黄河滩区东亚飞蝗天敌种类及其消长规律

2000~2005年对黄河滩区东亚飞蝗Locusta migratoria manilensis(Meyen)天敌种类普查,调查结果显示,东亚飞蝗天敌104种,隶属6纲23目43科,优势种9种。评价了天敌对东亚飞蝗的控制作用,优势种为中国雏蜂虻Anastoechus chinensis Paramonow,在发生区内,对卵块寄生率为22.4%~56.5%,一般年份寄食率为36%。星豹蛛Pardosa astrigera L.Koch在蜘蛛类天敌中占50%~70%,是蝗蝻期的重要天敌。发现不同植被覆盖度内的飞蝗天敌群落和数量有明显的差异。     

论挖掘蝗卵和新翻蝗卵

东亚飞蝗自古以来是中国农业上的头号害虫,历史和地方志上记载很多。农民为了保护生产,想尽种种办法和蝗虫作斗争,在耕作过程中观察到雌蝗产一卵于土下一二寸处,集数十粒至百余粒成一卵块,挖掉一个卵块就可少生几十只蝗虫,因此挖掘蝗卵是很久以前农民自己创造的治蝗方法之一。后来生产发展了,也有用犁耕翻蝗卵的,耕翻时可以直接或间接地杀死部分蝗卵。所以在较早年代的农书或治蝗书     

基于GIS和GS的东亚飞蝗卵块空间格局的研究

本文以沿渤海蝗区东亚飞蝗Locusta migratoria manilensis (Meyen) 越冬卵块为研究对象,野外采用450 m和50 m规则栅格取样,包括卵量、植被覆盖度、土壤含水量、含盐量、土壤pH和有机质等,利用地统计学方法,在GIS平台下,分析研究区域内影响蝗虫产卵选择的环境因子、蝗虫卵块的空间异质性及分布格局。结果表明, 植被覆盖度、土壤含盐量和土壤含水量在有卵和无卵的环境中存在极显著的差异,飞蝗产卵时最适宜的植被覆盖度、土壤含水量和盐度范围分别为0～30%、10.1%～20.0%和0.09%～1.99%,且当小环境植被覆盖度>50%、土壤含水量>30%或含盐量>3%时,飞蝗不再选择产卵。蝗虫卵块具有高度空间异质性,其空间自相关范围平均为390 m且呈斑块、聚集分布,蝗虫卵块变异函数曲线为球状模型。利用块段克立格法进行空间局部插值,得到研究区域卵块的空间分布格局图,可较准确地描述飞蝗卵块在研究区域内的空间分布、形状、地理位置及相对位置。研究结果可为地面卵块抽样调查、实时跟踪蝗卵胚胎发育进程、确定蝗灾早期发生点、片防治区域及蝗灾早期遥感预警提供科学依据。     

飞蝗黑卵蜂的生物学特性和利用

飞蝗黑卵蜂在河北、河南、山东、安徽、江苏等蝗区均有分布,对蝗卵寄生率一般在10%左右,个别年份在50%以上,局部地区可达90%以上。它在江苏泗洪一年发生三代,在寄主卵内越冬。幼期在22—30℃之间的发育天数为22—34天,发育起点温度为16.3℃,积温平均为309.34日度(95%置信范围为253.72—364.96日度);成虫羽化温度在20—30℃之间(以25℃为最适)。第一代幼期为25—29天,第二代24天、第三代260—280天;成虫最长寿命为34天。雌蜂喜在新产的飞蝗卵块内产卵,每头可寄生2—3个卵块(约80—130粒),亦可寄生大垫尖翅蝗及中华蚱蜢的卵内;能孤雌生殖,其后代均为雄性。本文也介绍了对飞蝗黑卵蝗蜂人工饲养与繁殖释放的技术。     

越北腹露蝗卵寄生蜂：东方蝗卵蜂

东方蝗卵蜂Scelio oriemalis Dodd是越北腹露蝗Fruhstorferiola tonkinensis Will.卵的寄生性天敌.2004-2006年对广东省北部越北腹露蝗卵粒和卵块寄生率分别为43.18%和89.34%.东方蝗卵蜂产卵在越北腹露蝗卵中,幼虫期为2龄,每粒被寄生的蝗卵只出l头蜂.东方蝗卵蜂的产卵系统发达,不仅骨化程度高,而且具有伸缩性.雌雄件比约为1:0.6,羽化后即可交配.以5%的葡萄糖溶液喂养成蜂,最多可存活31 d.东方蝗卵蜂可能是某些年份越北腹露蝗种群下降的重要因子.     

