Acaricidal effects of cardiac glycosides, azadirachtin and neem oil against the camel tick, Hyalomma dromedarii (Acari: Ixodidae).
The cardiac glycoside, digitoxin, from Digitalis purpurea L (Scrophulariaceae), a cardiac glycosidal (cardenolide) extract from Calotropis procera (Ait) R Br (Asclepiadaceae), azadirachtin and neem oil from Azadirachta indica A Juss (Meliaceae) were tested for their effects against larvae and adult stages of the camel tick, Hyalomma dromedarii Koch (Acari: Ixodidae). The contact LC50 values of the first three materials against adults were 4.08, 9.63 and >40.7 microg cm(-2), respectively, whereas the dipping LC50 values of the four materials were 409.9, 1096, >5000 and >5000 mg litre(-1), respectively. Contact and dipping LC50 values of the extract and azadirachtin against larvae were 6.16, >20.3 microg cm(-2) and 587.7 and >2500 mg litre(-1), respectively. Azadirachtin had no effects on egg production or feeding of adults up to 5000 mg litre(-1); however at 2500 mg litre(-1), it caused significant reduction in feeding activity of larve, prolonged the period for moulting to nymphal stage, and caused 60% reduction in moultability. Results of the two cardiac glycoside materials are comparable with those of several commercial acaricides. The risks and benefits associated with the use of cardiac glycosides are considered.
Al-Rajhy
DiefAlla H
DH
Department of Plant Protection, College of Agriculture, King Saud University, PO Box 2460, Riyadh 11451, Saudi Arabia.
Alahmed
Azzam M
AM
Hussein
Hamdy I
HI
Kheir
Salah M
SM
D000818:Animals; D031107:Calotropis / Q000737:chemistry; D002162:Camelus / Q000469:parasitology; D002301:Cardiac Glycosides / Q000494:pharmacology*; D004074:Digitoxin / Q000494:pharmacology; D004333:Drug Administration Routes; D005260:Female; D005989:Glycerides / Q000494:pharmacology*; D007302:Insect Repellents / Q000494:pharmacology*; D007306:Insecticides / Q000494:pharmacology*; D026863:Ixodidae / Q000254:growth & development* / Q000502:physiology; D007814:Larva / Q000254:growth & development; D007928:Lethal Dose 50; D036701:Limonins / Q000494:pharmacology*; D008297:Male; D010058:Oviposition / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology; D011817:Rabbits; D013729:Terpenes / Q000494:pharmacology*; D013984:Tick Infestations / Q000188:drug therapy / Q000517:prevention & control / Q000662:veterinary; D016896:Treatment Outcome
D002301:Cardiac Glycosides; D005989:Glycerides; D007302:Insect Repellents; D007306:Insecticides; D036701:Limonins; D010936:Plant Extracts; D013729:Terpenes; C002443:neem oil; D004074:Digitoxin; C010329:azadirachtin