Abstract

VILLANUEVA-SANCHEZ, Evert; IBANEZ-BERNAL, Sergio; LOMELI-FLORES, J. Refugio  and  VALDEZ-CARRASCO, Jorge. Identification and characterization of the black fly, Bradysia difformis (Diptera: Sciaridae) on "poinsettia" crops (Euphorbia pulcherrima) of central Mexico. Acta Zool. Mex [online]. 2013, vol.29, n.2, pp.363-375. ISSN 2448-8445.

The aim of this study was to identify and characterize the developmental stages of the most abundant black fly species associated with poinsettia crops (Euphorbia pulcherrima Willd. ex Klotzsch) in the producing area of Central Mexico. Collecting samples were conducted in greenhouses of the locations of Atlacomulco (Mexico), Tenango de las Flores (Puebla), Xochimilco (Mexico City), and Zacatepec and Tetela del Monte (Morelos). A total of 2,141 adult specimens of Diptera were obtained, being Bradysia difformis Frey (Diptera: Sciaridae) the most abundant species (99.5%). Life cycle of this species was completed between 26-28 days under controlled conditions of temperature and humidity (25°C and 70% RH). The differentiation of larval instars by morphometrics of the head capsule between instars I vs II, showed very low error probabilities (1:10,000); while differentiation between instars II vs III, and III vs IV resulted with higher error probabilities, between 17:100 and 36:100 individuals, respectively. For this reason it is recommended to explore other features in addition to measurements of width of the cephalic capsules for discriminating different larval stages. This is the first record of B. difformis for Mexico, although this genus was previously reported affecting poinsettia crops.

Keywords : taxonomy; immature stages; poinsettia pest; Mexico.