Investigation Of Arthropod Predators And Insect Pest Control

Project and Seminar Material for Agricultural Science Students

Abstract

Insect pests are those insect species that are injurious or a nuisance. They cause injury or damage to crops in the field and grains in storage. Man and his domesticated animals are also attacked by insect pests. Arthropod predators belong to the phylum Arthropoda and are most times beneficial in the control of insect pests. Arthropod predators are members of the phylum Arthropoda which capture and feed on the prey. They are generally larger than their prey and kill or consume many prey during their life time. Examples of arthropod predators include the lady beetles, spiders, praying mantids, damsel bugs, lace wings, syrphid flies etc. They can feed on insect pests like aphids, moths, mites, butterflies, brown plant hoppers etc. These arthropod predators have been very effective in some cases of biological control programes of insect pests. Examples include the use of the cocinellid beetle, Radoliacardinalis (a lady bird beetle) to control the cottony-cushion scale, Iceryapurchasi(a scale insect) which was a citrus pest in carlifornia, U.S.A. also wolf spiders have been effectively used to control the rice pest (the brown plant hoppers) in Indonesia.

Chapter One

Introduction

1.1 Background of the study

Arthropod species occur from below the soil surface to the tree canopy. However, only a small fraction are observed on a frequent basis because many are microscopic or hidden below ground or plant tissue. Very few species are classified as pest. Whether they feed on plants or plant produce invade our homes, inflict painful bites or stings. Infect most insects and other arthropods are beneficial and serve a variety of important functions in the garden. The abundance of beneficial insects especially predators is often limited in urban landscapes because these environments typically are characterized by disturbance. Disturbance factors include use of pesticides and other chemicals, air pollution and wind-borne dust, all of which may increase mortality of beneficial arthropods. Residential landscapes often lack adequate amounts of essential resources such as food, nesting sites and shelter than enhance reproduction and survival of natural enemies. Some common strategies are employed to conserve them in residential landscapes and these strategies may help reduce insecticide use and improve plant health by enhancing natural control of arthropod pests.

Because many arthropod pests are exotic the aim of classical biological control is to reduce pest numbers by reuniting old enemies through importation of predators from the area of insect pest origin. Lady beetles, green lace wings and spiders are familiar examples of predator arthropods inhibiting residential landscapes and gardens. In general, predators are larger than their prey, consume many prey items during their life time and feed on a broad range of species immature and/or adults may be predatory and often do not leave behind any evidence of attack.
However, these arthropod predators often help to keep aphids, spider mites, caterpillars and other insect pests under control.

This study discusses on what pest are, and why insect become pest, types of damage caused by insect to agricultural plant. Pest status and economic decision level will be discussed. General methods of insect pest control including biological, legislative, cultural, physical and mechanical, use of host plant resistance, use of plant botanical and the use of chemical insecticide will be discussed. Chemical insecticidal classification based on chemical composition of the insecticide and the mode of action will be discussed.

1.2 Aim of the study

The main aim of this study is to discuss control measures that may be performed as part of an integrated pest management strategy. The study also focused on insect pest affecting cowpea.

1.3 Objective of the study

The objectives of this study are to:

Introduce students to pest and how insects pest are control.
Educate the students on the ranking of a pest relative to damage to specific crop
Enlighten students on the level of insect population at which control measure should be instigated. Educate them on the general methods of insect pest control

1.4 Outcome of the study

Upon successful completion of this course, the student will be able to:

Define a pest; describe how insects become pest of major agricultural crops; indicate the course of action to be taken in any given pest situation; guide against indiscriminate use of pesticide (chemical insecticides)

1.5 Importance of the study

Pest control is made up of all the methods and practices of keeping pests away. Its application goes beyond what we usually know of it in homes. It is used in agriculture and in other vital industries.

Beyond its use in homes, pest management is very important for us for a number of reasons. Here are some of those reasons:

One of the most important reasons why pest control is needed is because of health. Pests can bring diseases that can be quite serious. One of the most serious epidemics, the bubonic plague which caused millions of death in the World in Medieval times came from rats and other rodent pests. Cockroaches and other pests can also carry germs into their body. That should be your main concern when it comes to having pests in your home.

Pests can have an impact on production and resources. This is the main reason why pest control is vital to in agriculture and other industries. Sometimes pests can be such a huge problem that they will seriously affect the production of one industry. They can wipe out production and bring it down to zero if they are not controlled.
Aside from the damage that they can do to resources and production, they can also cause some serious damage to existing structure and things. Sometimes the damage can be so severe that a whole structure would be rendered useless because of it, like in cases where termites have eaten away at a wooden structure.

Then there is also the fact that pest control is needed in order to keep appearances. Whether it is a home or an office, having pests running around is never going to be a good thing. It would have to be taken care of.

1.6 Problem of the study

Several problems associated with insect pest control are as below:

Resistance:

Resistances to pesticide treatments were first noticed in flies, mosquitoes and later in cockroaches. Due to genetic variation, certain pests may not be affected by a pesticide. A pesticide will kill most of the susceptible pests, leaving those most resistant to the pesticide to dominate reproduction. This process of genetic selection now leaves pest populations of over 800 species resistant to one or more pesticides.

Resurgence:

Because pesticides may kill off the natural enemies of a pest, the pest population may rebound in numbers greater than before the application. A further complication with the resistance problem is insect predators and parasites which prey on the pests are less likely to develop resistance to the pesticides used, reducing their ability keep the pest population in check.

Secondary Pest Outbreak:

Pesticides may kill off not only the natural enemies of the pest concerned, but those of other pests as well, resulting in problems with pest species that were previously irrelevant.

Residues:

Because pesticides are difficult to confine to the target, residues may be left in the environment. These may cause damage directly to wildlife and to man by occupational exposure, or indirectly through biomagnification of pesticide concentrations in the food chain. Synergism, where mixed compounds cause a magnified effect greater than the individual compound effects added together, is also a problem brought about by residues, mixing with other environmental factors to increase toxic effects.

Chapter Four

4.0 Effectiveness Of Arthropod Predators In The Control Of Insect Pests

4.1 Introduction

Arthropod predators have been very effective in some cases of biological control programs. Examples where this has been achieved include:

In 1980, the coccinellidbettle, Rodoliacardinalis, a ladybird bettle was successfully used to control a cottony cushion scale ,Icaryapurchasi in a citrus pest. The predators was imported from Australia [the native country] into the USA [California].

In 1988, the spider wolf were successfully used to control the rice pest, the brown plant hopper in Indonesia
Also a small wasp, Trichogrammaostrinia was introduced from china to help control the European corn borer,ostrinia nubilalis.one of the most destructive insect in North America.

4.2 Conclusion

Generally insect pest indirectly lower agricultural output by disabling farmer and labourers due to their damage on harvested food crops and these insect pests have so many effect such that they are annoying or a nuisance which can threaten the welfare of useful plant

Insect predators can be found in almost all agricultural and natural habitats. However arthropod predators are important in keeping insect pests in check and helps to control the population of these pests.