松突圆蚧花角蚜小蜂的生物学

松突圆蚧花角蚜小蜂Cocvobius azumai Tachikawa是松突圆蚧Hemiberlesla pitysophila Takagi的重要寄生蜂,1987-1989年从日本引入我国广东省。对松突圆蚧花角蚜小蜂的形态、发育、繁殖、成虫寿命和取食寄主行为等生物学特征进行了观察。该蜂的雌性幼虫是松突圆蚧雌蚧的初级内寄生蜂,而雄性幼虫则是次级寄生蜂,重寄生在同种或它种膜翅目的老熟幼虫、预蛹和蛹上。雌雄两性的形态在所有发育阶段均不相同。交配过的雄蜂喜欢寄生产卵初期和盛期的雌成蚧,对巳寄生的寄主具有识别能力。在19.7℃一30.9℃变温条件下每头雌蜂平均产卵14.95粒,约60%的卵是在最初3天内产出。松突圆蚧花角蚜小蜂雌性蜂在21℃,24℃,27℃和30℃时从卵发育到成虫的平均历期分别为41.24,32.60,25.60和23.00天,发育起点温度10.1℃,有效积温448.3日度。该蜂在广东省一年发生。9-10代。     

花角蚜小蜂对松突圆蚧的寄生功能反应

在实验室条件下,以松突圆蚧(Hemiberlesia pitysophilaTakagi)雌成蚧为寄主,研究了花角蚜小蜂(Coccobius azumaiTachikawa)的寄生功能反应.结果表明:寄生功能反应均符合HollingⅡ型方程,且功能反应受到温度、寄主密度和寄生物密度的影响.在同一温度下,寄生数量随寄主密度的增大而增加;在15℃~25℃范围内,随着温度的升高,被寄生的松突圆蚧雌成蚧数量增加,而在25℃~35℃之间呈相反趋势.花角蚜小蜂的寄生功能反应有较强的种内干扰作用,随自身密度的增加,寄生数量逐渐减少.Hassell(1969)模型E=QP-m和Bedding-ton(1975)模型E=aT/[1 btw(P-1)]均能较好地反映花角蚜小蜂的寻找效应与其自身密度之间的关系,模拟结果分别为E=0.1659P-0.5597和E=0.1437T/[1 0.2691(P-1)].     

松突圆蚧及友恩蚜小蜂空间分布型和种群消长动态研究

通过对广东省试验林区内松突圆蚧Hemiberlesia pitysophila Takagi及其本地种寄生蜂友恩蚜小蜂Encarsia amicula Viggiani et Ren林间空间分布型和种群消长动态的调查研究发现:两者空间分布型相吻合,都为均匀分布;两者在林间全年种群消长曲线均呈"S"型变化。松突圆蚧种群密度高峰期出现在3月下旬至4月下旬,友恩蚜小蜂种群密度高峰期则分别出现在2月下旬和4月下旬至5月中旬。另外友恩蚜小蜂对松突圆蚧的寄生率全年共出现2个高峰期,分别是2月下旬和4月下旬至6月上旬。结果表明,友恩蚜小蜂和寄主松突圆蚧在林间时空发生规律具有高度一致性。     

松突圆蚧黑蚜小蜂的产卵分布

采用m*－m方法分析了黑蚜小蜂的产卵频数分布,在25种密度组合下,产卵平均拥挤度m*的值从0．09（1：80）增加到2．96（9：5）,并建立了m*与蜂蚧比、m*与平均密度m的回归模型。结果表明,松突圆蚧黑蚜小蜂产复寄生卵的程度与寄生蜂密度呈正相关,与寄主密度呈负相关,产卵呈随机分布。     

