Influence of the host plant of the cassava mealybug Phenacoccus manihoti on life‐history parameters of the predator Exochomus flaviventris

To our knowledge, there is still no data available on the influence of plant quality on the trophic suitability of cassava mealybug as prey for Exochomus flaviventrisMader (Coleoptera, Coccinellidae). E flaviventris, a polyphagous ladybird indigenous to subsaharan Africa, is the most active predator of the cassava mealybug in Central Africa (Iziquel & Le Rü, 1989). Cassava-mealybug and mealybug-predator systems have been widely studied both in the laboratory and in the field (Fabres & Kiyindou, 1985; Kiyindou et al., 1990; Reyd & Le Rü, 1992). Until now, only van den Meiracker et al . (1990) have analyzed at plant level the influence of cassava mealybug on the searching behavior ofExochomussp. They showed that inexperienced adult females spend more time searching on cassava leaves previously infested with cassava mealybug than on healthy cassava leaves, and that they are arrested by both wax exuviae and honeydew from the mealybug. Of the three main categories of resistance defined by Painter (1951), antibiosis, which is defined as plant factors that alter the herbivore’s growth, fecundity and survival, is most likely to negatively affect the third trophic level (van Emden, 1991). The purpose of this study was to investigate the influence of four different host plants having shown various antibiosis resistance levels to P. manihoti, on the survival, development time, fecundity and prey consumption of the ladybird E. flaviventris. These life-history components can have an important effect on the efficiency of a predator. Material and methods