基于沿海蝗区飞蝗卵块分布格局的土壤空间异质性

以沿海蝗区南大港水库为研究区域,通过连续2a野外450m,50m规则栅格取样,利用地统计学方法,在GIS平台下,分析东亚飞蝗卵块分布格局与土壤空间异质性的研究,结果表明：（1）飞蝗卵块呈斑块、聚集分布,并具有明显的空间异质性,其空间自相关范围为390m,且主要分布在南大港水库的中部和东部,少数分布在南部,而在西部和北部地块几乎没有卵的分布。（2）研究区域内土壤含盐量和5cm含水量由空间自相关引起的空间异质性分别占总空间异质性的76.15%、78.04%,即表现出较强的空间相关性,空间自相关范围分别为594m,621m,土壤有机质和pH值具有中等强度的空间相关性,由空间自相关引起的空间变异分别为61.85%和57.19%,空间变异尺度分别为1014m,1368m。（3）研究区域内卵块主要集中在土壤含盐量较低（〈1.9%）、含水量适中（10.1%~29.9%）的中部和东部地块,而在土壤含水量较高（〉30%）的西部和盐分过重（〉3%）的北部几乎没有卵块的分布。即在一定程度上,蝗区土壤理化特性的空间异质决定了飞蝗卵块的空间分布特点。（4）卵块和土壤理化特性的空间格局图不仅为野外抽样调查、蝗灾预测预报及其防治提供科学依据,而且对蝗区环境改造具有重要指导作用。     

内蒙古蜂虻三新种及—中国新记录种(双翅目:蜂虻科)

双翅目(Diptera)短角亚目(Brachycera)的蜂虻科(Bombyliidae)昆虫常见于草原和田间,访花吸蜜,有助于植物授粉。蜂虻的幼虫多为捕食性或寄生性,蜂虻亚科(Bombyliinae)的雏蜂虻属(Anastoechus Osten—Saeken)昆虫主要在蝗虫的卵袋内寄食,庸蜂虹亚科(Exoprasopinae)的绒蜂虹属(Villa Lioy)昆虫主要寄生于夜蛾科幼虫,少数为鞘翅目的天敌。这两个属的蜂虻主要分布在古北区,体均粗壮而密生长毛,但从亚科的特征,特别是头部形态容易区分,绒蜂虻属的头近球形,后头极发达。     

飞蝗黑卵蜂是中华稻蝗的寄生天敌

<正> 1988年入冬前从田间采集中华稻蝗 Oxya chinensis Thunberg卵块进行越冬和室内孵化观察。至1989年5月下旬～6月上旬,在若虫孵化期间,羽化出一批黑色寄生蜂,我们鉴定为飞蝗黑卵蜂 Scelio uvarovi Ogloblin,但蜂体只有2.75～3.05mm,比文献记载的明显为小,后又将标     

土灰虻(Tabanus griseus Krber)的生活史研究(双翅目:虻科)

