The Effect of Application Rate of GF-120 (Spinosad) and Malathion on the Mortality ofApis mellifera(Hymenoptera: Apidae) Foragers

Abstract

Beneficial organisms like the honey bee, Apis mellifera L. (Hymenoptera: Apidae), are heavily affected by pest control practices that incorporate insecticides. Safer alternatives as the spinosad-based formulation GF-120 have been developed to overcome this issue. Though both the low concentration of spinosad and the ultra-low-volume application rate of GF-120 are supposed to have a low acute toxicity in honey bee foragers, to our knowledge such claims have not been explicitly proven. We thus carried out a series of experiments to assess the effect of GF-120, malathion, and Spintor (spinosad) on honey bee foragers when applied at two concentrations (80 and 1,500 ppm) and two application rates (low density rate [LDR]—80 drops of 5 mm diameter per square meter; high density rate [HDR]—thousands of 200 -µm-diameter droplets per square meter). Interestingly, the three pesticides caused low mortality on foragers when applied at LDR-80, LDR-1,500, or HDR-80. However, HDR-1,500 caused a very high mortality. Based upon these results, we developed a computer program to estimate the average number of foragers that are exposed at LDR and HDR. We found that more foragers receive a lethal dose when exposed at HDR than at the other rates. Our results support the hypothesis that the impact of GF-120 and malathion upon honey bees is minimal when applied at LDR and that computer simulation can help greatly in understanding the effects of pesticides upon nontarget species.

Field Tests of Three Alternative Insecticides with Protein Bait for the Development of an Insecticide Rotation Program to Control Melon Flies, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae)

“…Another important consideration, especially with widespread or areawide use, is the susceptibility of nontarget species to the insecticides, including bees and natural enemies of pests. All of the insecticides we tested can be harmful to nontarget species and beneficial insects (abamectin [ 53 , 54 ], malathion [ 55 , 56 ], and zeta-cypermethrin [ 57 , 58 ]), including GF-120 at high density application rates [ 56 ]. The protein in Nu-Lure Insect Bait might also attract nontarget species.…”

Acttra SWD Bait Formulation Against Drosophila Suzukii and its Compatibility with Berry Pollination by the Honey Bee, Apis Mellifera

“…When Acttra is not used, the application of Entrust or Exalt is carried out in such a way that the plantation is completely covered with a layer of the insecticide. This mode of application leaves no chance for bees to escape contact, particularly if it is done during periods of high foraging activity (Cabrera-Marín et al, 2016). However, if it is done during nighttime or very early in the morning, the risk to bees is greatly reduced, as shown in laboratory, semifield and field tests for spinosad (Miles et al, 2012;Schoonover & Larson, 1995).…”

“…Non-targets are not attracted to the bait, and the probability of contact between non-target insects and the insecticide formulation dramatically decreases. Therefore, the use of "attract and kill" formulations should be significantly more compatible with the management of honey bee colonies for crop pollination than conventional cover sprays of chemical pesticides for crop protection (Kirkland, 1999;Cabrera-Marín et al, 2016). GF-120 (Dow Agrosciences, CA) is a formulation that consists of NH 3 -releasing compounds, sugars and the bioinsecticide spinosad (a mixture of spinosyns A and D), aimed to control fruit flies in Mexico (Sánchez et al, 2012).…”

“…However, given that the GF-120 formulation has shown to be mostly repellent to bee pollinators (Mangan & Moreno, 2009;Gómez-Escobar et al, 2014), actual oral toxicity to pollinators is substantially reduced. More importantly, application at an ultra low volume (ULV, 2 liters of diluted formulation per ha) with large size droplet completely eliminates the necessity of complete crop coverage, leaving most of the crop free of insecticides, which might provide refuge for pollinators (Cabrera-Marín et al, 2016). The Spotted-Wing Drosophila, Drosophila suzuki (Matsumura) (SWD) (Diptera: Drosophilidae) is a serious pest of soft fruit and berries (e.g.…”

Spinosad‐mediated effects on the walking ability, midgut, and Malpighian tubules of Africanized honey bee workers

“…non-target species) to sublethal concentrations of spinosad in laboratory conditions. [12][13][14] Although the probability of this concentration reaching the bees is low in field conditions as a result of degradation by light and by microorganisms, 26,27 the LC 50 , which was approximately 220-fold lower than the field concentration, still had toxic effects on bees. The honey bees exposed to spinosad at LC 5 and LC 50 had adversely affected walking behavior.…”