Potency of Papaya Leaf (Carica papaya L.) as Toxicant and Repellent against German Cockroach (Blattella germanica L.).

Abstract

Papaya leaves have the potency to be developed as alternative insecticide to control the German cockroaches that have been resistant to synthetic insecticides. This study aimed to determine the potency of ethanolic extract of papaya leaf as toxicant and repellent against 2 populations of German cockroaches which are known resistant to synthetic insecticide. The methods that used was contact toxicity test and repellency test. The ethanolic extract of papaya leaf residues were used in contact toxicity test of 4 residues and a sub-lethal residue in repellency test. Three populations of German cockroach were collected in field and kept in laboratory. Lethal residue 50% (LR50) of ethanolic extract of papaya leaf between 2.97-4.72 mg cm-2 while lethal residue 90% (LR90) between 6.05-8.92 mg cm-2 and very effective killed all population of German cockroach. Repellency value of ethanolic extract of papaya leaf with a sub-lethal residue of 0.39 mg cm-2 between 88.89 -94.74% and level of repellency was very repellent. Ethanolic extract of papaya leaf could be formulated as a potent natural insecticide to control populations of German cockroach that have been resistant to synthetic insecticides.