|Coffee borer beetle|
|adults on damaged bean|
Cryphalus hampei Ferrari, 1867
The coffee borer beetle or coffee berry borer (Hypothenemus hampei) is a small beetle native to Africa. It is among the most harmful pests to coffee crops across the world where coffee is cultivated. Spanish common names of the insect include barrenador del café, gorgojo del café, and broca del café.
Females have two larval stages and males only one. They have strong mandibles, and their larval phase lasts 10 to 26 days. The adults are small black beetles. Females are 1.4–1.8 mm long. The males are 1.2–1.6 mm long. Female beetles can fly short distances; males have rudimentary wings. H. hampei is confused sometimes with the false coffee berry borer (H. obscurus or H. seriatus) and Xylosandrus (Scolytidae), but these species do not enter the coffee bean endosperm.
The maturation of the insect (from egg to adult) lasts between 24 and 45 days, varying according to the weather. Usually, the female drills the berry through the central disc, although it can enter through the side walls if the fruit is dry. Two days after the access, the beetle lays 35–50 eggs, which produce 13 females for each male. The lifespan for females is 35–190 days and for males 40 days. The new insects mate inside the seed. Some females lay the eggs in the same coffee plant, others colonize new ones. The males never leave the fruit.
The same plant can host three to five generations of beetles. Up to 100 beetles can be found in a single fruit. The insect is very sensitive to desiccation, and waits for the rains to leave the fruit. The most affected areas in the crops are the shady and moist ones.
The main host of H. hampei is Coffea arabica, but other coffee species have been affected in some cases. The female beetles attack the fruits from 8 weeks past the flowering to 32 weeks. When the insect enters, it builds galleries in the endosperm where the eggs are deposited.
The insect is endemic to central Africa and has now spread to most coffee-producing countries through the accidental introduction of contaminated seeds. The first report in the American continent were in Brazil (1926). In the 1970s, it affected Guatemala and Mexico. The beetle entered Colombia during the late 1980s. It entered the Dominican Republic in the 1990s. It was detected in Puerto Rico in August 2007. It was discovered in Kona (Big Island), Hawaii in August 2010.
The draft genome of the coffee berry borer consists of ca. 163 million base pairs (Vega et al. 2015 . Caffeine demethylase has been shown to be responsible for caffeine breakdown in the alimentary canal of the insect (Ceja-Navarro et al. 2015 .
The presence of the insect affects the economy of over 20 million families that depend on the coffee harvest. Due to the losses in yield and quality caused by the insect, growers end up losing significant amounts of income. The main pest management strategies involve different components, including monitoring, controlled harvest, and the use of biological control agents.
Prevention is based in the careful inspection of the coffee beans before leaving the coffee farms to avoid spreading of the insects. Also, a number of border controls has been established in countries with coffee crops.
Insecticides are useful only before the female beetle penetrates the berry. Resistance to endosulfan, which has been banned in many countries, has been reported in New Caledonia.
Biological control methods use the natural enemies of the coffee berry borer to reduce the population. Pest management through biological control can utilize predators, parasites and diseases that attack the larvae or adult beetles.
During the time when beetle offspring emerge from each commercially ruined berry to disperse, they are vulnerable to predation. The yellow warbler, rufous-capped warbler, and other insectivorous birds have been shown to reduce by 50% the number of coffee borer beetles in Costa Rican coffee plantations.
The parasitoids used to control the borer beetle are Hymenoptera (wasps) native to Africa. Although they have a low impact in the beetle population, the use of biological controls allows the product to qualify as organic food.
Ants (Hymenoptera: Formicidae) have been reported as predators of H. hamper but they do not control the insect. Research at the Centro Nacional de Investigaciones de Café (Cenicafé, Colombia) reported other insect families as predators: Anthocoridae (Hemiptera) and Cucujidae (Coleoptera). The following are the genus and species that have been reported to attack the borer beetle:
Metaparasitylenchus hypothenemi (Nematoda: Allantonematidae) has been reported in Mexico. A Panagrolaimus sp. has been reported in the field in India. In laboratory experiments, Heterorhabditis sp. and Steinernema feltiae have been shown to infect the insect.
Beauveria bassiana infection causes high mortality of the insect and products have been developed in Colombia and elsewhere. Other fungi recorded to attack CBB include: Hirsutella eleutheratorum, Isaria sp. (previously placed in the genus Paecilomyces), and Metarhizium sp.