Le RĂ¼, B.P., & Makosso, J.P.M. 2001 Prey habitat location by the cassava mealybug predator Exochomus flaviventris: olfactory responses to odor of plant, mealybug, plant-mealybug complex, and plant-mealybug-natural enemy complex.. Journal of Insect Behavior 14(5): 557-572.
Notes: Exochomus flaviventris Mader is considered to be the most active predator of the cassava mealybug Phenacoccus manihoti Matile-Ferrero in Central Africa. The response of experienced gravid female coccinellids to the odor of cassava plant (var. Zanaga), unparasitized mealybugs, plant-mealybug complex with or without feeding prey (parasitized or not), and plant-mealybug complex with or without conspecific coccinellids was investigated in a Y-tube olfactometer. The odor of uninfested cassava plants was not more attractive than clean air. Dual-choice tests revealed that mealybug-infested plants were preferred to mealybugs alone and mealybug-damaged plants were the major sources of volatiles that attract female coccinellids to the microhabitat of its prey. The emission of volatile chemicals did not appear to be limited to the infested parts of the plant but did occur systemically throughout the plant. The presence of conspecific coccinellid larvae or adult males did not modify the attractiveness of the mealybug-infested plants. However, when an infested plant with conspecific predator females (alone or with conspecific males) was compared to an infested plant or infested plant with conspecific males, E. flaviventris females showed a preference for the last two sources of odor. The uninfested plant with conspecific males was also preferred to the uninfested plant with conspecific females. In addition, the odor of conspecific males was preferred over that of conspecific females. Female predators preferred the plant infested with unparasitized mealybugs to the plant infested with mealybugs previously parasitized. These results showed that E. flaviventris females use herbivore-induced plant volatiles during foraging and can detect via olfaction the presence of conspecific gravid females and parasitized prey, thus assessing patch suitability from a distance.