红圆蚧三种寄生蜂的相互竞争研究

本文研究了红圆蚧（Ａｏｎｉｄｉｅｌｌａａｕｒａｎｔｉｉ）三种寄生蜂：盾蚧长缨蚜小峰（Ｅｎｃａｒｓｉａｃｉｔｒｉｎａ,ＥＣ）、岭南蚜小蜂（Ａｐｈｙｔｉｓｌｉｎｇｎａｎｅｓｉｓ,ＡＬ）和印巴黄蚜小蜂（Ａｐｈｙｔｉｓｍｅｌｉｎｕｉｓ,ＡＭ）的相互竞争。结果表明,ＥＣ蜂寄生过的寄主对ＡＭ蜂和ＡＬ蜂没影响,ＡＭ蜂能辩认被ＡＬ蜂寄生过的寄主,反之亦然,幼虫竞争能力ＡＬ蜂最强,其次ＡＭ蜂,最差为ＥＣ蜂。不同的寄主龄期产生不同的竞争结果：当ＡＭ蜂和ＡＬ蜂竞争时,若只供给３龄寄主则ＡＬ蜂获胜,若供给只有２龄寄主则ＡＭ蜂获胜;而ＡＭ或ＡＬ蜂与ＥＣ竞争时。若大多数寄主为２龄则ＥＣ蜂获胜,若大多数寄主为３龄则ＡＭ或ＡＬ蜂获胜。     

日本食蚧蚜小蜂对橡副珠蜡蚧的控制作用研究

【目的】为了明确日本食蚧蚜小蜂Coccophagus japonicus Compere对橡副珠蜡蚧Parasaissetia nigra Nietner的控害潜能。【方法】在18、21、24、27、30、33℃条件下研究了日本食蚧蚜小蜂对橡副珠蜡蚧3龄若虫的寄生功能反应及27℃条件下该蜂自身的干扰效应。【结果】该蜂的寄生功能反应符合Holling-Ⅱ和Holling-Ⅲ模型,但各温度间功能反应的参数存在差异,其中以瞬时攻击率/处理时间(a'/T_h)为评价指标,在18-33℃范围内,在24℃时寄生效能最大,为53.86;日本食蚧蚜小蜂个体间存在干扰效应,随着自身密度增大,相互干扰作用增强,在27℃时,Hassell模型E=QP~(-m)能够很好的反映出不同寄生蜂密度对橡副珠蜡蚧的寄生情况。【结论】日本食蚧蚜小蜂对橡副珠蜡蚧3龄若虫有较好的控害能力。     

三种寄生物与一种寄主的系统模型研究

建立了红圆蚧与３种寄生蜂,盾蚧长缨蚜小蜂、岭地蚜小蜂和印黄蚜小蜂相互作用的系统模型,按红圆 的面积大小分成３种,ｓ（０．５５ｍｍ＾２以上）,ｔ（０３９－０．５５ｍｍ＾２）、ｕ（０．３９ｍｍ＾２以下）,分析三维系统（２种寄生物与１种寄主）和四维系统３种寄生物与１种寄主）在不同红圆蚧大小分布（ｓ,ｔ,ｕ）条件下系统的动态变化,确定了寄生物相互排扩和边界条件,为红介的生物防治决防治决策提供理论指导。     

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。     

粉虱寄生蜂种类的调查与鉴定

通过采集调查、室内饲养和鉴定,初步获得福建省部分地区粉虱寄生蜂２２种,隶属于蚜小蜂科Ａｐｈｅｌｉｎｉｄａｅ的恩蚜小蜂属Ｅｎｃａｒｓｉａ Ｆｏｅｒｓｔｅｒ（１９种）和桨角蚜小蜂属Ｅｒｅｔｍｏｃｅｒｕｓ Ｈａｌｄｅｍａｎ（２种）,以及广腹细蜂科Ｐｌａｔｙｇａｓｔｅｒｉｄａｅ的Ａｍｉｔｕｓ（１种）。     

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)].     

