Insect growth regulators, which are primarily used to kill the larval stages of certain insect groups, have indirect effects on the adult stage of whiteflies. In this study, we assessed the effect of the insect growth regulator novaluron (Pedestal) on the reproduction of silverleaf whitefly (Bemisia argentifolii). Two experiments were conducted by exposing adult female silverleaf whiteflies to the low [0.47 mL·L-1 (6 floz/100 gal)] and high [0.63 mL·L-1 (8 floz/100 gal)] label-recommended rates of novaluron. There was also an untreated control. Infested plants [mist flower (Eupatorium coelenstinum) and transvaal daisy (Gerbera jamesonii) for Expt. 1 and Expt. 2, respectively] containing adult female silverleaf whiteflies were sprayed with novaluron using a carbon dioxide (CO2) backpack sprayer. Plants were immediately placed into cages covered with antivirus insect screening. After 24 hours, six adult female silverleaf whiteflies were aspirated from the treated plants, and immobilized with CO2 before being placed onto untreated plants [transvaal daisy for Expt. 1, and rose-of-china (Hibiscus rosa-sinensis) for Expt. 2]. Three munger cells containing two adult female silverleaf whiteflies per cell were attached to leaves of each of the untreated plants. The number of live and dead eggs, and live nymphs per plant was assessed 4 and 8 days after treatment (DAT). In Expt. 1, the low rate of novaluron significantly reduced egg viability compared to the untreated control based on live nymphal counts 8 DAT. In Expt. 2, both rates of novaluron significantly reduced egg viability compared to the untreated control, based on live nymphal counts and number of dead eggs 8 DAT. The results from this study indicate that novaluron negatively affected female silverleaf whitefly reproduction by reducing egg viability, which may decrease the number of silverleaf whiteflies produced during a cropping cycle. This is an important long-term pest management strategy that may reduce the number of insecticide applications and decrease labor costs.
Raymond A. Cloyd, Stephen R. Keith, and Cindy L. Galle
Raymond A. Cloyd
Greenhouse trials were conducted in 2000-2001 to evaluate the indirect effects of insect growth regulators, whether stimulatory or inhibitory, on the egg production of female citrus mealybug [Planococcus citri (Risso)]. Green coleus [Solenostemon scutellarioides (L.) Codd] were infested with 10 late third instar female citrus mealybugs. The insect growth regulators kinoprene, pyriproxyfen, azadirachtin, buprofezin, and novaluron were applied to infested plants at both the high and low manufacturer recommended rates. Beginning two days after treatments were applied, plants were monitored daily to determine when female mealybugs began to oviposit. Individual mealybugs were removed from plants, placed into glass vials containing 70% isopropyl alcohol when female mealybugs started to oviposit, and dissected to determine the number of eggs. Overall, there were no consistent patterns to suggest that the insect growth regulators and different rates tested had any effect on the egg production of citrus mealybug females. Although, in one instance, the insect growth regulators kinoprene and pyriproxyfen actually lowered citrus mealybug egg production. In addition, the insect growth regulator buprofezin numerically increased female citrus mealybug egg production.
measured. Results indicated significant reductions in direct application of agrichemicals to surface waters and adjacent ground surfaces can be achieved easily by appropriate nozzle operation. Insect growth regulator novaluron affects silverleaf whitefly
Clinton C. Shock, Erik B.G. Feibert, Alicia Rivera, Lamont D. Saunders, Nancy Shaw, and Francis F. Kilkenny
on flowers in mid-May 2015. On 21 May 2015, Capture ® 2EC (bifenthrin) at 0.05 kg a.i./ha and Rimon ® (novaluron) at 0.04 kg a.i./ha were broadcast sprayed in the evening to minimize harm to pollinators. On 28 May 2015, Rimon ® at 0.04 kg a
Raymond A. Cloyd
-way tank mixtures of spinosad and pymetrozine (Endeavor®; Syngenta Professional Products), and spinosad and novaluron (Pedestal®; OHP) were cited five and four times, respectively, by the survey respondents. Abamectin and spinosad were used in 26 and 23 of