ADAPTATION OF CITRONELLA GRASS OIL (CYMBOPOGON WINTERIANUS JOWITT) TECNOLOGIES AS AN ALTERNATIVE METHOD FOR COCKROACHES (BLATTELLA GERMANICA L.) REPELLANT

Mihiret MEKONNEN^1*, Solomon ABATE², Begashaw MANHILE³
¹Wondo Genet Agricultural Research Center, P.O. Box 198, Shashemene, Ethiopia
²Wondo Genet Agricultural Research Center, P.O. Box 198, Shashemene, Ethiopia
³Wondo Genet College of Forestry and Natural Resource, Hawassa University,
P.O. Box 128, Shashemene, Ethiopia
*Corresponding Author: hanamihiret0@gmail.com

ABSTRACT
Cockroaches (BlattellagermanicaL.) are considered major pests of homes, restaurants and other structures which contaminate food and eat utensils. This study was aimed to adapt citronella grass oil as an alternative method for cockroach repellent. Cockroaches were reared in the dark and hot area of insect cages set at 25 ± 20C. In the first experiment, different concentrations of citronella oil (5, 10, 15 and 20 µl) were mixed with 1ml of 70% alcohol and poured into Petri dishes. For the second experiment however, similar aliquots were applied on filter papers with 3 replications. Twenty adult cockroaches were then introduced in to the centre of the cages. After 10-15 min, number of cockroaches at each treated and controls were counted and repellency was computed. The third experiment was done by spraying similar aliquots of citronella oil directly on the cockroaches in the cages. In all cases, Water and alcohol alone each at 1ml were used as controls. The results of this study clearly demonstrated that, repellence activity of citronella oil against cockroach was effective in all experiments. Spraying method using 20µl/ml showed 87.77% repellency followed by 15µl/ml, 10µl/ml and 5µl/ml with 76.66%, 72.22% and 66.11% repellency respectively.
Key Words: Citronella grass, insect, repellency bioassay, cockroaches