Age and time exposure-related toxicity of fenthion to male and female Anastrepha fraterculus (Wied.) (Diptera: Tephritidae)

Abstract

Effect of age, sex and time exposure of Anastrepha fraterculus (Wied.) to toxicity of fenthion was evaluated. The age of the flies was important to the appearance of the first intoxication symptoms; males and females of reproductive ages (30 and 60 days-old, respectively) were less susceptible to insecticide than flies in the remainder ages (four and 120 days-old). The effect of body weight on insect intoxication was not detected. LT 50 biossay with fenthion (varying from 3-7 minutes) showed a lower susceptibility of males than females at all ages. Adults of both sexes and 30 days-old submitted to continuous and discontinuous exposure to fenthion did not show toxic cumulative effect of the insecticide. The statistical analysis suggests a possible general detoxification mechanism (quantitative and/or qualitative) to fenthion sex-, age- and time-related. Once the species is highly mobile in nature we suggest that in fruit fly toxicological bioassays, these biological traits need to be observed in order to obtain more realistic data.

Toxicity of Different Dilutions of Spinosad Bait against Two Fruit-fly Species (Diptera: Tephritidae)

“…For these species, it was assumed that the higher susceptibility of males was due to the smaller size and/or greater physiological susceptibility [28,29]. Significant differences in body weight between males (131 mg) and females (170 mg) of A. fraterculus were observed in a Brazilian population of the fruit fly; however, it was not detected any correlation between the body weight and the susceptibility of adults to fenthion, when the insects were exposed to the insecticide via residual contact [30]. In the present experiment, the adults of C. capitata and A. grandis were exposed to spinosad through ingestion, which may have contributed to the differences detected between the sexes.…”

“…After the treatment, the flies were maintained at room temperature (25 ± 3ºC) and ambient humidity (50 ± 10%). Evaluations of cumulative mortality were conducted at 15,30,45,60,90,120,150,180,240,360, 480 minutes and 24 h after initial exposure. Irreversible knockdown followed by the death of the adults was the criterion to determine mortality [20].…”

Toxicity of synthetic and biological insecticides against adults of the Eucalyptus snout-beetle Gonipterus scutellatus Gyllenhal (Coleoptera: Curculionidae)

“…At present, it has been reported for Diptera (Humeres et al 1999;Hahn et al 2001), Hemiptera (Nielsen et al 2008 and Lepidoptera (Shearer and Usmani 2001), after the application of synthetic insecticides. A sex-biased mortality in insects is often related to sexual dimorphism and body mass (Nielsen et al 2008), being females usually larger than males (Teder and Tammaru 2005).…”

Bioassay Method for Toxicity Studies of Toxic Bait Formulations to Ceratitis capitata (Diptera: Tephritidae)

“…In testing and toxicological characterization of formulations of toxic baits on fruit fly species, there is no methodological standardization for evaluations and this may negatively affect results and compromise the reliability of the data (Humeres et al 1999, Robertson et al 2007, Gazit et al 2013, Paramasivam & Selvi 2017. To address these limitations, in this study, was to develop a bioassay methodology, considering factors such as age and origin of the population, time of food deprivation, and form and time of availability of the product to assess the effects on adults of C. capitata using as toxicological standard the Success™ 0.02CB commercial formulation (96 mg L −1 active ingredient spinosad).…”