ABSTRACT The parasitoid Diachasmimorpha longicaudata is an important control agent for several species of fruit flies. Research on the characteristics of the reproductive system and reproductive biology of this parasitoid can be valuable for studies in taxonomy and phylogeny of insects of the order Hymenoptera. In this study we analyzed the histology and histochemistry of the male reproductive system of D. longicaudata. In this species the male reproductive system consists of a pair of testes, two accessory glands, and an ejaculatory duct. Each testicle consists of only one follicle. The testicular follicles are filled with cysts in different stages of spermatogenesis. Histochemical analyses detected proteins and carbohydrates in the cytoplasm of secretory cells and in the lumen of accessory glands. The morphology of the male reproductive system of D. longicaudata differs in some respects from other species of Hymenoptera.

RESUMO: Objetivou se neste estudo avaliar a proporção de larvas de Ceratitis capitata e fêmeas de Diachasmimorpha longicaudata que resulta no incremento do parasitismo e da produção de fêmeas na progênie. Foram utilizadas fêmeas de Diachasmimorpha longicaudata copuladas, com experiência em parasitar e oito dias de idade, e larvas de terceiro instar de C. capitata, provenientes da criação mantida no Laboratório de Controle Biológico da Universidade Estadual de Montes Claros (UNIMONTES). Cinco densidades de larvas de C. capitata foram oferecidas (10, 20, 30, 40 e 50) às fêmeas do parasitoide, em cinco densidades diferentes (1, 2, 5, 10 e 15). As larvas foram expostas às fêmeas do parasitoide por meio de “unidades de parasitismo”, em gaiolas adaptadas, pelo tempo determinado de uma hora. Foram avaliadas as variáveis: razão sexual, porcentagem de parasitismo e mortalidade pupal. Tanto a densidade de larvas de C. capitata quanto a densidade de fêmeas do parasitoide influenciaram no parasitismo, na produção de fêmeas na progênie e na mortalidade pupal. Foi observada nas proporções 1:1 e 1:2 (larvas/fêmeas) maior produção de fêmeas na progênie. Proporções acima de 1:2 reduziram a razão sexual, e valores abaixo de 1:1 causaram altas porcentagens de mortalidade pupal. As fêmeas apresentaram maior atividade de parasitismo quando estavam em grupos dividindo o mesmo espaço. Proporções iguais de larvas de C. capitata e fêmeas do parasitoide resultaram em melhor eficiência na produção de fêmeas na progênie.

ABSTRACT: The objective of the present study was to evaluate the ratio of Ceratitis capitata larvae/female of Diachasmimorpha longicaudata that results in the increase of parasitism and the production of females in the progeny. We used 8-day-old copulated D. longicaudata females with oviposition parasite experience and third instar larvae of C. capitata from rearing stock maintained at the Laboratory of Biological Control of Universidade Estadual de Montes Claros (Unimontes). Five densities of C. capitata larvae (10, 20, 30, 40, and 50) were offered to parasitoid females that were at five different densities (1, 2, 5, 10, and 15). The larvae were exposed to the parasitoid females by means of “parasitism units” in adapted cages for 1 hour. Sex ratio, percentage of parasitism, and pupal mortality were evaluated. Both host larval density and female parasite density influenced parasitism, female progeny production, and pupal mortality. Higher female production was observed in the progeny in ratios of 1:1 and 2:1 (larvae/females). Ratios above 1:2 reduced the sex ratio, and ratios below 1:1 caused high pupal mortality rates. The females had higher parasitism activity when they were in groups dividing the same space. Equal ratios of Ceratitis capitata larvae and parasitoid females resulted in improved efficiency in progeny females.