1.土灰虻是北京附近地区虻类的主要种类之一。它分布在东北、华北及华东等地。成虫为害牛、驴、骡等家畜。本文是1951—54年在北京进行生活史研究的一个报告。 2.土灰虻的成虫自6月上旬开始出现,6月下旬至7月下旬发生最多,9月中旬以后,则极少发现。全年的活动时间约为3(1/2)月。 3.本种虻的卵期平均为4.5日,每一卵块孵出的幼虫平均为564个。幼虫期在当年羽化的幼虫,平均为61.3日;在翌年羽化的幼虫,平均为359日。蛹期平均为10.6日。本种虻主要一年发生1代,仅有少数的个体当年可以发生第2代。 4.本种虻的孳生地主要在水稻田,在芦苇塘和长有窄长叶杂草的水塘亦常有孳生,但在河、溪等流动的水源则未有发现。本种以幼虫越冬,其中以成熟幼虫占极多数。越冬的处所多在堤岸下22—25厘米深的冻结土中。 5.本种虻有一种卵寄生蜂——黄胸黑卵蜂,寄生率达23—34％。这种卵寄生峰在7月间发生最多。 6.关于本种虻各虫期的形态,本文均有描述;其中雄虻及各幼期的形态,尚系初次记述。 7.根据生活史与习性的研究,对本种虻的防治问题,提出了几点意见;铲除田埂,清理池塘和积水洼地,利用天敌以及适当期间进行药治等。     

茶毒蛾黑卵蜂的生物学

茶毒蛾黑卵蜂Telenomus euproctidis Wilcox是茶毒蛾卵的主要寄生蜂,它以一龄幼虫在寄主卵内过冬。雌蜂寿命平均为11.6—15.2天,单雌产仔数平均38.6头。蜂群产卵期为10—20天,80%以上的卵在前半期产下且多为雌蜂。一粒寄生卵育出一蜂。母蜂食蜂蜜比食清水者寿命长10倍,产仔数多11.8倍,子代雌性比高1.8倍。在日均温21.1℃时,完成一代需21—22天:30.1—30.9℃时10—12天。雌蜂羽化2日内交尾所得精子可供其一生受精之用。盗毒蛾、幻带黄毒蛾、乌桕毒蛾、戟盗毒蛾及一种黄毒蛾的卵是此蜂良好的补充寄主。幻带黄毒蛾卵期为9—10天,第8天的卵仍可寄生。在林间,对寄主卵块外层的卵粒寄生率较高;树冠各部位的卵块均可寄生。     

改治结合,根除蝗害的关键因子是“水”!

改治结合,根除蝗害的关键因子是“水”。其主要原因为:(1)水灾是为东亚飞蝗创造发生地和转移到临近地区危害的关键因子;(2)东亚飞蝗产卵的适宜的土壤含水量为10%～20%(沙土为10%～12%,壤土为15%～18%,粘土为18%～20%);(3)先涝后旱,飞蝗成片;(4)黄(河)患是东亚飞蝗蝗害发生的源泉。南水北调东线工程的实施,有利于滨湖(库)蝗区东亚飞蝗的持续控制。     

Influence of soil moisture on egg cold hardiness in the migratory locust Locusta migratoria (Orthoptera: Acridiidae)

Abstract.  The present study investigates the influence of environmental moisture on cold hardiness of the migratory locust, Locusta migratoria . The water content of locust eggs kept in soil at 30 °C varies according to the moisture content of the substrate. In turn, it can significantly affect the supercooling point of locust eggs (range from −26 to −14.8 °C) and the mortality when exposed to subzero temperatures. Environmental moisture influences the supercooling capacity of eggs and their survival at low temperature. When locust eggs of the same water content are exposed to subzero temperatures under different soil moistures, their mortality varies between short-time exposure and long-time exposure at subzero temperatures. Given a short-time exposure, mortality in wet soil is lower than in dry soil due to the buffering effect of soil water against temperature change. The pattern of egg mortality is reversed after long-time exposure at low temperature, suggesting that inoculative freezing may be an important mortality factor. It is suggested that interactions between soil moisture and low temperature can influence the cold hardiness of locust eggs, and partial dehydration is beneficial to over-wintering eggs of the migratory locust.     

Chill injury in the eggs of the migratory locust, Locusta migratoria （Orthoptera： Acrididae）： the time-temperature relationship with high-temperature interruption

Abstract Mortality of the overwintering egg of the migratory locust, Locusta migratoria L. , was attributed to chill injury because of its occurrence well above the egg's super cooling point. In this study, two parameters, upper limit of chill injury zone (ULCIZ) and sum of the injurious temperature (SIT), were used to examine the locust egg's cold hardiness. The value of ULCIZ for the locust egg is 1.06 ± 0.54°C, and the SIT is -329.7 (hour · degree). The superoxide dismutase (SOD) and catalase (CAT) activities changed dramatically after cold stress, indicating that oxygen and hydroxide free radicals are probably efficiently detoxified at low temperatures. It was suggested that the nature of chill injury in locust egg might be a complex of metabolic disorder and a non-proportional decrease in enzymatic reaction and transports, because the LDH activity at low temperature increased significantly and the ATPase activity decreased with prolonged duration of exposure to low temperatures. The results from high temperature interruption revealed that the high temperature intervals significantly increased the survival of locust eggs.     

