RESUMO A citricultura está crescendo no Estado do Pará, Brasil, mas faltam informações sobre as pragas conhecidas como moscas-das-frutas e os parasitoides associados na região. Visando abordar esta lacuna no conhecimento, foram coletados frutos de laranja (Citrus sinensis), laranja var. lima (C. sinensis), lima-da-pérsia (C. limettioides), limão-cidra (C. medica) e tangerina (C. reticulata). Registramos, pela primeira vez, infestação em condições naturais de campo por Anastrepha obliqua em C. sinensis no Pará e identificamos uma tritrófica entre C. sinensis, A. obliqua e os parasitoides Opius bellus e Asobara anastrephae.

ABSTRACT Citriculture is a growing industry in Pará state, Brazil, but information regarding fruit flies and their associated parasitoids in this region is lacking. To address this gap in knowledge, we collected oranges (Citrus sinensis), lime oranges (C. sinensis), common sweet limes (C. limettioides), citrons (C. medica) and mandarins (C. reticulata). We recorded field infestation by Anastrepha obliqua in C. sinensis under natural conditions for the first time in the study region, and a tritrophic relationship between C. sinensis, A. obliqua, and the parasitoids Opius bellus and Asobara anastrephae was identified.

RESUMO: O objetivo deste trabalho foi avaliar o parasitismo de larvas de Tephritidae por duas linhagens de Diachasmimorpha longicaudata em duas espécies de mosca-das-frutas. Foram utilizadas fêmeas do parasitoide criadas sobre Ceratitis capitata ou Anastrepha fraterculus acondicionadas em gaiolas adaptadas. Para cada fêmea foram oferecidas 20 larvas durante 1 hora, em ensaio com chance de escolha (20 C. capitata ou 20 A. fraterculus) e sem chance de escolha (10 larvas de cada espécie). Após o parasitismo, o número de cicatrizes foi verificado e os pupários classificados como: não parasitados (ausência de cicatrizes), parasitados (presença de uma cicatriz) e superparasitados (duas ou mais cicatrizes). A intensidade de parasitismo foi avaliada por meio da proporção de larvas não parasitadas, parasitadas ou superparasitadas. As variáveis intensidade de parasitismo e frequência de cicatrizes em virtude do hospedeiro e da linhagem do parasitoide foram analisadas quanto à distribuição de frequência utilizando-se o teste qui-quadrado. No teste sem escolha, independentemente da espécie hospedeira, as fêmeas das duas linhagens parasitaram as larvas oferecidas e, quando tiveram escolha, preferiram superparasitar larvas de A. fraterculus, que são maiores que as de C. capitata. A frequência de pupários sem cicatriz foi maior quando o hospedeiro oferecido foi diferente daquele em que a fêmea foi criada. Independentemente da linhagem do parasitoide, as fêmeas parasitam a maioria das larvas hospedeiras das duas espécies, mas discriminam o hospedeiro, preferindo superparasitar a espécie na qual foi criada o hospedeiro. A. fraterculus foi o preferido para postura de fêmeas.

ABSTRACT: The aim of the present study was to investigate the parasitism of two fruit fly species by different Diachasmimorpha longicaudata strains. Females of two parasitoid strains were reared on Ceratitis capitata or Anastrepha fraterculus that were conditioned in adapted containers. Individual parasitoids were offered 20 larvae for 1 h, using no-choice (20 C. capitata or 20 A. fraterculus) or free-choice (10 of each species) assays. Parasitism was verified by counting scars, and the pupae were classified as non-parasitized (no scars), parasitized (one scar), or superparasitized (multiple scars). Parasitism intensity was compared by evaluating the proportions of non-parasitized, parasitized, and superparasitized larvae. Parasitism intensity and scar frequency were analyzed as functions of host species and parasitoid strain, using chi-square tests. In the non-choice tests, females of both parasitoid strains parasitized the larvae, regardless of host species. However, when the parasitoids had a choice, they preferred to superparasitize A. fraterculus larvae, which are larger than C. capitata larvae. In addition, the female parasitoids parasitized most of the host larvae, regardless of parasitoid strain or host species. However, the frequency of non-parasitized pupae was higher when the offered host species was different from the one in which the parasitoid was reared, and the frequency of superparasitized pupae was higher when the offered host species was the same as the one in which the parasitoid was reared.

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.

Os frutos de Dimorphandra mollis são coletados de forma indiscriminada para fins comerciais, comprometendo a viabilidade das populações naturais. Este estudo teve como objetivo avaliar o efeito da qualidade do solo na germinação das sementes e no desenvolvimento de plântulas de D. mollis. Solos de três procedências (cerrado arenoso, cerrado argiloso e mata seca) foram usados como substratos nos testes de germinação e desenvolvimento das plântulas. As sementes de D. mollis apresentaram maior germinabilidade em solo de cerrado arenoso (60,5%), seguido por solo de cerrado argiloso (29,7%) e solo de mata seca (13,6%). Além disto, o índice de velocidade de germinação (IVG) das sementes de D. mollis foi maior no solo de cerrado arenoso. As raízes das plântulas cultivadas em solo de cerrado arenoso apresentaram maior comprimento do que as cultivadas nos solos de mata seca e cerrado argiloso. Contudo, a massa seca das raízes não variou entre os três tratamentos. As plântulas de D. mollis apresentaram maior crescimento e produção de biomassa da parte aérea quando cultivadas em solo de mata seca. Os solos das matas secas normalmente apresentam melhor qualidade nutricional que os solos do cerrado, justificando os resultados observados. Assim, para melhor sucesso da produção de mudas de D. mollis, as sementes devem ser germinadas em substratos que retêm pouca água e as plântulas devem ser cultivadas em solos de melhor qualidade nutricional.

The exploitative collection of Dimorphandra mollis fruits by farmers has negatively affected the natural population dynamics of this species. The aim of this study was to compare the effects of three soil types (Cerrado sand soil, Cerrado clay soil and dry forest soil) on seed germination and seedling development of D. mollis. The seeds of D. mollis showed greater germinability in Cerrado sand soil (60.5%), followed by Cerrado clay soil (29.7%) and dry forest soil (13.6%). The seedling root growth in Cerrado sand soil was higher compared to Cerrado clay soil and dry forest soil. However, no differences were verified for root dry mass between the soil treatments. The seedlings of D. mollis cultivated in dry forest soil presented a higher growth rate and total dry mass. These results are probably associated with higher nutrient availability, which was verified in the dry forest soil when compared to the Cerrado soils. Our results indicate that D. mollis seeds need a low water-retaining substrate to increase the germination rate and that seedlings develop better in nutrient-rich soils.