Hyperaspis Trifurcata (Coleoptera: Coccinellidae) And Its Parasitoids In Central Mexico

Abstract

Dactylopius opuntiae is a key pest of the prickly pear crop, Opuntia ficus-indica, which is cultivated as a vegetable (called "nopalitos") in Mexico and for its fruit in Mexico and other regions of the world. In this study, ladybird predators associated with D. opuntiae in Central Mexico were studied as potential natural enemies to be used in future biological control programs. Collections were concentrated at the principal prickly pear crop production areas (Tlalnepantla, Morelos), where high population density of the pest is common. In this area, systematic samples were completed every other week, from February to June, for two years (2008 and 2009) on five nopalitos sites. The list of Coccinellidae associated with D. opuntiae was complemented with non-systematic collections in Mexico City (Milpa Alta) and Mexico State (Texcoco). Entomological material from INIFAP-Celaya (Guanajuato collection), where the main Mexican Coccinellidae collection is hosted, was also checked. Hyperaspis trifurcata was the major predator collected in Tlalnepantla, Morelos, Mexico. Three hymenopteran species were obtained from larvae and pupae of this predator. Homalotylus cockerelli was the most abundant parasitoid, acting as the primary parasitoid; others species found were Pachyneuron sp. and Tetrastichus sp., which were infrequently collected and acted as hyperparasitoids. Ho. cockerelli populations increased at the same time as their host, H. trifurcata. This parasitoid emerged from 0 to 46.2% of the ladybird larvae and pupae collected. Four new Coccinellidae species associated with cochineal insect pests in central Mexico were found in the non-systematic collections undertaken in this study and the INIFAP-Celaya collection.