Carlos H. MarchioriI; Luiz A. PereiraII; Otacilio M. Silva FilhoII; Lalyne C.S. RibeiroII; Vanessa R. BorgesII
Instituto Luterano de Ensino Superior de Itumbiara, Itumbiara, GO Curso de Iniciação Científica do Instituto Luterano de Ensino Superior de Itumbiara, Itumbiara, GO
ABSTRACT
The objective of the study was to report the first occurrence of the parasitoid Brachymeria podagrica in pupae of Ophyra aenescens, a fly of medical-sanitary importance. Human feces was used as bait to collect the insects. In the study 20 pupae of Ophyra aenescens (Wiedemann) (Diptera: Muscidae) were obtained, of which 20% of the total yielded the parasitoid Brachymeria podagrica (Hymenoptera: Chalcididae).
Key-words: Medical-sanitary importance. Synanthropy. Parasitoid. Muscoid fly.
RESUMO
O objetivo do presente estudo é relatar a primeira ocorrência do parasitóide Brachymeria podagrica como inimigo natural de Ophyra aenescens, mosca de importância médico-sanitária. Para coleta dos insetos foi utilizado como isca fezes humanas. Obtiveram-se 20 pupas de Ophyra aenescens (Wiedemann) (Diptera: Muscidae), das quais 4 emergiram parasitóides pertencentes à espécie Brachymeria podagrica (Hymenoptera: Chalcididae), apresentando uma incidência de parasitismo de 20,0%.
Palavras-chaves: Importância médico-sanitária. Sinantropia. Parasitóide. Mosca.
Diptera is an optimal model to study synanthropy, not only for its ecological importance, but also due to the medical-veterinary aspects, as vectors of etiological agents, such as amoeba cysts, helminth eggs, pathogenic enterobacteria, viruses and fungi2 5.
According to D’Almeida3 Ophyra aenescens (Wiedemann) (Diptera: Muscidae) possesses great capacity for colonizing a wide range of habitats and has an ecological versatility, that contributes to its geographic distribution, as such it as a very successful biological colonizer species.
All the representatives of Chalcididae behave as parasites and most involve Lepidoptera, Diptera, Hymenoptera and Coleoptera6. The Chalcididae are cosmopolitan insects1 with a high diversity in the tropics4 including approximately 1500 species. They are predominantly solitary endoparasitoids4.
Species of genus Brachymeria Westwood are important primary parasitoids of muscoid Diptera, such as species of the Sarcophagidae family6 and Calliphoridae. Some species are of economical importance, since they attack insect pests4. The aim of this paper was to report a new host for Brachymeria podagrica in Brazil.
This study was conducted at the Agriculture Faculty (Itumbiara, GO, 18º25’S – 49º13’W), Brazil. The flies were attracted to 19x9cm opaque dark can traps, constructed with two openings like blinders, located in the third inferior part to permit the entrance of the flies. Nylon funnels were coupled to the upper part of the cans, opened in the ends, with bases pointing down and wrapped with plastic bags, enabling the collection of flies and parasitoids (Figure 1). Human feces were used as bait inside the cans, over a layer of sand. Five traps hanging on eucalyptus trees were placed one meter above the ground two meters apart from each other and 50 meters from domestic garbage cans. The collected insects were taken to the laboratory, killed with ethyl ether and kept in 70% alcohol for further identification. The contents of the traps were placed in plastic containers with a layer of sand to be used as a substratum for larvae to pupate. The sand was sifted after 15 days and pupae were extracted and placed individually in gelatin capsules (number 00) to obtain flies and/or the parasitoids.
The prevalence of parasitism was calculated by the following formula: P = (parasite pupae/total of pupae) x100.
Through March to December 2001, four specimens of Brachymeria podagrica (Fabricius) were collected in 20 pupae of Ophyra aenescens (Wiedemann) (Diptera: Calliphoridae) demonstrating a 20% parasitism. The high prevalence of parasitism can also be related to the type of methodology used. The species B. podagrica occurs almost everywhere around the world and lives associated to synanthropic dipterous and other Diptera, emerging from their pupae.
According to Roberts8 B. podagrica was collected as a solitary parasitoid of Sinthesiomyia larvae (Muscidae), Cochliomyia, Lucilia, Calliphora sp, Calliphora coloradensis Hough, Callitroga macellaria(Fab.) Phaenicia sericata (Meig.) Phaenicia mexicana (Macq.), Phormia regina (Meig.) (Calliphoridae), Sarcophaga carnaria Linné, Sarcophaga haemorrhoidalis Fallén, Sarcophaga imparAldrich and Sarcophaga peregtina Robineau-Desvoidy (Sarcophagidae)8.
This species occurred as a dipterous parasitoid, developed in rat carcasses in areas of tropical woods in the State of Goiás, Brazil. Its preferred host was Patonella intermutans (Walker) (Sarcophagidae) from which the predominantly female parasitoid pupae emerged9. The decomposition and colonies of insects in the carcasses of rats during the summer and winter in South Carolina (EUA) collected B. podagrica in pupae of Sarcophaga sp (Sarcophagidae)10.
Fly control using insecticides usually selects resistant populations, albeit just a palliative measure. Some investigations7 believe that research into new methods of fly control are needed. Natural regulators, such as parasitoids are agents responsible for reduction of fly populations7. The aim of this communication is to report a new host for B. podagrica species in Brazil.
This is the first report of B. podagrica in pupae of O. aenescens in Brazil. .
REFERENCES
1. Askew RR Further observations of Chalcididae (Hymenoptera) from Spain with some nomenclatural changes and the description of a new species. Graellsia 50: 29-34, 1994. [ Links ]
2. D’Almeida JM. Calyptrate Diptera (Muscidae and Anthomyiidae) of the State of Rio de Janeiro – I. Synanthropy. Memórias do Instituto Oswaldo Cruz 87: 381-386, 1992. [ Links ]3. D’Almeida JM. Ovipositional substrates used by Calyptrate Diptera in Tijuca Forest, Rio de Janeiro. Memórias do Instituto Oswaldo Cruz 89: 261-264, 1994. [ Links ]
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5. Greenberg B. Flies and disease: ecology, classification and biotic association. Princeton University Press, New Jersey, 1971. [ Links ]
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7. Mendes J, Linhares AX. Atratividade por iscas, sazonalidade e desenvolvimento ovariano em várias espécies de Muscidae (Diptera). Revista Brasileira de Entomologia 37: 289-297, 1993. [ Links ]
8. Roberts RA. Activity of blowflies and associated insects at various heights above the ground. Ecology 14: 306-314, 1933. [ Links ]
9. Silva AS. Himenópteros parasitóides associados a dípteros saprófagos, com especial referência aos Alysiinae (Braconidae). Dissertação de Mestrado, Universidade Federal de São Carlos, São Carlos, SP, 1991. [ Links ]
10. Tomberlin JK, Adler PH. Seasonal colonization and decomposition of rat carrion in water and on land in non open field in South Carolina. Journal of Medical Entomology 27: 704-709, 1998. [ Links ]
Correspondence to
Prof. Carlos H. Marchiori
Instituto Luterano de Ensino Superior de Itumbiara/ULBRA
Av. Uruguai 686, Bairro Jardim América
75500-000 Itumbiara, GO
E-mail: pesquisa.itb@ulbra.br
Recebido para publicação em 1/4/2002
Aceito em 20/8/2003
