Thursday, July 25, 2019
Discuss how an understanding of the biology of insect pests assists in Essay - 1
Discuss how an understanding of the biology of insect pests assists in the control of stored product pests - Essay Example Due to the heavy economic damage caused by these pests, it is important to identify the biological characteristics of these pests in order to formulate effective strategies of eliminating them in our premises. This paper discuses how understanding of the biology of insect pests assist in the control of stored products pests. Characteristics of insects Entomologists and biologists have researched on different characteristics of insects including those infesting stored products. Examples of insect pests that infest stored products include grain weevils, grain and flour beetles, spider beetles, flour moths, mites and psocids among others (Heikki et al 1996). According to Robinson et al (2007), insects exhibit distinct physical, reproductive, and behavioural characteristics that enable them survive and multiply in different habitats. The major defining characteristics of insects are three pairs of legs, three body regions including the head, thorax and abdomen. In addition, insectsââ¬â ¢ bodies are usually enclosed in an endoskeleton (Robinson et al 2007). Because they have jointed appendages, insects are classified under bigger animal group called arthropod (Robinson et al 2007). Many insects have wings for locomotion, and others use their legs to crawl on surfaces. Another defining characteristic of insects is that they develop from eggs. They go through different stages called metamorphosis after hatching until they become full-grown adults. Insects undergo complete or incomplete metamorphosis (Isaac, & Rami, 2009). Complete metamorphosis comprises of four stages, namely egg that hatches into larvae, then pupae and later an adult develops from the pupa stage. Incomplete metamorphosis comprises of three stages, namely egg, nymph and adult (Isaac, & Rami, 2009). Another defining characteristic of insects is that they breathe through spiracles that are located in the thoracic and abdominal cavity (Heikki, et al 1996). The body of insects is relatively small and i t varies in shape and colour depending on the particular species. In addition, insects have one pair of antennae that is used as sensory organ to detect smell, temperature, and other forms external stimuli (Robinson, et al 2007).Insets have different feeding habits and they have specialized mouthparts adapted to suit a particular feeding method. For instance, insects that suck blood from animals or sap from plants have long sharp proboscis. Others that feed on stored products such as grains have different mouth parts, such as mandibles and sharp tooth like structures to enable them feed on the particular stored food material (Isaac, & Rami, 2009). Methods of controlling stored product pests Entomologists have developed different methods of eradicating insect pests infesting stored products basing on their biological characteristics. However, Jack and Nancy (1999) note that no method is 100% effective and a combination of several techniques are applied. Some of the methods used to co ntrol insect pests include insecticides such as fumigants, biological control, sanitation, drying stored products, temperature regulation among other methods. Fumigants work by interfering with respiratory process of insects in large and medium sized storage premises (Jack, & Nancy, 1999). According to Heikki et al (1996), fumigants are volatile and toxic chemicals and they kill the pest by suffocating. Chemicals applied in fumigation are effective at killing insect pests in different stages of metamorphosis. Biological information about these pests is
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