The British species of Gonatocerus Nees (Hymenoptera: Mymaridae), egg parasitoids of Homoptera

Abstract. The thirteen British species of Gonatocerus Nees are characterized by means of a key and short diagnostic notes based on the females, with notes on their hosts and distribution. The species-groups proposed by Debauche are discussed; two species, Gonatocerus rogersi and G.minor, are described as new, and eighteen specific synonymies are proposed.     

柄翅缨小蜂属一新种及一中国新记录种记述(膜翅目:缨小蜂科)

记述采自新疆的柄翅缨小蜂属Gonatocerus Nees菱胸柄翅缨小蜂种团G.SULphuripes groups 1新种:直茎柄翅缨小蜂Gonatocerus orthopennitus,sp.nov.;报道该属1中国新记录种:菱胸柄翅缨小蜂Gonatocerus sulphuripes(Fōrster),1847...     

Progeny quality of Gonatocerus ashmeadi (Hymenoptera: Mymaridae) reared on stored eggs of Homalodisca coagulata (Hemiptera: Cicadellidae)

This study assessed the effects of refrigerated storage on the suitability of eggs of the glassy-winged sharpshooter, Homalodisca coagulata (Say) (Hemiptera: Cicadellidae), as hosts for propagation of the parasitoid Gonatocerus ashmeadi Girault (Hymenoptera: Mymaridae). Development of the host eggs was terminated by chilling at 2 degrees C for 5 d before storage was initiated at 10 degresC for up to 70 d. Parasitism, adult emergence rate, developmental time, and sex ratio were used to gauge the suitability of the eggs as hosts after storage. In addition to these measures, demographic growth parameters also were used to assess the quality of the wasp progeny through the F2 generation. Host eggs stored 20 d remained fully acceptable to the wasps for attack. Although the parasitism rate decreased with storage time, > 80% adult parasitoid emergence was realized from eggs stored 30 d. After 70 d storage, adult emergence rate was decreased by 48%, fecundity decreased by 53%, female production by 19%, developmental time was extended 3 d, and female longevity was shortened 5 d. The emergence pattern of F1 but not F2 adults varied with storage time of the parental and grandparental hosts, respectively. For the F1 generation, emergence rate, development, and sex ratio did not vary with storage time when the F1 parents parasitized fresh host eggs. Demographic parameters for the F, population showed that net reproductive rate was > 20 although it decreased significantly after their parental host eggs were stored for > 30 d. The intrinsic and finite rates of increase, population doubling time, and mean generation time decreased only after storage for 60 d. Our results show that short-term cold storage could be used for maintaining wasp populations in a mass-rearing program and that the detrimental effects of chilling host eggs in storage for over 30 d do not extend to F2 generation.     

Brochosome influence on parasitisation efficiency of Homalodisca coagulata (Say) (Hemiptera: Cicadellidae) egg masses by Gonatocerus ashmeadi Girault (Hymenoptera: Mymaridae)

Abstract. 1. Many cicadellid females in the tribe Proconiini (Hemiptera: Cicadellidae) cover their egg masses with specialised, usually rod‐shaped, brochosomes as the eggs are being laid. The brochosomes are produced in Golgi complexes in the Malpighian tubules of Cicadellidae. In contrast to the gravid females, adult males, pre‐reproductive adult females, and nymphal males and females produce specialised, usually spherically shaped brochosomes. Brochosomes are also used to cover the external surfaces of nymphs and newly moulted adult males and females. 2. The function of the brochosome covering the egg masses is unknown but various hypotheses have been suggested, including protecting the eggs against pathogens, predators, and parasitoids. Based on preliminary observations of Gonatocerus ashmeadi Girault (Hymenoptera: Mymaridae) parasitising the eggs of the cicadellid, Homalodisca coagulata (Say), it is speculated here that brochosomes covering an egg mass hinder parasitisation of eggs by G. ashmeadi. This hypothesis was tested by observing G. ashmeadi females foraging on leaves with H. coagulata egg masses heavily covered with rod‐shaped brochosomes vs. those lacking brochosomes. 3. Cox's proportional hazards model was used to evaluate the probability, per unit time, that a female G. ashmeadi displayed the sequence of behaviours that ended in successful oviposition as influenced by five variables: (a) presence or absence of brochosomes on an egg mass, (b) the leaf surface, upper or lower, being searched by the parasitoid (the egg masses are laid in the parenchyma on the lower leaf surface), (c) the parasitoid's previous ovipositional experience, (d) egg mass size, and (e) the parasitoid's age. 4. Brochosomes significantly decreased oviposition efficacy of G. ashmeadi females. Scanning electron microscopy showed that females exposed to brochosome‐covered egg masses had brochosomes adhering to their tarsi, legs, antennae, and eyes, all of which prompted extensive bouts of grooming.     

