For sex and more: attraction of the tephritid parasitoid Psyttalia concolor (Hymenoptera: Braconidae) to male sex pheromone of the olive fruit fly,Bactrocera oleae

The braconid parasitoid Psyttalia concolor foraging for larvae of Bactrocera oleae (Diptera: Tephritidae) uses olfactory cues from the larval microhabitat. However, it could rely on the sex pheromones of adults of its host, since B. oleae mating leks usually occur on olive plants and a high number of infested fruits can be easily located in their close proximity. We quantified the behavioural responses of P. concolor towards different doses of the two major sex pheromone components of B. oleae, the female-borne 1,7-dioxaspiro[5.5]undecane (DSU) and the male-borne (Z)-9-tricosene (ZT). Results showed that P. concolor females and males were attracted only to the highest amounts of ZT (10 B. oleae male equivalents), regardless of the mating status. Wasps remained longer on the surfaces treated with high ZT amounts over the control. P. concolor females could exploit the ZT produced by lekking olive fruit fly males as a foraging kairomone. This could allow them to rapidly track B. oleae-infested olive plants, thus raising their chances to locate host larvae during their lifespan. On the other hand, the perception of ZT by P. concolor males could raise their chances to locate receptive females emerging from parasitised B. oleae pupae or also ovipositing in olive fruits. This study increases the knowledge of the reproductive biology of P. concolor, highlighting a case of chemical espionage in which a sex pheromone component from adult stages of the host is exploited both as a foraging kairomone by female parasitoids and as a sexual kairomone by male wasps.     

Bioecological characteristics of Bracon intercessor Nees (Hymenoptera: Braconidae) as a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lepidoptera: Sesiidae) in Bulgaria

The major bioecological characteristics of Bracon intercessor Nees (Hymenoptera: Braconidae), a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lepidoptera: Sesiidae), were studied from 1987 to 2003. Poplar shoots infested with P. tabaniformis larvae were collected in 11 localities in Bulgaria and examined in the laboratory, and infestations were also studied in the field. B. intercessor was recorded in seven localities and was found to be a gregarious external larval parasitoid of P. tabaniformis. Two generations of the parasitoid developed on the host. The first (summer) generation was associated with early and mid-stage (up to third instar) host larvae, and the second (overwintering) generation with third- to fifth-instar larvae. The average number of parasitoid individuals feeding on a host was 4.5 and 12.4 in summer and overwintering generations, respectively. The maximum number recorded was 25 individuals per host in the overwintering generation. B. intercessor overwintered as a mature larva on the host and completed its development in early spring. The adults from the overwintering generation appeared in April, about 1 month prior to emergence of P. tabaniformis. The life cycle of B. intercessor was not in close synchrony with the development of P. tabaniformis in the spring, but the parasitoid adults which fed on honey-sugar solution lived for up to 31 days (males) and 86 days (females), respectively. This suggests that, in the field, B. intercessor females eclosing in the spring could survive until the host larvae appear if nectar is available. Adults of the summer generation emerge from July to September when sufficient suitable host larvae are available. B. intercessor was responsible for 1.5% of the average mortality of the P. tabaniformis overwintering larvae. The host mortality caused by the summer generation of the parasitoid ranged from 3.2% to 5.8%.     

Zwei von Uganda nach Hawaii importierteOpius-Arten(Hymenoptera,Braconidae)

Ohne Zusammenfassung     

Laboratory rearing of the solitary egg-larval parasitoid, Chelonus oculator Panzer (Hymenoptera: Braconidae) on a newly recorded factitious host Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae)

Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) is recorded as a new factitious host for the solitary egg-larval parasitoid, Chelonus oculator Panzer (Hymenoptera: Braconidae). A short biology and rearing method of the parasitoid on the new host were studied at 30±1°C, 60–70% relative humidity, with a photoperiod of 16:8 (L: D). Chelonus eclosed from 74.60% of parasitized hosts. No significant difference was found between development times of male and female parasitoids. Development of the parasitoid was completed in 28.14±0.47 days in male, and 28.87±0.58 days in female. However, a significant difference was found between adult sizes of male and female parasitoids. Adult dry mass was found 0.88±0.04 mg in male, and 1.99±0.11 mg in female. In addition, C. oculator was successfully reared from P. interpunctella in twenty generations with the explained method. Significant knowledge about biology of C. oculator is still lacking. However, the parasitoid can be candidate for future research as a biological control agent against some important lepidopteran pests, and P. interpunctella may be suitable factitious host for mass rearing of C. oculator.     

