Effect of Temperature on Efficacy of Insecticides to Differential Grasshopper (Orthoptera: Acrididae)

Abstract

The effect of temperature on activity of insecticides for controlling grasshoppers in leafy green vegetables was evaluated. Insecticides evaluated had differing modes of action and included diflubenzuron, azadirachtin, Beauveria bassiana, spinosad, endosulfan, esfenvalerate, and naled. We evaluated these insecticides for efficacy to third instars of differential grasshopper, Melanoplus differentialis (Thomas), at temperatures ranging from 10 to 35 degrees C. In the laboratory, treatment with esfenvalerate resulted in 100% mortality at temperatures of 10 to 35 degrees C, and efficacy was not temperature dependent. Treatment with spinosad resulted in similar mortality as with esfenvalerate at all temperatures except 10 degrees C. The activity of B. bassiana was greatest at 25 degrees C and was adversely affected by high and low temperatures. Treatment with diflubenzuron resulted in increased mortality at high temperatures, and at 35 degrees C its activity was similar to that of esfenvalerate and spinosad. The activity of azadirachtin ranged from 19 to 31% and was not influenced by temperature. In field studies, spinosad, diflubenzuron, and esfenvalerate provided differing levels of mortality both at application and when nymphs were exposed to 1-h-old residues. However, only spinosad and diflubenzuron provided similar levels of mortality when nymphs were exposed to 24-h-old residues. The residual activity of endosulfan, naled, esfenvalerate, and spinosad decreased with increasing time (0-24 h) after exposure to sunlight and high summer temperatures. Compared with other insecticides, naled had a short residual activity period and activity was dependent upon immediate contact with the nymphs or their substrate. B. bassiana was inactive under high temperatures and intense sunlight as occurs in summer.

Effect of temperature on efficacy of three natural substances to Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

“…The results of related research showed that the activity of azadirachtin on the differential grasshopper, Melanoplus differentialis [Thomas], does not depend on air temperature (Amarasekare & Edelson, 2004). Our results are not in accordance with the findings of the authors, while azadirachtin showed the highest efficacy on all three developmental stages of Colorado potato beetle at 208C.…”

Biotic and abiotic factors investigated in two Drosophila species – evidence of both negative and positive effects of interactions on performance

“…This is in agreement with other studies finding species specific effects of multiple stressors3031, suggesting that the exact effects of interactions depend on the experimental setup, as well as on the species investigated. This highlights the potential problems of extrapolating results from studies investigating interactions on one species to, e.g., community scale or to ecological risk assessments12, and thereby emphasizing the need for further studies using standardised methods and/or multiple species.…”

Impact of Phlebotomine Sand Flies on United State Military Operations at Tallil Air Base, Iraq: 6. Evaluation of Insecticides for the Control of Sand Flies

“…Orshan et al (2006) suggested the high temperatures, blowing dust, and intense radiation found in parts of Israel limit the efÞcacy of residual insecticides, whereas Kiss and Virág (2009) and Uyanik and Ozdemir (1999) demonstrated higher intensities of ultraviolet light and warmer ambient temperatures, respectively, increased the degradation of insecticides. Amarasekare and Edelson (2004) reported the residual activity of endosulfan, naled, esfenvalerate, and spinosad decreased with increasing time (0 Ð24 h) after exposure to sunlight and high summer temperatures, whereas Tietze et al (1996) found the half-life of naled was reduced from 8 to 1Ð1.2 h by direct sunlight. As reported by Colacicco-Mayhugh et al (2011) andColeman et al (2006), environmental conditions at TAB were harsh during the period in which we evaluated the various control measures, with high temperatures and winds frequently creating dust storms from the talcum-like silt that blanketed the base and surrounding area.…”