Biological traits of cadra cautella (Lepidoptera: Pyralidae) reared on khodari date fruits under different temperature regimes

Abstract

The almond moth, Cadra cautella (Walker) (Lepidoptera: Pyralidae), is a serious worldwide pest of dates and other crops, both in the field and in storage. Infestation by this pest significantly limits the sale and export of dates. Modified atmospheres, the temperature manipulations, are the best eco-friendly alternatives in stored product protection. We examined temperature regulation as an ecologically friendly method of pest management in stored food commodities, in particular, its effects on characteristics of C. cautella biology, including development time, oviposition period, fecundity, fertility, and longevity of adults reared on date cultivar 'Khodari,' at temperatures of 15, 25, and 3561°C, with 6565% relative humidity and a photoperiod of 15:9 (L:D) h. Six larval instars were recorded at each temperature. Larval development was sluggish at 15°C; therefore, daily observations were terminated after 180 d of the larval span for this temperature. Total larval spans of 48.9560.76 and 32.1261.08 d were recorded at 25°C and 35°C, respectively. A mean ovipositional period of 5.8060.44 d yielding 213.60613.41 eggs per female, with hatchability of 85.9462.97%, was recorded at 25°C, whereas at 35°C, a mean ovipositional period of 1.6060.26 d yielded 19.8065.11 eggs per female, with no hatchability. These differences were highly significant. Our observations of poor development at 15°C, lower numbers of eggs and absence of hatchability at 35°C, together with head capsule measurements and growth ratios, can be of benefit when planning management strategies to reduce C. cautella infestation.