Additional diet of the parasitoids (Hymenoptera: Braconidae) and the parasitizing of the Elm Bark Beetle (Coleoptera: Scolytidae)

Supplementing the diet of Coeloides scolyticida, Dendrosoter protuberans and Ecphylus silesiacus (Hymenoptera: Braconidae) with Parker's diet and the nectars of melliferous plants: Daucus carota L., Sinapis alba L. and Stachys recta L. had a significant effect on longevity, reproduction, developmental rate, and parasitizing of Scolytus scolytus (Fab.), Scolytus multistriatus (Marsh.) and Scolytus pygmaeus (Fab.) (Coleoptera: Scolytidae). These values were considerably lower for wasps fed with the nectar of Sinapis arvensis L. and Trifolium repens L. and the lowest for those without dietary additives. Parker's diet had the most significant effect on the parasitoids and parasitizing of the bark beetles. Nectar of S. recta and S. alba proved most suitable for C. scolyticida and D. protuberans, while E. silesiacus using the nectar from D. carota flower significantly increased parasitizing of S. pygmaeus. T. repens flowers were not a suitable additive for the diet of parasitoids. The parasitoids without additives in their diet had shorter lives, shorter development, and were less effective in reducing host numbers. E. silesiacus wasps had the longest development, and C. scolyticida the shortest. Generally, the parasitoids of the second generation had a slightly prolonged development (1?–?2 days).     

Parasitoid complex (Hymenoptera, Braconidae, Aphidiinae) of Aphis craccivora Koch (Hemiptera: Aphidoidea) in Iran

The parasitoids (Hymenoptera, Braconidae, Aphidiinae) of the cowpea aphid, Aphis craccivora Koch, were investigated throughout two far distant provinces, Tehran and Sistan-Baluchestan. Colonies of the cowpea aphid were collected from different host plants and reared under laboratory conditions until the parasitoids emerged. The aphids were parasitized by an expected range of parasitoids. The species were Aphidius colemani Viereck, Lysiphlebus fabarum (Marshall), Lysiphlebus confusus Tremblay and Eady, Lysiphlebus testaceipes (Cresson), Binodoxys acalephae (Marshall), Binodoxys angelicae (Haliday), Praon volucre (Haliday) and Ephedrus persicae Froggatt. L. testaceipes is reported here for the first time in Iran. The most common species was L. fabarum followed by B. acalephae and L. confusus. A key is provided for identification and host plant associations are considered.     

寄主树木、寄主和环境因子对松褐天牛深沟茧蜂寄生率的影响研究

[目的]松材线虫病是我国对森林危害和威胁最严重的病害,控制其传播媒介昆虫松褐天牛是防治松材线虫病的主要手段。作者发现的松褐天牛深沟茧蜂(Iphiaulax monochamusi Yang)是寄生松褐天牛中老龄幼虫的重要天敌。为明确松褐天牛深沟茧蜂的寄生率与寄主树木、寄主和环境因子的关系,开展了本研究。[方法]通过解剖46株松褐天牛危害致死的马尾松,调查了松褐天牛深沟茧蜂寄生率与马尾松、松褐天牛和环境因子之间的关系。[结果]调查研究表明:寄主树木的高度、胸径和树龄对松褐天牛深沟茧蜂寄生率没有显著影响,松褐天牛的数量对松褐天牛深沟茧蜂寄生率亦没有显著影响,而松褐天牛幼虫龄期和松褐天牛幼虫在树干上的位置显著影响松褐天牛深沟茧蜂寄生率。松褐天牛深沟茧蜂寄生率与松褐天牛龄期呈显著正相关,其偏好寄生3~5龄幼虫;就天牛在其危害寄主树木上的位置而言,松褐天牛深沟茧蜂偏好寄生马尾松主干上部和在韧皮部危害的松褐天牛幼虫,其对位于马尾松树干上部的寄主幼虫寄生率最高,达27.38%,对在韧皮部生活、危害的寄主幼虫寄生率为20.18%,显著高于位于木质部生活的寄主幼虫寄生率(5.46%)。逐步回归分析表明:影响松褐天牛深沟茧蜂寄生率的关键环境因子是寄主树木的坡位和其它天敌寄生率,其中,坡位与松褐天牛深沟茧蜂呈显著正相关,其它天敌寄生率与松褐天牛深沟茧蜂寄生率呈显著负相关。[结论]以上研究初步明确了松褐天牛深沟茧蜂的寄生率与寄主树木、寄主害虫和天敌之间的关系,为今后利用该重要天敌控制松褐天牛打下了基础。     