松毛虫卵期几种寄生蜂的共寄生现象及其对寄生率的影响

松毛虫赤眼蜂Ｔｒｉｃｈｏｇｒａｍｍａｄｅｎｄｒｏｌｉｍ　Ｍａｔｓｕｍｕｒａ,白跗平腹小蜂ＰｓｅｕｄａｎａｓｔａｔｕｓａｌｂｉｔａｒｓｉｓＡｓｈｍｅａｄ,松毛虫宽缘金小蜂Ｐａｃｈｙｎｅｕｒｏｎ　ｓｏｌｉｔａｒｉｕｍ（Ｈａｒｔｉｇ）,松毛虫黑卵蜂Ｔｅｌｅｎｏ－ｍｕｓ　ｄｅｎｄｒｏｌｉｍｕｓｉ　Ｃｈｕ和大蛾卵跳小蜂Ｏｏｅｎｃｙｒｔｕｓｋｕｗａｎａｅ（Ｈｏｗａｒｄ）是松毛虫卵期几种主要寄生蜂。通过对上述几种寄生蜂寄生习性的研究表明：赤眼蜂和平腹小蜂不但能寄生新鲜害虫卵,还可以寄生对方已寄生并已发育１—３天的寄生卵,但羽化率均不高;松毛虫宽缘金小峰不寄生新鲜害虫卵,专门寄生赤眼蜂寄生后已发育１—７天的寄生卵,其中又以赤眼蜂发育３—５天的卵寄生率和羽化率为最高。除赤眼蜂和平腹小蜂可以混合使用外,其它蜂种混用都不同程度地存在相互排挤的现象。如果先让平腹小蜂寄生尔后再让赤眼蜂寄生或先让赤眼蜂寄生,尔后再让跳小蜂或黑卵蜂寄生,能够提高卵块寄生率和充分发挥各自天敌的作用。     

矢尖蚧发生动态及其寄生性天敌

柑桔矢尖蚧在福建闽北地区一年发生3代。以雌成虫和部分若虫及少数雄蛹越冬．一龄幼蚧盛期,第一代为4月中,下旬。第二代7月上．中旬,第三代9月中旬前后。二龄幼蚧盛期．第一代为5月上、中旬,第二代7月下旬,和第三代9月下旬．后期世代重叠．福建已知寄生蜂6种．其中一种为重寄生蜂,以矢尖蚧黄蚜小蜂为优势种．寄生生蜂自然寄生率最高达49.1%。     

竹类害虫的六种寄生蜂及二新种记述（膜翅目：跳小峰科）

本文报导与竹类害虫有关的６种跳小蜂。长缘刷盾跳小蜂Ｃｈｅｉｌｏｎｅｕｒｕｓｃｌａｖｉｇｅｒ及优赛跳小蜂Ｅｕｓｅｍｉｏｎｃｏｒｎｉｇｅｒｕｍ,寄生竹巢粉蚧Ｎｅｓｔｉｃｏｃｃｕｓｓｉｎｅｎｓｉｓ的初寄生者花翅跳小蜂Ｍｉｃｒｏｔｅｒｙｓｓｐｐ．;瓢虫隐尾跳小蜂Ｈｏｍａｌｏｔｙｌｕｓｆｌａｍｉｎｉｕｓ,寄生黑缘光瓢虫Ｅｘｏｃｈｏｍｕｓ（Ｘａｎｔｈｏｃｏｒｎｓ）ｎｉｇｒｏｍａｒｇｉｎａｔｕｓ;白胫短缘跳小蜂Ｚａｏｍｍａｅｒｉｏｃｏｃｉ（Ｔａｃｈｉｋａｗａ）中国新记录,寄生竹巢粉蚧的初寄生者花翅跳小蜂;四斑长索跳小蜂ＡｎａｇｙｒｕｓｑｕａｄｒｉｍａｃｕｌａｔｕｓＸｕｅｔＨｅ,ｓｐ．ｎｏｖ,寄生竹绒粉蚧Ｅｒｉｏｃｏｃｃｕｓｔｒａｎｓｖｅｒｓｕｓ;长脉卵跳小蜂ＯｏｅｎｃｙｒｔｕｓｌｏｎｇｉｖｅｎｏｓｕｓＸｕｅｔＨｅ,ｓｐ．ｎｏｖ,寄生竹卵圆蝽Ｈｉｐｐｏｔｉｓｃｕｓｄｏｒｓａｌｉｓ。标本及模式标本保存在浙江农业大学寄生蜂标本室。     

