilinae act at the end of the fruit succession to be studied was placed in the second tube and the distilled process in the field. They parasite the larvae that escape the water was placed in the third tube to moisten the air and filter opiines (Braconidae) that, because of the size of the the impurities that penetrate the system (Fig. 1B). An air flow ovipositor, only parasite the larvae that are found on the fruit of 300 ml/min was used in each arm of the olfactometer, obtained surface (Sivinski et al. 1999, 2001). The parasitism of the fly by a vacuum pump attached to the lower hole located in the larvae in the fruits probably leads to inter and intraspecific central part of the arena and regulated by four flowmeters competition that imply different search and host assessment installed in each arm of the apparatus (Vet et al. 1983). strategies (Vet & Alphen 1985). Natural parasitoid populations were used obtained from The process by which the microhimenopterous parasitoids fruit-eating fly pupae collected directly from guavas in the find the hosts can be divided into three stages: (1) habitat counties of Monte Alegre do Sul and Piracicaba, SP. The localization, that generally involves long distance fruits were harvested randomly from the trees and/or the displacements, guided by the volatiles released from the plants; ground, placed on plastic trays containing about 2 cm (2) localization of the host, that consists in the search for vermicelli covered with organza and kept in a greenhouse for signals emitted directly by the host (feces, exuvia), vibrotaxis approximately 15 days. The vermicelli was then sieved to (search based on the movements produced by the larvae inside remove the pupae. These were counted and transferred to a determined substrate) and examination with the ovipositor glass containers with a layer of wet vermicelli and covered (fruit fly parasitoids) to locate the larvae in the fruit and (3) with organza. The parasitoids (male and female) were identified host suitability (size, age, parasitism) (Weseloh 1981, Vet 1985, at emergence and transferred to maintenance cages where Vinson 1985, Tumlinson et al. 1993, Lewis & Sheehan 1997). they were supplied daily with water and honey at 30% as Little is known about the behavior and biology of the food supply. The cage was kept in the laboratory (T = 25 ± Eucoilinae in the neotropical region and most of the studies 3oC, RH = 75 ± 5% and light period = 14h) until the experiments have been about taxonomy and populational surveys (Diaz were carried out. The female parasitoids had no direct contact 1998, Guimarães 1999, Guimarães et al. 2003). Most of the with either the host larva or the fruit until the experiment was behavior studies are restricted to the Leptopilina species, carried out. Each female was tested once in the olfactometer drosophilid parasitoids in Europe (Vet et al. 1983, Vet 1985, to prevent associative learning and consequently, tendacious Vet & Alphen 1985, Vet & Bakker 1985, Vet & Opzeeland results (Vet et al. 1983). 1985). Recently, parasitism behavior has become more The test samples were formed by Anastrepha spp. or C. important because it was observed that natural enemies have capitata (Tephritidae) larvae and by Zaprionus indianus great capacity for associative learning that may be used to Gupta (Drosophilidae) in guava fruit (ripe or rotting). The maximize the use of these parasitoids in biological control Anastrepha spp. larvae were obtained