Assessment of the parasitism rate of the coconut scale insect, Aspidiotus destructor (Signoret) and A. rigidus (Reyne) (Hemiptera: Diaspididae) during an outbreak

Date

7-2022

Degree

Bachelor of Science in Agriculture

Major Course

Major in Entomology

College

College of Agriculture and Food Science (CAFS)

Adviser/Committee Chair

Celia D.R. Medina

Request Access

To request access of this material, please email the administrator at uscs-mainlib.uplb@up.edu.ph

Abstract

Insect population outbreaks are often explained by the failure or absence of natural control. Natural control constitutes biotic and abiotic elements that regulate the number of a species within the general equilibrium point. Parasitism is one such biotic element of natural control. This study investigated the role of parasitism in the local outbreaks of the coconut scale insects (CSI), Aspidiotus rigidus (Reyne) in Basilan (2015), Zamboanga City (2016) and Guinobatan, Albay (2016) and A destructor (Signoret) in Legazpi, Albay. Survey data of sample leaflets were reexamined to determine the parasitism rate and other population parameters like abundance, age structure and percent mortality. The results showed that the level of parasitism was very low (Rnage: 0.01 to 2.9%) in all outbreak cases. The populations of CSI however were compost mostly of immature stages indicating the availability of the suitable hosts. A comparison of the level of mortality and parasitism showed that they were not correlated. These findings suggest that parasitism was not a significant factor in the regulation of the CSI populations during an outbreak. The expected density effect on the % parasitism was not observed. It even declined over time as observed in the Zamboanga City case. There must be abiotic factors in the environment that favored the CSI reproduction but detrimental to the parasitoids.

Language

English

LC Subject

Coconut palm -- Diseases and pests, Aspidiotus, Parasitoids, Agriculture, Entomology Institute of Weed Science, Entomology and Plant Pathology Entomology 200

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2022 A3 A23

Document Type

Thesis

This document is currently not available here.

Share

COinS