广聚萤叶甲在豚草上的空间分布

广聚萤叶甲Ophraella communa LeSage是恶性入侵杂草豚草Ambrosia artemisiifolia L的一种重要天敌,为了了解广聚萤叶甲卵、幼虫、蛹、成虫在豚草上的分布情况,本文对各虫态广聚萤叶甲在豚草植株上的空间分布进行了调查。调查结果表明,各虫态广聚萤叶甲在豚草上的空间分布均为聚集分布;不同受害程度豚草植株上各虫态广聚萤叶甲主要分布于上部和中部。就不同受害程度豚草植株上同一虫态广聚萤叶甲而言,卵比例随受害程度的加重逐步递减,幼虫和蛹的比例则逐步增加。由此可见,广聚萤叶甲为了确保后代能获得更充足的食物,成虫倾向于在受害程度较轻的植株上产卵。     

空心莲子草叶甲室内大量繁殖研究

为了大量繁殖供环境释放的空心莲子草叶甲Agasicles hygrophila以实现空心莲子草区域减灾, 我们探索出室内大量饲养与繁殖空心莲子草叶甲的方法与流程, 包括用叶片法或苗水培法孵化卵粒、用盒养法饲养各龄幼虫与成虫并供成虫产卵、用栽培活苗笼养法化蛹羽化。在室内成虫终日均能取食、交配、产卵, 产卵前期约4～5 d, 产卵高峰期在羽化后第7～24 天, 每雌平均产卵21.08块, 约570粒。盒养法叶片平均可着卵4.28块, 叶背与叶面着卵量相近; 笼养法叶片平均着卵为1.46块, 卵主要产于叶背。盒养法与笼养法得到的卵孵化率分别为94.02%与92.50%。空心莲子草叶甲除化蛹需在栽培活苗上完成外, 各龄幼虫与成虫均可用离体新鲜苗盒养法密集饲养。初孵1龄幼虫转株（叶）期、3龄老熟幼虫转化蛹苗期是室内大量饲养与繁殖空心莲子草叶甲的关键时期, 高密度成功饲养与繁殖空心莲子草叶甲的最适化蛹接虫量是每株8头, 产卵期雌虫的最适密度是每株5头。     

豚草条纹萤叶甲的交配和产卵行为

在我国大陆发现的豚草条纹萤叶甲Ophraella communaLeSage原产于北美洲,取食入侵生物豚草(Ambrosia artemisiifoliaL.)。通过观察该叶甲的交配和产卵行为以及两者之间的相关性,结果表明,豚草条纹萤叶甲一生多次交配,室内观察1次交配时间平均为38.2min,产卵历期平均13.2d,每雌平均产卵312.1粒;但野外产卵量高于室内,平均为553.8粒;卵多聚产在植株幼嫩叶片的背面。雌成虫平均寿命为16.0d。雌成虫随交配次数的增多,产卵量增大、产卵历期和成虫寿命延长,存在显著的直线相关性。     

粉虱小毛瓢虫Nephaspis oculatus(鞘翅目,瓢虫科)捕食功能反应与寄主植物选择(英文)

Nephaspisoculatus (Blatchley)属毛瓢虫亚科的小毛瓢虫族 ,专食粉虱。它源于中美洲 ,自七十年代初就在美国佛州被发现 ,是柑橘和蔬菜上白粉虱的重要天敌。本研究确定了该瓢虫各幼虫龄期和雌雄成虫在青菜 (col lard)叶上捕食银叶白粉虱BemisiaargentifoliiBellows&Perring卵在 6个密度的捕食功能反应及其成虫对 5种寄主植物的选择。结果表明 ,该瓢虫捕食率与白粉虱卵的密度呈线性相关。除第四龄幼虫其相关系数 (r2 )仅为0 .6 33外 ,其它各虫态的相关系数高达 0 .82 7～ 0 .94 4。根据该瓢虫各龄幼虫和雌雄成虫捕食量和白粉虱卵密度的关系 ,其捕食功能反应符合Holling圆盘方程的第二种反应模式。随着龄期的增加 ,幼虫捕食白粉虱卵的量也随之增加。第四龄幼虫捕食白粉虱卵量最多可达 312粒 ,其次为第三龄幼虫 2 2 9粒 ,第二龄幼虫 73粒 ,而第一龄幼虫捕食量仅为 34粒。雌成虫捕食白粉虱卵量 (32 1粒 )明显高于雄成虫 (2 37粒 )。雌成虫特别喜欢在青菜上活动、取食和产卵 ,而不喜欢番茄 ,大豆 ,茄子和甘薯。有 4 4 .9%的雌成虫在青菜上活动 ,只有 9.9% - 17.1%的雌成虫在其它植物上活动。雌成虫在青菜 ,甘薯和茄子上的产卵量占总产卵量的比率依次为 95 .8% ,2 .8%和 1.4 % ,而无任何卵产在番茄和大豆上。     

