Coffee cherry beetle
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Coffee cherry beetle ( Hypothenemus hampei ) |
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| Hypothenemus hampei | ||||||||||||
| ( Ferrari , 1867) |
The coffee berry borer ( Hypothenemus hampei ) is a small, originally in Africa beheimateter beetle . It is the most common pest on coffee plants .
features
It is a very small beetle with a body length between 1.2 and 1.9 millimeters, with the typical body shape of the bark beetle . The pronotum is raised in the middle in the shape of a hump, the head partially retracted into it and not visible from above. The head carries antennae with a three-part, fused antenna lobe, the parts of which appear separated by rows of bristles. A tubercle in the middle of the forehead is absent in this species. The front edge of the pronotum has six teeth, its entire surface is articulated and hairy by raised, rasp-shaped points. The elytra have fine stripes of dots and a rather dense, protruding hairs made up of fine hair and scale hair. There is a fine hair in each row point. In the spaces between the row points sits a row of long, weakly flattened scale hairs. The species is not easy to distinguish from other species of the species-rich genus Hypothenemus .
Biology and way of life
Hypothenemus hampei is a pest of unripe coffee cherries and does not damage leaves, branches or trunks. It attacks both commercially grown coffee types, Arabica coffee and Robusta coffee , with the Robusta coffee Coffea canephora being considered the host of origin; in addition, some legumes are presumably accepted as alternative hosts and occasionally enable successful reproduction. They eat passages in the endosperm of the seeds ("coffee beans"). If the infestation rate is high, even mature seeds are attacked and damaged, although they do not allow reproduction. In addition to the direct damage and the resulting crop failures, the injury leads to infections and infestation by secondary pests. The females eat galleries in the pulp of the coffee cherries. A female lays between 31 and 119 eggs on beans of a suitable degree of ripeness, with each cherry being infested by only one female. The larvae hatch after about four days. The larvae eat their way through the outer layers to the endosperm and mine inside the seed. Although fruits growing on the bush are preferentially attacked, development can be completed on those that have fallen to the ground. As with many other bark beetles, the larvae may need symbiotic fungi to digest their food, but this has not yet been proven with certainty. At 27 degrees Celsius, the larval stages are completed in 15 days and the pupal stage in seven days, the entire life cycle in 28 to 34 days. Due to the rapid development, numerous generations can follow one another in the same year. In the Ivory Coast up to nine consecutive generations are given per year, in Colombia it is only two or three. The beetles usually form aggregations, so that a patch-like pattern of infestation results. In coffee-growing areas with an annual dry season, the beetles remain in the resting phase in dry coffee crops and become active again in the following rainy season. The activity is usually not limited by the cold, the activity threshold of 15 degrees is below the limit of 16 degrees that limits coffee cultivation.
The coffee cherry beetle is separate sexes, with females being around ten times more common than males. The males have no functioning wings and usually do not leave the beans, mating occurs immediately after hatching. The females are able to fly. They don't leave the bean until about 12 days after they hatch. The flight activity of the females is different, but can lead to new infestations even in very distant regions, but they are also very often transported in infected seeds by humans. The flight activity mostly falls in the afternoon.
Horizontal gene transfer
A 2012 study by Ricardo Acuña and colleagues found evidence that the insect had acquired the HhMAN1 gene for the digestive enzyme mannanase by horizontal gene transfer from a bacterium . The beetle uses the enzyme to break down and digest galactomannans , the most important storage carbohydrates in the coffee bean. Mannanases are otherwise unknown in insects, and the closely related species Hypothenemus obscurus does not have such an enzyme. Additional biogeographical analyzes show that the horizontal HhMAN1 gene transfer in H. hampei must have already occurred before the insect spread from West Africa to Asia and South America.
It is one of only a few cases so far in which horizontal gene transfer to an animal species has been found. This is possibly more widespread, but so far only rarely proven. The transmission mechanism has not yet been scientifically clarified.
distribution
Central Africa is considered the original home of the beetle. From here it was abducted almost worldwide by humans to almost all cultivation areas, with the exception of Nepal , China and Papua New Guinea . It was introduced to Hawaii in 2010. The genetic variability of the species is low worldwide, which is attributed to the short migration period.