Life history of a dipteran predator (Scathophagidae: Acanthocnema) of insect egg masses in a northern California stream

1. Little is known about the predators of insect eggs in fresh waters. This study describes aspects of the life history of a scathophagid fly (Acanthocnema sp.), whose larvae are predators of aquatic insect eggs. 2. Because the Acanthocnema predator oviposits its eggs on the surface of aquatic insect egg masses, all insect egg masses were collected regularly within a 200‐m reach of Redwood Creek (California, U.S.A.) between September 2003 and June 2007. Acanthocnema predators were found predominantly within egg masses of the caddifly Neophylax rickeri (Trichoptera: Uenoidae). 3. There was a mean of 0.25 Acanthocnema individuals per N. rickeri egg mass (n = 2367 egg masses). In general, N. rickeri egg masses were more commonly found clustered in aggregations (93.7%) than singly (6.3%), and Acanthonema were found more often within the aggregations of N. rickeri (98.7%) compared to singly laid egg masses (1.3%). 4. The duration of the Acanthocnema predator life stages was: egg 2.9 ± 0.8 (mean ± SD) days, larva 15.6 ± 10.2 days, pupa 80.3 ± 24.9 days and adult 7.2 ± 4.8 days. The short duration of the Acanthocnema egg stage (1–7 days) compared to that of its prey N. rickeri (2–4 weeks) raises the probability that the undeveloped eggs of N. rickeri would be available to the young predators upon hatching. Egg consumption of N. rickeri eggs by Acanthocnema averaged 262.6 eggs per larval period. 5. Acanthocnema had a bivoltine life cycle in which the first generation fed exclusively on N. rickeri egg masses in the winter and the second generation fed on the egg masses of several species, including other Trichoptera (Brachycentridae) and Diptera (Ceratopogonidae, Chironomidae) in the spring. These findings suggest differing feeding strategies by the first and second generations of Acanthocnema in response to the seasonal availability of prey species. This type of autecological information is important for understanding mechanisms of community interactions.     

Two eggs,two different constraints: a potential explanation for the puzzling intraclutch egg size dimorphism in Eudyptes penguins

Phenotypic plasticity and phenotypic stability are major components of the adaptive evolution of organisms to environmental variation. The invariant two-egg clutch size of Eudyptes penguins has recently been proposed to be a unique example of a maladaptive phenotypic stability, while their egg mass is a plastic trait. We tested whether this phenotypic plasticity during reproduction might result from constraints imposed by migration (migratory carry-over effect) and breeding (due to the depletion of female body reserves). For the first time, we examined whether these constraints differ between eggs within clutches and between egg components (yolk and albumen). The interval between colony return and clutch initiation positively influenced the yolk mass, the albumen mass, and the subsequent total egg mass of first-laid eggs. This time interval had only a slight negative influence on the yolk mass of second-laid eggs and no influence on their albumen and subsequent total masses. For both eggs, female body mass at laying positively influenced albumen and total egg masses. Female investment into the entire clutch was not related to the time in the colony before laying but increased with female body mass. These novel results suggest that the unique intraclutch egg size dimorphism exhibited in Eudyptes penguins, with first-laid eggs being consistently smaller than second-laid eggs, might be due to a combination of constraints: a migratory carry-over effect on the first-laid egg and a body reserve depletion effect on the second-laid egg. Both these constraints might explain why the timing of reproduction, especially egg formation, is narrow in migratory capital breeders.     

