ABSTRACT
This work was carried out to study the development of populations of the genus Planococcusin different plant species, aiming at the verification of host specificity. The mealybugs Planococcus minorwere obtained from cocoa plants (Theobroma cacaoL.) and coffee crop (Coffea canephoraL.), andPlanococcus citrifrom citrus seedlings (Citrus sinensisL. Osbeck). Single eggs were transferred to Petri dishes containing leaf discs of cocoa (T. cacaocultivar Catongo), coffee (Coffea arabicaL. cultivar Mundo Novo) and citrus (C. sinensiscultivar Pêra Rio). They were maintained on a water-agar slide at 1%, with the abaxial surface turned upwards. The dishes were sealed with a PVC plastic film and kept in climatized chambers regulated at 25 ± 1º C, 70 ± 10% RH and 12 hours of photophase. For the mealybugs coming from cocoa plants, the citrus substrate prolonged the nymphal development of the males (26.0 days). In the nymphal period of females and males coming from coffee plants, the coffee substrate allowed a shorter duration of that period (19.2 and 21.3 days, respectively) and, in addition to having providing a longer longevity to the females (59.1 days). The highest rates of mortality were obtained when they were reared on the cocoa substrate, regardless of the host plant from which they were originally collected, and when kept on citrus, for insects collected on coffee plants. P. citriand P. minorhave higher preference for coffee substrate regardless of the original host, thus showing partial host specificity.
KEY WORDS
Citrus-mealybugs; biology; specificity