Laboratory evaluation of Bacillus thuringiensis (Vectobac WDG) against mosquito larvae, Culex pipiens and Culiseta longiareolata.
Mosquitoes are vectors of many human diseases and cause environmental nuisances. Due to their Large geographical distribution and abundance, Culex pipiens and Culiseta longiareolata represent the most important mosquito species in ALgeria and many countries in the world. They are generally controlled by conventional insecticides. The high reproductive ability and development of insecticide resistance of mosquito species are Leading to a search for novel molecules. As so, Vectobac that is based on the insecticidal toxins of Bacillus thuringiensis isroelensis (Bti), may provide economical control of mosquito larvae. In this study, we tested the activity of Vectobac (WDG) at different concentrations, ranging between 2 and 30 microg/L, against the different Larval stages (L1-L4) of Cx. pipiens and C. longiareolata. Bioassays were done on newly moulted Larvae under Laboratory conditions according to the guidelines of WHO. In Cx. pipiens, mortality was scored already after 24 h, and in addition developmental effects were observed like inhibition of growth with incomplete moulting and failure of adult emergence. From a dose-response curve LC50 were calculated: 9.22 microg/L for L1 and 35.33 microg/L for L4. For C. longiareolata, the respective LC50's were 6.05 microg/L and 23 microg/L for L1 and L4. The results are discussed in relation to the susceptibility of the two mosquito species tested, lethaL doses, direct toxicity, and effects on growth and development.
Boudjelida
H
H
Laboratoire de Biologie Animale Appliquée, Département de Biologie, Faculté des Sciences, Université Badji Mokhtar, DZ-23000 Annaba, Algérie. boudjelidahamid@yahoo.fr
Aïssaoui
L
L
Bouaziz
A
A
Smagghe
G
G
Soltani
N
N
D000462:Algeria; D000818:Animals; D001413:Bacillus thuringiensis / Q000472:pathogenicity*; D003465:Culex / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology*; D009033:Culicidae / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D007306:Insecticides / Q000633:toxicity; D007814:Larva / Q000187:drug effects / Q000382:microbiology; D010571:Pest Control / Q000379:methods*
D007306:Insecticides