Design, Synthesis, and Toxicological Activities of Novel Insect Growth Regulators as Insecticidal Agents against Spodoptera littoralis (Boisd.).

As a result of some major problems that come from using insecticides, the use of safe alternatives to these pesticides has become very necessary. Thus, a novel series of predicted toxicologically active urea, thiourea, thiosemicarbazide, oxadiazole, pyrazole, and triazine derivatives have been synthesized in a pure form to be lufenuron analogues as insect growth regulators which were screened and examined against Spodoptera littoralis (Boisd). The structure of synthesized compounds was established by means of spectroscopic and elemental analyses. Compounds b5, b2, b3, and a4 showed high insecticidal toxicity, and their LC50 values for the second larvae instar were found to be 26.63, 46.35, and 60.84 ppm, respectively, whereas the LC50 value for lufenuron as a reference insecticide was 17.01 ppm.

Chemical design and bioefficacy screening of new insect growth regulators as potential insecticidal agents against Spodoptera littoralis (Boisd.).

The 13 new compounds were chemically synthesized and their spectroscopic analysis was done to determine their chemical structure. All the compounds were screened for their insecticidal potential against Spodoptera littoralis (Boisd.). Among the tested compounds, the compound 13 was found to be the most potent. It displayed one fold more activity than a reported insect growth regulator, fenoxycarb. The other target compounds demonstrated weak to strong toxicological activities against Spodoptera littoralis (Boisd.).