Locomotor behavioral responses of Anopheles minimus and Anopheles harrisoni to alpha-cypermethrin in Thailand.
Excito-repellency responses of 3 test populations, representing 2 sibling species within the Minimus Complex, Anopheles minimus and An. harrisoni, were characterized for contact irritant and noncontact repellent actions of chemicals during and after exposure to alpha-cypermethrin at half the recommended field (0.010 g/m2), the recommended field (0.020 g/m2), and double the recommended field concentration (0.040 g/m2), using an excito-repellency escape chamber system. Two field populations of An. minimus and An. harrisoni collected from the malaria-endemic areas in Tak and Kanchanuburi provinces in western Thailand, respectively, were tested along with a laboratory population of An. minimus maintained since 1993. Females of all 3 test populations rapidly escaped after direct contact with treated surfaces for each concentration. In general, increased escape responses in the An. minimus test populations were proportionate to increased insecticide dosages. The greatest escape response for An. harrisoni was observed at the operational field concentration of alpha-cypermethrin. The noncontact repellency response to alpha-cypermethrin was comparatively weak for all 3 test populations, but significantly different from each paired contact test and respective noncontact controls. We conclude that strong contact irritancy is a major action of alpha-cypermethrin, whereas noncontact repellency plays no role in the escape responses of 2 species in the Minimus Complex in Thailand.
Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, 10900 Thailand.
Naritsara
N
Malaithong
Rungarun
R
Tisgratog
Krajana
K
Tainchum
Atchariya
A
Prabaripai
Waraporn
W
Juntarajumnong
Michael J
MJ
Bangs
Theeraphap
T
Chareonviriyaphap
D000818:Animals; D000852:Anopheles / Q000187:drug effects*; D004924:Escape Reaction / Q000187:drug effects*; D005260:Female; D007303:Insect Vectors / Q000187:drug effects; D007306:Insecticides / Q000008:administration & dosage*; D009043:Motor Activity / Q000187:drug effects*; D011722:Pyrethrins / Q000008:administration & dosage*; D013785:Thailand
D007306:Insecticides; D011722:Pyrethrins; C017160:cypermethrin