副珠蜡蚧阔柄跳小蜂对橡副珠蜡蚧的控制作用

在实验室条件下,研究了副珠蜡蚧阔柄跳小蜂对橡副珠蜡蚧的控制作用.结果表明:该蜂的寄生功能反应符合Holling Ⅱ型方程,但各温度间功能反应的参数存在差异,以瞬时攻击率/捕食处理时间(a/Th)为评价指标,在30℃捕食效能最强,a/Th 为23.4211.副珠蜡蚧阔柄跳小蜂的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,寄生数量逐渐减少,在温度21℃～33℃范围内,Hassell(1969)模型E=QP-m均能较好地反映副珠蜡蚧阔柄跳小蜂的寻找效应与其自身密度之间的关系;在21℃～27℃,随着温度的上升干扰作用增强,27℃时干扰系数最大(0.6626),温度上升至30℃、33℃时干扰作用略有下降,分别为0.6161、0.5916.副珠蜡蚧阔柄跳小蜂对产卵前期的橡副珠蜡蚧成虫控制效果好,寄生后能完全控制,有少量幼虫爬出的橡副珠蜡蚧被寄生后,控制效果下降至81.4%.     

REVISION OF THE GENUS APHYTIS (HYMENOPTERA: APHELINIDAE) WITH DESCRIPTIONS OF TWO NEW SPECIES FROM EGYPT

Abstract  The Egyptian species of the aphelinid genus Aphytis Howard are reviewed. Aphytis azai Abd-Rabou and Aphytis matruhi Abd-Rabou are described as new species from Egypt. Each species is briefly diagnosed and known information on hosts and distributed is given. A. azai sp. nov. is similar to A. melinus but different in the measurement of antennal segments. A. matruhi sp. nov. differs from A. lepidosaphes by the relative length of propodeum, metanotum and scutellum. A key to the Egyptian species of Aphytis is provided.     

Host selection and egg allocation behaviour by Aphytis melinus and A.lingnanensis: comparison of two facultatively gregarious parasitoids

Abstract. 1. The ovipositional and egg allocation behaviour of individual females of Aphytis melinus DeBach and A.lingnunensis Compere were compared.
2. Both Aphytis species exhibit the same behavioural sequence during oviposition.
3. Aphytis melinus laid most of its female eggs on the dorsum of a scale-insect beneath its cover, and most of its male eggs under the scale-insect's body. Aphytis lingnanensis also oviposited both dorsally and ventrally on scale-insect hosts, but female and male progeny arose with equal frequency from eggs laid in both locations.
4. Both A.melinus and A. lingnanensis are facultatively gregarious parasitoids. The degree of gregariousness depends on host size, i.e. the larger the host, the more the Iikelihood that several eggs will be deposited at each visit by the parasitoid.
5. When two eggs were laid during the same host visit, both A.melinus and A.lingnanensis laid one female and one male egg more often than would be expected under an assumption of random allocation of sexes.
6. Because A.melinus successfulIy utilize smaller hosts than A.lingnanensis to produce progeny, these parasitoids should not be considered ecological homo-logues, as suggested by DeBach & Sundby (1963).     

埃及Aphytis黄蚜小蜂属记述附二新种描述（膜翅目：蚜小蜂科）

对埃及的黄蚜小蜂属进行了综述,并描述了2个新种,即Aphytis azai Abd—Rabou和Aphytis matruhi Abd—Rabou。文章对产自埃及的17个种做了简要描述,还提供了寄主和分布信息,以及埃及黄蚜小蜂属的分种检索表。新种A．azai sp．nov．与A．melinus相似,但区别在于触角节的大小。新种A．matruhi sp．nov．区别于A．lepidosaphes之处在于间节、后胸腹板以及小盾片的相对长度不同。     

Competition, resource partitioning and coexistence of an endoparasitoid Encarsia perniciosi and an ectoparasitoid Aphytis melinus of the California red scale

