Weiser L A, Obrycki J J, Giles K L
Department of Entomology, Iowa State University, Ames, IA 50011, USA.
J Econ Entomol. 2003 Aug;96(4):1184-92. doi: 10.1093/jee/96.4.1184.
The effects of a 3-m wide uncut alfalfa strip on the within field distribution of Empoasca fabae (Harris) (Homoptera: Cicadellidae) and several species of insect predators were examined for 3 yr (1998-2000). The objectives were to determine whether this uncut strip would serve as a trap crop for E. fabae and a refuge for insect predators at first harvest. Empoasca fabae and insect predators in the families Coccinellidae, Nabidae, Anthocoridae, Chrysopidae, and Hemerobiidae were collected weekly using sweep samples and sticky traps from the uncut strips and up to 40 m into the alfalfa regrowth. For 2 yr, both small- (0.34 ha) and large-scale (approximately 11.3 ha) field trials showed higher numbers of E. fabae in 73% of the uncut strips for 2-3 wk after harvest. Similarly, the number of insect predators found within <50% of the uncut strips was also higher during the first or second week after harvest. In 1999, however, we did not observe higher numbers of E. fabae in the uncut strips. Differences may be because of higher E. fabae population numbers in 1999 compared with 1998 and 2000. This research provides alfalfa growers a potential cultural management technique for E. fabae while conserving predatory insects.
在3年时间里（1998 - 2000年），研究了一条3米宽未割苜蓿带对田间豆叶蝉（Harris）（同翅目：叶蝉科）及几种捕食性昆虫分布的影响。目的是确定这条未割带在首次收割时是否会成为豆叶蝉的诱集作物和捕食性昆虫的避难所。每周使用扫网样本和粘性诱捕器，从未割带以及进入苜蓿再生区达40米的范围内收集豆叶蝉和瓢虫科、花蝽科、花蝽科、草蛉科和褐蛉科的捕食性昆虫。在为期2年的时间里，小型（0.34公顷）和大型（约11.3公顷）田间试验均表明，在收割后的2 - 3周内，73%的未割带中豆叶蝉数量较多。同样，在收割后的第一周或第二周，在不到50%的未割带中发现的捕食性昆虫数量也较多。然而，在1999年，我们并未观察到未割带中豆叶蝉数量较多的情况。差异可能是由于1999年豆叶蝉的种群数量比1998年和2000年更多。这项研究为苜蓿种植者提供了一种在保护捕食性昆虫的同时，对豆叶蝉进行潜在栽培管理的技术。
