Summary
Adverse effects of extracts from the plants Artocarpus altilis and Azadirachta indica on egg laying and hatching in the tick Boophilus microplus were quantified. A 50% inhibition of egg laying was achieved by a dose of 0.54 and 0.46 μg crude ethanol extract per tick, respectively. These doses also caused a 65% and 80% hatching failure, respectively. Extracts, particularly those of A. indica, inhibit protein and lipid sequestration by ovaries and oocytes. GC-MS analyses revealed reductions in the quantities of four methyl esters sequestered from the ovaries into the oocytes oviposited on the 12th day of engorgement by the treated ticks in the order of (A. indica effects are in parentheses): undecanoic acid 10-methyl-,methyl ester 40% (100%); tetradecanoic acid, methyl ester 100% (100%); tetradecanoic acid, 12-methyl-,methyl ester 100% (100%) and pentadecanoic acid, 14-methyl-,methyl ester 30% (75%).