Paraffin Wax Emulsion for Increased Rainfastness of Insecticidal Bait to Control <I>Rhagoletis pomonella</I> (Diptera: Tephritidae)

Abstract

In regions with a humid summer climate, the use of water-soluble bait to control apple maggot is often limited by rainfall. We studied increasing the rainfastness of GF-120 fruit fly bait by adding paraffin wax emulsion. First, we verified that adding 10% wax to a mixture containing 16.7% GF-120 did not reduce the mortality of female apple maggot compared with GF-120 without wax. In addition, we determined that fly mortality caused by GF-120 plus wax subjected to simulated rain was similar to that caused by GF-120 without wax not subjected to rain. Other assays showed that higher fly mortality resulted from increasing the proportion of wax from 10 to 15%, and lower mortality resulted from decreasing GF-120 from 16.7 to 10 or 5%. The availability of spinosad on or near droplets of a mixture consisting of 5, 10, or 15% GF-120 and 15% wax was determined before and after the droplets were subjected to three 15-min periods of simulated rain. We found an initial steep decline in dislodgeable spinosad and smaller decreases after subsequent periods of rain. In a small-plot field trial, fruit infestation by apple maggot in plots treated with a mixture consisting of 16.7% GF-120 and 19.2% wax was less than in plots treated with 16.7% GF-120 without wax but not less than in control plots. Overall, we found that adding paraffin wax emulsion to GF-120 increased rainfastness in laboratory bioassays, and specifically that it retained the active ingredient spinosad. However, our field data suggest that optimal rainfastness requires the development of mixtures with > 19.2% wax, which may preclude application using standard spray equipment.

Transgenerational Transmission of the Glossina pallidipes Hytrosavirus Depends on the Presence of a Functional Symbiome

“…Antibiotic treatment and concomitant reduction of bacterial symbiont levels in the F 1 of the virus-injected parents was correlated with suppression of the SGH + phenotype in the F 1 . This finding was surprising as microbial symbionts have been reported frequently to prime the insect immune system increasing host resistance to infection by various viruses, protozoans, and nematodes [32], [34], [62], [65]. In the case of tsetse flies, the bacterial associates at several levels have been reported to modulate host innate defences.…”

Efeito de Iscas Tóxicas sobre Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae)

“…No experimento com chuva simulada, tanto para lâminas de 20 como 50 mm, a isca tóxica formulada com ANAMED ® proporcionou maior mortalidade que as demais nas avaliações realizadas 48 e 72 HAT (Tabela 4). A baixa eficácia da isca Success* 0,02 CB ® no controle de A. fraterculus após chuva já foi relatada por diversos autores (Prokopy et al 2003, Raga 2005, Teixeira et al 2009. Passadas 72 HAT, com 20 e 50 mm de chuva o ANAMED ® manteve 69,2% e 41,0% de mortalidade, respectivamente (Tabela 4), sendo superior aos demais tratamentos que apresentaram reduzida mortalidade.…”

Long-term attraction and toxic effects of tephritid insecticide-bait mixtures by applying Torricelli's barometer principle in a trapping device

“…The system also allows the addition of other substances, such as propylene glycol or paraffin wax emulsion, which increases rainfastness and reduces insecticide-bait evaporation. 22 For example, it has been observed that propylene glycol reduces evaporation and, in traps where insects are killed by drowning, also helps to preserve the insects that are caught. 10,15 Also, new enzymatic yeast hydrolysate with long-lasting attraction properties, such as CeraTrap ® , could be maintained for longer periods.…”