Deleterious activity of natural products on postures of Spodoptera frugiperda (Lepidoptera: Noctuidae) and Diatraea saccharalis (Lepidoptera: Pyralidae).

The control of Lepidoptera pests should be carried out before hatching of their caterpillars to avoid damage to the crops. The aim of this work was to assess the activity of neem (trade name: Natuneem, producer: Base Fértil, Chapadão do Sul, Brazil) and pyroligneous extracts (trade name: Biopirol 7M, producer: Biocarbo, Itabirito, Brazil) at 10 mL/L (1%) and 20 mL/L (2%) contents on egg masses of different ages of Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) and of Diatraea saccharalis F. (Lepidoptera: Pyralidae) at Embrapa Corn and Sorghum in Sete Lagoas, Minas Gerais State, Brazil. The tests took place in an unbiased casualized design with 12 treatments and four replications. The insecticides were diluted in water, and 0.04 mL of the solution was applied to recently laid and one- and two-day-old eggs of S. frugiperda and D. saccharalis. Caterpillars hatching from recently laid egg masses of S. frugiperda was lower with 2% pyroligneous extract [(0.02 +/- 0.00)%]. Recently laid eggs and one- or two-day-old eggs of D. saccharalis presented lower caterpillar hatching with 1% neem extract [(0.00 +/- 0.00)%, (0.00 +/- 0.00)%, and (1.00 +/- 0.01)%] and 2% neem extract [(0.00 +/- 0.00)%], compared to 1% pyroligneous extract [(27.30 +/- 3.22)%, (28.40 +/- 3.32)%, and (37.80 +/- 4.14)%] and 2% pyroligneous extract [(42.20 +/- 4.49)%, (48.70 +/- 4.97)%, and (56.60 +/- 5.52)%], respectively. Neem and pyroligneous extracts had impact on hatching of S. frugiperda and D. saccharalis caterpillars.