Impact of Schinus molle and Cotton Seed Extracts on the Biology of the Spiny Bollworm, Earias insulana

Abstract

This study aimed to investigate the impact of some extracts of Schinus molle Rev L. (Anacardiaceae) leaves, and cotton seed; Gossypium hirsutum L. (Malvacae) on the biological aspects of Earias insulana (Boisduval) such as mortality, developmental duration, feeding inhibition, and fertility of emerging adults. First and fourth instar larvae were fed with cotton leaves treated with 0.5, 1.5, 4.0 and 10 ppm concentrations of the plant extracts. The results obtained indicated that the sensitivity of first instar larvae to both extracts was higher compared to that of fourth instar larvae, and this effect was concentration-dependent. The highest mortality rate for applying 10 ppm concentration (95.36%) was recorded for the first instar larvae treated with cotton seeds extract, whereas for S. molle leaves extract it reached 77.62%. Furthermore, the extracts prolonged the larval and pupal durations in a concentration-dependent manner, with the longest duration observed in the larval and pupal stage treated with 10 ppm cottonseed extract. In addition, the S. molle leaf extract showed a repellent effect. Moreover, the plant extracts had a significant impact on the fertility of the emerging adults. The egg-laying rate was 58 eggs/female, and the hatching rate was 68% when treated with 10 ppm cotton seed extract in adults resulting from the treatment of first-instar larvae. In conclusion, these findings suggest that using these plant extracts could be a promising component in the management of E. insulana.

Keywords:

Spiny cotton bollworm, Earias insulana, cotton seeds, extract, Schinus molle, mortality.