A life table analysis to evaluate biological control of banks grass mite using the predatory mite, Galendromus flumenis (Acari: Phytoseiidae)

Abstract

A life table analysis to evaluate biological control of banks grass mite using the predatory mite, Galendromus flumenis (Acari: Phytoseiidae) FATEMEH AbstractThe predatory mite, Galendromus flumenis (Chant) (Acari: Phytoseiidae), has shown promising traits for biological control of Banks grass mite, the major pest of date palms in California. In the present study, reproduction and population growth parameters of G. flumenis on Banks grass mite eggs were studied at 34ºC, 50±10% RH and a photoperiod of 16: 8 (L: D) hours. 100 percent of eggs hatched and 63.5 percent of the emerged larvae survived to adulthood. The total immature developmental time was 5.7 and 5.5 days for females and males, respectively. The sex ratio of G. flumenis was 0.70 (females/ females+ males). Mated females laid on average 1.6 eggs per day and 19.9 eggs during their mean ovipositional period of 12.5 days. The net reproductive rate (R 0 ) was 11.5 females/ female/ generation, the intrinsic rate of increase (r m ) was 0.200 females/ female/ day, the finite rate of increase (λ) was 1.222 population multiplication/ day, the mean generation time (T) was 12.2 days, and the doubling time (DT) was 3.5 days. The lower r m value of G. flumenis than that of its prey (0.24-0.48) explains why Banks grass mite escapes control by G. flumenis in field. These results suggest that augmentative release of this predator would offset the lower r m of the predator, thereby contributing to the control of Banks grass mite. Combined with the benefit of early releases determined in companion studies, future field studies with G. flumenis are being planned.

Lethal and Sub-Lethal Effects of Insecticides on the Pink Hibiscus Mealybug, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae)

“…For PHM in dates, it is essential to consider the effects of candidate chemicals on the two important parasitoids of the pink hibiscus mealybug in the Coachella Valley, A. callidus and G. indica . In addition, it is important to consider the impact on Galendromus flumenis (Chant), which is a key predator for another major pest of dates, the Banks grass mite, Oligonychus pratensis (Banks) [49,50]. Several studies have shown that bifenthrin and fenpropathrin are extremely toxic to beneficial arthropods, including the parasitoid wasps and the predatory mites [48,51,52,53,54,55]; therefore, the use of these pyrethroids should be carefully considered.…”

Galendromus occidentalis (Acari: Phytoseiidae) life table parameters on Oligonychus yothersi (Acari: Tetranychidae) colonies and its behavior to odors of mites, avocado shoots volatiles and synthetic compounds

“…Galendromus occidentalis fed with mobile stages of T. pacificus got a rm = 0.20 females female -1 d -1 (Bruce-Oliver and Hoy, 1990). Ganjisaffar and Perring (2017) recorded a similar rm value for Galendromus flumenis (Acari: Phytoseiidae) reared with eggs of Oligonychus pratensis (Banks) (Acari: Tetranychidae). Our results yielded a rm = 0.19 females female -1 d -1 , when they preyed on all stages of O. yothersi.…”