CHAPTER ONE

1.0 INTRODUCTION

1.1 Background Information

Coffee is one of the world’s most popular drinks and the most traded commodity in terms of

monetary value after oil and an important primary export for many developing countries. Coffee

has two main species that are economically exploited worldwide, Coffea arabica Linnaeus and

Coffea canephora Pierre. The coffee plant C. arabica L. is the most widely cultivated species. It

is an evergreen, multiple stemmed shrubs of about 8 to 10 metres tall, that bears small green

berries that mature into deep red cherry. The cherry is harvested by hand picking and is

processed either by wet or dry method. The wet method gives bean parchment where dry method

gives Mbuni beans. The effect of the beverage is largely derived from the alkaloid caffeine after

the beans are cured, roasted and finely ground to bring out the characteristic coffee aroma.

Coffee thrives well within the confines of the tropics, 23.5° latitude north and south of the

equator that provide a forest environment where coffee become a secondary canopy. The

environment have a well distributed rainfall (l,200 to 1,500 mm/year), a 12 hour photoperiod,

and temperature ranges of 17° to 25°C that favour coffee growth. Though native to East Africa,

coffee production has found a solid base in the New World (the Western Hemisphere), where

Brazil, Colombia, Mexico, and the Central American countries account for 59 % of global

exports (Arabica and Robusta combined).

Coffee is Kenya’s most important crop, cultivated by two distinct sectors, namely small-scale

producers and the plantations (estates). The crop is grown by about 700,000 farmers who belong

to about 2,000 co-operative societies and 2,000 medium farmers’ category and about 200

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planters. Kenya produces about 1% of the global Arabica coffee that account for 2% of global

exports value (Anon, 2003; Kegole, 2005) and was ranked position 21st largest producer of

coffee in the world with an annual production of 50,000 metric tones. It is grown in

approximately 158,000 hectares (Anon, 1992) and it is believed that six million Kenyans are

employed directly or indirectly in the coffee industry and is the fourth foreign exchange earner

accounting for approximately 5% of all exports (Karanja and Nyoro, 2002).

Coffee growing has been often affected by the world market demand, diseases, pests and

unreliable climatic regimes. The global coffee market is currently plagued by two paradoxes, a

coffee boom in consuming countries and a coffee crisis in producing countries. The paradoxes

refer to an oversupply of low quality coffee coupled with a shortage of high quality coffee that

actually drives the global coffee market (Daviron and Ponte, 2005).

The downward trend in coffee prices is expected to continue in the near future, this may be due

to the increased production of Brazil, Vietnam and Colombia. The farmers are, therefore, looking

for viable economic alternatives to relying solely on the production of coffee. The incorporation

of shade tree species that offer direct economic benefits into coffee plantations is considered to

be a promising option for farmers. It has been shown that timber and fruit production from shade

trees used in coffee plantations can contribute significant income that may equal or exceed that

of coffee when coffee prices are low (Albertin R.A, 2002).

Antestia bugs (Antestiopsis sp) are shield shaped, dark-brown, white and yellow in colour.

Antestiopsis spp. is among one of the most important pests of Arabica coffee in Kenya. It is

highly sensitive to temperatures and humidity changes within the environment and likely to be

affected by global warming and climatic changes. The bugs affect the coffee beans by

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introducing fungi (Nematospora gossypii) into the beans during feeding, resulting to rotting.

Antestia bugs are known to dwell in dense foliage, are mobile, moving in and out of shade. The

Antestia affect coffee by reducing the quantity and also down grading the quality at the cup

stage, resulting to poor coffee grades that are not competitive in the market.

1.2 Coffee and the shade environment

Traditionally coffee has been grown under shade trees. Shade improves the climate for coffee

plants by buffering temperature extremes in the air and soil and also reduces the wind velocity

within coffee plantations. The shade affects different environmental requirements necessary for

successful colonization and reproduction in insect pests. Shading produces a micro-climate that

enhances or impend pest’s infestations. The incidence of coffee leaf miner (Leucoptera merycki)

was reduced by shade and increased damage from coffee berry borer (Hypothenemus hampei

Ferrari) has been recorded in coffee plantations under shade (Acland, 1971).

The introduction of shade in coffee plantations has become a proven strategy in alleviating the

negative effects of the changing climate and global warming, especially warmer temperatures

and is likely to affect pest populations in coffee.

