Toxicity and deterrence of pyroligneous extracts on Liriomyza sativae (Diptera: Agromyzidae)

Liriomyza sativa is a cosmopolitan and polyphagous insect, a key pest of crops such as tomato and melon. The inadequacy of insecticide application techniques has developed resistant populations. The objective of this research was to evaluate the toxicity, insecticidal activity and deterrence of pyroligneous extracts on the leafminer fly. The experiments were carried out under laboratory conditions of 25 ± 2°C and humidity of 60 ± 10%. For the toxicity test, solutions were prepared in different concentrations by diluting them in distilled water. Leaf discs containing L. sativae larvae were immersed in the solutions. For insecticidal activity and deterrence tests, jack bean plants were subjected to application of treatments using an airbrush, spraying 6 mL of the solutions on each plant. All extracts showed significant mortality for the larvae, with emphasis on the pyroligneous extract of coffee straw at 350ºC. The extracts did not interfere with the other developmental stages of the leafminer fly. The pyroligneous extract from the commercial company Agttec and the coffee straw extract at 600ºC were classified as attractive and the coffee straw extract at 350ºC as detergent. It is concluded that pyroligneous extracts can be used in the management of L. sativae.