Proteinex Bait Gel Formulations Suitable for Increased Field Stability and Enhanced Trapping of Melon Fly (Zeugodacus cucurbitae) Coquilette

Abstract

Cucurbit fruit fly, Zeugodacus cucurbitae is an important insect pest of cucurbits. Fruit flies consisted of over 250 species worldwide and its maggots damage fruit from inside and hence, insecticides remain practically ineffective. Trapping the adult flies through parapheromenes, protein and food based traps is the most common practice. The protein and food baits attract both sexes over the parapheromones and are more effective due to their attractiveness and comparatively less weathering under field conditions. Hence, the present study was undertaken to prepare gel based formulations of liquid proteinex bait to increase it’s trapping efficiency. The gelling agents viz., xanthan gum powder, gaur gum powder, pectin powder, carrageenan powder, sodium alginate and gum arabic powder were used to prepare gel formulations of liquid proteinex bait developed by us. Among them, pectin and xanthan gum powders turned the liquid proteinex bait to semi-liquid at very less concentrations thus making them economical to use. Pectin, guar gum and carrageenan powder gel formulations maintained semi-liquid to slightly thickened consistency up to 9th day after preparation of bait and is advantageous for stability under field conditions. Protein content of pectin and guar gum powder formulations are similar as liquid proteinex bait which contributes for more attraction. pH of pectin and guar gum powder gel formulations was higher than the liquid proteinex bait thus increasing their attractiveness. As viscosity of pectin and carrageenan powder formulations was close to liquid proteinex bait, acceptability of these baits closely follows that of liquid bait. Study concluded that pectin powder gel formulation of liquid proteinex bait was found to be ideal and economical to use in field conditions to attract both male and female fruit flies.