Abstract. 1. Laboratory experiments and field studies were conducted to explain the coexistence of an endoparasitoid, Encarsia perniciosi Tower, and an ectoparasitoid, Aphytis melinus DeBach, both of which were introduced into California to control the California red scale, Aonidiella aurantii (Mask.).
2. Encarsia parasitized all scale stages but it preferred first and second instar scales. This is in contrast to Aphytis melinus , in which previous studies have shown that it parasitizes second and third instar females and second instar males but prefers third instar female scales. Encarsia developed most rapidly when it parasitized an early second instar and slowest when it parasitized the mature female scale. However, on early second instar scales it was about 80% as fecund as a wasp that emerged from a mature female scale.
3. Second instar scales parasitized by Encarsia were accepted by Aphytis as readily as unparasitized scales.
4. Encarsia did not distinguish between unparasitized hosts and those previously parasitized by Aphytis.
5. Encarsia always outcompeted by Aphytis when both species parasitize the same host.
6. Encarsia prefers scale on stems whereas Aphytis prefers those on leaves and fruits. This, too, may be a result of interspecific competition with Aphytis.
7. The partitioning of the scale resource by the two species explains why they coexist in coastal southern California but it does not explain why Encarsia disappeared from citrus groves in the inland valleys coincident with the introduction of Aphytis melinus into southern California.     

Fitness components of Aphytis melinus (Hymenoptera: Aphelinidae) reared in five California insectaries

Shipments of 50,000 commercially reared Aphytis melinus DeBach were obtained from each of the five insectaries that produce and sell this parasitoid to citrus growers in California for control of California red scale, Aonidiella aurantii (Maskell). Shipments were received from each insectary every 2 mo over a period of a year to assess variability in quality through time and between insectaries. As indices of quality, we assessed the percentage of live parasitoids (both sexes) 1, 3, 7, 14, and 28 d after receipt of the shipment, shipment sex ratio, and the size of female wasps. We found a fair amount of variation in the percentage of A. melinus that were alive on different sampling days. Despite the fact that all insectaries rear A. melinus in temperature controlled rooms and all of our studies were done at 22°C, wasp mortality occurred more quickly in the colder months of November, January through February, and March. Similar trends were observed with sex ratios; many of the insectaries had male-biased sex ratios in the colder months, especially January through February. Wasp size varied significantly for each of the insectaries throughout the year, with the summer months of July through August yielding significantly smaller females than other months. Collectively our results have important implications for biological control on citrus in California.     

Effects of constant and variable temperature extremes on sex ratio and progeny production by Aphytis melinus and A.lingnanensis (Hymenoptera: Aphelinidae)

Abstract. 1. Aphytis melinus DeBach and A.lingnanensis Compere were exposed to temperature extremes during development, mating, preoviposition, and opposition to assess the effect of these exposures on the progeny per female and F₁ sex ratio.
2. Both species showed a significant reduction in the expected proportion of F₁ females when the male parent was exposed to 32°C during its development.
3. The proportion of females was further reduced when mating and/or oviposition occurred at 32°C and these effects on sex ratio appeared cumulative.
4. Preovipositional exposure of the females of both species to 38°C, 2°C or -2°C for 1 5, 4 or 7 h in most cases significantly reduced the expected proportion of females.
5. In general our results showed that the sex ratios of A.melinus was less severely affected by these exposures than were those of A.lingnanensis.
6. It is suggested that this difference may be one factor explaining the ability of A.melinus to exclude A.lingnanensis from the climatically more extreme areas of southern California.     

Parasitoid behaviour: predicting field from laboratory

Abstract.  1. Most of what is known about parasitoid behaviour comes from laboratory observations: field quantitative observations on searching parasitoids are extremely difficult to do and are rare. The basic components of Aphytis melinus 's response to California red scale ( Aonidiella aurantii ) were studied in the laboratory: encounter, rejection, drumming, probing, oviposition, and host-feeding. It was then asked whether these observations provided a reliable guide to behaviour in the field in a situation that was very different from the laboratory.
2. Field observations were carried out on bark on the trunk and interior branches of trees where live scale density is extremely high in patches, dead scale make up 90% of all scale, and could be expected to interfere with Aphytis search.
3. The laboratory observations predicted well the time taken in the field for each basic event (drumming or probing) and average times spent on a scale. Also well predicted were the distributions of times spent on drumming, probing, and total time on a scale. Rejection rates were much higher in the field. Thus, the laboratory studies predicted foraging behaviour in the field with variable success; potential explanations for observed mismatch between laboratory and field and its possible larger implications are discussed.     

