Efficacy of Noni (Morinda citrifolia L.) Ethanolic Leaf Extract Against German Cockroach (Blattella germanica L.).

<b>Background and Objective:</b> The ethanol extract of noni leaves (<i>Morinda citrifolia</i> L.) can be used as insecticides to control populations of German cockroaches that have been resistant to synthetic insecticides. This study aimed to determine the potency of the ethanol extract of noni leaves to kill and repel German cockroaches and affect the amount of food consumed. <b>Materials and Methods:</b> The methods used in this study were the contact toxicity test, the repellency test and the food consumption test. The noni leaves extract and German cockroach populations were provided in the laboratory. <b>Results:</b> The noni leaves extract concentration of 20% (residue of 3.14 mg cm² ¹) was very effective in killing the standard population and effective in killing the field population of German cockroaches. The sub-lethal concentration noni leaves extract of 0.36% (residue 0.056 mg cm² ¹) and 1.08% (residue 0.169 mg cm² ¹) was very high grade as repellent of German cockroaches. The sub-lethal concentration of noni leaves extract did not inhibit the amount of food consumption in German cockroach populations. <b>Conclusion:</b> Leaves of noni plants can be used as bioinsecticides to control German cockroach populations that have been resistant to commercial insecticides.