Evaluation of the problem of household pests

Introduction

Insect pest and disease vectors are a major threats to increase in agricultural production and to the health and wellbeing of the human population who live in the tropical developing countries. Although most people understand what is generally implied when an organism is called pest, a universally accepted definition of the term has been difficult to achieve over the years (Gore & Schal, 2007)

According to Hockings (2014), pest is a species that because of its great numbers, behaviour or feeding habits is able to inflict substantial harm on man or his valued resources. Olufemi (2009) stated that a pest is any organism which causes any sort of damage to crops or animals advantages to man and significantly reduce the efficiency of any agricultural system.

Speiser (2012) defined pest as anything that causes annoyance, irritation and problem to man. From the above definitions, pest refers broadly or includes variety of bird’s specie, miles, trick, nematodes, ants, wasp, bees, locust, termites, plant and animal pathogens and parasite nuisance, wild animals, rat’s mice etc.

Olufemi (2005) stated that in Nigeria, agricultural pest destroy about 50% of crops annually especially grains, ornamental plants, fruit etc.

Conceptual framework

According to Speiser (2012), a pest is an unwanted plant or animal detrimental to humans or human concerns (as agriculture or livestock production), alternative meanings include organisms that cause nuisance and epidemic disease associated with high mortality (especially plaque). In its broadest sense, a pest is a competitor of humanity. A pest is any living organism which is invasive or prolific, detrimental, troublesome, noxious, and destructive, a nuisance to either plants or animals, human or human concerns, livestock, human structures, wild ecosystems etc.

It is a loosely defined term; often over lapping with the related terms vermin, weed, plant and animal parasites and pathogens. It is possible for an organism to be a pest in one setting but beneficial, domesticated or acceptable in another. Pest often occurs in high densities, making the damage they do even more detrimental. Often animals are decided as pests as they cause damage to agricultural by feeding on crops or parasailing livestock, such as codling mouth on apples, or both weevil on cotton. An animal could also be a pest when it causes damage to a wild ecosystem or carries germs within human habitats.

Examples of these include those organisms which vector human disease, such as rats and fleas which carry the plaque disease, mosquitoes which vector malaria, and tricks which carry lyme disease (Richard, 2009).

The term pest may be used to refer especially to harmful animals but is also often taken to mean all harmful organisms including weeds, plant pathogenic fungi and viruses. Pesticides are chemical and other agents (e.g. beneficial micro-organisms) that are used to control or protect other organisms from pests. The related term vermin has much overlap with pest but generally only includes those creatures that are seen to be vectors of diseases (Greenhill, 2011).

Factors that favour the breeding/infestation of pests (household pests)

According to Wike and Marelli (2012), pest infestation/ breeding depend on the manner in which man disposes off their refuge (waste) in the environment, store food in their homes etc.

These factors include the following:

• Poor environmental sanitation
• Indiscriminate dumping of refuge (waste) in the environment.
• Improper storage of food items in homes thereby creating feeding avenue for these pest and rodents.
• Planting of water bearing plants around homes which are agricultural and economic value.
• Presence of overgrown weeds in our environment.
• Indiscriminate defecation in and around premises.
• Inadequate provision/improper use of sanitary facilities.
• Presence of pot holes which accumulate water and water receptacle that retain water in our premises.
• Problems on how to control these pests as a result of light cost of chemical; and sprayers.
• Ignorance a side of individual whether these pest actually transmit disease or not.
• Improper or inadequate practices of personal hygiene
• Presence of dirty drains in premises.

Mode of disease transmission by pests

The modes of disease transmission include the following:

Mechanical transmission

Filth-inhabiting insects such as house flies, blow flies and cockroaches. ingest or pick pathogenic viruses, bacteria, protozoa and helminth eggs up on their bodies when feeding on faecal materials, decaying garbage or festering wounds. These pathogen can be transmitted to man when the insect defecate, vomit (regurgitate) when the insects perch on man’s food. Flies regurgitate materials that were previously eaten, particularly on solid or semi-solid foods to soften them, thereby contaminating them. Typhoid fever, cholera and dysentery may be transmitted by flies in this way. Also, the pathogen does not depend solely on vector for transmission because they could also be spread by am n directly through handling of food with contaminated hands or indirectly in infected water (Sherbini, 2011).

Biological transmission

In this mode of transmission, the pest (insects) harbour viruses, bacteria or parasite inside their body and thereby spread the disease by transmitting it through food to man and also through bit and only a small percentage of insect transmit diseases to man in this way. For instance, there are thousands of species of mosquitoes but only those female anopheles with the germ (plasmodium) transmit malaria (Gore & Schal, 2007).