广聚萤叶甲实验种群生命表

通过在(26±1)℃恒温条件下的饲养观察,组建了广聚萤叶甲实验种群的特定年龄生命表和生殖力表。结果表明:广聚萤叶甲卵、幼虫、蛹和产卵前期的历期分别为7.51、12.14、7.67和4.75d;各虫态的存活率变幅在77%～94%,其中以卵期存活率最高,3龄幼虫存活率最低,且种群存活曲线呈DeeveyⅡ型分布;单雌平均产卵量为193.8粒;种群趋势指数为36.95,世代平均历期为31.37d,内禀增长能力为0.095,周限增长率为1.10。     

印度瓜野螟种群的增长力及其密度制约

在养虫室内群体饲养条件下,对印度瓜野螟种群动态的测定结果表明:第二代和第三代的种群内禀增长力(rm)分别为0.0792和0.0487,它们的累计产卵率随时间而表现出逻辑斯蒂曲线变化。在相同的生活和取食空间内,幼虫的发育速率和存活率随种群密度的增长而下降;每对成虫的每天产卵量随成虫密度的增加而递减,单对成虫密度下的产卵率比17对成虫密度下的产卵率高达18倍左右。     

广聚萤叶甲成虫产卵行为及其产卵部位的选择性

【目的】明确广聚萤叶甲成虫产卵行为及其产卵部位的选择性。【方法】在室内条件下,对广聚萤叶甲成虫交配及产卵的系列行为、产卵场所选择、不同部位豚草植株叶片叶绿素b的含量进行了观察和测定:(1)将1对成虫放到养虫笼内的一株豚草上,观察交配时间,记录产卵数量、前后2粒卵之间的产卵时间间隔;(2)在均匀分为5部分(0～10、11～20、21～30、31～40和41～50 cm)的豚草植株上,随机放置10对成虫,观察雌虫对于产卵场所的选择。(3)将上述5个部位的豚草叶片通过丙酮匀浆法处理,用紫外分光光度计测定其在645和663 nm的吸光值,计算叶绿素b含量。【结果】广聚萤叶甲成虫完成一次成功交配平均需96.09 min。雌虫一般需45 min的时间来寻找其适应的产卵场所,在产卵过程中,成虫习惯将卵产于叶片背面,雌虫喜欢用口器来清理刚产下的卵粒。在一株50 cm高的豚草植株上,雌虫喜欢将卵产在植株中部21～30 cm和中上部31～40cm的叶片上(从下往上划分)。卵块数量和豚草不同部位叶片叶绿素b含量呈显著的正相关性。【结论】广聚萤叶甲成虫喜欢产卵在叶绿素b含量较高的叶片背面,可能以视觉识别叶片颜色来选择和定位产卵场所。     

亚非草蛉的生物学及其对柑桔潜叶蛾幼虫的捕食效应研究

在实验室条件下,亚非草蛉的平均发育历期为:卵期3.1天,幼虫8.9天,成虫寿命雌虫101.7天、雄虫61.8天,产卵前期8.4天。每雌虫平均产卵量400.3粒。最大产卵量746粒。产卵高峰期为羽化后的16—24天。亚非草蛉对湿度的适应范围较广,但幼虫的死亡率与湿度的关系大。 亚非草蛉幼虫一生捕食柑桔潜叶蛾幼虫数平均为149.1头,其日捕食量随龄期的增大而增加。温度对草蛉幼虫的捕食效应具有显著的影响,在35℃时达到最高的捕食效应,而在15℃以下和40℃以上,则受到明显的限制。湿度对草蛉捕食潜叶蛾幼虫的影响呈Iogistic曲线。草蛉对潜叶蛾幼虫密度的功能反应属HollingⅠ型反应。草蛉幼虫对其自身密度的功能反应可用Watt模型模拟。草蛉对潜叶蛾幼虫的捕食作用率随捕食者个体间的相互干扰作用的增加而下降,两者之间的关系随草蛉幼虫数的增加呈幂函数下降曲线。 田间观察及室内试验结果表明,亚非草蛉是柑桔潜叶蛾的一种重要的捕食性天敌。     

