Chrysoperla externa (Neuroptera: Chrysopidae): Life History and Potential for Biological Control in Central and South America

The predacious insect Chrysoperla externa (Hagen) has a number of traits that make it amenable to mass-rearing and use as a biological control agent. Developmental and reproductive rates were relatively high and directly related to temperature between 15.6 and 26.7°C. Survival also was high throughout this temperature range. Lower thermal thresholds for development (t) of all immature stages fell between 11 and 12.5-degrees-C, and the K value for total development was 320 heat degree-days above 11.8°C. At 21.1°C, oviposition averaged 284 eggs during the first 30 days. Variability in diapause induction occurred within and among populations: a proportion of the Chilean and the Brazilian populations went into diapause under a short daylength, whereas no diapause occurred in the Honduran population. Chrysoperla externa appears well suited as a biological control agent for use in pest management programs in tropical and temperate regions of Central and South America.