Cumulative oxygen consumption during development of two postharvest insect pests: Callosobruchus maculatus Fabricius and Plodia interpunctella Hübner

Hannah E Quellhorst,Scott B Williams,Larry L Murdock,Dieudonne Baributsa

doi:10.1016/j.jspr.2018.03.006

Hannah E Quellhorst, Scott B Williams + Show 2 more

Open Access

https://doi.org/10.1016/j.jspr.2018.03.006

Copy DOI

Abstract

Insect pests such as Callosobruchus maculatus Fabricius and Plodia interpunctella Hübner cause substantial losses to grain during postharvest storage. In the last few years, hermetic storage technologies have been successfully used by smallholder farmers in Africa and Asia to protect their harvested grain against insect pests. Hermetic technologies owe much of their effectiveness to restricting oxygen availability to insects confined in the containers. There is a need to better understand the biology of specific storage insect pests and their responses to hypoxia. We employed a novel and non-invasive analytical technology, the OxySense 5250i, to measure oxygen levels in closed containers, and evaluated its effectiveness in measuring the total oxygen consumption of two insect pests during their development: C. maculatus and P. interpunctella. The total amount of oxygen consumed by C. maculatus during its larval development period determined with the OxySense apparatus was not different from that previously recorded using another instrument, the Mocon Pac Check 325 gas analyzer. Using the OxySense 5250i, we found that P. interpunctella consumes nearly three times as much oxygen per insect over its larval-to-adult developmental period compared to C. maculatus. Information on the lifetime oxygen consumption of insects provides relevant information to the effectiveness and ability of hermetic technologies to protect stored products against insect pests.

Highlights

Cereal grains and legumes comprise the majority of the staple subsistence crops of African farmers, accounting for 60e80% of the caloric intake (Awika, 2011)
The average cumulative oxygen consumption obtained by the Oxysense instrument for C. maculatus was 8.3 ml per insect
The maximum rate of oxygen consumption for C. maculatus over a period of 8 days was 0.8 ml/ day, while P. interpunctella had a maximum rate of oxygen consumption of 1.4 ml/day over a period of 18 days (Fig. 1 & Table 1)

Summary

Introduction

Cereal grains and legumes comprise the majority of the staple subsistence crops of African farmers, accounting for 60e80% of the caloric intake (Awika, 2011). In West Africa, these staple food crops are produced by smallholder farmers who intercrop cereals with legumes such as cowpea with sorghum or millet (Singh et al, 1997). Major postharvest insect pests such as Callosobruchus maculatus Fabricius and Plodia interpunctella Huebner damage stored food crops by feeding on the grain. This reduces the edible mass, and damages the endosperm or seed germ, resulting in a loss of grain quality and seed viability (Malek and Parveen, 1989; Santos et al, 1990). Insect pests contribute to secondary bacterial and fungal infestations (Sallam, 1999)

Objectives

Methods

Results

Conclusion