豚草条纹萤叶甲各虫态的空间分布型

豚草条纹萤叶甲Ophraella communa LeSage是恶性入侵豚草(Ambrosia artemisiifolia L.)的天敌,用频次分布拟合和多种聚集指数测度等方法对该叶甲的成虫、幼虫和蛹、卵的空间分布型进行研究。结果表明,豚草条纹萤叶甲卵、幼虫+蛹、成虫的空间分布符合负二项分布,种群个体的空间分布为聚集分布。用几种衡量聚集度的指标,对上述各虫态分布的聚集程度进行测定;然后计算出各虫态田间最适理论抽样数。     

异色瓢虫非同胞间食卵自相残杀对成虫生殖力的影响

【目的】食卵自相残杀现象常见于瓢虫中,业已明确取食同胞卵对于初孵瓢虫至关重要,但取食非同胞卵的营养价值是否高于蚜虫仍存争议。本研究旨在明确异色瓢虫Harmonia axyridis在幼虫期除取食蚜虫外兼捕食非同胞卵是否影响其雌成虫的生殖表现。【方法】在异色瓢虫幼虫期设置3个饲喂处理,即仅饲喂禾谷缢管蚜Rhopalosiphum padi(对照)、除饲喂蚜虫外还分别给各龄幼虫饲喂少量非同胞卵(分散食卵)以及除饲喂蚜虫外仅给高龄幼虫饲喂较多非同胞卵(集中食卵)等,观察雌成虫体型大小、产卵前期、连续10 d的逐日产卵量和卵孵化率等形态和生殖特性。【结果】饲喂处理对瓢虫雌成虫体型大小无显著影响,对照、分散食卵和集中食卵3种饲喂处理下的雌成虫身体体积分别为92.30,89.73和93.98 mm~3;饲喂处理对雌成虫产卵前期也无显著影响,3种饲喂处理下雌成虫产卵前期分别为7.50,7.74和7.70 d;但饲喂处理对雌虫生殖力具有显著影响,分散食卵处理与对照无显著差异,羽化后10 d分散食卵和对照下累计产卵量分别为185和205粒,但集中食卵(88粒)比对照或分散食卵的产卵量显著降低;饲喂处理对卵孵化率无显著影响,对照、分散食卵和集中食卵3种饲喂处理下的卵孵化率分别为63.10%,72.58%和66.61%。【结论】结果说明,异色瓢虫各龄幼虫偶尔取食非同胞卵不影响其成虫的生长发育和生殖,但高龄幼虫捕食较多非同胞卵可降低其雌成虫的生殖力。     

幼虫密度对甜菜夜蛾生长发育与繁殖的影响

为了研究甜菜夜蛾Spodoptera exigua(Hübner)幼虫的密度对其发育及繁殖的影响,本实验观察了5种幼虫密度下（1,5,10,20,30头/瓶）,幼虫发育和成虫繁殖情况。结果表明：幼虫和蛹历期、存活率和蛹重均差异显著。幼虫和蛹历期均以20头/瓶的最短,1头/瓶的最长,其余随幼虫密度增加而延长;幼虫至蛹存活率以10头/瓶的最高,其余随幼虫密度增加而降低;1头/瓶的蛹最重,显著高于其他密度的,其余随幼虫密度增加而下降。尽管密度间成虫羽化率和产卵前期均无显著差异,但成虫产卵量、寿命和畸形率差异显著。1头/瓶的产卵量最多,其次为10头/瓶的,其余随幼虫密度增加而减少,30头/瓶的产卵量显著少于其他密度的; 密度在1～20头/瓶范围内,雌蛾寿命均较短,显著短于30头/瓶的,而雄蛾寿命以5头/瓶的最短,显著短于其他密度的（10头/瓶除外）,10头/瓶的次之,其余密度间差异不显著;不同幼虫密度下羽化的成虫畸形率差异显著,10头/瓶的最低,其余随幼虫密度增加而升高; 生命表结果表明甜菜夜蛾在10头/瓶下世代存活率和种群增长指数均最高,幼虫密度过低或过高均不利于种群增长;世代存活率（S）和种群增长指数（I）与幼虫密度之间的关系均呈抛物线关系：S =－0.2087x²+2.5694x+211.52 (R²=0.88),I=－0.0552x²+0.9166x+54.168 (R²=0.95)。结果提示幼虫密度影响甜菜夜蛾种群动态的重要生态因子之一。     

