Abstract:
The use of insect repellents to reduce the attack rate of Culicoides species (Diptera:
Ceratopogonidae) should form part of an integrated control programme to combat African
horse sickness and other diseases transmitted by these blood-feeding midges. In the present
study the repellent effects of a commercially available mosquito repellent, a combination
of citronella and lemon eucalyptus oils, on Culicoides midges was determined. The number
of midges collected with two 220 V Onderstepoort traps fitted with 8 W 23 cm white light
tubes and baited with peel-stick patches, each containing 40 mg of active ingredient, was
compared with that of two unbaited traps. Two trials were conducted and in each trial the
four traps were rotated in two replicates of a 4 x 4 randomised Latin square design. Although
more midges were collected in the baited traps, the mean number in the baited and unbaited
traps was not significantly different. This mosquito repellent did not influence either the
species composition or the physiological groups of Culicoides imicola Kieffer. The higher
mean numbers in the baited traps, although not statistically significant, may indicate that this
mosquito repellent might even attract Culicoides midges under certain conditions.