1.3 The coffee insect pest problem and management approaches

There are about 850 insect species affecting coffee globally, where 36 species affect coffee in

Kenya and are classified as either major or minor pest of coffee (Rene’coste, 1992). The pests

include coffee leaf miner (Leucoptera spp), Antestia bugs (Antestiopsis spp), stem borer (white

and yellow headed borer) and the coffee scales (Coccus spp) among the major insect pests.

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Insect pest are affected by the shade differently; some favour shade and while others are

negatively affected. Agronomical cultural practices that include pruning, mulching, irrigation

and weeding may either promote or negatively affect the pest’s problem.

Farmers have taken a lot of time and attention in the control of the insect pests with huge

expenditures being incurred. Though modern insecticides can give effective control in most

areas, unremitting attention must be given to the coffee, to ensure timely measures if severe loss

is to be avoided. Available methods of control include cultural, chemical, biological and

integrated pest management (IPM).

Cultural practices involve the opening up of the coffee bushes by pruning, chemical (insecticide)

control is by insecticides applications, where biological control is by natural enemies associated

with the specific pests, and integrated pest management (IPM) approach involve the harmonious

co-operation of all the control approaches into one single system.

Although insecticide applications are supposed to be carried-out after the economic threshold

levels are established this has not been followed and the practice has been mixing insecticides

with fungicides, a practice that has greatly affected the natural enemies. An insecticides

application is done in a selective and timely manner in order to kill the target pests and conserve

the natural enemies. The integrated pest management (IPM) approach is the recommended mode

of insect pest management, where insecticides use is reduced and the activity of natural enemies

is encouraged with a close monitoring of the pest populations (Anon, 2009). Biological control is

based on mass rearing and release of parasitoids.

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1.4 The Antestia problem

Antestia bugs are serious direct pests of coffee that are indigenous to East Africa. They are the

most destructive pests of Arabica coffee, and are found throughout Africa (Greathead, 1966).

Antestia bugs are known to dwell in dense foliage, mobile and important pest affecting coffee

causing the blackening of flower buds, fall of immature berries, rotting and zebra stripping of

coffee parchment (coffee beans in husks). The Antestia bugs affect the coffee beans by

introducing fungi (Nematospora gossypii) into the beans during feeding in immature beans

resulting to rotten beans (posho beans) where mature beans form zebra stripes in parchment. In

the absence of the berries, the bug may feed on the tips of coffee branches stimulating

development of multiple shoots and may also attack flower buds resulting to failure in fruiting.

Damaged beans are of lower a grade which translates to reduced earnings. Two (2) Antestia bugs

per coffee tree can cause 24% loss in bean weight, where 2-8 bugs can cause 7-35% berry drop

(Wanjala, 1980). The pest has a low economic threshold level of 1 and 2 bugs per tree in the east

and west of the rift valley respectively (Anon, 2009).

1.5 Problem Statement

Coffee thrives well within an environment that has a well distributed rainfall, enough light and

warm temperatures. Shade trees have been found to offer direct economic benefits into coffee

plantations and are considered to be a promising option for farmers. Coffee is now being

cultivated under shade cover and although it effects have been extensively researched very little

have been conducted on its effects to Antestias bugs in coffee in Kenya.

It is believed that the microclimate provided by the shade have an effect on both pests and their

predators. Due to the low economic threshold levels of the Antestia bugs in coffee, chemical

5

control has become a very sensitive area because of its effects on the environment. The use of

insecticides even on low populations has caused unnecessary worries resulting to the market not

favouring coffee from such farms.

The certification of coffee as a specialty (organic or shade grown) have brought about another

dimension in the coffee market due to the campaign by Ecological conservist’s, through climatic

change and global warming debates, trying to establish the positive and the negative effects of

shade. With the conservation of the forests and reduced use of pesticides the growing coffee in

the shade may boost the biodiversity where pest population will be reduced and their natural

enemies.

1.6 Justification

It is a reality now that the climate that once favoured our delightful coffee cup has turned against

it. The green house gas (GHG) emission as a result of ignorant human activities has contributed

to an unfavorable survival climate for the coffee trees. The smallholders, who produce the

majority of the world’s coffee, will be the most vulnerable group as they have limited resources.

Rising temperatures are expected to make certain coffee producing areas less suitable or

completely unsuitable for coffee growing. This means production may have to shift and

alternative crops will have to be identified for such areas. More coffee will need to be grown

under irrigation, and this will burden the already scarce water resources and increased production

cost. The incidences of insect and diseases are anticipated to increase and coffee quality is likely

to suffer. Pest and diseases may limit the viability of the current high quality coffee producers.

