With the use of regression techniques, associations are found between genetic variability and the number of oviposition sites [on plants] utilized by 2 exotic and 16 endemic species of Hawaiian Drosophila. [The 18 spp. studied are D. silvestris, D. heteroneura, D. cyrtoloma, D. melanocephala, D. planitibia, D. neopicta, D. picticornis, D. orthofascia, D. engyochracea, D. silvarentis, D. sproati, D. grimshawi, D. recticilia, D. setosimentum, D. odontophallus, D. mimica, D. immigrans and D. simulans.] An additional association is found for altitudinal location of populations of D. setosimentum and genetic variability. These findings provide support for the niche width-genetic variability hypothesis. Additional studies to confirm these findings and establish their genetic basis are suggested.