Effect of Liquid Smoke Applications on the Predator Populations Menochilus Sexmaculatus and Paedorus Fuscipes in Soybean Plants

Abstract

In soybean culture the pest infestation that attacked in soybean crop occurs since the start germinate until harvest. The continued use of synthetic pesticides and improper application can lead to pest resistance and resurgence, in addition to increased production costs also negatively impacting the environment and killing of natural enemies. Liquid Smoke is a natural insecticide that works not killing of pest. The purpose of this study was to determine the population of predators Menochilus sexmaculatus and Paedorus fuscipes in soybean crops that sprayed liquid smoke and synthetic insecticide. The research was conducted on farmer's land with wetland agro-ecosystem in Bumi Setia village, Seputih Mataram sub-district, Central Lampung regency, Lampung Province, Indonsia. The study was conducted from April to June 2015. Research in a stretch of 0.25 ha of soybean plant with a treatment sprayed with liquid smoke of coconut shell and 0.25 ha sprayed with synthetic insecticide with active ingredients of pirifos and sidametrin. The used Randomized Block Design with 2 treatments and 16 replications. Plants was sprayed biweekly until the plants was formed pods. Dosage of liquid smoke 15 ml/lt of water and dose of synthetic insecticide as recommended.

The observed variables were the intensity of armyworms (Spodoptera sp.) attack, pod borer (Etiela sp.) attack and predator population Menochilus sexmaculatus and Paedorus fuscipes since plant age 24 to 66 days after planting with interval of seven days, so the observation was done six times. The results showed that spraying of natural insecticides such as liquid smoke did not reduce the presence of predators of M. Sexmaculatus and P. fuscipes in soybean crops, so that liquid smoke should be considered as alternative insecticides for replacement synthetic insecticides that are very harmful to human health and the environment.