Abstract
The present investigation included the toxicity, fecundity, residual effect,
biochemical effects and quantitative recovery of pesticides by HPLC. The two selective
neem compounds viz. NfC and NC and an insect growth regulator dimilin were used
against adults of pulse beetle Callosobruchus analis. For all the experiments conducted,-
the two laboratory methods were used i.e. filter paper impregnation and glass film
method. The LD50 of NfC, NC and dinmilin were calculated as 39.28 µg/cm², 7.16
µg/cm² and 13.0 µg/cm² respectively by filter paper impregnation whereas 10.0 µg/cm²
2
and 3.2 µg/cm² for NC and dimilin by glass film method. No toxicity of NfC was
recorded by glass film method. On the basis of the efficiency, the tested compounds
could be arranged descendingly as NC>dimilin> NfC by filter paper impregnation and
by glass film method as dimilin>NC. Residual and fecundity observations of dimilin,
NC and NfC were found to be slightly varied when all the compounds are compared.
Biochemical analysis were made on total protein content, percent activity of acid
and alkaline phosphatase, totar esterase, acetylcholinesterase, transaminases (GOT and
GPT) and nucleic acids (RNA and DNA). It was found that NfC, NC and dimilin
inhibited the total protein content, acid and alkaline phosphatase, acetylcholinesterase,
total esterase and nucleic acids (RNA and DNA). To some extent by both methods of
treatment on the other hand GOT and GPT were slightly activated when insects were in
contact with the tested compound (dimilin by glass film method after 72 and 144
hours).
HPLC method was used for quantitative analysis of pesticides in treated insect
and treated media samples of NfC, NC and dimilin after 24 and 144 hours of treatment.
Recovery of compounds in treated insect samples was higher than media treated
samples. Comparatively recovery of NfC was highest in treated insects than NC and
dimilin (highest quantity of NfC used in all cases). NfC has low toxic effect.