Behavioral response and relative toxicity for the active compounds of Caulerpavera veravalensis (Thivy and Chauhan) against nymph of Dysdercus cingulatus (Fab.) (Hemiptera: Pyrrhocoridae)

• Published in: Journal of Asia-Pacific entomology 2019, 22(2), , pp.417-426
• Main Authors: Sahayaraj, K., Asharaja, A., Ponsankar, A., Martin Rathi, J., Senthil-Nathan, S.
• Format: Article
• Language: English
• Subjects: C. veravalensis; D. cingulatus; GC–MS; Nymphicidal; Oviposition; RGR; Sea weed; 농수해양학
• ISSN: 1226-8615; 1876-7990
• DOI: 10.1016/j.aspen.2019.02.009

Outburst of harmful insects in the agricultural environment cause potential risk to farmers and it makes an alarm to scientific communities for the development of effective pest management strategies. Prevalent usage of synthetic pesticides results in the development of insect resistance and make higher toxicity to non-target organisms. Phytochemicals derived from seaweeds offers an alternative solution for controlling the agricultural pest. The growth and development of Dysdercus cingulatus was affected by the chloroform extract of sea weed Caulerpa veravalensis at various concentrations (25, 50, 75 and 100 μg/mL). Similarly, relative growth rate (RGR) and oviposition also significantly decreased compared to control. The crude extract of C. veravalensis was further eluted through the column chromatography and partially purified fractions were tested to find toxicity against third instar nymph of D. cingulatus. The active fraction FVI illustrates higher mortality hence it was subjected to GC–MS analysis to find the active chemical constituents. The GC–MS results revealed that nine major compounds with nymphicidal activity against D. cingulatus. Probit analysis of 95% confidential level showing a LC50 value of 183.307 μg/mL against the third instar nymph of D. cingulatus. Our findings suggest that Tetradecanoic acid, 10, 13-dimethyl-, methyl ester from fraction FVI shows highest peak area percentage of 89.2% and it may be one of the insecticidal compounds affecting the behavior of D. cingulatus. [Display omitted] •Seaweed alter the behavioral response of red cotton bug•Growth, development and relative growth rate are affected by crude extract of Caulerpa veravalensis present in Tamil Nadu•Crude extract was fractionated using column chromatography, which showed toxicity against cotton strainer nymphs•Insecticidal and ovicidal activities are due to Tetradecanoic acid of seaweed fraction.