Pierce C M F, Gray M E
Department of Entomology, University of Illinois, Urbana-Champaign, IL 61801, USA.
J Econ Entomol. 2007 Aug;100(4):1104-15. doi: 10.1603/0022-0493(2007)100[1104:pdoawc]2.0.co;2.
Three on-farm sites in Iroquois County, IL, each containing an adjacent 16.2-ha commercial production maize, Zea mays L., and soybean, Glycine max (L.) Merr., field, were monitored for western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), adults from June through September 1999-2001. Mean captures of D. v. virgifera adults as measured with Pherocon AM yellow sticky traps were significantly greater in maize than in soybean. Overall mean numbers of D. v. virgifera adults captured with vial traps were significantly greater in soybean than in maize. Emergence cage data revealed that after 50% emergence of D. v. virgifera adults occurred, peak captures of D. v. virgifera adults occurred in maize as measured with vial and Pherocon AM traps. After maize reached the R2 (blister stage, 10-14 d after silking) stage of development and 90% emergence of D. v. virgifera adults had occurred, peak captures of D. v. virgifera adults were observed in soybean by using vial and Pherocon AM traps. Also, after maize reached the R2 stage of development, numbers of females significantly increased in soybean and decreased in maize. Captures of female D. v. virgifera adults frequently exceeded published economic thresholds in soybean, regardless of trap type used. Estimated survival of variant D. v. virgifera (egg to adult) in these commercial rotated maize fields was 10.7 and 9.4% from 1999 to 2000 and from 2000 to 2001, respectively. This compares with nonvariant D. v. virgifera survival estimates in continuous maize production systems in Iowa of 6.7 and 11% from 1983 to 1984 and from 1984 to 1985, respectively.
对伊利诺伊州易洛魁县的三个农场地点进行了监测，每个地点都有相邻的16.2公顷商业化种植的玉米（Zea mays L.）田和大豆（Glycine max (L.) Merr.）田，在1999年至2001年的6月至9月期间监测西部玉米根虫（Diabrotica virgifera virgifera LeConte，鞘翅目：叶甲科）成虫。用Pherocon AM黄色粘虫板测量，玉米田中D. v. virgifera成虫的平均捕获量显著高于大豆田。用小瓶诱捕器捕获的D. v. virgifera成虫的总体平均数量在大豆田中显著高于玉米田。羽化笼数据显示，在D. v. virgifera成虫羽化50%后，用小瓶诱捕器和Pherocon AM诱捕器测量，玉米田中D. v. virgifera成虫的捕获量达到峰值。在玉米进入R2（水泡期，抽丝后10 - 14天）发育阶段且D. v. virgifera成虫羽化90%后，用小瓶诱捕器和Pherocon AM诱捕器在大豆田中观察到D. v. virgifera成虫的捕获量达到峰值。此外，在玉米进入R2发育阶段后，大豆田中雌虫数量显著增加，玉米田中雌虫数量减少。无论使用何种诱捕器类型，大豆田中雌性D. v. virgifera成虫的捕获量经常超过已公布的经济阈值。在这些商业化轮作玉米田中，变异型D. v. virgifera（卵到成虫）的估计存活率在1999年至2000年以及2000年至2001年分别为10.7%和9.4%。相比之下，爱荷华州连续玉米生产系统中，非变异型D. v. virgifera在1983年至1984年以及1984年至1985年的存活率估计分别为6.7%和11%。
