Rahman Khalidur, Bridges William C, Chapin Jay W, Thomas James S
Department of Entomology, University of Georgia, Athens, GA 30602, USA.
J Econ Entomol. 2007 Aug;100(4):1229-40. doi: 10.1603/0022-0493(2007)100[1229:TAHHMS]2.0.CO;2.
A survey of threecornered alfalfa hopper, Spissistilus festinus (Say) (Hemiptera: Membracidae), damage in 60 South Carolina peanut, Arachis hypogaea L., fields showed that 89 and 58% of plants had feeding girdles during 2003 and 2004, respectively. Use of a foliar insecticide for other target pests reduced hopper damage. Hopper damage was not affected by sampling distance from the field edge; therefore, injury was adequately assessed at 10 m from field borders. In-furrow insecticide choice, planting date, soil texture, previous crop, or tillage did not measurably affect girdling. Subsequent field experiments demonstrated a cultivar effect on threecornered alfalfa hopper injury, with the standard runner-type cultivar ('Georgia Green') more susceptible than the standard Virginia-type ('NC-V11'). More than 50% of stem girdling occurred on the basal quarter (first five internodes) of the plant. Most feeding occurred on secondary branches of main and lateral stems. Weekly sampling of seven grower fields showed that adult hoppers colonize peanut during June and produce two generations on peanut. Only low levels of plant girding were observed in June, but plant girdling increased gradually through late July, when girdling markedly increased contemporary with peak populations of first generation nymphs and adults. A second increase in plant girdling, observed in early September, coincided with the second generation of nymphs on peanut. Foliar treatments at 45- 60 d after planting (DAP) were most effective in suppressing injury. Granular chlorpyrifos treatment also suppressed hopper injury. There was no yield response to insecticide treatments at the hopper injury levels in these tests (up to six girdles per plant). Although the economic injury level (EIL) for this pest has not been defined, our data indicate that a critical interval for monitoring hopper activity is the first 3 wk of July, before the occurrence of significant injury. Where growers have a consistent risk of economic injury, applying foliar treatment in mid-July would be most effective in suppressing damage.
对南卡罗来纳州60块花生田（落花生）中的三角苜蓿盲蝽（Spissistilus festinus (Say)，半翅目：角蝉科）危害情况的调查显示，2003年和2004年分别有89%和58%的植株出现取食环痕。用于防治其他目标害虫的叶面杀虫剂减少了盲蝽的危害。盲蝽危害不受距田边采样距离的影响；因此，在距田边10米处即可充分评估危害情况。沟施杀虫剂的选择、播种日期、土壤质地、前茬作物或耕作方式对形成取食环痕均无显著影响。后续田间试验表明，品种对三角苜蓿盲蝽的危害有影响，标准蔓生型品种（‘佐治亚绿’）比标准弗吉尼亚型品种（‘NC-V11’）更易感虫。超过50%的茎部取食环痕出现在植株基部四分之一处（最初的五个节间）。大多数取食发生在主茎和侧枝的二级分枝上。对七个种植户田地的每周采样显示，成虫盲蝽于6月在花生田定殖，并在花生上繁殖两代。6月仅观察到低水平的植株取食环痕，但到7月下旬取食环痕逐渐增加，此时第一代若虫和成虫数量达到峰值，取食环痕显著增加。9月初观察到的第二次植株取食环痕增加与花生上的第二代若虫期一致。种植后45 - 60天（DAP）进行叶面处理对抑制危害最为有效。颗粒状毒死蜱处理也能抑制盲蝽危害。在这些试验中，在盲蝽危害水平下（每株多达六个取食环痕），杀虫剂处理对产量没有影响。尽管尚未确定该害虫的经济危害水平（EIL），但我们的数据表明，监测盲蝽活动的关键时期是7月的前三周，即显著危害发生之前。在种植户面临持续经济危害风险的地方，7月中旬进行叶面处理对抑制危害最为有效。