Artificial diets for rearing the coconut hispine beetle Brontispa longissima and its parasitoid Asecodes hispinarum

We tested artificial diets for rearing the coconut hispine beetle, Brontispa longissima, a serious invasive pest of coconut (Cocos nucifera) in Southeast Asia. We examined three artificial diets that were identical except for their agar content. The survival rate from hatching to adult emergence was 26.0% when beetles were reared on a ‘soft diet’ (20 g/l agar), 16.0% on a ‘hard diet’ (40 g/l agar), and 41.0% on a ‘mixed diet’, in which the hard diet was used for the first instar and the soft diet for later instars. Females raised as larvae on the mixed diet and then as adults on the soft diet laid few eggs, which did not hatch. However, females reared on the mixed diet as larvae and then on fresh leaves as adults consistently laid eggs that hatched. We then examined the suitability of B. longissima larvae reared on the mixed diet as hosts for the larval parasitoid Asecodes hispinarum, a specialist parasitoid of this beetle. Of the oviposited hosts, 75.0% became mummified and 41.7% produced adult wasps. These results indicate that the mixed diet may be useful for rearing B. longissima larvae as hosts for the rearing of A. hispinarum.     

Laboratory evaluation of Toxorhynchites splendens (Diptera: Culicidae) for predation of Aedes albopictus mosquito larvae

Biology of the mosquito Toxorhynchites splendens (Wiedemann) was studied in the laboratory to provide baseline data for using the predatory larvae of this species against those of Aedes albopictus (Skuse) in a biological control programme. The mean incubation time of Tx.splendens eggs was 43.8 h and the time required for newly-hatched larvae to initiate predation was 2.5 h. Mean numbers of prey larvae consumed and killed by each Tx.splendens larva totalled 389 and 345 respectively. The larval period of Tx.splendens was not significantly different for rearing individually or in groups of nine, with equal prey density, and duration of larval development was proportional to prey density. In mass rearing, larval cannibalism was usually observed during days 1-3 post-eclosion. The incidence of cannibalism decreased sharply on the fourth day after hatching when some larvae became fourth-instar. Adult female Tx.splendens usually commenced oviposition on day 4 after emergence. The number of eggs laid daily increased on day 7 and the peak oviposition of 6.3 eggs/female/day occurred on day 11. When oviposition containers were provided only intermittently, gravid females of Tx.splendens scattered most of their eggs on the dry floor of the cage. Viability of eggs laid by females aged 4-14 days was high (60-90%) but decreased to less than 40% as the females aged.     

Rearing the 28-spotted ladybird beetle,Henosepilachna vigintioctopunctata (Coleoptera: Coccinelidae), with a switchover from host plant leaves to artificial diet

In this study, I tested an artificial diet, Insecta LFS, for rearing the 28-spotted ladybird beetle, Henosepilachna vigintioctopunctata (Fabricius). H. vigintioctopunctata larvae could not be reared through all of the larval stages on the artificial diet. However, initially they could be reared on tomato leaves up to the second or third instar, and thereafter exclusively on the artificial diet. The larval and pupal periods were not significantly different from those reared only on tomato leaves. For females reared by the diet-switching method, the preoviposition period was significantly longer and the number of eggs laid significantly lower than for those on tomato leaves. However, these differences did not become a hindrance to laboratory rearing. This rearing method saves labor involving obtaining fresh plant leaves and produces a reliable supply of the insects.     

Influence of Bacillus thuringiensis var. israelensis on oviposition of Aedes albopictus (Skuse).

