LABORATORY STUDY ON AZADIRACHTIN TO PROTECT SALTED SUN-DRIED FISH FROMCHRYSOMYA MEGACEPHALAINFESTATION

Abstract

Laboratory investigations on azadirachtin to protect salted sun‐dried fish from blowfly infestation were conducted by studying the effects of azadirachtin on the repellence, oviposition, larval growth and mortality of Chrysomya megacephala, in salted sun‐dried fish during drying processing. The results on repellence and oviposition indicated that azadirachtin could repel C. megacephala and inhibit its oviposition on fish during drying days. When the salted fish were dipped for 1 min in aqueous azadirachtin preparation for a range of concentrations before sun‐drying, repellence of 89.25, 95.61 and 100% in the morning and 55.56, 71.23 and 94.52% in the afternoon of the first drying day was obtained by azadirachtin at the concentrations of 18, 54 and 162 mg/L, respectively. The inhibit concentrations (IC) of azadirachtin were 21.54 and 167.75 mg/L during the first drying day, 31.52 and 286.67 mg/L during the second drying day for IC50 and IC95, respectively. The results on larval growth and mortality showed that azadirachtin strongly inhibited larval growth and had high toxicity on larvae in fish. Concentrations of 6, 18 and 54 mg/L gave corrected mortalities of larvae by 14.67, 44.67 and 86.67% as compared with the control group. PRACTICAL APPLICATIONS Azadirachtin, an extract from neem, is efficient in protecting salted sun‐dried fish from Chrysomya megacephala infestation. Reductions of adult landing and egg laying on fish during drying processing result in azadirachtin having a repellent activity on adult blowfly and a potential inhibition on oviposition of blowfly on fish. Decreased growth rate and delayed larval pupation and high mortality of larvae make azadirachtin as growth deterrent and larvicide against blowfly larvae on fish. A 100% protection efficiency is obtained at the concentration of 160 mg/L azadirachtin, indicating that it is feasible to substitute chemical pesticides with azadirachtin for protecting salted sun‐dried fish from blowfly infestation.

Efficiency of organic pesticides, turmeric (Curcuma longa) and neem (Azadirachta indica) against dry fish beetle (Dermestes sp.) during storage condition

“…beetle ( Table 2). The Rate of repellency and mortality of beetle larvae rose with higher concentration of doses (Xia et al, 2010). Highest mean repellency (57.00 %) was found with 4% turmeric extract and the lowest mean repellency (29.67 %) was found with 3% neem extract.…”

Evaluation of traditional fish preservation method of Masmin from skipjack tuna (Katsuwonus pelamis) in Lakshadweep, India, with respect to nutritional and environmental perspectives

“…However, we observed no differences in bacterial load on tuna at four processing stages suggesting the overall processing arrest the further bacterial growth or have no effect on bacterial content. In literature boiling, smoking, and sun drying were reported to reduce the microbes, however, poor handling in open with bare hands during processing enhanced the chances of product contamination by microbes (Xia, Li, & Ma, ). Unfortunately, the bacterial load could not be represented quantitatively because characteristically hexagonal, metallic shine colonies were spread all over the ZMA plate that made it impossible to count bacterial colonies.…”