Also, arthropods involves in this mode of transmission are majorly blood-sucking, they pick up the pathogen when feeding on a disease host and later infect a disease free host.

Furthermore, this mode of transmission is of four kind which are type 1, type 2, type 3, and type 4. In the type 1, which is the developmental transmission, the disease agent undergoes biological development in the vector but no multiplication. In type 2, which is the cyclo propagative transmission, the disease agent undergoes both cyclical development and multiplication. In the type 3, which is the propagative transmission, the disease agent under-goes no cyclical change but multiply in the vector. The pathogens multiply in a great number in the vector and then infect the salivary glands. In the type 4, which is the meta-propagative transmission, the parasite or pathogen not only multiple with their host (vector) but also have asexual reproduction cycle and also affect the salivary gland (Bruce & John, 2014).

Tran-stadia transmission

Disease transmission by pest (insect) at each stage of development picks up infection and transmit the infection at all stages. When it picks up the disease agent at the larvae stage, it can also transmit it at the larvae stage (Saunders, 2015).

Trans-ovarian transmission

This mode of transmission involves only one stage in the developmental process of the vector that transmit the disease it pick and after that stage passes, the disease will be carried to the next generation (Saunders, 2015).

Health problems and damages caused by pests

Insects and rodents are public health problem all over the world, especially in developing countries like Nigeria. For instance, cockroach, mosquito, rat, tick etc. are some of the major pests that cause health problems and damaged to man, and also they are attack one or more of the following by their feeding and other activities, such as; growing plants, stored materials, structural materials, such as wood (furniture), household materials such as clothing, animals and also transmit diseases to man. Like mosquitoes which transmit malaria, filariasis and yellow fever, tse-tse fly which transmit sleeping sickness, body lice which transmit typhus, trial-mine, bug which transmit Chaga’s disease, rat which transmit plaque etc. (Olufemi, 2009).

Table 1: Some major vector borne disease transmitted to man by pest

(Source: Olufemi, 2009).

Causes of disease transmitted by insect vectors malaria

Anopheles mosquitoes are vectors of malaria, a life threatening parasitic disease that kills more than a million persons, globally about 90% of this death occur in African, mostly among young children. It is African’s leading cause of under-five mortality, accounting for an estimated 20% of deaths in the age group. It is also responsible for 10% of the continent’s overall disease burden and accounts for 40% of public health expenditure, 80-35% of inpatient admission and about 50% of outpatient visits the hyper endemic area (Saunders, 2015).

American trypanosomiasis

In Central and South America about 10 million people are infected with a different form of trypanosomiasis causing chagas disease which is transmitted by large blood sucking reduvid (trial tomines) bugs. It is not basically a killing disease but causes chronic infection leading to incurable heart damage and sometimes death in people in their mid forties.

Problems with household pests

Household pests are those pests that attack man’s properties in the home for example cockroach which is the most common insect pest infestation in the home, food establishment and other structures. Cockroaches are repulsive and objectionable to most people simply by their presence. They are also capable of mechanically transmitting disease organisms such as bacteria which cause food poisoning. Recently, cockroaches have been found to be an important source of allergy in people, second only to house dust (Saunders, 2015).

Cockroaches prefer to live where there is food, warmth and moisture. Since cockroaches flourish where food and moisture are readily available, sanitation is an important step in prevention and control. Empty soft drink bottles, cardboard boxes and paper bags should not be allowed to accumulate. Food containers should be sealed and dry crumps or spillage cleaned up (Olufemi, 2009).

Table 2: Losses of major world crops due to insect and other pests

Source: Chairappa (2007).

Public health (economic) importance of pests

According to Olufemi (2009), economic and public health importance means those problems which are caused by pest and insects vectors. Therefore, the economic and public health importance of pest includes: destruction books, clothing, papers and food, in the process of eating anything, they may spread disease-organisms to man.

1. They help in the pollination of plants and flower.
2. Pest destroys wooden materials, e.g. boxes, furniture and timber of wooden houses.
3. They attack some crop plants e.g. rubbers trees, oil palm.
4. They help in the process of decay and recycling of nutrient by borrowing the soil and bringing dead matter into the soil.
5. Their borrowing also aerates the soil thereby increasing fertility.
6. Some pests serve as source of food in some places.
7. Their damages encourage infection by fungi.
8. They aid in the transmission of disease from one place to another.
9. They eat up the leaves of green vegetable.