Maximum realised lifetime parasitism and occurrence of time limitation in Gonatocerus ashmeadi (Hymenoptera: Mymaridae) foraging in citrus orchards

The relationship between body size (hind tibia length), <12 h egg load, wing wear and parasitoid age was used to estimate realised lifetime parasitism of recently dead Gonatocerus ashmeadi collected in a citrus orchard. Under prevailing field conditions and methodology assumptions, it was estimated that female G. ashmeadi lived on average for 183 ± 17 degree-days, parasitised a total of 87 ± 9 Homalodisca vitripennis eggs, and died with 34 ± 5 eggs remaining in the ovaries. Only 17% of dead G. ashmeadi died with no mature eggs suggesting that 83% of G. ashmeadi were not egg limited at time of death. Estimates of realised lifetime parasitism for female G. ashmeadi under prevailing field conditions in July and August in a southern California citrus orchard indicated that time of year had a significant effect on reproductive output. Additionally, live G. ashmeadi captured daily during June through August 2006 had body size, egg load and wing wear recorded to detect possible monthly changes in parasitoid age and egg load. Foraging G. ashmeadi captured alive in June were older and oviposited more eggs in the field compared with August. Only 0.5% of live G. ashmeadi were captured with no mature eggs in their ovaries indicating that the vast majority of live G. ashmeadi were not egg limited.     

Some British species of Anagrus (Hymenoptera: Mymaridae)

Five species of Anagrus , egg parasites of various leafhopper species (Delphacidae and Cicadellidae, Honioptera), were bred for 3–13 generations in laboratory conditions. Biological and niorphological characteristics as well as attempts at crossbreeding were used to recognise the species Anagrus ensijer Debauche and four new. species. A. ensifer occurred in two varieties. The four new species and the two varieties of A. ensifer are described, and a key is given to both sexes.     

Molecular characterization of Gonatocerus tuberculifemur (Ogloblin) (Hymenoptera: Mymaridae), a prospective Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) biological control candidate agent from South America: divergent clades

We genetically characterized the prospective South American egg parasitoid candidate, Gonatocerus tuberculifemur, of the glassy-winged sharpshooter (GWSS), Homalodisca vitripennis, for a neoclassical biological control program in California. Two molecular methods, inter-simple sequence repeat-polymerase chain reaction DNA fingerprinting and a phylogeographic approach inferred from the mitochondrial cytochrome oxidase subunit I gene (COI), were utilized. Five geographic populations from South America were analyzed; in addition, a phylogenetic analysis was performed with several named and one unnamed Gonatocerus species using the COI gene. DNA fingerprinting demonstrated a fixed geographic banding pattern difference in the population from San Rafael, Mendoza Province, Argentina. The COI analysis uncovered haplotype or geographic structure in G. tuberculifemur. A neighbour-joining distance (NJ) and a single most parsimonious tree (MP) clustered the populations into two well-supported distinct clades with strong bootstrap values (97-99% and 92-99%, respectively) with populations from San Rafael clustering into clade 2 and the rest of the populations clustering into clade 1. No haplotype sharing was observed between individuals from the two clades. Phylogenetic analyses performed by NJ and MP methods with 15 Gonatocerus species confirmed species boundaries and again uncovered two distinct clades in G. tuberculifemur with strong bootstrap support (95-100% and 68-100%, respectively). However, the NJ tree supported the morphologically defined relationships better than the MP tree. The molecular evidence in the present study is suggestive of a species level divergence. Because G. tuberculifemur is under consideration as a potential biological control agent for GWSS in California, understanding cryptic variation in this species is critical.     