引进花角蚜小蜂成虫的寿命和羽化节律

通过室内饲养和连续观察,研究了食物、温度对引进花角蚜小蜂成虫寿命的影响及其羽化的时间节律.结果表明：食物对该寄生蜂成虫寿命有极显著影响,喂食20％蜂蜜或20％蜂蜜＋新鲜松针可将雌虫寿命从不喂食的1.5 d延长到14.8 d和17.3 d,将雄虫寿命从不喂食的1.5 d延长到11.3 d和12.3 d.喂食20％蜂蜜条件下,温度也表现出极显著影响,23 ℃和26 ℃下雌、雄成虫的寿命均明显较长,32 ℃下均最短,相同温度下雌虫的寿命显著长于雄虫.日周期中,雌虫主要在11:00-15:00羽化,18:00以后基本不羽化;雄虫主要在9:00-12:00羽化,17:00以后基本不羽化.在花角蚜小蜂的主要羽化期7-9月,7月羽化量最大 ,此后8、9月呈波浪式递减;单日羽化的成虫中,雌虫大多占80％以上,雄虫则长期在一个较低水平波动.对比试验发现,花角蚜小蜂在收蜂棚中的出蜂量比在收蜂箱中更大.花角蚜小蜂在羽化前积累的能量十分有限,人工放蜂前提供必要的营养补充将有助于提高生物防治效果.福建和广东夏季的高温、花角蚜小蜂雌成虫和松突圆蚧雌成蚧虫口高峰期不吻合、极高的雌性比例等是影响该寄生蜂种群稳定的潜在因素.收蜂棚有利于大量收集花角蚜小蜂,适合在生产上应用.     

利用生物防治技术控制大面积松林虫害

利用生物防治技术控制大面积松林虫害中国科学院上海昆虫所通过林区繁育和人工助迁利用花角蚜小蜂防治松突圆蚧获得大面积成功。１９８２年起，我国广东省在毗邻港澳的沿海地区发现马尾松林遭到一种蚧虫的严重危害，松林成片枯死，虫害蔓延迅速，每年以１００万亩的速度向...     

寄生白蜡虫雌虫的蚜小蜂

四川是我国养殖白蜡虫最多的地区。寄生白蜡虫雌虫的蚜小蜂,尚未见有报道。本文报道的二种蚜小蜂是寄生在白蜡虫雌虫二龄幼虫和成虫体内,在四川白蜡虫养殖区较为常见的种类,即日本软蚧蚜小蜂及环刺花翅蚜小蜂。白蜡虫雌虫是它们的新宿主。1.日本软蚧蚜小蜂Coccophagus japonicu     

间伐修枝措施对松突圆蚧的控制效果

4 a的调查研究结果表明：不同强度的修枝间伐措施对松突圆蚧虫口密度和雌蚧死亡率均有一定的影响,从总体上看,松突圆蚧虫口密度减退率和雌蚧死亡率随着修枝间伐强度的增大而增大.从时间上看,间伐控制害虫危害作用限于2 a左右,间伐2 a后虫口密度和雌蚧死亡率均不存在显著差异;从间伐强度上看,对照与30%以上的间伐强度（C、D、E）之间、间伐强度25%（B）与40%（E）之间虫口密度有显著差异,其他两两之间没有显著差异;35%以上的间伐强度（D、E）与对照之间、间伐强度25%（B）与40%（E）之间雌蚧死亡率有显著差异,其他两两之间没有显著差异.     

放蜂密度对桨角蚜小蜂Eretmocerus sp.控制烟粉虱效果的影响

研究了不同放蜂密度对桨角蚜小蜂Eretmocerussp .控制烟粉虱种群效果的影响。结果表明 ,按 1头、2头、3头、5头雌蜂 /株的密度释放桨角蚜小蜂 ,3周后烟粉虱种群的增长趋势指数分别为 2 4 .13、18.5 1、12 .4 1和 8.0 6 ,随着放蜂密度的增加 ,烟粉虱种群增长趋势指数逐渐减小 ,蚜小蜂寄生对烟粉虱种群增长的干扰作用控制指数分别为 0 .80 5 1、0 .6 176、0 .4 14 1和 0 .2 6 89。研究表明在生产中以 3头或 5头雌蜂 /株的密度释放桨角蚜小蜂Eretmocerussp .,对烟粉虱种群的控制效果较好     