The effects of climatic changes have brought about change, where areas known to be high in

coffee production have lost their position making them loose on their economic viability. Areas

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that have cold temperatures and high rainfall were earlier thought not to be favorable for coffee

farming has become good producers. This means that coffee production will shift from low

altitude areas (drier) to higher altitude area (wetter) due the global warming effects. To mitigate

these negative effects, coffee shading will be the way to go, where coffee is protected from the

negative effects of global warming and climatic change at both low and high temperature

extremes. At low altitude the high day temperatures are brought down and at high altitude the

low night temperatures are moderated by the shade. In total the shade shelters the coffee from the

negative effects of climatic changes (temperature extremes).

With raising temperatures as a result of the global warming, flower setting which is generally

triggered by rainfall after a period of drought is adversely affected reducing on yield while coffee

berries grow and ripen more quickly leading to fall in inherent quality and low income that may

not support the farming. High temperature has also lead to faster rate of proliferation of Antestias

bugs and other pests and diseases even to areas where they were not previously recorded. The

control of these diseases and pests makes coffee farming more complicated and expensive.

Although coffees grown in the sun have a higher production, it has both high cost of inputs and

low quality with high pest and disease incidences. Coffee grown under the shade has a moderate

production with low production costs and high quality beans and less pest and disease incidences

and is sustainable. During the period of low prices farmers either abandon the crop or earn very

little proceeds from the activity and thus a negative attitude towards the crop has been conceived.

Shade trees modify the environment (micro-climate) affect the pests and diseases and provide a

habitat for natural enemies. Interest in shade-grown coffee is now increasing because of the

declining coffee prices in the world market and an increasing trend towards ‘green

consumerism’. A platform for specialty coffee, ‘shade grown or organic coffee’ came in

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promising premium prices for coffee with a ‘specialty label’ (Staver et. al, 2001). The urge to

improve on the coffee quality has been paramount, driven by the market requirements and the

premium prices.

Antestia bugs are major pests of coffee feeding primarily on berries, resulting to a reduction in

both quantity and quality of the beans. Antestia bugs are known to dwell in dense foliage

moving in and out of the shade, to warm up or to cool down. During the night they are found

under the shade to avoid the low temperatures and during the day they bask in the sun although

they later hide in dense foliage (Kirkpatrick, 1935 and 1937).

This study is directed towards giving an insight on the effect of the shade on the pest

(Antestiopsis sp) population’s dynamics. The study intends to provide a useful basis for decision

making in response to the shade practice in coffee which has become an invertible alternative in

organic coffee production. The knowledge acquired will be important to both the farmer and the

researcher by giving an understanding on the effect of shade on the Antestia bugs population

dynamics.

1.7 Research Objective

1.7.1 General objective:

To study the population dynamics of Antestias bugs (Antestiopsis sp) on coffee grown under

the shade and in the un-shaded environment

1.7.2 Specific objectives:

I. To determine the population dynamics of Antestia bugs (Antestiopsis sp) under shaded

and unshaded coffee.

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II. To establish whether shade or unshaded coffee had effect on the mean number of

Antestia bugs.

1.8 Research hypothesis,

Ho Shade is not a deterrent to Antestiopsis sp habitation.

H1 Antestiopsis sp are sun lovers

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CHAPTER TWO

2.0 LITERATURE REVIEW

2.1 Taxonomy, Ecology and Biochemistry

Coffee is a small understory tree that originated from East and Central Africa. It belongs to

Kingdom Plantae, sub-kingdom Angiospermae, class Dicotyledoneae, sub-class Sympetalae, or

Metachlamydae, order Rubiales, family Rubiaceae, genus Coffea that consists of about 90

species, all of which are endemic to tropical Africa and Mascerenes (Mabberly, 1997). The

coffee plant is a woody perennial evergreen dicotyledonous plant of relatively large height. It has

a main vertical trunk (orthotropic) and primary, secondary, and tertiary horizontal branches

(plagiotropic).

Plate 1: Typical Arabica coffee (K7 variety) bush with ripe red cherry ready for picking,

(Kasinga Coffee Society, Machakos, Kenya).

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It has two main cultivated species, Coffea arabica, (Arabica), accounting for 75-80 percent and

Coffea canephora, (Robusta) that accounts for about 20 percent of the world's coffee production.

Both plants can grow to heights of about 10 meters if not pruned, but are maintained at a

reasonable height for easy harvesting (Anon, 2012).

