There is good news for coffee lovers and growers worldwide: A predator食肉动物,捕食者 for the devastating2毁灭,摧毁 coffee berry borer钻孔器,穿孔者 has just been discovered in Africa. Looking at coffee berries in Western Kenya, Dr. Juliana Jaramillo from the International Centre of Insect Physiology3 and Ecology in Kenya, Dr. Eric Chapman from the University of Kentucky, and colleagues have identified a previously4 unknown predatory thrips牧草虫 – Karnyothrips flavipes – which feeds on the eggs and larvae幼虫,幼体 of the coffee berry borer Hypothenemus hampei. According to the authors, this discovery could have important implications for the management of the coffee berry borer throughout the world. Their study, the first to quantitatively6 prove predation on the coffee berry borer, is published online in Springer's journal Naturwissenschaften - The Science of Nature. Previous studies were based on mere7 observations, for example of ants preying9 on the coffee berry borer. The coffee berry borer H. hampei is the most widespread coffee pest in coffee producing countries. Yearly coffee losses are estimated at US $500 million, affecting the income of more than 20 million rural households家庭 in the tropics. The female coffee borer drills galleries into the coffee berries where she deposits her eggs. The larvae5 then feed on the coffee berries. Because the pest's lifecycle occurs mainly inside the coffee berry, H. hampei is very difficult to control, particularly in countries which pride themselves on their organic coffee production.
During routine dissections解剖,切开 of coffee berries in Western Kenya, Dr. Jaramillo observed, for the first time, adult thrips K. flavipes feeding on eggs of the coffee berry borer. Further observations in the laboratory showed that K. flavipes adults also prey8 on the larvae of H. hampei. She found that K. flavipes enters the coffee berry through the tiny hole bored by H. hampei and also deposits its eggs inside the berries. Newly hatched thrips then continue to develop inside the berries.
The authors used molecular10分子的 techniques to detect the presence of small amounts of prey DNA11 in the digestive tracts12 of the predators13 by analyzing14 their gut15 contents. Nearly 18,000 H. hampei-infested coffee berries from 100-150 trees were collected in the Kisii area of Western Kenya between January and September 2008. In total, over 3,000 K. flavipes emerged from the borer-infested berries and pest DNA was detected in 8.3 percent of DNA extractions抽出,取出 of the predator1. The highest percentage of positive results occurred in April, when 47 percent emerging K. flavipes tested positive for H. hampei DNA.
These findings confirm for the first time the presence of a coffee berry borer predator in Africa, based on molecular gut content analysis. The authors believe that K. flavipes has the potential to have a significant impact on H. hampei populations in other coffee growing regions. Controlling this pest could potentially help stabilize16 coffee harvest and market value.
They conclude: "Our findings provide coffee growers and coffee scientists with new insights into a biological control agent that could be conserved17保存,保全 and augmented18 in coffee growing regions where it occurs. This predator could make a significant contribution to integrated整合,联系 pest management of H. hampei."