Lethal Response of Manduca sexta (Tomato Hornworm) to Chrysanthemum Leaf Extracts

Abstract

INTRODUCTION

Most people in Rosario are farmers and majority of their plant yields are fruits and vegetables. Pests such as Manduca sexta or tomato hornworm damage the quality of these crops that results to less production. Chrysanthemum, a kind of flowering plants of the Genus Chrysanthemum in the family Asteraceae, has the capability to control the mechanisms that Manduca sexta or tomato hornworm. Thus, it is the intention of this scientific study to determine the lethal response of tomato hornworm to chrysanthemum leaf extracts (CLE).

METHODS

Experimental research design was used to prove the lethal response of tomato hornworm to CLE. Following CRBD, four experimental setups were created using the log-dose response relationship (LDR) standards with different mixtures of CLE and water; Set up A10mL CLE or 100% concentration, set up B 8mL or 80% concentration, set up C 6mL or 60% concentration and Set up D 4mL or 40% concentration. Physical characterization test was done to all experimental concentrated CLE. Acclimatized tomato hornworms were subjected for LDR test having mortality rate of the specimen vs time as the dependent variable to different CLE concentrations.

RESULTS

Based on physical property tests, pure CLE exhibited a very dark color and had the greatest viscosity and 4mL or 40% concentration of CLE is very light in color and least in viscosity. Pure CLE had the highest potent toxicity that caused immediate lethal effect on tomato hornworm within 4 minutes upon application. The computed F-value at 0.05 significance level is 20.490 (df=3) was not significant at p-value = 0.17, thus the null hypothesis was accepted. It simply revealed that different concentrations do not affect the potent toxic effects of chrysanthemum leaf extracts (CLE) to tomato hornworm. It also showed that CLE was a good organic pest control agent against tomato hornworm.

DISCUSSIONS

Chrysanthemum leaf extracts exhibited a highest form of potent toxic log-dose response to the targeted specie, tomato hornworm, in its purest concentration. It was also concluded that diluted concentration of CLE did not affect its potent toxic effects against tomato hornworm for as long as the specimen is exposed in a longer period of time. It is recommended that CLE may be further tested to extract more findings for its commercial use as an organic pest control agent. Lethal Response, chrysanthemum leaf extracts (CLE), organic pest control agent.