Traditionally, coffee has been cultivated under a shade cover but the development of new sun-

tolerant, high yielding coffee varieties during the 1950’s and 1960’s led to the conversion of

many traditional shaded systems to un-shaded ones. Negative effects associated with such

modernized cultivations have come to light over the past two decades. These include increased

soil erosion, loss of biodiversity, and high environmental and economic costs resulting from the

heavy use of fertilizers and pesticides (Muschler, 2000).

Coffee production occurs within the confines of the tropics, 23.5° latitude north and south of the

equator. C. arabica is mountain-loving shrub and does best in the temperate climatic regimes

associated with high tropical altitudes. Most coffee zones have temperature ranges from 17° to

25°C. The minimum rainfall for a profitable crop production is 1,200 to 1,500 millimeters per

year and is grown at all altitudes 1100m to 2200m above the sea level (Le Pelley, 1968).

Shade trees reduce the surface leaf temperatures by 5 - 6°C lower than those under the full sun

(Kirkpatrick, 1935) and also reduce the evapotranspiration of the crop, decreasing plant stress

(Beer, 1987). The shade situation provide an array of what ecologists call ecological services, the

foliage cover intercepts heavy tropical rainfall, lessening its impact upon the soil, the leaf litter

generated by the canopy provides a mulch layer that further helps to protect the soil, and

gradually decomposes into the soil, recycling the nutrients contained in the leaves and other

debris. Shade trees with deep roots draw nutrients from lower soil layers into the system; a

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diverse mix of plant species creates a relatively stable ecological system with little need for

chemical inputs such as synthetic fertilizers or pesticides. Shade reduces photosynthesis,

transpiration, metabolism and growth and therefore, the demand on soil nutrients and so enables

a crop to be obtained on soils of lower fertility. The shade trees provide habitats for natural

enemies of pests and wild life, and prevent soil erosion. It is estimated that a shade intensity of

about 40-50% gives optimum crop yields, discourage weeds growth, reduce pathogens infection,

offer protection from frost and increased population of pollinators resulting to better fruit set

(Craig; et al, 2009). Coffees grown under shade take long to ripen, resulting to highly improved

taste.

The negative effects of shade may include potential increase of some diseases and pests (e.g.

coffee berry borer), progressively lower yields with increasing shade intensity (due to a reduction

in flowering nodes; inflorescences per node and flowers per inflorescence). In addition,

competition for water between shade and coffee trees in seasonally dry regions; damage of the

coffee trees by falling branches from the shade trees and occasional tree felling and additional

labour costs for regularly pruning of over-head trees to avoid excessive shading (Beer, 1987;

Beer et al., 1998; Guyot et al., 1996; Muschler, 2001).

The idea of growing coffee under shade is a concept brought about to reclaim and re-install the

lost ‘hot spots’ of biological diversity, coffee growing was initially under forest cover and with

the knowledge that 95% of present day terrestrial ecosystems are managed ones, shade coffee is

now recognized as a human-manipulated land use type that maintains biodiversity. Shade coffee

can obviously play a role in both agricultural and environmental policy. In many countries where

forest cover has been removed at astounding rates in recent years, the agro-forestry

characteristics of shade coffee land represents some of the little remaining forest cover, for bird

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diversity. Shade coffee is only rivaled by natural forests with other organisms such as

arthropods; with an individual diversity level same as that of undisturbed tropical forest (Rice,

1996).

2.2 Growing Coffee in Shade and Pest Management

In the recent past, growing coffee under shade has gained momentum with coffee certification

being based on the aspects of wildlife friendly farming. It has therefore been realized that

growing coffee under shade trees offer an alternative to deforestation, and is regarded as an

important check against green house gas (GHG) emissions that contribute to global warming

(Miguel, et. al, 1995). Among the transferred land, shade grown coffee supports the highest

diversity of migratory birds (Perfecto et .al, 1996; Greenberg et. al, 1997). Farming coffee under

shade has been found to be more profitable and the effects of both pests and diseases are reduced

by the micro climate created by the shade (Le Pelley, 1968). It’s commonly thought that diverse

agro-ecosystems are less prone to pest out breaks because they support a high diversity of natural

enemies (Perfecto, et al, 2004).