ABSTRACT Diachasmimorpha longicaudata is an Old World parasitoid of tephritid fruit flies that was widely introduced in the Americas to control pest species such as the Mediterranean fruit fly Ceratitis capitata. Augmentative releases in irrigated coffee plantations in semiarid regions of Brazil are under consideration and dispersal capacity of D. longicaudata in this habitat are important to develop release strategies. Approximately 2,000 individuals of D. longicaudata (5 to 7 days old) were released in the center of a fruiting coffee plantation every two weeks from Dec. 2009 to Apr. 2010. Dispersal from the central release point was monitored to the north, south, east, west, northeast, northwest, southeast and southwest at 11 distances, beginning at 4.6 m and ending at 90 m from the release point. At each point, a parasitism unit (approximately 120 larvae of C. capitata in the 3rd instar wrapped in voile fabric) and 10 coffee beans were collected. The average dispersion distance and dispersion area were estimated by the model proposed by Dobzhansky and Wright (1943). The average dispersion distances were 27.06 m (as estimated by fruit collection) and 33.11 m (as estimated by oviposition traps). The average dispersion areas were 1,315.25 m2 and 1,752.45 m2 originating from the collection of beans and parasitism units, respectively. Cohorts of 2,000 adult D. longicaudata released at six points ha−1 are estimated to result in sufficient colonization to exert significant control of Ceratitis capitata.

Objetivou-se avaliar a influência da idade (tamanho) das larvas de Ceratitis capitata utilizadas na criação de Diachasmimorpha longicaudata sobre o parasitismo, a razão sexual e a longevidade das fêmeas da progênie, quando as fêmeas mães foram mantidas sozinhas ou competindo pelo mesmo hospedeiro. Para isso, foram oferecidas larvas de cinco, seis, sete e oito dias de idade às fêmeas do parasitoide em "unidades de parasitismo", no interior de gaiolas adaptadas, contendo uma ou duas fêmeas do parasitoide de sete dias de idade. O número de fêmeas do parasitoide dividindo a mesma "unidade de parasitismo" não afetou nenhum aspecto da qualidade do parasitoide. O tamanho do hospedeiro influenciou significativamente no número de parasitoides emergidos. Larvas hospedeiras menores (cinco dias) provocaram uma redução no parasitismo em relação às larvas de seis, sete e oito dias de idade. Houve maior emergência de parasitoides machos de hospedeiros com cinco e seis dias de idade, enquanto mais fêmeas emergiram de larvas com sete e oito dias de idade. As fêmeas de D. longicaudata provenientes de larvas com seis, sete e oito dias viveram mais do que as fêmeas obtidas de larvas com cinco dias de idade. Larvas hospedeiras maiores, quando utilizadas na criação de parasitoides de moscas-das-frutas, aumentam a porcentagem de parasitismo, o número de fêmeas na progênie e a longevidade das fêmeas da progênie, podendo proporcionar vantagens econômicas quando utilizadas para liberação aumentativa no campo.

This work was carried out in order to evaluate the influence of age (size) of larvae Ceratitis capitata used in the rearing of the Diachasmimorpha longicaudataon parasitism, sex ratio of the progeny and the longevity of progeny's females, when the mothers were maintained alone or sharing the same host. Larvae at different ages (five, six, seven and eight days old), in "units of parasitism" were offered to female parasitoids, inside adapted cages, containing one or two seven days old female parasitoids. The number of females of the parasitoid sharing the same "unit of parasitism" in the same cage did not affect any aspect of parasitoid quality. However, the size of the host had significant influence on the number of emerged parasitoids. The youngest host larvae (five days old) reduced parasitism more than larvae at six, seven and eight days old. There was higher emergence of male parasitoids of five and six days old hosts, while more females emerged from seven and eight days old larvae. The females of D. longicaudata from larvae with six, seven and eight days old lived more than those obtained from females of five days old larvae. When larger host larvae are used in the rearing of parasitoids of fruit flies, it increases parasitism, the number of female progeny and the longevity of female progeny; it can provide economic advantages when used for augmentative liberation on the field.

Este trabalho teve como objetivo registrar a infestação de C. capitata em frutos de mamoeiro em Minas Gerais. Foram coletados frutos em uma área comercial de mamão, em Jaíba, norte do estado. C. capitata foi a única espécie obtida (794 indivíduos). Doryctobracon areolatus (Szépligeti) foi encontrado parasitando larva/pupa de C. capitata. O índice de infestação encontrado foi em média de 7,7 pupários/kg de fruto ou 1,4 pupários/fruto. C. capitata é registrada pela primeira vez em frutos de mamão em Minas Gerais.

The objective of this work was to register the infestation of C. capitata on papaya fruits in Minas Gerais State. Papaya fruits were collected, in a commercial orchard, in Jaíba, north of the State of Minas Gerais. C. capitata was the only specie collected (794 individuals). Doryctobracon areolatus (Szépligeti) was collected parasitizing C. capitata larvae/pupae. The level of infestation was of 7,7 pupae/kg of fruit or 1,4 pupae/fruit, in average. C. capitata is registered for the first time on papaya fruits in the State of Minas Gerais.

