Casting light on the potency of photosensitizing compounds to combat the spiny bollworm, Earias insulana (Biosd.)

Abstract

The emergence of resistance among pests to conventional pesticides underscores the necessity for substantial efforts in identifying alternatives for managing cotton pests. So the research aimed to use the photosensitizing compounds Rose Bengal, Rhodamine B, and Methylene Blue for sustainable and eco-friendly managing of cotton pests, mainly, the second instar larvae of Earias insulana. Results indicated a high efficacy of Rose Bengal when scored 1.24x10⁻⁵M and 1.26x10⁻⁴M LC₅₀ and LC₉₀, respectively followed by other compounds. Rose Bengal, Rhodamine B and Methylene Blue scored 2 h highest LT₅₀ at concentrations 3x10⁻⁵M. While LT₅₀ values were 0.30, 0.55 and 1:45 h at 1x10⁻⁴M. Rose Bengal was high effective against E. insulana larvae compared to Methylene Blue and Rhodamine B. Moreover, the findings revealed a discernible negative correlation between the concentrations applied and the necessary median lethal time for all tested compounds indicating their efficacy against E. insulana larvae.

Keywords:

• Spiny bollworm
• Earias insulana
• photosensitizers
• median lethal time (LT₅₀)

Disclosure statement

No potential conflict of interest was reported by the author(s).