Following the decline in world coffee prices and an increase in “green consumerism,” the role of

shade trees in coffee production have received renewed attention. Becoming certified under a

specialty coffee labels, such as “Shade-Grown” or “Organic” has become a promising option for

the farmers as coffee with this label could be sold at a premium price. In a low-elevation dry

coffee zone, the use of 35 to 65% shade promoted leaf retention in coffee plants during the dry

season (Staver, et.al, 2001) and reduced the incidences of disease-causing fungi such as

Cercospora coffeicola without reducing yields or increasing the incidence of coffee leaf rust

disease, Hemileia vastatrix (Kucel, et. al, 2006).

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Several studies have been conducted on the financial benefits of timber trees, particularly Cordia

alliadora, in shaded systems (Beer et. al, 1998) and in all cases, it was found to be an

economically viable practice, particularly where market prices for coffee were low (Annon,

2004). Other shade trees in coffee include Albizia gumifera, Grevilllea robusta, Ficus thaunngii,

Prunus africana, Cordia sp, Acacia abyssinia (Chege, 2011).

Illustration: 1 a) Shade-grown coffee plantation with multi-level canopy and under-story

b) Non-shade coffee monoculture with single level tree height (Perfecto and Snelling, 2001)

2.3 The Antestia Bug and Its Life History

The adult bug is shield shaped, dark-brown, white and yellow in colour. Antestia is the adapted

common name with Antestiopsis sp as the genus name. Antestia bugs are also referred to as

‘shield bugs’. Antestia belong to order Hemiptera and family Pentatomidae, with a species

complex that includes; A. orbitalis orbitalis, Westw; A. orbitalis bechuana, Kirk; A.orbitalis

intricata, Ghesquire and Carayon; A. Facetoides, Greathead. Of these, A. o. intricata were found

in West and Central Africa, and A.o. orbitalis were found in East and Southern Africa where

they are one of most important pests of coffee (Greathead, 1966).

The female lays eggs that are white, barrel-shaped and in batches of 12 on the leaves’ underside.

They hatch in about 10 days into small nymphs which metamorphosis into adults in 3-4 months.

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The adult, depending on the species, measures between 7 – 9 mm in length. The female is larger

than the male. The Antestia bug favors dense foliage and is found on un-pruned, poorly managed

trees (Le Pelley 1968).

Illustration 2: An Enlarged Antestia bug, adult (Antestiopsis sp)

2.4 Economic Losses Caused by Antestia Bugs

The first signs of attack are damage to the immature berries and young branches or sight of the

both the nymphs and adult bugs. The pest mostly feed on immature green berries from which

they suck the sap, causing the fruits to shrink and fall. The bug may transmit a fungal disease,

which infects developing beans and turns them into a white powdery mass. The damaged

immature beans rot (posho beans) where mature beans form zebra stripes in parchment (Smee,

1931). In the absence of the berries, the bug may feed on the tips of coffee branches, stimulating

development of multiple shoots, which deplete the plant’s resources and bear no fruits causing

increased cost during pruning (Le Pelly, 1942). It may also attack flower buds resulting to

turning black and failure in set fruit. Wanjala (1979) recorded a loss of 15-27% in total beans

weight associated to 2-4 Antestia bugs per tree. Antestia bugs have low economic thresholds of

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1-2 Antestia bugs per tree that calls for an intervention with an insecticide (Odour and Simons,

2003).

2.5 Control of Antestia Bugs (Antestiopsis sp)

In the control of Antestia bugs a quantitative assessment of the pest density is essential (Melville,

1949). This has lead to the establishment of an economic threshold level of one bug per tree in

the West of Rift Valley (wetter areas) and two bugs per tree in the East of the Rift Valley (drier

areas) in Kenya (Anon, 2009). It is important to have a keen observation when the crop is in the

larger green berry stage as this is the most favoured stage of infestation. During this time

fecundity is high and the breeding season is in synchrony with the coffee berry development

(Anon, 1989).

Before any chemical application is carried-out an economic threshold level is established and

where the Antestia population exceeds 1-2 Antestia bug per tree a chemical control is applied in

a selective and timely manner in order to kill the target pests and conserve the natural enemies

(Rennison, 1962). The integrated pest management (IPM) approach is the recommended mode,

where insecticides use is reduced and the activity of natural enemies is encouraged (Anon, 2009).

Biological control which is a component of IPM and is based on mass rearing and release of

Antestia egg parasitoids has been reared and distributed in all coffee growing areas of Kenya

(Mugo; et al, 2000). About 20 parasitic wasps has been recorded attack the Antestiopsis sp in

East and Central Africa. Telenomus (Asolcus) seychellensis is the important egg-parasitoids

attacking the Antestiopsis sp at egg stage (Anon., 2009).

