LIFE HISTORY OF PINK HIBISCUS MEALYBUG, MACONELLICOCCUS HIRSUTUS (HEMIPTERA: PSEUDOCOCCIDAE) ON THREE HIBISCUS ROSA-SINENSIS CULTIVARS

The pink hibiscus mealybug, Maconellicoccus hirsutus Green, is a widespread invasive pest of Hibiscus rosa-sinensis in Florida and elsewhere. We evaluated 3 cultivars of H. rosa-sinensis expected to have high ('President'), low ('Double Red'), and intermediate ('Joanne') levels of susceptibility to this pest. We found little evidence that M. hirsutus responded differently among the 3 cultivars in terms of survival, development rate, size, or oviposition period in laboratory tests at a permissive temperature. However, higher average fecundity (377 eggs per female) was observed on "President" compared with the other 2 cultivars (approximate to 300 eggs/female). The F1 generation developed on all varieties, with similar cumulative survival rates of 71, 74, and 76% on "Double Red", "Joanne" and "President" cultivars, respectively. In greenhouse tests over 9 wk, feeding symptoms of stunted and deformed plant terminals ("bunchy top") were observed in all cultivars but increased more rapidly in "President", especially after the 4th wk post infestation. Significantly higher mealybug populations were also observed on "President" compared with the other 2 cultivars, reaching an average of approximate to 50 and 1,400 insect per terminal after the first and second generations, 30 and 60 d post infestation, respectively, on this variety. Although none of the hibiscus varieties tested were resistant to M. hirsutus in our studies, selection (or breeding) of additional cultivars tolerant to feeding symptoms may be useful in low management input landscapes for M. hirsutus infested areas, especially in conjunction with biocontrol programs.