Thrypticus

Abstract: Adults of the fly family Dolichopodidae (Diptera) are general predators on small soft-bodied invertebrates, and often are abundant in agroecosystems. However, information about their diversity and spatial distribution in agricultural landscapes are scarce. Using structured sampling, we identified the species of Dolichopodidae associated with organic vegetable crops, fallow, agroforestry, and native vegetation in the Federal District of Brazil, and evaluate their richness and abundance. We collected 70 species Dolichopodidae distributed in 17 genera and 9 subfamilies. Of these, some 80% of the specimens belong to the following 5 taxa: Chrysotus spectabilis (Loew), Thrypticus violaceous Van Duzee, Condylostylus depressus (Aldrich), Condylostylus “caudatus group” females, and Condylostylus erectus Becker (all Diptera: Dolichopodidae). Habitats with vegetable crops harbored a higher abundance and number of species (diversity α), with a gradual reduction towards more forested environments of native vegetation. This is an inverse gradient with the general patterns of community studies with other taxa. We also verified the importance of less disturbed habitats over time in the agricultural landscape, such as agroforestry and native vegetation, as complementary habitats for the maintenance and conservation of dolichopodid species in particular, a scenario to be tested for other insect groups. Resumo Os adultos da familia das moscas Dolichopodidae (Diptera) sao predadores generalistas de pequenos invertebrados de corpo mole, sendo geralmente abundantes em agroecossistemas. No entanto, informacoes sobre sua diversidade e distribuicao espacial em paisagens agricolas sao escassas. A partir de amostragens locais, identificamos as especies de Dolichopodidae associadas a hortalicas orgânicas, pousio, agrossilvicultura e vegetacao nativa no Distrito Federal, Brasil, e avaliamos sua riqueza e abundância. Foram coletadas 70 especies de Dolichopodidae distribuidas em 17 generos e 9 subfamilias. Destes, cerca de 80% dos especimes pertencem aos seguintes 5 taxons: Chrysotus spectabilis (Loew), Thrypticus violaceous Van Duzee, Condylostylus depressus (Aldrich), Condylostylus “grupo caudatus” e Condylostylus erectus Becker (todos dipteros: Dolichopodidae). Habitats com hortalicas abrigavam a maior abundância e numero de especies (diversidade α), com uma reducao gradual em direcao a ambientes mais florestados de vegetacao nativa. Este e um gradiente inverso com os padroes gerais de estudos comunitarios com outros taxons. Tambem verificamos a importância de habitats menos perturbados ao longo do tempo na paisagem agricola, como agrofloresta e vegetacao nativa, como habitats complementares para a manutencao e conservacao de especies de diclopodideos em particular. Este e um cenario a ser testado para outros grupos de insetos. Key Words: biological control; Neotropical region; Cerrado; habitat management; species richness; organic agro-ecosystems View this article in BioOne

Abstract: Since the beginning of the investigations on natural enemies of water hyacinth, Thrypticus has been mentioned among the top seven candidates for biological control. In 1995, a revived interest for biocontrol of water hyacinth directed the investigations to new agents and Thrypticus stood as a priority candidate. Thrypticus occurs in Central and South America, from Panama (probably introduced) to Argentina and it is probably the most prevalent phytophagous insect in the whole native range of water hyacinth. Until now, water hyacinth was the only host known in the family. We found five different species of Thrypticus attacking four plant species in the Pontederiaceae family: Eichhornia crassipes (Martius) Solm-Laubach (two species of Thrypticus), E. azurea (Sw.) Kunth , Pontederia cordata L. and P. subovata (Seub.) Lowden. Adults are 1.5 to 2 mm long, metallic green in color. Females lay eggs singly in petioles of E. crassipes, inserting the eggs into the tissues just above the water line. The larvae, which are only a few mm long, bore through the bases of the petioles. The horizontal tunnels, open at both ends, are blackish in color. When larvae are mature, the leaf is already senescent, and the adults emerge from petioles above or below water level and starting to rot. Although the effect of its damage on the demography of water hyacinth is unknown, other attributes of the fly like the apparent strict monophagy, ubiquity and abundance appear promising.

Abstract: . Checklist of species of Dolichopodidae (Insecta, Diptera) from Mato Grosso do Sul State. A checklist of the known species of Dolichopodidae from Mato Grosso do Sul state (Brazil) is provided. The list includes fi ve species (records from literature only): Chrysotus brasiliensis Van Duzee (Diaphorinae), Condylostylus fl agellatus Becker (Sciapodinae), Pelastoneurus brasiliensis Van Duzee, P. ochreifacies Van Duzee (Dolichopodinae), and Thrypticus romus Bickel & Hernandez (Medeterinae).KEYWORDS. Diaphorinae, Sciapodinae, Dolichopodinae, Medeterinae, Biota-MS Program.RESUMO. Uma lista das especies de Dolichopodidae conhecidas do estado do Mato Grosso do Sul (Brasil) e apresentada. A lista inclui cinco especies (baseado apenas em registros da literatura): Chrysotus brasiliensis Van Duzee (Diaphorinae), Condylostylus fl agellatus Becker (Sciapodinae), Pelastoneurus brasiliensis Van Duzee, P. ochreifacies Van Duzee (Dolichopodinae) e Thrypticus romus Bickel & Hernandez (Medeterinae).PALAVRAS-CHAVE. Diaphorinae, Sciapodinae, Dolichopodinae, Medeterinae, Programa Biota-MS.

Abstract: The Valdivian temperate forest of southern Chile comprises both broad leaf and mixed gymnosperm vegetation, and is usually dominated by southern beech, Nothofagus spp. (Nothofagaceae). These forests often have a distinctive biota, quite separate from that found elsewhere in South America (WWF 2007). For example, the fly family Dolichopodidae is composed primarily of the Sympycninae (Sympycnus s.l.), Diaphorinae, and the genus Chrysotimus Loew 1857 (Peloropeodinae), while other subfamilies show greatly reduced diversity or are totally absent (Van Duzee 1930, Parent 1932). Moreover, there is a similar faunal composition in the Nothofagus forests of New Zealand, Tasmania, and southeastern Australia, suggesting a Gondwanan origin for this ecological association. The subfamily Medeterinae is poorly represented or absent in Nothofagus forests, and only known from Thrypticus Gerstacker 1864, a stem mining genus associated with Poaceae and Cyperaceae in adjacent swamps and marshes (e.g., Bickel 1992). Therefore it is unusual to find a distinctive new medeterine genus in Valdivian forests, and with indications of it being associated with Nothofagus tree trunks.