Role of two insect growth regulators in integrated pest management of citrus scales

Portions of two commercial citrus orchards were treated for two consecutive years with buprofezin or three consecutive years with pyriproxyfen in a replicated plot design to determine the long-term impact of these insect growth regulators (IGRs) on the San Joaquin Valley California integrated pest management program. Pyriproxyfen reduced the target pest, California red scale, Aonidiella aurantii Maskell, to nondetectable levels on leaf samples approximately 4 mo after treatment. Pyriproxyfen treatments reduced the California red scale parasitoid Aphytis melinus DeBach to a greater extent than the parasitoid Comperiella bifasciata Howard collected on sticky cards. Treatments of lemons Citrus limon (L.) Burm. f. infested with scale parasitized by A. melinus showed only 33% direct mortality of the parasitoid, suggesting the population reduction observed on sticky cards was due to low host density. Three years of pyriproxyfen treatments did not maintain citricola scale, Coccus pseudomagnoliarum (Kuwana), below the treatment threshold and cottony cushion scale, Icerya purchasi Maskell, was slowly but incompletely controlled. Buprofezin reduced California red scale to very low but detectable levels approximately 5 mo after treatment. Buprofezin treatments resulted in similar levels of reduction of the two parasitoids A. melinus and C. bifasciata collected on sticky cards. Treatments of lemons infested with scale parasitized by A. melinus showed only 7% mortality of the parasitoids, suggesting the population reduction observed on sticky cards was due to low host density. Citricola scale was not present in this orchard, and cottony cushion scale was slowly and incompletely controlled by buprofezin. These field plots demonstrated that IGRs can act as organophosphate insecticide replacements for California red scale control; however, their narrower spectrum of activity and disruption of coccinellid beetles can allow other scale species to attain primary pest status.     

Toxicity of seven foliar insecticides to four insect parasitoids attacking citrus and cotton pests

Laboratory studies were carried out to compare the toxicity of seven foliar insecticides to four species of adult beneficial insects representing two families of Hymenoptera: Aphelinidae (Aphytis melinus Debach, Eretmocerus eremicus Rose & Zolnerowich, and Encarsiaformosa Gahan) and Mymaridae (Gonatocerus ashmeadi Girault) that attack California red scale, Aonidiella aurantii (Maskell); sweetpotato whitefly, Bemisia tabaci (Gennadius) (both E. eremicus and E. formosa); and glassy-winged sharpshooter, Homalodisca vitripennis (Germar), respectively. Insecticides from four pesticide classes were evaluated using a petri dish bioassay technique across a range of concentrations to develop dosage-mortality regressions. Insecticides tested included acetamiprid (neonicotinoid); chlorpyrifos (organophosphate); bifenthrin, cyfluthrin, and fenpropathrin (pyrethroids); and buprofezin and pyriproxyfen (insect growth regulators [IGRs]). Chlorpyrifos was consistently the most toxic pesticide to all four species of beneficial insects tested based on LC50 values recorded 24 h posttreatment compared with 48-h LC50 values with the neonicotinoid and pyrethroids or 96 h with the IGRs. Among the three pyrethroids, fenpropathrin was usually less toxic (except similar toxicity to A. melinus) than was cyfluthrin, and it was normally less toxic (except similar toxicity with E. formosa) than was bifenthrin. Acetamiprid was generally less toxic than bifenthrin (except similar toxicity with G. ashmeadi). The IGRs buprofezin and pyriproxyfen were usually less toxic than the contact pesticides, but we did not test for possible impacts on female fecundity. For all seven pesticides tested, A. melinus was the most susceptible parasitoid of the four test species. The data presented here will provide pest managers with specific information on the compatibility of select insecticides with natural enemies attacking citrus and cotton, Gossypium hirsutum L., pests.     

松突圆蚧(Hemiberlesia Pitysophila Takagi)寄生蜂Aphytis sp的寄生与摄食研究

本文观察了Aphytis sp.在25种密度组合下的寄生与摄食,表明Aphytis sp.的功能反应适合Ⅱ型曲线,摄食作用随寄生蜂密度的增加而加强,随寄主密度的增加而减弱。并建立了新的二元寄生模型,模拟效果较好。