Target and non-target toxicity of botanical insecticide derived from Couroupita guianensis L. flower against generalist herbivore, Spodoptera litura Fab. and an earthworm, Eisenia foetida Savigny

Authors: PONSANKAR, ATHIRSTAM - Manonmaniam Sundaranar University (MSU); VASANTHA-SRINIVASAN, PROBHAKARAN - Manonmaniam Sundaranar University (MSU); SENTHIL-NATHAN, SENGOTTAYAN - Manonmaniam Sundaranar University (MSU); THANIGAIVEL, ANNAMALAI - Manonmaniam Sundaranar University (MSU); EDWIN, EDWARD-SAM - Manonmaniam Sundaranar University (MSU); SELIN-RANI, SELVARAJ - Manonmaniam Sundaranar University (MSU); KALAIVANI, KANDASWAMY - Sri Jayachamarajendra College Of Engineering; Hunter, Wayne; Alessandro, Rocco; ABDEL-MEGEED, AHMED - Alexandria University Of Egypt; PAIK, CHAE-HOON - Kongiu National University; DURAIPANDIYAN, VEERAMUTHU - King Saud University; AL-DHABI, NAIF ABDULLAH - King Saud University

Submitted to: Ecotoxicology and Environmental Safety
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2016
Publication Date: 11/1/2016
Citation: Ponsankar, A., Vasantha-Srinivasan, P., Senthil-Nathan, S., Thanigaivel, A., Edwin, E., Selin-Rani, S., Kalaivani, K., Hunter, W.B., Alessandro, R.T., Abdel-Megeed, A., Paik, C., Duraipandiyan, V., Al-Dhabi, N. 2016. Target and non-target toxicity of botanical insecticide derived from Couroupita guianensis L. flower against generalist herbivore, Spodoptera litura Fab. and an earthworm, Eisenia foetida Savigny. Ecotoxicology and Environmental Safety. 133:260-270.

Interpretive Summary: Novel chemistries in botanical insecticides may provide alternatives to, or development of synthetic insecticides suitable for controlling insect herbivores. Many botanical chemistries are biodegradable, and have lower mammalian toxicity. We report on one chemical compound from a plant species that showed insecticide activity against an important insect pest but had no harmful effect on earthworms.

Technical Abstract: Novel chemistries in botanical insecticides may provide alternatives to, or development of synthetic insecticides suitable for controlling the Lepidopteran pests, like Spodoptera litura (F.). Many botanical chemistries are biodegradable, and have lower mammalian toxicity. Eight natural chemical compounds with larvicidal activity were identified from fractions produce from the flowers of the plant C. guianensis. Probit analysis at 95 percent confidence level, showed an LC50 of 223 parts-per-million against Spodoptera litura third instar larvae. The growth and development of S. litura was affected when treated with sub-lethal concentrations of Fraction F6 (50, 100, 150 and 200 parts-per-million) applied to leaves which were ingested compared to controls. Nutritional indices values decreased significantly compared to controls. Ingestion of Fraction F6 damaged the gut epithelial layer and brush border membrane. This study compared the effects of toxicity to non-target earthworm treated with Fraction F6 and the chemical pesticides (monotrophos and cypermethrin). Treatments with Fraction F6 had no harmful effect on E. fetida. Fraction F6 was eluted and sub fraction F6c (50 ppm) showed an increase in S. litura, third instar mortality. The main chemical in sub fraction F6c was Octacosane confirmed using IR spectrum and HPLC. The time of retention of F6c was confirmed against the octacosane standard. Ingestion of F6c caused dose-dependent mortality of S. litura, across all larval stages. Other minor compounds present in the main Fraction F6 were shown to cause developmental changes in S. litura at sub lethal concentrations, extending development times. These results suggest that octacosane may be useful as an insecticidal compound to reduce S. litura, and other lepidopteran pests.