Date of Publication

8-2019

Document Type

Master's Thesis

Degree Name

Master of Science in Chemistry

Subject Categories

Chemistry

College

College of Science

Department/Unit

Chemistry

Thesis Adviser

Gerardo C. Janairo
Jose Isagani B. Janairo

Defense Panel Chair

Raymond S. malabed

Defense Panel Member

Roger S. Tan
Allan Patrick Macabeo

Abstract/Summary

Cacao is a globally important crop from which chocolates are produced fro. Cacao only grows in the equatorial region and the Philippines is among the few countries which can cultivate it. However, the local cacao production is threated by insect infestations which can significantly decrease the yiled and quality of cacao pods. The insect Helopeltis bakeri Poppius (Hemiptera: Miridae) or commonly called as cacao mirdi bug (CMB) is one of the major insect pests of cacao, together with the cacao pod borer (Canopomorpha cramella). The CMB feeds on the cacao pods resulting to damage in the pods rendering them unusable. Thus, effective but environment friendly measures are needed in order to control and manage the infestation caused by the CMB. This alternative pest control strategy is called integrated pest management (IPM). One technique in IPM is the use of semiochemicals where natural chemical signals are used to confuse and disorient the pest. In this study, identification of the semiochemicals that attracts the CMB for feeding and mating are determined by headspace analysis using solid phase microextraction (SPME) coupled with gas-chromatography-mass spectroscopy (GC-MS). From the volatile profiles, common terpene compounds were determined. Olfactometry analysis using lab reared CMBs elicits a positive response towards the compound caryopphyllene. The suspected sex pheromone, alpha-pinene, was detected in the abdomen of a 96 hours old female virgin and bioassay results exhibit signs of attraction of the male virgin mirid bug. Data gathered from this study may help convince farmers to transition from old farming methods to a more sustainable cacao farming practices such as IPM.

Abstract Format

html

Language

English

Format

Print

Accession Number

TG07379

Keywords

Semiochemicals; Miridae—Control; Hemiptera—Control; Cacao—Diseases and pests—Control—Philippines

Upload Full Text

wf_yes

Embargo Period

9-6-2022

Download

Share

COinS