班氏跳小蜂对扶桑绵粉蚧的寄生功能反应

为评估班氏跳小蜂Aenasius bambawalei Hayat对其寄主扶桑绵粉蚧Phenacoccus solenopsis Tinsley的控制作用, 在实验室条件下（温度25±1℃, 相对湿度70%±5%, 光周期14L∶10D）, 研究了班氏跳小蜂对扶桑绵粉蚧3龄若虫、 雌成虫的寄生功能反应及其自身密度效应。结果表明: 寄生功能反应均符合Holling Ⅱ型方程, 且受寄主密度和寄生物密度的影响。当扶桑绵粉蚧 3龄若虫和雌成虫的密度分别大于15头/容器和10头/容器时, 班氏跳小蜂的寄生量增加幅度开始减小; 以瞬间攻击率/处理时间（α/Th)为评价指标, 班氏跳小蜂雌蜂寄生扶桑绵粉蚧3龄若虫时, α/Th为21.1307, 且大于雌蜂寄生雌成虫的情况（α/Th为6.2506）; 班氏跳小蜂寄生功能反应有较强的种内干扰作用, 随着自身密度的增加, 寄生效能逐渐降低; 通过方程E=QP^-m能很好地模拟班氏跳小蜂的寻找效应（E）与其自身密度（P）之间的关系, 对于3龄若虫和雌成虫的模拟结果分别为E=0.2931P^-0.6240和E=0.0944P^-0.4840。本研究为利用班氏跳小蜂开展扶桑绵粉蚧生物防治提供了基础数据和方法。     

Performance of Psyttalia humilis (Hymenoptera: Braconidae) reared from irradiated host on olive fruit fly (Diptera: Tephritidae) in California

The parasitoid Psyttalia humilis (Silvestri) was reared on Mediterranean fruit fly, Ceratitis capitata (Wiedemann), third instars irradiated at 0-70 Gy at the USDA, APHIS, PPQ, Moscamed biological control laboratory in San Miguel Petapa, Guatemala, and shipped to the USDA, ARS, Parlier, CA. Irradiation dose did not affect the parasitoid's offspring sex ratio (53-62% females), percentage of unemerged adults (12-34%), number of progeny produced per female (1.4-1.8), and parasitism (19-24%). Host irradiation dose had no significant effect on the forewing length of female P. humilis and its parasitism on olive fruit fly, Bactrocera oleae (Rossi) and offspring sex ratio, but dissection of 1-wk-old female parasitoids reared from hosts irradiated with 70 Gy had a significantly lower number of mature eggs than females from nonirradiated hosts. Longevity of P. humilis adults decreased with increased temperature from 15 to 35°C, regardless of food provisions, gender, and host irradiation dose. Females survived 37-49 d at 15°C with water and food, and only 1-2 d at 35°C without food, whereas males lived shorter than females at all temperatures and food combinations tested. Adult P. humilis reared from fertile C. capitata and aspirated for dispensing in cups lived significantly longer after shipment than those specimens chilled and dispensed by weight. At 21 and 32°C, 50% of parasitoids departed release cages after 180 and 30 min, respectively, but none departed at 12°C. Thirteen shipments of P. humilis (2,980-21,922 parasitoids per shipment) were received between September and December 2009, and seven shipments (7,502-22,560 parasitoids per shipment) were received between October and December 2010 from San Miguel Petapa, Guatemala. Daily number of olive fruit fly adult and percentage female trap captures ranged <1-19 and 8-58% in 2009, and <1-11 and 0-42% in 2010, respectively. The number of parasitoids released ranged 848-12,257 in 2009 and 3,675-11,154 in 2010. Percentage parasitism of olive fruit fly third instars at all locations ranged 0-9% in 2009 and 0-36% in 2010.     

松突圆蚧虫口数量与危害程度的关系

通过大面积的野外调查研究。结果表明：松突圆蚧每针束平均虫口数量（a）、针束最高虫口数量（b）、有虫针束率（c）和危害程度（d）4个指标之间均呈显著或极显著正相关。在野外虫口数量调查中可用针束最高虫口数量替代每针束平均虫口数量指标,以有虫针束率指标作为每针束平均虫口数量和针束最高虫口数量的有效参考指标。在危害程度的调查中,可用有虫针束率作为替代指标,以针束最高虫口数量和每针束平均虫口数量分别作为第1和第2参考指标。3个虫口数量指标中以有虫针束率对危害程度的直接作用最大,其次是针束最高虫口数量,每针束平均虫口数量最低。在间接作用中,针束最高虫口数量通过有虫针束率对危害程度的影响最大,每针束平均虫口数量通过有虫针束率的间接影响较大。     

Biological assessment of Tetrastichus brontispae,a pupal parasitoid of coconut leaf beetle Brontispa longissima

