Tertuliano, M., Doussougbete, S., & Le Rü, B.P. 1993 Antixenotic and antibiotic components of resistance to the Cassave mealybug Phenacoccus-manihoti (Homoptera, Pseudococcidae) in various host-plants.. Insect Science and its Application 14(5-6): 657-665.

Notes: Antixenotic and antibiotic components of resistance to the cassava mealybug, Phenacoccus manihoti Matt. Ferr. were evaluated in different varieties of cassava (Manihot esculenta Crantz), in Poinsettia (Euphorbia pulcherrima Wild), Talinum (Talinum triangulare Jack) and Faux-caoutchouc (hybrid of M. esculenta and M. glaziovii Mull. Arg.). Resistance was estimated in the field on 25 varieties of cassava by means of varietal screening. Although we were unable to identify varieties of cassava totally resistant to P. manihoti, there was evidence of partial resistance. Laboratory evaluations of the antibiotic component of resistance, made by estimating the intrinsic capacity for increase r(c), showed that the host-plants have a considerable effect on the multiplying capacity of the mealybug. The Incoza cassava variety is the most resistant, in terms of both antixenosis and antibiosis. Our results suggest that the resistance mechanisms of the host-plants of P. manihoti intervening in the fixation of the pest (antixenosis), are different from those acting on the development of the mealybug (antibiosis). We established significant correlations between the size of the mealybugs and their demographic characteristics for all the plants studied: the duration of the prereproductive period is shorter and the net reproduction rate is higher when the mealybugs are large-sized.