Chemical application is the main method of control with IPM as the recommended approach.

Culturally small infestations of the Antestia bugs can be controlled by hand-picked and pruning

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of the dense foliage is often recommended. In the long run, both natural and synthetic pyrethrum

insecticides have proven ineffective in many cases. The bugs have typically been controlled with

multiple applications of pesticides, usually Fentrothion, Chlorphrifos, Malathion, Trichlorfon,

and Diflubenzuron. Indiscriminate use of pesticides have had an undesirable effect on the

environment and non target organisms for instance the natural enemies which would have

otherwise kept pest populations in check. Uses of selective insecticides allow natural enemies to

thrive thus reducing the amount of insecticides used. Biological control of Antestia bugs in

coffee has been possible by the effects of Antestia egg parasitoids which are very effective in

searching and parasitizing the eggs. The combined effects of insecticides applications, physical

control, cultural control, and biological control have not effectively been able to manage this

important coffee pest and the search for a more sustainable program has continued.

2.6 Biological control of Antestia bugs (Antestiopsis sp)

Antestia bugs, (Antestiopsis sp) have natural enemies in all its developmental stages. Eggs are

damaged by a number of egg-parasitoids that includes Telenomus (Asolcus) seychellensis Dodd,

T. mopsus Nixon, T. suranus Nixon, Hadronotus antestiae Dodd, (Hymenoptera:Scelioniidae);

Anastatus antestiae Ferrière, (Hymenoptera:Eupelmidae) and Acroclisoides africanus Ferrière,

(Hymenoptera:Pteromalidae) (Le Pelley, 1959 and Abebe, 1987). Among all these Telenomus

seychellensis is the most common species and is considered to be the most important. Also both

the nymphs and adults are attached by Tachnid flies. The biological control concept has been

adapted in the control of Antestia bugs using the Antestias egg-parasitoid, Telenomus

seychellensis in coffee in Kenya (Anon, 2009).

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CHAPTER THREE

3.0 MATERIALS & METHODS

3.1 Study Site

The study was conducted at Namwela Coffee Demonstration Farm owned by Coffee Research

Foundation (CRF). The farm is located at Latitude 00 45.43N and longitude 340 33.426E at

elevation 1641metres above the sea level, 25 Kilometres North-East of Bungoma town on the

slopes of Mt. Elgon in Western Kenya. The farm which was established in 1955 has two coffee

blocks planted with K7 and Ruiru 11 coffee varieties with spacing of 2.75 X 2.75m and 1.5 x

1.5m respectively.. The experimental (study) block with K7 has 1825 coffee trees in the open

sun, and 1265 coffee trees under shade trees (Cordia africana). The shade trees are planted at a

spacing of about 30 X 60 metres apart.

3.2 Experimental Design and Sampling of Antestia bug (Antestiopsis sp) Populations

Illustration 3: A diagrammatic representation of the experimental plots, the shaded and unshaded coffee.

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X X X

SHADED COFFEEUNSHADED COFFEE

X X X

SHADED COFFEEUNSHADED COFFEE

X X X

SHADED COFFEEUNSHADED COFFEE

X X X

SHADED COFFEEUNSHADED COFFEE

X X X

SHADED COFFEEUNSHADED COFFEE

During data collection, the sampling was carried out randomly and only on coffee trees

experiencing full shade or coffee trees fully exposed to the sun (Illustration 3). Five coffee trees

were sampled within the shaded and the unshaded coffee. The coffee trees sampled were not

labeled and had a chance to have repeat sampling during the next data collection.

I. During the sampling, the Test Spraying Method designed by Wheatly (1962) and later

modified by Rennison (1979) was used where the selected coffee trees were sprayed with

natural Pyrethrum 4% EC (Plate 2) which has knockdown effect on most insect pests. Two

8ft x 5ft American ground sheets were laid down under each sample tree before spraying

with pyrethrum (4% EC) at a strength of 100ml in 20 litres of water, and given about 15-20

minutes to take effect. Thereafter the trees were vigorously shaken and the fallen Antestia

bugs counted and recorded accordingly (plate 3). The sampling was repeatedly done on

monthly basis and the data recorded and later analyzed to get the mean Antestia bugs per

tree.

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Plate 2: Coffee tree sprayed with Pyrethrum (4% EC) knock down the Antestia bugs (Antestiopsis sp)

II.