To control coconut leaf beetle, Brontispa longissima (Gestro), the pupal parasitoid Tetrastichus brontispae Ferrière was imported from Taiwan and its biology was studied in quarantine in Hainan, China. The parasitoid development includes an egg, three larval instars and three pupal stages. Its developmental time from egg to adult was 19.5±0.5 days under conditions of 24±2°C and 75±5% relative humidity (RH). Temperature had no effect on the sex ratio of offspring, but significantly affected the parasitism rate and reproduction. The parasitism rates were 98.07, 97.97 and 95.03% at 28, 24 and 20°C, respectively, whereas the parasitism rate was 52.18% at 18°C and 69.48% at 30°C, respectively. Furthermore, the parasitoids reared at 18 and 30°C produced fewer offspring than those at 20, 24 and 28°C, respectively. With the increase in temperature, developmental time decreased linearly from 46.19 days at 18°C to 17.10 days at 28°C. RH significantly influenced development, parasitism rate and the reproduction of T. brontispa. With the decrease of RH, developmental time increased from 22.94 days at 20% RH to 18.84 days at 95% RH. In contrast, parasitism rate and the number of offspring per female increased with the increase of RH. Though emergence rates between 50 and 95% RH were much higher than those between 20 and 35% RH, the sex ratios between 20 and 95% RH were not different. Photoperiod had no effect on parasitism, the number of offspring per female, emergence and the sex ratio of T. brontispae, but developmental time was significantly different for different photoperiods. Sucrose, honey and glucose significantly enhanced adult longevity, parasitism and the number of offspring per female of T. brontispae, but had no effect on the sex ratio and survival. Females of T. brontispae only parasitized fourth to fifth larval instars and 1–5-day-old pupae, but there was a significant difference in the number of offspring per female, development time, emergence and the sex ratio of offspring in different instars. These results showed that 1-day-old pupae, a temperature of 24–28°C and 65–95% RH were optimal for T. brontispae. These findings should be helpful in developing a production system to rear and release T. brontispae in large enough quantities to effectively control coconut leaf beetle.     

芦苇收割对宫苍仁蚧密度及其五种寄生蜂共寄生关系的影响

【目的】本文旨在揭示芦苇Phragmites australis(Cav.)Trin.ex Steudel收割对宫苍仁蚧Nipponaclerda biwakoensis Kuwana密度及其5种寄生蜂寄生率和共寄生关系的影响及作用机制。【方法】在上海九段沙湿地上沙的芦苇未收割区和收割区分别设置16个和20个样方,于2011年7月和9月进行重复采样,对未收割区和收割区的蚧虫密度、寄生蜂寄生率、共寄生关系和雌性比率分别进行比较分析。【结果】芦苇收割能够显著降低蚧虫密度(P<0.001);从7月到9月,寄生蜂总寄生率呈增高趋势,但7月芦苇未收割区和收割区间寄生蜂总寄生率差异不显著(P>0.05),而9月芦苇收割区寄生蜂总寄生率则显著高于未收割区(P<0.001);而寄生蜂总寄生率与蚧虫密度相关性并不显著。不同寄生蜂对芦苇收割的响应不同,且存在时间差异性。7月,Aprotocetus sp.的寄生率最高,且在收割区的寄生率显著高于未收割区(P<0.05),而其他寄生蜂寄生率均较低。9月,Aprotocetus sp.的寄生率呈下降趋势,而其余寄生蜂寄生率则呈升高趋势;而且除Encyrtidae sp.外,其他寄生蜂寄生率在未收割区和收割区间存在显著差异(P<0.001)。此外,芦苇收割还显著增加Boucekiella depressa与Astymachus japonicus的共寄生率(P<0.001),并显著减少B.depressa与Aprotocetus sp.的共寄生率(P<0.001)。除Aprotocetus sp.(P<0.05)外,芦苇收割对寄生蜂的雌性比率无显著影响。【结论】不同寄生蜂对芦苇收割的响应,不仅依赖于蚧虫密度,而且还与寄生蜂的扩散能力和竞争能力等生物学特性有关。因此,芦苇收割能通过多种途径影响寄生天敌和宫苍仁蚧的高营养级互作关系,需引起足够的重视。     

