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(Asterolecanium coffeae)

Credits: Biovision-Infonet

It is yellowish to reddish brown, covered with numerous small spines. It attacks stems and branches, causing deformation of branches. The growth of trees severely attacked is retarded and the trees may be die. Symptoms include green branches bent at nodes with pits in green bark beneath the bend, drooping dead leaves on affected nodes and numerous small red or yellow objects are found in the bark crevices especially near the ground. Alternative hosts include Jacaranda and loquat trees.

What to do:

• Ladybird beetles and their larvae are often found wandering about the bark eating crawlers.
• Parasitised scales turn into dark-brown or black colour and are easily distinguished from the reddish-brown healthy adults. The adult parasites emerge from the scales through a neat circular hole on the shield (carapace) of the scale.
• Prune infested trees severely and strip off the crop. Cut off severely infested heads.
• Burn the infested pruned branches.
• Apply optimum organic matter such as compost and mulch to infested trees as well as foliar feed.
• Where road dust promotes infestation, plant live dust barrier such as key apples.

(Planococcus citri)

Credits: Biovision-Infonet

This mealybug is usually a minor pest of coffee, but it is potentially a serious pest. The mealybugs attack the roots where they usually live in association with a fungus (Polyporus sp.), which forms a crust over the mealybugs. Seedlings and very young trees are often free of the fungus. Attacked trees show wilting yellow leaves as if suffering from moisture stress. When affected trees are uprooted, the roots are stunted and encased in brown fungus. When the fungus is pealed off, the white mealybugs can be seen.

Damage is more prominent in dry conditions. The pest is associated with poorly established coffee. Severe infestation may lead to loss of quality, failure of berries to ripen and overbearing and die-back. Identical mealybugs have been reported on Solanum spp., Combretum spp. and Indigofera spp. The root mealybug is also known as the citrus mealybug. It also attacks citrus and cocoa, where it normally attacks the aerial part of the plants.

In the highlands of Java, the shade tree Leucaena glauca is main food plant of citrus mealybug at altitudes above 600m (2000 ft.). Measures that proved successful for the control of citrus mealybug were mainly directed against infestation of this tree and consisted of removing the flower clusters or, when necessary, pruning all foliage and flowers. It is also claimed that citrus mealybug can be controlled by increasing the shade in plantations and that this was undesirable for Robusta coffee but suitable for Arabica at high altitudes. Good results were obtained by providing three covers, one above the other, of Leucaena, Erythrina and Albizia, or with Leucaena and Albizia only. It is further suggested that because the insect infests mainly the flowers and pods of L. glauca, other shade trees that seldom flower, such as L. pulverulenta (L. leucocephala), or a sterile hybrid of L. glauca and L. glabrosa should be planted.

What to do:

• Strictly observe the recommended nursery management and establishment procedures especially removal of all stem and root remnants. Destroy attacked suckers and do not use them as mulch.
• Uproot affected trees and burn on site.
• Allow infill holes to rest at least for 3 months before replanting in order for the remaining root mealybugs to die.
• Neem treatments have a good effect on mealybugs

(Planococcus kenyae)

Credits: Biovision-Infonet

This mealybug was a major pest of coffee in Kenya in the 20’s and 30’s in the East Rift area, but it was successfully controlled with introduction of natural enemies from Uganda. Sporadically severe attacks occur especially in the colder months of the year. The mealybugs appear as white masses between clusters of berries and flower buds or sucker tops. They are often attended by ants, which feed on the sticky honeydew excreted by the mealybugs. Honeydew leads to growing of black sooty mould on the upper surfaces of leaves.

What to do:

• Cut off unwanted suckers and remove any branches touching the ground.
• Control attending ants by banding trees.
• Neem treatments have a good effect on mealybugs.

(Ascotis selenaria reciprocaria)

Credits: Biovision-Infonet

The adult is a moth with a wingspan of up to 5 cm. They vary in colour from dark brown to light grey with numerous dark grey markings. They lay pale green eggs in crevices in the bark. The caterpillars are pale grey to dark brown resembling twigs, and move with a looping motion. They are about 5 cm when fully grown. Young caterpillars usually eat pits on the upper leaf surface and older caterpillars feed on the leaf margins leaving a jagged edge. All stages of caterpillar prefer tender and young leaves but berries and large flower buds may also be attacked. Alternate hosts include groundnuts, sweet potatoes, black jack weeds as well as some tree species like Datura and Eucalyptus.

What to do:

• Control is justified when more than 10 caterpillars are present on seedlings and young suckers or 20 caterpillars on cropping coffee trees.
• Spray with Bacillus thuringensis(Bt) products (Thuricide HP(r) or similar product) at a rate of 4 g in 20 l of water (200 g/ha).
• Spray with Neem products.
• Similar control measures are recommended for the Green looper (Epigynopteryx stictigramma)

(Leucoplema dohertyi)

Credits: Biovision-Infonet

The leaf skeletoniser is normally a minor pest but severe outbreaks could occur especially in nurseries.