玉米叶蝉缨翅缨小蜂Anagrus dmitrievi(膜翅目,缨小蜂科)DNA条形码研究

[目的]玉米叶蝉缨翅缨小蜂Anagrus dmitrievi Triapitsyn&Hu是玉米三点斑叶蝉Zyginidia eremita Zachvatkin卵期的重要寄生性天敌,在玉米三点斑叶蝉生物防治中具有广阔的应用前景.由于该寄生蜂个体微小,通过传统昆虫分类方法难以将其与同类卵寄生蜂准确分类.因此,本研究旨在为玉米叶蝉缨翅缨小蜂的快速准确鉴定提供技术支持.[方法]在室内,采集玉米三点斑叶蝉卯饲养玉米叶蝉缨翅缨小蜂至成虫.根据玉米叶蝉缨翅缨小蜂成虫的体色、触角、翅等形态特征对标本进行鉴定,并利用无损伤法提取样本基因组DNA,通过PCR扩增和测序对COⅠ和ITS2基因进行DNA条形码分子标记试验.[结果]形态学鉴定结果表明饲养获得的寄生蜂标本为玉米叶蝉缨翅缨小蜂.获得了该寄生蜂COⅠ和ITS2的部分序列,相似比对、遗传距离和分子进化树结果表明,玉米叶蝉缨翅缨小蜂COⅠ和ITS2序列分别与NCBI数据库中的同属其他种的相关基因有较高相似性,但存在一定遗传差异,可明显区分.[结论]获得的玉米缨翅缨小蜂的COⅠ和ITS2基因序列可作为玉米叶蝉缨翅缨小蜂的DNA条形码,为后续该寄生蜂的快速准确鉴定提供了分子数据.     

The relationships of the genusAustralomymar [Hymenoptera: Mymaridae]

The holotype female ofAustralomymar aurigerum Girault is redescribed and figured. Comparative data on the types of the five described species ofPolynemoidea Girault are given, and the affinities of both genera briefly discussed. They are maintained as distinct genera, probably related toSelenaeus Waterhouse and elements of the large genusPolynema Haliday,s. l.     

Egg maturation,oosorption, and wing wear in Gonatocerus ashmeadi (Hymenoptera: Mymaridae), an egg parasitoid of the glassy-winged sharpshooter,Homalodisca vitripennis (Hemiptera: Cicadellidae)

Egg maturation and oosorption in Gonatocerus ashmeadi were investigated in the laboratory and the relationship between hind tibia length (HTL) and <12 h egg load, and wing wear and parasitoid age were determined. G. ashmeadi given access to honey-water and hosts, on average, matured 77 eggs in excess of those they were born with. The number of mature eggs in female G. ashmeadi provided honey-water with no hosts significantly declined after 163 degree-days eggs, while the number of ‘dissolved’ eggs (partially disintegrated mature eggs) increased by nine eggs after 163 degree-days. These results are consistent with oosorption. There was a significant positive correlation between HTL and <12 h egg load. The ovigeny index (the number of mature eggs at female emergence divided by potential lifetime fecundity) for G. ashmeadi was calculated as 0.22 indicating that this parasitoid is a syn-ovigenic species when studied under laboratory conditions. There was a significant positive correlation between wing wear (measured as the number of broken setae per wing) and parasitoid age in the laboratory. The practical implications of these results for G. ashmeadi on the biological control of Homalodisca vitripennis are discussed.     

