The Antestia Bug Complex in Africa and Asia 487
bug chemical ecology should be encouraged to help develop monitoring or mass trapping systems, as
well as habitat management (push-pull strategies), for controlling these bugs.
10.7 Why Are Antestia Bugs Not Invasive Species?
10.7.1 A Limited Distribution Compared with Coffee Berry Borer
Worldwide, coffee is grown over 10 million hectares in humid regions of more than 70 tropical countries
(FAOSTAT 2013). With ≈2 million hectares grown with coffee, Africa accounts for 20% of the global
coffee area (FAOSTAT 2013). Originating in Africa in co-evolution with coffee plants, Antestia bugs
have not followed the host coffee plant as it was dispersed abroad unlike so many of the other coffee
pests. Today, the dozen species and subspecies of Antestiopsis have a distribution on coffee limited to
Africa. Antestiopsis cruciata is the only Asian species known on coffee, and it probably originated in
Asia. Antestia bugs are completely absent from Latin America, although that region accounts for more
than 50% of the world coffee-growing area.
By contrast, another coffee pest that originated in Africa, the coffee berry borer, Hypothenemus hampei
Ferrari (Coleoptera: Scolytinae), exhibits a different fate. Today, this tiny beetle that feeds upon coffee
beans inside the berries is present virtually everywhere coffee is grown, with the exception of high eleva-
tion Arabica coffees, causing considerable production losses (Jaramillo et al. 2006, Vega et al. 2009).
With this present section of the chapter, we will consider the reasons why Antestia bugs have not been
as successful as coffee berry borer in the colonization process of coffee plantations. So, why have the
Antestia bugs not become invasive?
10.7.2 Limited Opportunities of Spreading by Human Transport
Interregional and international travels of people and goods are known to be one of the main factors sup-
porting biological invasions (Mack et al. 2000). The coffee berry borer is a good example of an invasive
pest that reached new coffee growing areas largely by escaping detection during human transport. This
pest can survive for several months in green coffee beans that are often imported for commercial coffee
production or, to a lesser extent, as plant material for coffee growing (Chapman et al 2015). By contrast,
feeding habits of Antestia bugs do not allow these pests to survive on coffee beans alone (see Section
10.3.2, Feeding Habits). The only way they could be transported over long distances is through coffee
plants (seedlings) or plant parts, such as berries or grafting materials (cuttings and rootstocks). Transport
of coffee plant material usually is limited and subject to phytosanitary inspection and quarantine restric-
tion. Antestia bugs, which are both easily detected (eggs are big, white, and grouped in clusters [see
Section 10.3.3]) and sensitive to insecticides, would be unlikely to survive these measures.
10.7.3 Relatively Slow Growing Species
Another characteristic of invasive insects is a short life cycle and high fecundity leading to quick growth
of populations. Prolific invading species are more likely to compete successfully with indigenous spe-
cies and expand their range (Mack et al. 2000). With a life cycle of ≈1 month and an average fecundity
of 200 eggs per female at 25°C (Jaramillo et al. 2009), the coffee berry borer is considered a prolific
species, with potentially eight or nine generations per year in favorable conditions (Damon 2000). By
comparison, Antestiopsis thunbergii has a life cycle of between 3 and 6 months, depending on temperature.
A. intricata has a somewhat shorter life cycle than A. thunbergii and seems to be adapted to higher tem-
peratures (see Section 10.3.3). Mean fecundities of 150 and 200 eggs per female have been reported for
A. thunbergii and A. intricata, respectively, with maximum values of more than 400 eggs per females for
both species. However, these species can be considered slow growing as demonstrated by a recent study
on A. thunbergii, which reported an intrinsic rate of increase (r) of 0.013 at 20°C and 0.006 at 25°C and
a mean generation time of 3 and 4 months, depending on temperature (Ahmed et al. 2016).