The effect of Bacillus thuringiensis var israelensis (B.t.i.) on the oviposition behavior of Aedes albopictus was evaluated in the field and laboratory in Clemson, SC, U.S.A. In the field, water taken from containers in which mosquito larvae were reared (conditioned water) was placed in 16 containers. Eight containers received 50 jld of B.t.i., and eight with water only were kept as controls. In the laboratory, field-collected females of Ae. albopictus were placed in rearing chambers and provided two containers for oviposition, one with 50 microl of B.t.i and one a control with water only. Eight cage experiments were conducted, five using filtered tap water and three with conditioned water. In the field over the 13 trials, more eggs were laid in the containers with B.t.i. although no significant difference was found in the number of eggs between the treatment and controls over 72 h. In the laboratory, more eggs were laid in the containers with B.t.i. versus the controls. The containers had filtered tap water and B.t.i. had significantly more eggs laid in them compared to the controls.     

Development,survival, body weight,longevity, and reproductive potential of Oemena hirta (Coleoptera: Cerambycidae) under different rearing conditions

Oemona hirta (F.) is a New Zealand native longicorn beetle, whose larvae bore into the wood of branches and stems of living trees and vines, causing serious damage. To explore effective methods for maintaining laboratory colonies and biology of immature stages of this species we evaluated four laboratory rearing methods with both natural and artificial diets and compared biological parameters of laboratory colonies with those of field-collected insects. On an artificial diet, approximately 40% of neonate and 70% of autumn- and 11% of winter-collected larvae reached adulthood. Neonate larvae could not complete their development in cut poplar (Populus nigra variety italica Koehne) twigs; however, when twigs were standing in water >46% of neonate larvae survived to adulthood. Mean larval development time ranged from approximately150 to almost 300 d, depending on rearing methods. Mean pupal stage ranged from 15 to 19 d. Adult females were significantly heavier than males. Although adult females from field-collected twigs and reared on the artificial diet had similar mean body weight, which was significantly greater than that of other rearing colonies, the potential fecundity was the highest in the former (83.1 +/- 29.4 eggs) and the lowest in the latter (33.5 +/- 9.1 eggs). In all laboratory-reared and field-collected insects, the total number of eggs produced (eggs laid + eggs that remained in dead female body) by females was positively correlated with their body weight. When larvae fed on the artificial diet, there was no positive correlation between the number of eggs successfully laid and female body weight. However, when larvae lived on natural food, a positive correlation was found. In laboratory colonies, mean longevity of females (36 to 52 d) was slightly greater than that of males (30 to 50 d) without significant difference between sexes but in the adults from field-collected twigs, males (52 d) lived significantly longer than females (33 d). In terms of time, labor, and the number of resulting adults, collecting larvae in the field in autumn and then transferring them onto artificial diet is the most effective method for maintaining a laboratory colony.     

大螟人工饲养技术的初步研究

利用大豆粉、玉米粉、麦胚和鲜茭白等成分配制了大螟Sesamia inferens(Walker)的半合成人工饲料,利用该饲料配方,发展了大螟的长期、继代饲养技术,即初孵-2日龄幼虫在茭白上饲养,3日龄-化蛹在人工饲料上饲养。利用该方法连续饲养大螟3代,幼虫的发育历期、蛹重、幼虫存活率、化蛹率、羽化率、卵孵化率和单雌产卵量等生活史参数与在天然饲料茭白上饲养的大螟相比,二者没有任何显著差异。而且利用该方法饲养,成本低、省工省力,能显著减少病原菌的感染。这说明该饲养技术适于大螟种群的长期、继代饲养。     

黄粉虫成虫繁殖力及影响幼虫发育的因素

对单配或一雄多雌或经历不同交配历期的雌黄粉虫 Ｔｅｎｅｂｒｉｏ ｍｏｌｉｔｏｒ Ｌ．产卵量进行了研究,以期了解两性的繁殖力,为雌虫多产高质量卵提供科学依据。在幼虫期添加少量鲜马铃薯可极大地促进其生长。适当的高密度和不筛粪有利于低龄幼虫生长,４０日龄以后应定期筛粪并添加新饲料。幼虫的最适密度取决于其拥有的饲料量。幼虫生态生长效率高达３１．８％。