中国爱丽缨小蜂属3新记录种记述(膜翅目:缨小蜂科)

本研究报道了中国爱丽缨小蜂属3新记录种:全北爱丽缨小蜂Erythmelus (s. str.) agilis (Enock,1909)(黑龙江省伊春)、大爱丽缨小蜂Erythmelus (s. str.) magnus Triapitsyn,2003 (黑龙江省尚志)和窄翅爱丽缨小蜂Erythmelus (s. str.) psallidis Gahan,1937 (云南省普洱、迪庆)。本文详细记述了3种成虫的形态特征、已知寄主和分布,附有特征照片。     

Pre-introductory risk assessment studies of Gonatocerus ashmeadi (Hymenoptera: Mymaridae) for use as a classical biological control agent against Homalodisca vitripennis (Hemiptera: Cicadellidae) in the Society Islands of French Polynesia

Homalodisca vitripennis (Germar) (=H. coagulata [Say]) (Hemiptera: Cicadellidae) invaded French Polynesia in 1999. A classical biological control program against H. vitripennis was initiated in 2004 aiming to introduce the exotic egg parasitoid Gonatocerus ashmeadi (Girault) (Hymenoptera: Mymaridae) to the Society Islands archipelago. Prior to any release, two risks were assessed: (a) continued uncontrolled H. vitripennis spread and proliferation in French Polynesia, and (b) non-target impacts by G. ashmeadi on indigenous French Polynesian cicadellids. The primary risk of H. vitripennis is its potential to vector the lethal plant bacterium, Xylella fastidiosa. While the presence of X. fastidiosa in French Polynesia has not yet been demonstrated, the presence of uncontrolled H. vitripennis greatly elevates the risk of a disease outbreak and thus represents a major threat for numerous plant species. Assessing the risk of G. ashmeadi introduction for native cicadellids first required an inventory of the Cicadellidae of the Society Islands, resulting in at least 14 cicadellid species (nine not previously recorded). The risk to these species of attack by G. ashmeadi was assessed using four criteria: (1) their phylogenetic relationships to known hosts of G. ashmeadi, and their similarity in (2) body size, (3) egg laying biology, and (4) ecology. All indigenous cicadellid species found were considered to be at low risk of attack because they differed greatly from all known hosts for G. ashmeadi: (1) none of the indigenous species are in the tribe Proconiini, (2) all were very small and, when possible to determine, (3) lay tiny single eggs, which (4) are deposited on the undersides of leaves of trees. These results persuaded the French Polynesian Government that the benefits of establishing G. ashmeadi for H. vitripennis control outweighed the serious potential risks associated with either delaying release or not releasing G. ashmeadi in French Polynesia. Releases of G. ashmeadi in Tahiti began in May 2005.     

中国阿缨小蜂属分类研究（膜翅目：缨小蜂科）

本文简述了缨小蜂科阿缨小蜂属Acmopolynema的分类现状和已知寄主情况,描述了中国阿缨小蜂属5个种,其中3个新种.喜马阿缨小蜂A. himalum Hayat & Binte 和东方阿缨小蜂A. orientale (Narayanan, Subba Rao & Kaur) 为中国分布新记录,同时提供了中国阿缨小蜂属已知5个种的分类检索表,并附主要形态特征图.所有标本保存在福建农林大学生物防治研究所.1. 长基阿缨小蜂Acmopolynema longicoxilla, 新种 (图1～4)本新种与2双暗带阿缨小蜂A. bifasciatipenne (Girault) 相似,但前翅最长缘毛小于翅宽的一半、后足跗节小于胫节等特征可与后者相区别.正模 ♀, 福建将乐,1991-Ⅹ-10,林乃铨.2. 网基阿缨小蜂Acmopolynema reticoxilla, 新种 (图5～10)本新种与本属其它种较易区分,特征如下 前胸背板完整,不分裂;前翅无暗带;后足基节网状,侧缘具刚毛.正模 ♂,福建将乐,1991-Ⅹ-10,林乃铨.3. 弯尾阿缨小蜂Acmopolynema campylura, 新种 (图15～20)本新种与东方阿缨小蜂Acmopolynema orientale (Narayanan, Subba Rao & Kaur) 相似,但本种前胸背板完整、前翅仅中间一暗带上翅毛特化、并胸腹节上脊的形状以及后足基节上的毛列等特征可与后者相区别.正模 ♀, 福建福州, 1987-Ⅸ-21,林乃铨.     

Superparasitism and mutual interference in the egg parasitoid Anagrus delicatus (Hymenoptera: Mymaridae)

Abstract.

