486 Invasive Stink Bugs and Related Species (Pentatomoidea)
10.6.2.3.4 Biological Control Attempts
True attempts of biological control of Antestia bugs are scarce. Because egg parasitism is naturally high
in coffee plantations, main release attempts have employed parasitoids of nymphs and adults. From the
1940s to the 1960s, the strepsipteran Corioxenos antestiae and the tachinid Bogosia sp. were introduced
into some localities of Kenya, Tanzania, and Uganda where they had been absent previously, but the
introductions met with limited success (Greathead 1971).
10.6.3 Future Control Strategies
10.6.3.1 Conservation Biological Control through Plant Diversification
Antestia parasitoids already are present in coffee plantations with satisfactory parasitism potential, espe-
cially egg parasitoids. Thus, there is no need to introduce new species, which could compete with local
species and do more harm than good. A good strategy might be to enhance and maintain indigenous
parasitoid populations at such a level that they could keep Antestia bug populations under economic
thresholds. To this end, some research studies have been conducted to better understand parasitoid ecol-
ogy. For instance, the tachinid Bogosia rubens pupates in the soil, and pupal development is possible
only with good moisture. Therefore, shade, maintenance of plants covering the ground, or mulching are
practices favorable for this parasitoid (e.g., Taylor 1945).
In a more recent study conducted in Western Cameroon, flowers of weeds such as Ageratum conyzoi-
des L., Galinsoga parviflora Cav. and Bidens pilosa L. (Asteraceae), and some crops associated with cof-
fee such as banana (Musa sp.), have been examined for parasitoids with promising results. These plants
also have been tested for their ability to maintain adult parasitoids in the laboratory. Banana flowers gave
good results with a maximum parasitoid longevity of 26 days (Mbondji Mbondji 2001).
Plant diversification in crops is regarded as one of the main tenets of agroecology. There are many
examples where adding plants to the crop helps by encouraging pest regulation by natural enemies (e.g.,
Ratnadass et al. 2012). Taking into account high levels of indigenous parasitism for Antestia bugs, a
promising control strategy may be to add plants within coffee cropping systems, which could provide
shelter and food for adult parasitoids. Much work needs to be done to determine which plant species and
cropping design would best achieve these goals.
10.6.3.2 Semiochemical Control
As with most true bugs, semiochemicals play a crucial role in Antestia bug communication. For
these bugs, scent glands are present as early as the first instar, where orifices are visible on the
abdomen. For adults, scent glands are well developed on the metathorax and fully functional. Gland
secretions are repellent and irritant compounds involved in the defense of the bugs against enemies,
and it is likely that the brightly colored body of Antestia bugs is a visual signal alerting predators
to the unpleasant taste of the bugs. A recent study by Jackels et al. (2014) showed that the three
main compounds present in desiccated adults of Antestiopsis thunbergii ghesquierei from Rwanda
were tridecane, dodecane, and tetradecane. These compounds are known to be involved in true bug
defense (Millar 2005).
In their study in Burundi, Cilas et al. (1998) assumed that the aggregative distribution of Antestia bug
nymphs in coffee plantations was due to semiochemical communication, and it is likely that reproduction
behavior also involves pheromones. An olfactometry study recently conducted at icipe, Nairobi, Kenya,
showed that Antestiopsis thunbergii bechuana nymphs are attracted to Arabica coffee by the fully devel-
oped green berries but not by the mature red berries (Teresiah N. Njihia, unpublished data). This result
confirms the feeding preference of Antestia bug nymphs for immature berries (see Section 10.3.2.2,
Feeding on Coffee). Moreover, the study showed that 30-day-old adults of both sexes are attracted to
adult males of same age (Teresiah N. Njihia, unpublished data). This suggests the presence of a male-
aggregative pheromone involved in Antestia bug reproduction, as has been demonstrated for other stink
bugs (Millar 2005). If the results of this study are promising, then future research in the field of Antestia