Plate 3: Sorting out the Antestia bugs collected on the American calico sheets

3.3 Statistical Data Analysis

All data was analyzed using Microsoft Exel.Version 2010. Means were calculated from the data

collected from the experimental plot (coffee under shade and coffee in the open sun) and the

results tabulated and presented in graph and chart.

The raw data from the field were entered into a table and means for each month was calculated

and finally annual means was realized. The graph and chart were plotted using resultant data

from the monthly means. The standard errors calculated for bar chart where the significance

difference realized and bar generated using the Microsoft Excel Version 2010.

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CHAPTER FOUR

4.0 RESULTS AND RESULTS ANALYSIS

4.1 The population dynamics of Antestia bugs (Antestiopsis sp) under shaded and unshaded coffee.

Table1: Mean Antestia bugs per tree on Shaded and Unshaded coffee from May 2009 to July 2012

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MONTH/YEAR MEAN ANTESTIA BUGS/ TREE/ MONTH

SHADED COFFEE UNSHADED COFFEE

May-09 0.2 0.4

Jun-09 1.0 0.8

Sep-09 0.0 0.0

Oct-09 0.2 0.0

Nov-09 0.0 0.0

Dec-09 0.2 0.0

Jan-10 0.0 0.0

Feb-10 0.6 0.2

Mar-10 0.6 0.6

Apr-10 0.0 0.2

May-10 1.0 0.2

Jun-10 0.8 1.0

Jul-10 1.2 0.2

Aug-10 1.6 0.6

Sep-10 1.6 1.6

Oct-10 0.6 0.0

Nov-10 2.4 0.6

Dec-10 0.4 0.0

Jan-11 0.8 0.0

Feb-11 1.0 0.0

Mar-11 0.8 1.8

Apr-11 0.6 0.2

May-11 0.2 0.0

Jun-11 0.4 0.0

Jul-11 0.4 0.6

Sep-11 0.0 0.2

Oct-11 0.0 1.2

Nov-11 0.0 0.2

Dec-11 0.0 0.0

Jan-12 0.0 0.2

Feb-12 0.0 0.0

Mar-12 0.0 0.0

Apr-12 0.0 0.0

May-12 0.0 0.0

Jun-12 0.0 0.0

Jul-12 0.0 0.0

Mean 0.4 0.3

The monthly mean Antestia bugs per tree are presented in Table 1. The highest monthly mean

Antestia bugs per tree (2.4) was recorded in November 2010 under shaded coffee trees. The

Grand mean number of bugs per tree during the study period was higher under shaded coffee

(0.4) when compared with unshaded coffee (0.3) (Table 1). Between February and July 2012,

both shade and unshaded coffee had zero (0.0) mean Antestia bugs (Table 1).

Figure 1: Mean Antestia bugs (Antestiopsis sp) per tree in shaded and unshaded coffee

from year May 2009 to July 2012.

The Antestia bugs had the highest population levels of 2.4 mean bugs per tree in November 2010

in the shaded coffee and a mean of 1.8 in the unshaded coffee in March 2011 (Figure 1).

The graph trend for shaded coffee show year 2009 and 2010 having reflected higher Antestia

population levels and in year 2011 and 2012 reflected almost the same population levels (Fig.1).

22

The monthly mean number of Antestia bugs per tree oscillated from month to month both under

shaded and unshaded coffee (Fig.1).

4.2 The severity of Antestia bugs (Antestiopsis sp) under shade or unshaded coffee

Table 2: Annual mean Antestia bugs under shaded and unshaded coffee.

YEAR 2009 2010 2011 2012

Shaded 0.3 0.9 0.4 0.0

Unshaded 0.2 0.4 0.4 0.03

The annual mean number of Antestia bugs per tree was highest (0.9) in year 2010 under shaded

coffee, where unshaded coffee recorded a mean of 0.4 (Table 2). In year 2011 the annual mean

number of bugs per tree was 0.4 under both shaded and unshaded coffee respectively (Table 2).

23

Figure 2: Means of Antestia bugs (Antestiopsis sp) per tree in shaded and unshaded

coffee from year 2009 to 2012.

Both in year 2009 and 2010, the annual mean number of Antestia bugs per tree under shaded

coffee was at P< 0.05 significantly higher than the unshaded ones (Figure 2). In year 2011 there

was no significant (P<0.05) difference in mean number of bugs per tree both under shaded and

unshaded coffee (Fig. 2).

