Toxicity assessment of four insecticides with different modes of action on pupae and adults of Eriopis connexa (Coleoptera: Coccinellidae), a relevant predator of the Neotropical Region

FOGEL MARILINA; SCHNEIDER MARCELA; RIMOLODI FEDERICO; LADUX LORENA; DESNEUX NICOLAS; RONCO ALICIA

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2016

0944-1344

Pesticides can be toxic to nontarget organisms includingthe natural enemies of agricultural pests, thus reducingthe biodiversity of agroecosystems. The lethal and sublethaleffects of four insecticides with different modes of action?pyriproxyfen, teflubenzuron, acetamiprid, and cypermethrin?were evaluated on pupae and adults of Eriopis connexa, an effectivepredator in horticultural crops. Pupal survival was reducedby pyriproxyfen (26 %) and cypermethrin (41 %).Malformations in adults emerged from treated pupae were observedafter acetamiprid (82.7 and 100 % for 100 and 200 mga.i./l, respectively), pyriproxyfen (48.6 %), and cypermethrin(13.3 %) treatments. A longer mean oviposition time was alsoobserved in adults emerged from pupae treated withcypermethrin. Moreover, the latter insecticide as well asteflubenzuron did not reduce reproductive parameters, whereasfemales emerged from pyriproxyfen-treated pupae were not beable to lay eggs even when females showed large abdomens.Upon exposure of adults, survival was reduced to approximately90 % by acetamiprid, but no reduction occurred withpyriproxyfen, teflubenzuron, or cypermethrin though the fecundityat fifth oviposition time of the female survivors was reduced.Pyriproxyfen decreased the hatching at all the oviposition timestested, whereas fertility was reduced in the fourth and fifth ovipositionsby teflubenzuron and in the first and third ovipositionsby cypermethrin. In conclusion, all four insecticides tested exhibitedlethal or sublethal effects, or both, on E. connexa. The neurotoxicinsecticides were more harmful than the insect-growthregulators, and pupae were more susceptible than adults. Thetoxicity of insecticides on the conservation of predators inagroecosystems of the Neotropical Region is discussed.