Seasonal Drift of Lethocerus Americanus (Hemiptera: Belostomatidae) in a Lake Superior Tributary
Seasonal Drift of Lethocerus Americanus (Hemiptera: Belostomatidae) in a Lake Superior Tributary
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苏必利尔湖支流中美洲斑蝽（半翅目：Belostomatidae）的季节性漂移
DOI：
10.22543/0090-0222.1774
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发表时间：
2017
影响因子：
--
通讯作者：
Michael L Rackouski
中科院分区：
文献类型：
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作者：
R. B. Dubois;Michael L Rackouski
漂流的成年Lethocerus美国捕获和保留的倾斜屏幕小鲑鱼陷阱在两个领域的季节，在博伊斯布鲁尔河，威斯康星州。季节性漂移高峰出现在春季，持续4周，从9月中旬开始，持续7 - 8周，直到冰层形成，当我们的设备不工作时，可能会在冰层覆盖下继续漂移。这些发现与已知的这些昆虫从透镜栖息地飞到溪流越冬的运动模式一致，但也表明通过漂移的纵向运动，可能到达特定的越冬地点。1989年漂流与水温下降显着相关，但1990年则不然。大多数漂移发生在水温低于12°C时。漂流与河流流量之间没有相关性。漂流率一直很低，最大体积为每10,000 m3 9只。巨型水蝽（Lethocerus americanus [Leidy]）通常在各种类型和大小的低温生境中发现，它们在那里繁殖，有时越冬（亨格福德1920，兰金1935，Hilsenhoff 1984）。在溪流中的发生被认为是罕见的（Menke 1963）。然而，已知它们会飞到溪流中越冬，并经常在秋末和早春沿着河岸收集（Hilsenhoff et al. 1972，Hilsenhoff 1984）。霍夫曼（1924）在12月发现一些冬眠的成虫在明尼苏达州一条溪底的分解植物材料中约15厘米深，其他成虫在溪边附近的香蒲属植物根中6至8厘米深。虽然这种一般的生活史模式，包括河流越冬已经相当好地建立，很少有信息是关于漂流或其他方面的本物种在lotic系统。这些昆虫不常被流网捕获，可能是因为它们在溪流中相对不常见。它们也可以从许多传统的流网中爬出来。一个小鲑鱼陷阱用于捕捉迁移的萨尔莫类被证明是有效的捕捉和保留漂流L。美国。本文报道了这些昆虫在威斯康星州博伊斯布鲁尔河的春、秋漂流。l威斯康星州自然资源部，研究局，Box 125，Brule，WI 54820。2现住址：1806 6 th Street E.，阿什兰，威斯康星州54806。[1]杜波依斯和拉库斯基：美洲裸蝽的季节性漂流（半翅目：Belost出版者：ValpoScholar，1992 86大湖昆虫学家第25卷，第2号研究地点和方法79公里长的Bois Brule河排出约320平方公里的多样化且稀疏开发的水流域，向北流入上级湖的西端。这条四阶河流的平均流量约为6 m3/sec，总碱度平均为58 mg/L CaCO 3。L. americanus的采样与倾斜的屏幕小鲑鱼陷阱[见杜波依斯等。（1991）的设计规范和oJ？在离河口约11公里处的七鳃鳗屏障上运作。存水弯安装在堰塞坝的下游面。将待取样的水（根据河流水位，占河流总流量的6 - 10%）分流到由间隔6.4 mm的平行铝棒制成的倾斜筛上，并流入覆盖有防水油布的浮动捕获驳船。由于陷阱的覆盖和大量的水进入陷阱，巨大的水虫从陷阱中爬出来或飞出来的可能性不大。我们假设所有的L。进入诱捕器的美洲个体被保留，直到我们移除内容物。
Drifting adult Lethocerus american us were captured and retained by an inclined-screen smolt trap during two field seasons in the Bois Brule River, Wisconsin. Seasonal peaks of drift occurred in spring for 4 weeks following ice out and in autumn for 7 -8 weeks from mid-September through ice formation, and may have continued under ice cover when our gear was not operated. These findings are consistent with the known movement pattern of these insects to fly from len tic habitats to streams to overwinter but also suggest longitudinal movement via drift, perhaps o reach specific overwintering sites. Drif was significantly correlated with declining water temperatures in 1989 but not in 1990. Most drift occurred at water temperatures less than 12°C. There was no correlation between drift and river discharge. Drift rates were consistently low with a maximum by volume of 9 animals per 10,000 m 3• Giant water bugs (Lethocerus americanus [Leidy]) are generally found in len tic habitats of various types and sizes where they breed and sometimes overwinter (Hungerford 1920, Rankin 1935, Hilsenhoff 1984). Occurrence in streams is thought to be infrequent (Menke 1963). They are, however, known to fly to streams to overwinter and ar frequently collected in late autumn and early spring along stream banks (Hilsenhoff et al. 1972, Hilsenhoff 1984). Hoffman (1924) found some hibernating adults in December about 15 cm deep in the disintegrated plant material of a Minnesota stream bottom, and others 6 to 8 cm deep among Typha roots near the stream edge. Although this general life history pattern involving riverine overwintering has been fairly well established, little information is available about drifting or other behav ioral aspects of thi species in lotic systems. These insects are not often captured in drift nets, probably because they are relatively uncommon in streams. They may also be able to crawl out of many conventional drift nets. A smolt trap used to capture migrating salmo nids proved to be effective in capturing and retaining drifting L. america us. This paper reports on the spring and autumn drifting of these insects in the Bois Brule River, Wisconsin. lWisconsin Department of Natural Resources, Bureau of Research, Box 125, Brule, WI 54820. 2Present address: 1806 6th Street E., Ashland, WI 54806. 1 DuBois and Rackouski: Seasonal Drift of Lethocerus Americanus (Hemiptera: Belost Published by ValpoScholar, 1992 86 THE GREAT LAKES ENTOMOLOGIST Vol. 25, No.2 STUDY LOCATION AND METHODS The 79-km Bois Brule River drains a diverse and sparsely developed water shed of about 320 km2 and flows north into the western end of Lake Superior. Discharge from this spring-fed, fourth-order river averages about 6 m3/sec, and total alkalinity averages 58 mg/L CaC03• A more complete description of the Bois Brule River watershed was given by DuBois (in press). L. americanus was sampled with an inclined-screen smolt trap [see DuBois et al. (1991) for design specifications and oJ?erational details] operated t a lamprey barrier about 11 km above the river s mouth. The trap was attached to the downstream face of the barrier dam. Water to be sampled (6 to 10% of the total river flow depending on river level) was shunted down an inclined screen made of parallel aluminum rods spaced 6.4 mm apart and flowed into a floating catch barge covered with a tarpaulin. Because of the covering and the large volume of water entering the trap, escape of giant water bugs from the trap by either crawling or flying out was unlikely. We assume that all L. americanus individuals entering the trap were retained until we removed the contents.