The adult is a grey and brown moth with a wing-span of about 1.3 cm. It is often found on leaves during the day with the hind wings drawn back alongside of the body and the narrow forewings held at right angles to the body. They lay yellow-green eggs (0.5 mm in diameter) singly or in small groups mainly on the underside of leaves. The caterpillars are greyish white with many pimple-like projections on the body. They turn red the day before pupation. Fully-grown caterpillars are about 8 mm long. They feed on underside of the leaf, usually near the near mid-rib leaving many irregular lace-like patches.

What to do:

• Eggs are attacked by parasitic wasps; parasitised eggs turn black.
• Caterpillars are attacked by an external parasitoid, which can be seen as shining, light brown objects stuck to the side of the caterpillars.
• Control is justified if over 35 moths are seen when a tree is shaken or when there are 20-30 caterpillars per tree.

(Leucoptera meyricki and Leucoptera caffeina)

Credits: Biovision-Infonet

The adults of leafminers are very small (3-4 mm long) white moths. They lay very small eggs (just visible to the naked eye) on the upper leaf surface scattered in small groups (L. meyricki) or touching each other in a neat row along a main vein (L. caffeina). Upon hatching, the caterpillars bore into the leaf and mine just below the upper leaf surface. The mines of each L. meyricki caterpillar are initially separated but after few days they join to form one large mine. The young caterpillars of L. caffeine produce one communal mine. These mines appear as irregular brown blotches on upper side of leaves, which when opened reveals many whitish caterpillars.

Caterpillars are flattened, white and very small (4-8 mm when fully grown). Mature caterpillars come out of the mine and pupate in a H- shaped cocoon (6 mm long) on dead leaves on the ground or on the underside of leaves on the tree.

The mining activity causes a reduction of the active leaf surface, reducing assimilation. Attacked leaves are usually shed prematurely. Leafminers can live on shrubs belonging to the same family as coffee (Rubiaceae family).

What to do:

• The caterpillars and pupae are attacked by a large number of parasitic wasps, which occur naturally in the field, and eggs are sucked dry by a predacious mites.
• Economic threshold level: If they tree is shaken vigorously and more than 35 moths are seen, the yield of coffee can be affected. The indiscriminate applications of insecticide usually kill the natural enemies faster than it kills the moths, resulting in more serious attacks.
• When intercropping Artemisia with coffee in East Africa, the incidence of coffee leafminers is drastically reduced (Per Diemer, FAO consultant).

(Lamprocapsidea (Lygus) coffeae)

Credits: Biovision-Infonet

The capsid bug is a serious pest in all areas. The adult bug is green or brownish and about 0.7-0.8 mm long, and has a sharp downward bent in its wings, which is highly characteristic. Females insert eggs into flower buds, and thus eggs are not visible. Nymphs are pale green and pear shaped. Wing buds are visible on older nymphs. Both adults and nymphs feed on flower buds, but when they are not present they would feed on any soft green part of the coffee bush. As a result of feeding flower buds blacken due to death of stamens and petals. The style however remains healthy and usually takes a club shaped appearance with pale green shaft and black head. Damaged flowers do not set fruit. This bug is frequently considered beneficial on unshaded coffee at lower altitudes since the pruning effect of the damage caused by this bug reduces the tendency to overbear.

What to do:

• Control measures should only be applied when developing flower bugs are present, when most of the buds are required to set fruit, and when there is an average of more than 4 capsid bugs per tree.
• Spray with pyrethrum (Flower DS(r) or similar product) 10 ml to 20 l of water or according to instructions.

(Antestiopsis spp)

Credits: Biovision-Infonet

Antestia bugs are major pest of Arabica coffee in East African countries. The adult bug is shield-shaped, about 6 to 8 mm long and strikingly coloured dark brown with orange and white markings. They hide in berry or flower clusters. Females lay eggs in groups of about 12 on the underside of leaves. Newly hatched nymphs are about 1 mm long. Nymphs resemble the adults in colour but have a more rounded shape and lack functional wings.

Both adults and nymphs cause severe damage to green berries by feeding and indirectly by the transmission of a fungus (Nematospora coryli), which causes rotting of beans. The bug also attacks flower buds and shoots causing blackening of flower buds with no flower/fruit set. Attacked branches grow side shoots (fan branching). No visible surface marks / scars or wounds on berry are noticeable until seen on drying beds as “zebra” beans. “Zebra” beans produce poor quality coffee and are possible avenues for fungal infection. Antestia bugs can live on shrubs belonging to the same family as coffee (Rubiaceae family).

What to do:

• Naturally occurring parasitic wasps attack antestia eggs. Attacked eggs are black while normal eggs are white.
• Undertake regular and timely pruning and desuckering. Antestia bugs prefer dense foliage.
• Spraying with Neem has been recommended when more than 3 bugs per tree are found in Tanzania, and 2 bugs are found per tree in drier areas and more than 1 bug per tree in wetter areas in Kenya.