Examples of pest that are of public and economic importance

1. Mosquitoes
2. Housefly
3. Cockroach
4. Rat
5. Bedbug
6. Termites
7. Ticks
8. Rattan
9. Army worms
10. Beetles
11. Weevils lice
12. Snipe
13. Grasshopper
14. Crickets
15. Centipedes
16. Scorpion

Pests control and management

According to Bruce and John (2014), pest management and control is the process or ways in which pest and the environment are manipulated to keep population below the level that will not cause economic lose or damage.

In view of the enormous damage/injuries and disease, which they cause to human possession and his animals, called for the need for pest control or management. The general principles of pest control are based on reducing the pest to a low level of the population so that the loss incurred is minimum.

To effectively control and manage pest, one need to be able to recognized the various types of pest, the nature of their damage and the likely time of attacks so as to effectively control or killed those not wanted or cause damage or diseases to human and his animals, while the useful ones like the bees, millipedes etc. are useful in agricultural production.

The need for pest management therefore includes:

1. To prevent nutritional diseases like marasmus kwashiorkor, due to low output of farm product.
2. To reduce waste substances generated by pest during the destruction period.
3. To prevent zoonotic diseases among farm animals such as rabies, anthrax.
4. To promote health
5. To reduce pest population
6. To make the environment safe for human population
7. To improve the economic standard and status of the economy.
8. To enhance agricultural product.
9. To increase the value of agricultural product.
10. To prevent the nuisances caused by the presence of the pest.
11. To prevent the destruction of household property by pest.
12. To prevent the transmission of disease in which pest act intermediate.

The methods of pests control/management

The various methods used in pest control include:

Biological method

This method is sometimes referred to as naturalistic control but there is little if anything natural about the approach, because exotic pathogens, parasite or predators have to be into the environment and control effectively.

Because of the growing concern over insecticidal contamination of the environment by powerful synthetic insecticide, the continuous appearance of insecticides, resistance in vectors, are more recently the rising cost of insecticides, increasing attention has been focused on biological control methods for example, predatory fish have been used for mosquito control since the easily 1990s.

Genetic control

This is the introduction of highly sterilized insect in large numbers to suppress the reproductive ability of the initial natural population. Research have shown that the successful eradication of the screw-worn fly (cochling khominivorax) from certain areas of the southern USA by repetitive release of sterile make man gave encouragement to the idea that genetic method could be used to control or eradicate disease vectors or insect vectors as mosquito vectors (Wike & Marrelli, 2012)

Environmental sanitation

This involved the elimination or destruction of breeding places including emptying of water receptacles, filling of depressions or lowlands, cleaning of over grown weeds, proper wastes and refuse disposal and protection of food and water sources (Wike & Marrelli, 2012)

Chemical control

This is the use of formulated insecticides (chemical) of different kind to destroy insect or vectors (Wike & Marrelli, 2012). The table below illustrates the various chemicals use in killing or destroying insects or vectors.

Table 3: Various chemicals use in killing insects or vectors

Source: Prince (2005).

References

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Environmental Health Watch (2011). Policy Guideline on pest and vector control.  Retrieved on 20^th August 2015 from http://lltsaftarmuhalli. blogspot.com/2011/12_Policy-guidelines –on – pest – and – vector. html.

Gore, J.C & Schal, C. (2007). Cockroach allergen biology and mitigation in the indoor  Environment. Annu Rev Entomol, 52, 459-63.

Green-Hall, A. M. (2011). Bats in Agriculture. Trinidad and Tobago: Ministry of Agriculture

Hockings, F. D. (2014). Pest, Diseases and Beneficials, Melbourne: CSIRO.

Olufemi, P. (2009). Introduction to Public Health Pest Management. Ibadan: Book Wright Nigeria.

Prince, L .A. (2005). Control of Malaria: Oiling as an Anti-mosquito Measure. Public Health Reports 30(9), 56-61.

Richard, D. (2009). Medical biology. New York: Mosby Elsevier

Sanders, G. (2015). Veterinary Dictionary. Philadelphia: Elsevier Health Service.

Sherbini, E. (2011). The Role of insects in mechanical transmission of Human Parasites. Iranian Red Crescent Medical Journal, 13(9), 678-679.

Speiser, B. (2012).Biological Properties of Molluscides. Luton: Prentice-Hall.

Wike, A.B. & Marrelli, M.T. (2012). Genetic control of Mosquitoes: Population Suppression Strategies. Rev. Inst Med Trip, S 5(5), 287-92.