Phytochemical screening and evaluation of the insecticidal effect of <i>Ageratum conyzoides</i> (Asteraceae) and <i>Croton hirtus</i> (Euphorbiaceae) leaf distillates on <i>Macrotermes bellicosus</i> (Rambur, Isopt

Pesticides used against crop pests are the cause of environmental pollution and poisoning of some farmers. To overcome these problems, research is now focused on plants with insecticide effects. It is in this sense that we have evaluated the insecticidal effect of Croton hirtus and Ageratum conyzoides distillates was evaluated on Macrotermes bellicosus workers in the present study. After phytochemical screening, direct toxicity and consumption tests were carried out on M. bellicosus workers. Phytochemical screening showed the presence of flavonoids and quinones in both distillates. Alkaloids were found only in the A. conyzoides leaf distillate while sterols and polyterpenes were specific to the C. hirtus distillate. Phytochemical screening did not show an absence of tannins (gallic tannin and catechic tannin) in both distillates. Toxicity test revealed the insecticidal effect of both distillates. The A. conyzoides leaf distillate was more active than the C. hirtus leaf distillate. The LD50 of A. conyzoides and C. hirtus distillates were 169.24 and 269.43 μl, respectively. The LD50 of A. conyzoides distillate was 1.59 times lower than that of C. hirtus distillate. Total worker mortality with A. conyzoides distillate was obtained after 96 hours of treatment. On the other hand, with C. hirtus distillate it was obtained after 120 hours of treatment. Plating and consumption surfaces were observed in both controls and treated. The distillates had no repellent or anti-feedant effects. Distillates of C. hirtus and A. conyzoides should be used to combat crop-destroying termites.