Toxicity of Baits and Their Effects on Population Suppression of Anastrepha fraterculus (Diptera: Tephritidae): Implications for Field Management.

Anastrepha fraterculus (Wiedemann, 1830) is the main pest of fruit in southern Brazil. The use of toxic baits is one of the alternatives for its management. In this study, the toxic baits Anamed + malathion (10,000 mg/liter), Flyral 1.25% + malathion (2,000 mg/liter), and Gelsura (alpha-cypermethrin, 2,000 and 4,000 mg/liter) were highly toxic to the adults of A. fraterculus (lethal time [LT50] < 7 h). In contrast, Success 0.02 CB had an LT50 of 48.4 h. In the absence of rain, all the formulations had residual effects (>90% mortality) on A. fraterculus adults up to 21 d after treatment (DAT). In the presence of 5, 25, and 50 mm of rainfall, there was a significant reduction in the residual effect over time. However, with up to 50 mm of rain, Anamed + malathion and Gelsura 2,000 and 4,000 mg/liter caused between 43.0 and 79.0% of mortality. In the field, during two consecutive seasons (2015/2016 and 2016/2017), applications of Gelsura 2,000 mg/liter (four applications/season) caused population suppression of the pest throughout the apple fruiting period. However, in the 2016/2017 season, in the area using Gelsura, a higher percentage (≈12%) of apple fruits damaged by A. fraterculus females was observed when compared with the area with insecticide application (damage <3%). The toxic bait Gelsura (2,000 and 4.000 mg/liter) was shown to be promising for use in the management of A. fraterculus, with results similar to those with the application of synthetic insecticides.

Population suppression of Ceratitis capitata (Wiedemann) on table grapes using toxic baits.

To provide alternatives to the use of spraying synthetic insecticides in C. capitata management, was evaluated the effect of "attract and kill" toxic baits on population suppression of C. capitata in three commercial areas producing table grapes. Toxic baits of Gelsura™ (4.5 L ha-1) and Success™ 0.02 CB (4.0 L ha-1) resulted in lower population levels of C. capitata adults in monitoring traps after five sequential applications at weekly intervals during the maturation period of the grapes when compared with control plots with or without insecticidal spray. In addition, plots with Gelsura™ and Success™ 0.02 CB applications showed a significant reduction in damage (%) by C. capitata on grape berries and grape bunches when compared with control plots without or with insecticidal spray. However, when compared with a plot treated by conventional management with sprays of etofenprox (Safety™, 100 g c.p. (commercial product) 100 L-1) and applications of spinosad (Success™ 0.02 CB toxic bait) with a brush, only Gelsura™ (4.5 L ha-1) showed a lower level of damage of grape berries and grape bunches. Toxic baits Gelsura™ (4.5 L ha-1) and Success™ 0.02 CB (4.0 L ha-1) are promising alternatives for the population suppression of C. capitata on table grapes.

Toxicities and effects of insecticidal toxic baits to control Drosophila suzukii and Zaprionus indianus (Diptera: Drosophilidae).

BACKGROUND: Drosophila suzukii is a primary insect pest that causes direct damage to fruits with a thin epidermis such as strawberries, cherries and blueberries. In strawberry fields, the co-occurrence of D. suzukii and Zaprionus indianus has increased production losses. This study evaluated the toxicities and effects of insecticidal baits to control adults and larvae of both D. suzukii and Z. indianus. RESULTS: Organophosphate (dimethoate and malathion), spinosyn (spinosad and spinetoram), pyrethroid (lambda-cyhalothrin) and diamide (cyantraniliprole) insecticides exhibited high toxicity to both adults and larvae of D. suzukii and Z. indianus (mortality >80%) in topical and dip bioassays. However, when the insecticides were mixed with a feeding attractant, a positive effect was observed only for adults of D. suzukii. Insecticides containing neonicotinoids (acetamiprid and thiamethoxam) and pyrolle (chlorfenapyr) caused intermediate mortality to adults of D. suzukii (40-60%) and low mortality for Z. indianus (mortality <23%); however, these compounds reduced the larval infestation of the two species by 55-86%. Botanical (azadirachtin) and sulphur insecticides exhibited low toxicity (mortality <40%) on adults and larvae of both species. CONCLUSION: Dimethoate, malathion, spinosad, spinetoram, lambda-cyhalothrin and cyantraniliprole are highly toxic to both larvae and adults of D. suzukii and Z. indianus. The use of toxic baits for adults of D. suzukii could be an alternative in management of this species. © 2016 Society of Chemical Industry.