Insect abtifeedant and growth-inhibitory activity of limonoids from dalanghita (Citrus reticulata Blanco cv. Ladu) seeds against Asian Corn Borer (Ostrinia furnacalis Guenee) larvae

Date

10-2012

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Mary Grace E. Guardian

Abstract

Ethyl acetate solutions of crude and partially-purified seed extract (PPE) of Citrus reticulata were tested against Ostrinia furnacalis larvae. Feeding bioassays in choice and in no-choice tests were performed to determine the insect antifeedant and growth-inhibitory activity of the PPE. Third-instar larvae were fed with artificial diets treated with PPE at concentrations ranging from I to 20 mg/g of diet for 240 hours. The choice tests showed that feeding deterrence increases as the concentration of the PPE increases. with observed avoidance of PPE-treated diets. In the no-choice test, significant antifeedant activity was observed, with an EC50 value of 7.502 ± 1.096 mg/g. Growth inhibition index. with respect to change in larval weight after 10 days of treatment, was determined to have an EC50 value of 5.728 ± 1.285 mg/g. Larval durations of the treated O. furnacalis were also shown to be extended. Molting success of 0. fnrnacalis was scored, showing that the crude seed extract was effective in reducing pupal emergence. The 20-mg/g PPE exhibited greater frequencies of developmental abnormalities, including malformation of the wings, legs and antennae. Chromatographic analysis of PPE led to the isolation of two limonoids, whose structural features were studied using spectroscopic techniques. Based on the results, C. reticulata seed extracts and its bioactive limonoid components exhibit interesting potential for use in pest control programs.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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