• 1 In nature, interference among Anagrus delicatus (Hymenoptera: Mymaridae) parasitoids reduced the per-capita number of hosts parasitized. Interference increased with parasitoid density.
• 2 Anagrus delicatus did not avoid parasitizing hosts that had recently been parasitized by conspecific wasps. Evidence indicated that this superparasitism was largely a random process, increasing with the ratio of parasitized to unparasitized hosts.
• 3 Individual parasitoid efficiency, the number of hosts killed per wasp per unit time, decreased with increasing wasp density. This occurred whether wasps searched the patch together (simultaneously) or one by one (sequentially), and was the result of an increase in time spent superparasitizing hosts at higher wasp density. This is known as indirect mutual interference.
• 4 Increasing numbers of parasitoids together on the same patch caused a significant decline in the rate and per-capita number of hosts parasitized. However, there was not a correspondent decline in searching efficiency with increasing wasp density (i.e. no direct mutual interference).
• 5 These forms of parasitoid density dependence should contribute to the stability of the host—parasitoid interaction.

     

应用巢式PCR-DGGE技术分析稻虱缨小蜂体内Wolbachia的多样性

以采集自中国杭州和菲律宾的稻虱缨小蜂Anagrus nilaparvatae为研究对象,采用巢式PCR扩增Wolbachia的16S rDNA和wsp基因片段,并用DGGE分析稻虱缨小蜂体内Wolbachia的多样性.基于16S rDNA基因的分析结果准确地检测到稻虱缨小蜂体内细菌主要是Acinetobacter sp...     

The genus Dicopus Enock (Hymenoptera: Chalcidoidea: Mymaridae) in India with description of two new species

The Indian species of Dicopus Enock are reviewed and illustrated. Two species are described as new: D. kamrani sp. nov., D. obesus sp. nov. Dicopus noyesi Manickavasagam is recorded from Karnataka. A key to Indian species is provided.     

Comparison of oviposition behavior of a solitary and a gregarious parasitoid (Hymenoptera: Mymaridae)

Anaphes victus Huber andAnaphes listronoti Huber (Hymenoptera: Mymaridae) are respectively solitary and gregarious egg parasitoids of the carrot weevil,Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae). We made detailed ethograms of the oviposition behavior on unparasitized and parasitized hosts for the two species. We then compared the behavior of virgin and mated females for the oviposition of male and female progenies. The two species did not always oviposit after insertion of the ovipositor, but these punctures without oviposition could be readily differentiated from oviposition.A. victus oviposited only once by puncture, whileA. listronoti deposited one to three eggs during the same sequence. The variability of the duration of the various components was generally lower for a given female than between females. Two components, the abdominal vibrations and the pause, were significantly shorter in ovipositions that resulted in male progency for the two species. However, an important overlap in duration prevents using these differences to sex the progeny at oviposition. Virgin females of both species, although capable of producing only males, exhibited both behaviors. Parasitized hosts were recognized through internal and external markings that were used in host discrimination.     

Symbiotic bacteria in the relationship between Anaphes nitens (Hymenoptera: Mymaridae) and Gonipterus platensis (Coleoptera: Curculionidae)

The egg parasitoid Anaphes nitens (Hymenoptera: Mymaridae) parasitizes the Eucalyptus snout-beetle Gonipterus platensis (Coleoptera: Curculionidae), one of the main defoliating beetles of Eucalyptus. Outbreaks of this pest are being recorded in areas with low parasitism rates by A. nitens. Endosymbiont bacteria can affect the reproductive characteristics of host insects increasing or decreasing the parasitism rate. The objectives of this study were to identify the presence, phylogeny and transmission modes of endosymbiont bacteria in A. nitens and G. platensis. Six populations of A. nitens and one of G. platensis were evaluated. Genomic DNA from these populations was extracted and nine genera of cell endosymbionts were searched by PCR. Three species of the Enterobacteriaceae family, Erwinia amylovora, Serratia grimesii, Yersinia massiliensis and the cell endosymbiont Rickettsia belli were identified in all A. nitens populations. Only Serratia grimesii was found in G. platensis. The presence of E. amylovora, Y. massiliensis and R. belli in the F1 and F2 generations indicates vertical transmission in A. nitens, while S. grimesii is vertically transmitted in G. platensis.