The Antestia Bug Complex in Africa and Asia 481
10.6.2 Control Methods
10.6.2.1 Cultural Methods
10.6.2.1.1 Coffee Pruning and Shade Management
Shade-tree regulation and pruning of coffee trees are the common cultural practices recommended to
reduce Antestia bug outbreaks. Because the pests prefer dense foliage, pruning is recommended to keep
the coffee bush open. Shade and pruning measures modify the microclimate and create unfavorable
conditions for Antestia bugs, reducing infestations (Crowe and Gebremedhin 1984, Wrigley 1988, IAR
1996b). In Ethiopia, studies on the effect of pruning indicated a significant reduction in the amount of
coffee bean damage and berry loss due to Antestia bugs. These measures also increased insecticide effi-
ciency towards Antestia bugs (Chichaybelu 1993).
10.6.2.1.2 Handpicking
In the 1930s, handpicking was used to control Antestia bugs in East Africa. Prior to collection, bugs were
forced down on the coffee stem by using smoke obtained from smoldering cow dung. Le Pelley (1968)
reported that many millions of Antestia bugs were collected this way in Kenya in 1933 and 1934 but with
little benefit compared to the costs.
10.6.2.2 Control with Insecticides
10.6.2.2.1 Poison-Bait Sprays
This control practice was used in the past in East Africa, but although it no longer is used, it gave good
results in Tanzania and Uganda (Le Pelley 1968). The method is based on the fact that Antestia bugs
usually drink water from dew on coffee leaves and are attracted by sugar baits. The method was to spray
a water solution of arsenic and sugar on coffee bushes (Le Pelley 1968).
10.6.2.2.2 Botanical Insecticides
Botanical insecticides such as pyrethrum and neem developed for use on tropical crops were notable
because they were produced locally and cheaper than commercial synthetic insecticides. For decades
they have been considered good alternatives to commercial insecticides because of their harmlessness
for human health and the environment due mainly to selectivity of action.
Pyrethrum extracted in kerosene has been used in Kenya for the control of Antestia bugs since the
early 1930s. The method consisted of covering coffee bushes with cotton sheets and spraying them with
the insecticide using a hand-atomizer (Le Pelley 1932). The high toxicity of pyrethrum for Antestia bugs
has led researchers to improve the method, and pyrethrum water emulsions and dusts have been devel-
oped and used with success in East Africa (Crowe et al. 1961).
In Rwanda, pyrethrum products are currently approved for the control of Antestia bugs in organic
certified coffee. Because of the short persistence of photounstable pyrethrum (24 hours only), spraying
is recommended when the bugs are active (i.e., in the morning between 6 and 9 and in mid-afternoon
between 3 and 5 [N. D. T. M. Rukazambuga, unpublished data]).
Recently, in Ethiopia, different plant species present in coffee growing areas were tested under labora-
tory conditions for the control of Antestiopsis intricata. Extracts of Millettia ferruginea (Hochst.) Baker,
a natural product, resulted in 84% adult and 78% nymphal mortality, 24 hours after treatment, whereas
Chrysanthemum cinerariifolium L. (pyrethrum) extracts caused 79% adult and 80% nymphal mortal-
ity under the same laboratory conditions (Mendesil and Abdeta 2007). The study also showed toxicity
of some plant extracts against eggs of Antestia bugs. In another laboratory-based experiment, essential
oils of the three plants Dysphania (Chenopodium) ambrosioides (L.) Mosyakin & Clemants, Thymus
vulgaris L., and Ruta chalepensis L. resulted in 92.5, 90, and 87.5% mortality of Antestia bugs, respec-
tively (Mendesil et al. 2012).