Loss of host fidelity in highly inbred populations of the parasitoid wasp <Emphasis Type="Italic">Aphidius ervi</Emphasis> (Hymenoptera: Braconidae)

Inbreeding frequently reduces the fitness of organisms, but little is known about how this phenomenon can affect the biological control. Host fidelity provides an adaptive advantage to aphid parasitoids, allowing females to find their aphid host more quickly in heterogeneous environments. This trait is mediated by the learning of signals, mainly chemical cues emitted from the host in which parasitoids developed (natal). This article is aimed at studying whether host fidelity can be altered after many generations of inbreeding reproduction in caged laboratory populations, for which host preference and fitness parameters were measured in the parasitoid wasp Aphidius ervi. Also, the effect of the natal/non-natal hosts was studied, using parasitoids originated from the pea aphid (Acyrthosiphon pisum) and the grain aphid (Sitobion avenae). We observed a loss of host fidelity in the studied A. ervi populations, irrespective of their natal aphid host, which contrasts with previous reports showing preference for natal hosts in outbred laboratory populations. The loss of host fidelity is discussed in terms of the origin of populations; the sex ratio was strongly biased toward males and long-time maintenance under laboratory conditions. Our results highlight the need for controlling the genetic diversity of caged parasitoids before they are released into fields, as a long period of inbreeding could negatively affect the biological control.     

Experimental release of a parasitoid, Doryctes yogoi Watanabe (Hymenoptera: Braconidae), onto Semanotus japonicus Lacordaire (Coleoptera: Cerambycidae) inoculated into live Japanese cedar trees (Cryptomeria japonica D.DON)

Release experiments of Doryctes yogoi Watanabe onto Semanotus japonicus Lacordaire larvae inoculated into Japanese cedar, Cryptomeria japonica D. Don, were conducted to clarify the role of the parasitoids in the mortality of S. japonicus and the efficiency of the parasitoid as a natural enemy of the beetle. S. japonicus larvae were inoculated into three types of samples: live trees, girdled trees, and logs, each of which was treated in three ways: D. yogoi was released into the sample, the sample was screened (excluding natural enemies), or the sample was used as a control. In live trees, more than 90% of the larvae were killed by resin flow, and the percentage of parasitism by D. yogoi was less than 6%. In girdled trees, most of the larvae were dead due to the resin in the trees, having survived inoculation as well as in live trees, but many larvae were parasitized by D. yogoi in dead trees like logs. The present study revealed three negative effects of resin flow on parasitism by D. yogoi in the live trees. First, most of the host larvae died before reaching a size suitable for parasitism. Second, parasitoid larvae were caught in the resin with their hosts and died. Third, the host-searching and oviposition of female D. yogoi were obstructed by resin flow on the surface of the trunk. The efficiency of D. yogoi as a natural enemy of S. japonicus is discussed.     

Aphidius colemani Vier. (Hymenoptera, Braconidae, Aphidiinae) detected in cereal fields in Germany

