Botanical extracts against the potato tuber moth, Phthorimaea operculella (Zeller 1873) (Lepidoptera: Gelechiidae), during storage conditions

The potato tuber moth (PTM), Phthorimaea operculella (Zeller 1873) (Lepidoptera: Gelechiidae), is a destructive pest of stored potatoes and potato crop. Biopesticides are certain types of pesticides derived from animals, plants, and bacteria. Botanicals are especially efficient in the form of antifeedant, repellent, protectants, and growth-disrupting hormones. They are also sources of secondary metabolites that are safer than synthetic insecticides. Present research was conducted to evaluate some botanical extracts as natural local alternatives against PTM under storage conditions. Twelve different 80% ethanolic plant extracts were tested on PTM during storage condition (30 ± 2°C and 70 ± 5% RH) at a light regime of the day 10-h light and 14-h dark. Biological parameters of the pest, evidence of the potato tubers damage, and continuation of protection to the tubers were recorded. Extracts of mint, zygophyllum, coriander, arnoglosse, harmel, and solanum indicated a total inhibition of egg deposition at 2.5% concentration; also, they provided high protections to the potato tubers from the PTM infestation for about 3 months and without observations’ effect on tubers germination. Senna, colocynth, and basil reduced the number of deposited egg/female. Jasmine, geranium, and chamomile recorded a low potential on egg deposition. Basil showed the highest potency in decreasing development of larvae that hatched from eggs, therefore, reduced the number of next adult offspring (F1) and followed by jasmine and geranium. Variable levels of extracts’ protection can be arranged according to their damage evidence as follows: basil > colocynth > jasmine > geranium > senna > chamomile.