CHAPTER FIVE

5.0 DISCUSSION

The study was the first attempt in the determination of the effects of shaded coffee on Antestia

bugs (Antestiopsis sp) in Namwela (Mount Elgon) coffee growing region of Bungoma County in

Kenya. Result from the data showed highly significant mean numbers of Antestia bugs in the

shaded coffee. The documented literatures (reference) support the findings; shade environment

24

affects the Antestia bugs negatively where recommendations in the cultural control of Antestia

bugs promotes the pruning to open up the coffee tree canopy for sun light penetration. According

to available literatures (reference) the shade environment has a moderated temperatures regime

that could favour higher Antestia bug numbers within the shaded coffee. The likely cause of

higher Antestia populations could be related to effect of the shade that gave reduced light

penetration, moderate temperature levels during the day and at night. In cited literatures, Antestia

bugs are known to dwell in dense foliage; they are mobile, moving in between the coffee under

shade and coffee in the sun, to warm up or to cool down. During the night they are found under

the shade to avoid the low temperatures they bask in the sun although they later hide in dense

foliage. This makes it necessary to carryout further studies to find out the effects of temperature

and precipitation (rainfall) effects on Antestia bugs.

Although low mean Antestia bug numbers were observed in year 2012 the experimental plots

was disturbed where two coffee stems were cut off to change the cropping cycle. The cycle

change reduced the size of the canopy greatly and this could have affected the Antestia bugs

population in the coffee trees. Other factors could also have affected the population level and

considerations for studying the pest on an undisturbed environment can be carried out.

According the results of this study and the available literatures, more research work is necessary

to investigate the usefulness of Antestia bugs (Antestiopsis sp) in the monitoring of climatic

change and global warming in the coffee growing regions.

25

CHAPTER SIX

6.0 CONCLUSIONS AND RECOMMENDATIONS

6.1 Conclusions

The Antestia bug (Antestiopsis sp) population levels were higher under shaded coffee than in

unshaded coffee. The shaded coffee supported more Antestia bug population levels than the

unshaded coffee.

This concludes that Antestia bugs are less affected by the shade and thus shade is not a deterrent

to Antestia bugs habitation and finally Antestia bugs are not sun lovers.

6.2 Recommendations

The results of this study have concluded that Antestia (Antestiopsis sp) bug population levels

increased within the shaded coffee as opposed to those in the unshaded coffee. With these

findings, when considering Antestia bug cultural control interventions, the recommendation is to

do away with shade tree in coffee where Antestia bugs are a problem.

26

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31

APPENDICES

APPEDIX 1

A sample form used for the data collectionAntestia bugs (Antestiopsis sp) per tree for both in the shaded and in the unshaded coffee.

DATE………………………………….

SHADED COFFEE

UNSHADED COFFEE

DATE ………………………………….

32

Tree No. Antestia Eggs Remarks

1

2

3

4

5

Total

Mean

Tree No Antestia Eggs Remarks

1

2

3

4

5

Total

Mean

APPEDIX 2

Data summary for mean Antestia bugs (Antestiopsis sp) per tree.

YEARLY BY YEAR DATA ON SHADED AND UNSHADED COFFEE AT NAMWELA DEMONSTRATION FARM

2009 2010 2011 2012

MONTHSSHADED

UNSHADED

SHADED

UNSHADED

SHADED

UNSHADED

SHADED

UNSHADED

JANUARY X X 0.00 0.00 0.80 0.00 0.00 0.20FEBRUARY X X 0.60 0.20 1.00 0.00 0.00 0.00MARCH X X 0.60 0.60 0.80 1.80 0.00 0.00APRIL X X 0.00 0.20 0.60 0.20 0.00 0.00MAY 0.20 0.40 1.00 0.20 0.20 0.00 0.00 0.00JUNE 1.00 0.80 0.80 1.00 0.40 0.00 0.00 0.00JULY X X 1.20 0.00 0.40 0.60 0.00 0.00AUGUST X X 1.60 0.60 X X SEPTEMBER 0.00 0.00 1.60 1.60 0.00 0.20 OCTOBER 0.20 0.00 0.60 0.00 0.00 1.20 NOVEMBER 0.00 0.00 2.40 0.60 0.00 0.20 DECEMBER 0.20 0.00 0.40 0.00 0.00 0.00

GRAND MEANS 0.3 0.2 0.9 0.4 0.4 0.4 0.00 0.03

KEY: ‘X’ = UNRECORDED DATA (The data was not collected).

33

APPEDIX 3

MAP ON COFFEE GROWING REGIONS OF KENYA

34