Economic importance
The coffee cherry beetle is the most important pest in coffee cultivation worldwide, the damage is estimated at more than 500 million US dollars annually. It is threatening the livelihoods of more than 25 million rural households that earn their livelihood from growing coffee. Infestation rates between 60 percent (Mexico) and 90 percent (Tanzania) are reported in untreated coffee cultures. Fighting is usually done with synthetic insecticides, especially endosulfan and chlorpyrifos . In addition, a number of biological antagonists are tested for control, including the parasitoid wasps Cephalonomia stephanoderis , Cephalonomia hyalinipennis and Prorops nasuta (family Bethylidae ), Phymastichus coffea (family Eulophidae ) and Heterospilus coffeicola (family Braconidae ) and the entomophage mushroom Beauveria bassiana . The fringed winged Karnyothrips flavipes is also regarded as effective for biological pest control. In the future, increasing damage from climate change is expected, as the species comes from the tropical lowlands and is favored by rising temperatures in the mountain regions, the center of Arabica cultivation.
Individual evidence
- ↑ Plant research (Federal Ministry of Education and Research): bacterial gene turns insects into pests ; accessed on January 26, 2015.
- ↑ Walker, K. (2007) coffee berry borer (Hypothenemus hampei) Updated on 11/25/2011 10:32:06 AM Available online: PaDIL Pests and Diseases Image Library
- ↑ DE Bright & JA Torres (2006): Studies on West Indian Scolytidae (Coleoptera) 4. A review of the Scolytidae of Puerto Rico, USA with descriptions of one new genus, fourteen new species and notes on new synonymy (Coleoptera: Scolytidae) . Coleopterological Review 76: 389-428.
- ^ A. Damon (2000): A review of the biology and control of the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae). Bulletin of Entomological Research 90: 453-465.
- ↑ Fernando E. Vega, Francisco Infante, Alfredo Castillo, Juliana Jaramillo (2009): The coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae): a short review, with recent findings and future research directions. Terrestrial Arthropod Reviews 2: 129-147.
- ↑ Ricardo Acuña, Beatriz E. Padilla, Claudia P. Flórez-Ramos, José D. Rubio, Juan C. Herrera, Pablo Benavides, Sang-Jik Lee, Trevor H. Yeats, Ashley N. Egan, Jeffrey J. Doyle, Jocelyn KC Rose (2012): Adaptive horizontal transfer of a bacterial gene to an invasive insect pest of coffee. Proceedings of the National Academy of Sciences USA vol. 109 no. 11: 4197-4202. doi : 10.1073 / pnas.1121190109
- ↑ Patrick J. Keeling & Jeffrey D. Palmer (2008): Horizontal gene transfer in eukaryotic evolution. Nature Reviews Genetics 9: 605-618. doi : 10.1038 / nrg2386
- ↑ J. Jaramillo, C. Borgemeister, P. Baker (2006): Coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae): searching for sustainable control strategies. Bulletin of Entomological Research 96: 223-233.
- ↑ Juliana Jaramillo, Eric G. Chapman, Fernando E. Vega, James D. Harwood: Molecular diagnosis of a previously unreported predator-prey association in coffee: Karnyothrips flavipes Jones (Thysanoptera: Phlaeothripidae) predation on the coffee berry borer. Natural Sciences: March 2010, Volume 97, Issue 3, pp 291–298. doi : 10.1007 / s00114-009-0641-7
- ↑ J. Jaramillo, E. Muchugu, FE Vega, A. Davis, C. Borgemeister (2011): Some Like It Hot: The Influence and Implications of Climate Change on Coffee Berry Borer (Hypothenemus hampei) and Coffee Production in East Africa. PLoS ONE 6 (9): e24528. doi : 10.1371 / journal.pone.0024528