Studies conducted in the 2000 cropping season at two different localities, Flaeming and Magdeburger Boerde in Germany, have provided new information on cereal aphid (Sitobion avenae (F.), Metopolophium dirhodum (Walker), and Rhopalosiphum padi (L.)) parasitoids in winter wheat; their species composition, relative abundance, hosts, and location effects. The average aphid population density was higher at Magdeburger Boerde and lower at Flaeming. Among the aphid species, Sitobion avenae was more abundant at Flaeming and Metopolophium dirhodum at Magdeburger Boerde. In total, eight species of primary parasitoids were recorded: Aphidius colemani Viereck, Aphidius rhopalosiphi DeStefani Perez, Aphidius uzbekistanicus Luzhetzki, Aphidius ervi Haliday, Aphidius picipes (Nees), Ephedrus plagiator (Nees), Praon gallicumStarý, and Praon volucre (Haliday). The predominant parasitoid species were Aphidius colemani and Aphidius rhopalosiphi on Metopolophium dirhodum and Aphidius uzbekistanicus on Sitobion avenae. A low number of hyperparasitoids were also recorded. Aphidius colemani was recorded for the first time in the open winter wheat fields in Germany, although it has been used as a biocontrol agent in glasshouses in many European countries and overseas. An analysis of the aforementioned information shows that Aphidius colemani detected as a parasitoid of cereal aphids in Germany is likely a result of an accidental escape of parasitoids from a glasshouse, as well as their successful overwintering and establishment in the area. This study provides baseline information essential for assessing future changes in aphid parasitoid species guild and dynamics in cereal fields in Germany.     

Residual effects and foliar persistence of pesticides used in irrigated rice on the parasitoid Telenomus podisi (Hymenoptera: Platygastridae)

Journal of Pest Science - We evaluated the lethal and sublethal effects of azoxystrobin, cyhalofop-butyl, and thiamethoxam on Telenomus podisi after spraying rice plants in a greenhouse, as well as...     

瘿孔象刻腹小蜂(膜翅目:刻腹小蜂科)生物学及其与寄主赵氏瘿孔象的关系

通过野外采集寄主虫瘿进行室内饲养观察与适时林间采集虫瘿进行解剖分析,研究瘿孔象刻腹小蜂的生物学及其与寄主的关系.结果表明:瘿孔象刻腹小蜂在山东济南与北京两地均1年发生2代,以幼虫单个外寄生于赵氏瘿孔象4～5龄幼虫,以老熟幼虫在虫瘿内被其杀死的寄主尸体旁越冬,翌年5月下旬成虫羽化寻找新的虫瘿进行产卵.其整个生活史均在虫瘿内完成.在山东济南的寄生率为13.7%,在北京仅第2代寄生率达30.7%.而且,因其寄主赵氏瘿孔象1年只发生1代,瘿孔象可连续寄生2次寄主幼虫,对赵氏瘿孔象的种群数量具明显的抑制作用,是生物防治这种害虫的优势天敌.     

Apanteles glomeratus (L) als Parasit vonAporia crataegi (L.)(Hymenoptera: Braconidae)

Ohne Zusammenfassung     

Hymenoptera (Insecta: Hymenoptera) associated with silvopastoral systems

The objective of this work was to estimate the abundance, diversity and constancy of families from the order Hymenoptera, such as the seasonality of those through a survey on the insect population in a silvopastoral system. We installed a Malaise-type trap in a Brachiaria decumbens area managed by a silvopastoral system in Coronel Pacheco, MG, from August 2006 to July 2008. The trapped insects were screened, and those of the order Hymenoptera were classified into their respective family categories and quantified. We adopted the methodology of Bodenheimer to calculate the indices of constancy, while other indices were estimated PAST program. We sampled 5841 specimens in total, which included 549 morphospecies and were distributed among 11 families. Of the total specimens sampled, 80% were Formicidae, which besides being the most abundant, was also the most diverse and constant family. When entomophagous insects were analyzed, the highest values for these indices were recorded for the families Ichneumonidae, Braconidae, and Vespidae. Pollinators were less prevalent compared to the total number of sampled individuals. The population density in the Hymenoptera was not correlated between the two sampling years and climate factors.     

A Revision of the GenusMicrogaster Latreille (Hymenoptera: Braconidae). (Revision der GattungMicrogaster Latreille).

Ohne Zusammenfassung

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A Revision of the GenusMicrogaster Latreille (Hymenoptera: Braconidae). (Revision der GattungMicrogaster Latreille).