Functional response to host density by the egg parasiteTrichogramma pretiosum

The effect of host density on parasitism byTrichogramma pretiosum Riley was studied by exposing groups of 150, 300, 600 or 1200 eggs of potato tuber moth to 2, 4 or 8 female parasites per group. The parasite exhibited a type 2 functional response. As host density increasedT. pretiosum parasitised more hosts, but at a decreasing rate. The attack coefficient (a′) decreased as parasite density increased, whereas the handling time (T _h ) remained almost constant. The search rate (a) decreased with increasing host density.T. pretiosum responded to increasing host density by increasing the number of its encounters with hosts and the number of hosts it parasitised only up to host density of 300 when the parasite density was 2 and up to host density of 600 when the parasite densities were greater and then remained almost constant. The observed incidence of parasitism was higher than that expected on the assumption that the parasites behaved the same at higher host densities as at the lowest. When parasite density was raised from 2 to 8 females per group the percentage of female progeny fell from about 73 to about 48%. A 2-fold increase in the number of female progeny was observed when parasite density was reduced from 8 to 2 and also when the host density was raised from 150 to 1200 eggs.     

Trichogramma exiguum (Hymenoptera: Trichogrammatidae) releases in North Carolina cotton: evaluation of heliothine pest suppression

Field studies were conducted in 1996 and 1997 to reevaluate the use of augmentative releases of Trichogramma wasps for heliothine management in cotton. In 1996, nine releases of Trichogramma exiguum Pinto & Platner, spaced 3-4 d apart, were made into three 0.4-ha cotton plots. Six weekly releases were made in 1997, each containing two T. exiguum cohorts developmentally staggered by 45 degrees C degree-days. Field release rates, estimated from laboratory and field quality control data, averaged 108,357 T. exiguum female female per hectare per cohort per release in 1996 and 193,366 female female per hectare per cohort per release in 1997. In 1996, mean +/- SD adult emergence under laboratory conditions for released cohorts was 92 +/- 7%; 62 +/- 5% of emerged adults were females, 3 +/- 2% of females displayed brachyptery (nonfunctional wings), mean female longevity under laboratory conditions was 15 +/- 4 d, and mean +/- SD field emergence was 97 +/- 2%. Quality control measurements were similar in 1997. In 1996, mean +/- SD percent parasitism of heliothine eggs in field plots on the sampled dates ranged from 67 +/- 4 to 83 +/- 5% in T. exiguum release plots and 25 +/- 9 to 55 +/- 8% in control plots. In 1997, parasitism levels ranged from 74 +/- 4 to 89 +/- 5% in T. exiguum release plots and 18 +/- 18 to 69 +/- 11% in control plots. Despite increased parasitism levels in T. exiguum release plots, there were no significant differences in density of fifth instars, boll damage, or yield between T. exiguum release and control plots. Therefore, it is concluded that Trichogramma augmentation is not an effective heliothine management tool in North Carolina cotton.     

Movement of an insect parasitoid in simple and diverse plant assemblages

Abstract. 1. It has been proposed that herbivore populations are lower in diverse than in simple plant habitats because of greater abundance and/or higher efficiency of natural enemies in mixed plant stands. However, higher enemy colonization is expected in monorather than multispecific vegetation if the response of specialist natural enemies to habitat diversification is similar to that of monophagous herbivores.
2. We used release-recapture experiments to determine how the presence of maize (non-host plant) influences the movement of the parasitoid Pediobius foveolatus in the absence of hosts. We then assessed how vegetation diversity affects wasp reproduction (parasitism) and subsequent density in the presence of its hosts, Mexican bean beetle larvae.
3. Fewer female wasps immigrated into and more emigrated out of a bean-tall maize intercrop than bean monocultures. Bean plant density and the presence of maize per se did not significantly affect parasitoid immigration. Instead, maize height was the primary factor contributing to lower female immigration into the bean-tall maize plots. However, tall maize plants did not impede the wasps' within-habitat movement.
4. When wasps were released outside the plots, higher parasitism was recorded in monocultures, irrespective of host density. In contrast, when wasps were released within the plots, significantly higher parasitism rates were found in the bean-tall maize habitat.
5. Results suggest that female wasps accumulate in the bean-tall maize habitat in response to resources other than hosts and, ultimately, wasp density may be determined primarily by differential emigration rather than by immigration rates.