Biology of Pentalonia nigronervosa (Hemiptera, Aphididae) on banana using different rearing methods.

The banana aphid, Pentalonia nigronervosa Coquerel, is present worldwide where banana (Musa spp.) is grown. It is the vector of Banana bunchy top virus (Nanoviridae, Babuvirus), the etiological agent of banana bunchy top disease, currently the most important constraint for banana producers in Hawaii. P. nigronervosa is not well studied, and effects of temperature on its growth and reproduction are unknown. We studied the longevity and fecundity of one clone of banana aphid on different types of plant materials to determine an effective method to study the insect in the laboratory. We found that insects performed better unconfined on plantlets, followed by leaf midrib cuttings. We also conducted complete life table studies with P. nigronervosa on banana leaf midrib cuttings at 20, 25, and 30 degrees C, with a photoperiod of 12:12. Intrinsic rate of increase (r), net reproductive rate (R0), doubling time (DT), nymphal mortality, and mean offspring per female all showed maximal rates at 25 degrees C. Population growth was studied on whole banana plantlets as well, and growth rates were also highest at 25 degrees C. We found r to be greater when aphids were reared on intact banana plantlets than on cuttings. Our results show the importance of comparing insect rearing methods for studies such as life tables.