Differences in egg thermotolerance between tropical and temperate populations of the migratory locust Locusta migratoria (Orthoptera: Acridiidae)

The migratory locust Locusta migratoria L., which is widely distributed throughout the world, exhibits within- and between-population variation in cold tolerance. To understand physiological adaptation in populations, we studied the genetic basis of thermotolerance in Hainan (tropical) and Liaoning (temperate) populations and measured expression of Hsp70 and Hsp90 mRNA in both populations at low (0 degrees C) and high temperatures (40 degrees C). Phenotypic variation of thermotolerance is heritable. Heritable characteristics differed among different stages of locust egg development, as well as among different measures of thermotolerance. Nuclear genetic factors, rather than cytoplasmic factors, contribute to differences in cold tolerance between the tropical and temperate populations of the migratory locust; for heat tolerance, maternal effects were involved in three stages of egg development. Expression of Hsp90 mRNA was induced in temperate population after heat shock (40 degrees C x 12h), whereas expression of Hsp70 and 90 was induced in tropical population after cold shock (0 degrees C x 12h). We suggest that thermotolerance of locust eggs has a complex genetic basis and heat shock proteins may be involved in differences of thermotolerance between locust populations.     

Is juvenile hormone involved in the maternal regulation of egg size and progeny characteristics in the desert locust?

The role of juvenile hormone (JH) in the maternal regulation of progeny characteristics was examined in the desert locust, Schistocerca gregaria. Female adults of this species are known to produce smaller but more eggs when reared in isolation than do those reared in a group. Eggs laid by isolated females develop green hatchlings typical of solitarious forms, whereas those laid by the latter produce black hatchlings typical of gregarious forms. Topical application of a juvenile hormone analog (JHA), fenoxycarb, or implantation of corpora allata (CA) taken from the migratory locust, Locusta migratoria, caused crowded S. gregaria females to deposit smaller eggs, but did not have a significant effect on the number of eggs per egg pod except at high doses of JHA. The production of smaller eggs by treated and untreated crowded females was closely associated with earlier deposition of the egg pods and shorter oviposition intervals. However, neither JHA application nor CA implantation influenced the progeny characteristics in actively reproducing aged females under crowded conditions, while untreated control females started producing smaller and more eggs upon transfer to isolated conditions. These results may suggest that JH is not directly involved in the maternal regulation of phase-dependent progeny characteristics.     

飞蝗越冬卵过冷却点的季节性变化及生态学意义

运用热电偶方法测定了飞蝗LocustamigratoriaL .越冬卵过冷却点月份间的变化。结果表明 :飞蝗卵的过冷却点值波动较大 ,主要形成 2部分 ,一部分分布在 -2 5℃左右 ,另一部分分布在 -1 0℃左右 ,同时 ,这两部分的比例随着季节性气温的变化有明显的差异 ,气温较低的月份 ,-2 5℃左右的比例增加 ,而且最小过冷却点的值也更低 ;反之 ,-1 0℃左右的比例增加 ,过冷却点最高值也升高。这种现象说明了飞蝗卵对冬季低温的一种生态适应。     

Egg hatching of two locusts,Schistocerca gregaria and Locusta migratoria,in response to light and temperature cycles

The present study showed that the eggs of the desert locust, Schistocerca gregaria, and the migratory locust, Locusta migratoria, responded to photoperiod by hatching when placed on sand in the laboratory. S. gregaria mainly hatched during the dark phase and L. migratoria during the light phase. The importance of light as a hatching cue depended on the magnitude of the temperature change during the thermoperiod; photoperiod played a more important role in the control of hatching time in both species when the magnitude of the temperature change was small. In addition, the eggs of the two species that were covered with sand did not respond to photoperiod and hatched during both the light and dark phases, indicating that light did not penetrate through the sand. Because locust eggs are normally laid as egg pods and a foam plug is deposited between the egg mass and the ground surface, we tested a possibility that naturally deposited eggs perceived light through the foam plug. The eggs that were deposited and left undisturbed in the sand hatched during the light and dark phases at similar frequencies. These results suggest that the eggs of both locust species responded to light and controlled their hatching timing accordingly but would not use light as a hatching cue in the field. The evolutionary significance of the ability of eggs to respond to light in these locusts was discussed.