Evaluation of citrus, butternut and sprouting potato as mass rearing substrates for the oleander mealybug, <i>Paracoccus burnerae</i> (Brain) (Hemiptera: Pseudococcidae)

Abstract

Biological control programs of mealybug species have relied on sprouting potatoes, pumpkins and butternut for rearing of both mealybugs and their natural enemies. In this study, the suitability of sprouting potatoes, butternuts and citrus as mass rearing substrates for the oleander mealybug, Paracoccus burnerae was investigated. Developmental times, rate and fecundity on each substrate were determined and compared at three different temperatures. The developmental time on sprouting potatoes was shorter than on citrus. P. burnerae was unable to complete its life cycle on butternut. The rate of development increased linearly with an increase in temperature on both sprouting potatoes and citrus. P. burnerae required 666.7 degree-days on citrus and 434.8 degree-days on sprouting potatoes which is above lower developmental thresholds of 7.6 and 10.4°C, respectively, to complete one generation. The mean number of eggs per female was higher on sprouting potatoes (121.3) than on citrus (68), but declined with an increase in temperature from 22 to 27°C. Despite the shorter shelf life, sprouting potatoes are the preferred host for mass rearing of the oleander mealybug.

Key words: Paracoccus burnerae, temperature, degree-days, mass rearing, nymphal, fecundity, rate of development, lower developmental threshold, thermal constant.