Foram realizados testes para avaliar a eficiência de parasitismo de Diachasmimorpha longicaudata (Ashmead) sobre quatro cultivares de goiaba (Paluma, Sassaoca, Pedro Sato e Kumagai) infestadas com larvas de Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Cinco lotes de oito frutos de goiaba, sendo dois frutos por cultivar, foram acondicionados em gaiolas contendo adultos de C. capitata, por 2h para oviposição. Após uma semana, quando as larvas já haviam se desenvolvido dentro dos frutos, estes foram expostos aos parasitóides durante 24h. Foram avaliados o peso médio dos frutos, a mortalidade das larvas, o número de pupários e as porcentagens de moscas e parasitóides emergidos. Não houve diferença estatística entre as cultivares para peso dos frutos, mortalidade das larvas, número de pupários e emergência de moscas. O parasitismo foi significativamente maior na cv. Pedro Sato (19,8%), em relação à cv. Kumagai (2,9%), não diferindo, porém, das outras cultivares.

The parasitism efficiency of the Braconidae wasp, Diachasmimorpha longicaudata (Ashmead), was checked on four guava cultivars (Paluma, Sassaoca, Pedro Sato and Kumagai) infested with larvae of medfly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Five blocks of eight fruits, each with two fruits of each cultivar, were put inside C. capitata adult cages, during 2h for oviposition, and a week later, when the larvae inside guavas were developed, the fruits were exposed to parasitoids for 24h. The mean fruit weight, larvae mortality, number of pupae, percentage of medfly and parasitoid emergence were evaluated. There was not statistical difference among cultivars to weight, larvae mortality, number of pupae e emergence of medfly. The percentage of parasitism was higher in Pedro Sato cultivar (19.8%) compared with Kumagai cultivar (2.9%), but it was statistically similar to the other cultivars.

O objetivo deste trabalho foi conhecer a capacidade de Diachasmimorpha longicaudata (Ashmead) em parasitar larvas de moscas-das-frutas em pomares comerciais de goiaba, localizados nos municípios de Jaíba e Nova Porteirinha, no ecossistema semi-árido do norte de Minas Gerais. Em cada um dos pomares foram liberados 34.000 casais do parasitóide no período de fevereiro a agosto/2003. Para recapturar os parasitóides, sete dias após as liberações, foram coletadas as goiabas (maduras ou em fase de amadurecimento), independente da altura da copa das árvores e frutos recém-caídos ao solo. Os frutos foram levados ao laboratório e mantidos em condições controladas de temperatura (27 ± 1ºC), para a obtenção de pupários. Foram recuperados 37 espécimes de D. longicaudata (24 em Jaíba e 13 em Nova Porteirinha) indicando que a espécie completou o ciclo nas condições locais e portanto, tem possibilidade de se estabelecer na região.

The objective of this work was to evaluate the capacity of Diachasmimorpha longicaudata (Ashmead) to attack fruit fly larvae in commercial guava orchards in Jaiba and Nova Porteirinha, in the north of Minas Gerais State, Brazil. A total of 34,000 parasitoids couples was released in each one of the two orchards from February to August/2003. To recover the parasitoids, guavas (green or mature) were collected from any height of the trees, beyond the fruits just-fallen on the ground, seven day after the release. The fruits were taken to the laboratory and kept under controlled conditions of temperature (27 ± 1ºC), to obtain pupae. Thirty seven specimens of D. longicaudata were recovered (24 in Jaiba and 13 in Nova Porteirinha) This shows that the species completed its life cycle under local conditions and indicates the possibility of its establishment in the region.

The infestation levels by Anastrepha zenildae Zucchi in common guava (Psidium guajava L.) were evaluated. The surveys were carried out in commercial groves of three counties of the North of the State of Minas Gerais, Brazil, from January to April 1996. A. zenildae should be considered a species of economic importance in the region as infestation indices (larvae/kg and larvae/fruit) were higher than those obtained for A. sororcula Zucchi. Only these two species were obtained directly from guava fruits. Besides A. zenildae and A. sororcula, specimens of A. fraterculus (Wied.), A. obliqua (Macquart) and of a new species of Anastrepha were also collected in traps set in the area.