     

中国跳小蜂科四新记录属五新记录种(膜翅目:小蜂总科)

该文报道采自甘肃、江苏、浙江、广西等省的５种跳小蜂,即绒蚧艾菲跳小蜂ＡｐｈｙｃｕｓｅｒｉｏｃｏｃｉＴｉｍｂｅｒｌａｋｅ、五斑佳丽跳小蜂ＣａｌｉｐｔｅｒｏｍａｑｕｉｎｑｕｅｇｕｔａｔａＭｏｔｓｃｈ、毛角尖梗跳小蜂Ｃｅｒａｐｔｅｒｏｃｅｒｕｓｐｉｌｉｃｏｒｎｉｓ、混淆莱曼跳小蜂Ｌａｍｅｎｎａｉｓｉａａｍｂｉｇｕａ、三色丽突跳小蜂Ｌｅｐｔｏｍａｓｔｉｄｅａａｂｎｏｒｍｉｓ。这５种跳小蜂在我国属首次报道,主要寄生各种介壳虫,其中除艾菲跳小蜂属Ａｐｈｙｃｕｓ外,其余４个属是中国分布新记录属。     

Effects of different neem preparations in comparison to synthetic insecticides on the whitefly parasitoid Encarsia sophia (Hymenoptera: Aphelinidae) and the predator Chrysoperla carnea (Neuroptera: Chrysopidae) on cotton under laboratory conditions

The contact and feeding toxicity of NeemAzal T/S (EID Parry, Chennai, India) to the parasitoid Encarsia sophia (Girault & Dodd) was compared with three synthetic insecticides (chlorpyriphos, endosulfan and triazophos) against immatures and adult emergence. NeemAzal T/S (1.0%) at lower dose (200 mg/l) did not cause any effect on the emergence of E. sophia adults, but there was a significant reduction in emergence at higher doses (800 mg/l). Also, it did not show contact toxicity to adults of E. sophia, but there was a significantly high feeding mortality in a dosage dependant manner, whereas chlorpyriphos, endosulfan and triazophos showed high toxicity both by contact and feeding method. Three neem preparations registered in India, NeemAzal T/S, Nimbecidine (T. Stains, Coimbatore) and Godrej Achook (Godrej Agrovet, Mumbai) were tested against egg and larval stages of Chrysoperla carnea (Stephens) at three dosages, using a synthetic insecticide, triazophos 40 EC (200 mg/l), for comparison under laboratory conditions. The three biorationals did not induce any adverse effect on the hatchability of C. carnea eggs. The mortality of the first instars of C. carnea was not affected by any of the azadirachtin enriched formulations; however, at higher dosage of 800 mg/l these neem based products resulted in increased mortality of the first and second instar larvae of C. carnea relative to the untreated controls. Whereas, triazophos induced very high mortality rates (85.0, 89.0 and 81.5%) of all the three larval instars. The neem based insecticides showed a dosage-dependant effect on the larval instars of C. carnea. Thus, these biorationals show that there is a potential to use them in an IPM system, being safe for natural enemies of B. tabaci in cotton.     

Mass rearing of <Emphasis Type="Italic">Neochrysocharis formosa</Emphasis> (Westwood) (Eulophidae: Hymenoptera), a parasitoid of leafminers (Agromyzidae: Diptera)

A method for mass rearing the parasitoid Neochrysocharis formosa (Westwood) was developed, using the leafminer Liriomyza huidobrensis (Blanchard) as insect host, and the Phaseolus vulgaris L. bean as host plant. About 1,500 parasitoids per tray of 84 plants emerged from about 2,000 leafminer larvae; 70% of these were females. The most suitable release density of host was two pairs of leafminer adults per bean plant, and that of parasitoid was three pairs per 24 leafminer larvae. Adult parasitoids were harvested based on positive photo-tactic response with 94.5% efficiency. Plants were improved by trimming their tips to increase the leaf area. The trimming process increased the number of leafminer larvae by about 32%. Furthermore, nitrogen fertilization of plants overcame the size reduction of the insects due to continuous rearing. Rearing of leafminer under light—dark (16:8 h) cycle decreased the development period of larvae and pupae. In addition, it restricted the time and duration of larval emergence and adult eclosion. Storage of parasitoid males and females at 7 and 10°C ± 0.5, respectively, proved to be optimal. The fertility of the mass-produced parasitoids after 1 year of rearing reduced by about 23%, and the sex ratio shifted toward males. In conclusion, successful mass production of N. formosa was achieved through designing suitable rearing cage and an efficient harvesting device, improving the host plant, and determining the age and the conditions for cold storage of the parasitoid and its host. Next, we checked the characteristics of the mass-produced wasps to ensure the efficacy when used in the field.