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1.
Trichogramma platneri Nagarkatti (Hymenoptera: Trichogrammatidae) was recently introduced into Israel to improve the control of two lepidopterous pests,Boarmia selenaria (Schiffermiiller) andCryptoblabes gnidiella (Millière). Laboratory tests showed thatT. platneri attacks the eggs of both species. A method of freezing the eggs of the host,Ephestia cautella (Walker), at -20°C and gradual defrosting, used in the large laboratory breedings of the parasites, is described briefly. In laboratory tests 68.5% of the frozenE. cautella eggs, after 2 months of storage, were parasitized, compared with 70.3% of the fresh eggs.  相似文献   

2.
The South American tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a major threat to tomato (Solanum lycopersicum L.) crops. After its first detection in Spain in 2006, it spread rapidly through the Western Palaearctic region, arriving in Tunisia 2 years later. The aim of this research was to assess whether generalist indigenous parasitoids are adapting to this exotic host in Tunisian tomato crops. For this, we conducted a survey in four Tunisian tomato-growing areas by sampling infested leaves of tomato and solanaceous weeds and exposing artificially infested sentinel plants. Two ectoparasitoid species were found attacking and developing on T. absoluta: Bracon sp. (Hymenoptera: Braconidae) and Necremnus sp. nr artynes (Hymenoptera: Eulophidae), whereas no egg or pupal parasitoids were found. The eulophid wasp was the most abundant with a peak of apparent parasitism rate of 25.5%. It emerged from parasitized T. absoluta young larvae in exposed sentinel plants and in sampled infested tomato leaves, both in greenhouse and open field cultivations. Bracon sp. showed a gregarious development on T. absoluta mature larvae and it was collected only on sentinel plants exposed in the Ragueda (Kiarouan) site, with 10.23% of estimated parasitism. Although further research is still needed to assess properly the ecological role of these parasitoids in the biological control of T. absoluta, this study represents the first step toward establishing the scientific basis for including these parasitoids in the Tunisian IPM and biological programs against this pest.  相似文献   

3.
Vespa velutina Lepeletier, 1836 (Hymenoptera: Vespidae) is reported for the first time from the Iberian Peninsula based on catches made during 2010 in Guipuzcoa and Navarra provinces (northern Spain). Notes about its current geographical distribution, biology, and economic and medical importance are also provided.  相似文献   

4.
Aenasius arizonensis (Girault) (Hymenoptera: Encyrtidae) is an important solitary endoparasitoid of mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae). Studies on seasonal and biological interactions between host and parasitoid are important to optimize the mass production and field release of high-quality females. We investigated the influence of different crop seasons viz., pre-monsoon, monsoon and post-monsoon and host stages viz., three nymphal instars (1st, 2nd and 3rd) and adult stage of P. solenopsis on the development, longevity, fecundity and sex ratio of its parasitoid, A. arizonensis. A. arizonensis female parasitized all life stages of its host except the 1st instar nymphs. Only males emerged from parasitized 2nd instar nymphs, while the sex ratio in the later host instars was strongly female-biased. The adult host stage was most suitable for A. arizonensis in terms of shorter development time, while the 3rd instar nymphal stage was most suitable with respect to higher fecundity, proportion of adults emerged and more females in the progeny. Among different seasons, post-monsoon season (September–October) with temperature (25 to 29 °C) and relative humidity (68 to 73%) was most suitable for the overall fitness of the parasitoid. The findings of this study have implications in designing mass rearing of this parasitoid and devising an effective biological control strategy for P. solenopsis on cotton.  相似文献   

5.
The diversity of lepidopterous stem borers, their parasitoids and their associated wild host plants was studied in South Africa between 2006 and 2009 and in Mozambique between 2005 and 2010. In South Africa, 20 species of parasitoids were recovered from 17 stem borer species collected on 16 wild host plant species. From Mozambique, 14 parasitoid species were recorded from 16 stem borer species collected on 14 wild host plant species. The highest diversity of parasitoids was recorded on stem borers that attacked the host plants Phragmites australis (7 spp.) and Panicum maximum (6 spp.), in South Africa and Mozambique, respectively. Bracon sp. (Hymenoptera: Braconidae) and Procerochasmias nigromaculatus (Hymenoptera: Ichneumonidae) were the most recorded parasitoid species in South Africa while Cotesia sesamiae (Hymenoptera: Braconidae) parasitized most stem borer species in Mozambique. The most common tachinid parasitoid recorded in this study was Sturmiopsis parasitica (Diptera: Tachinidae). Parasitism of stem borers during the off season was previously thought to occur mainly in natural habitats but this study shows that although natural habitats provided refuges for some parasitoid species, stem borer parasitism was generally low in wild host plants, irrespective of whether collections were done during the cropping or off-season. Parasitoid beta diversity did not depend on habitat or host plant species, but was determined by stem borer diversity.  相似文献   

6.
The frequency of encapsulation of eggs ofAnagyrus pseudococci (Girault) (Hymenoptera: Encyrtidae) by four mealybug species:Planococcus citri (Risso),PL vovae (Nasonov),Pl. ficus (Signoret) andPseudococcus cryptus Hempel (=citriculus Green), was studied under controlled laboratory conditions. The aggregate percentage of encapsulated eggs (AE) and the percentage of efficient encapsulation (EE) (= percent parasitized mealybugs wherein encapsulation prevented the development of all parasitoid larvae) byPl. citri andPl. vovae did not differ significantly (39.0%vs 38.2% AE and 15.4%vs 17.6% EE, respectively), but was significantly higher than inPs. cryptus (16.2% AE and 5.4% EE). Encapsulation byPl. vovae was significantly higher than byPl. ficus (38.2%vs 20.1% AE and 17.6% vs 7.7% EE, respectively). Neither the host plant nor the rearing temperature significantly affected the incidence of parasitoid encapsulation. It is suggested thatA. pseudococci displays a relatively low physiological adaptation toPl. citri; thus, in a citrus grove, for example,ca 40% of the parasitoid eggs might be lost due to encapsulation. The question of a possible association between encapsulation and host—parasitoid relationships among the mealybugs studied andA. pseudococci, is discussed.  相似文献   

7.
The species of the genus Yponomeuta Latreille (Lepidoptera: Yponomeutidae) are known as ermine moths and can be found on various host plant species, sometimes appearing as pests. They are attacked by a wide range of parasitoids. We studied parasitoid complexes of several communities in Austria, Poland, Serbia, Slovenia and Sweden during 2014–2018. From four species, Yponomeuta cagnagella (Hübner), Yponomeuta evonymella (Linnaeus), Yponomeuta malinellus Zeller and Yponomeuta padella (Linnaeus), we reared 15 parasitoid species of seven hymenopteran and one dipteran family. In this study, the family Ichneumonidae is the most numerous, while Ageniaspis fuscicollis (Dalman) (Hymenoptera: Encyrtidae) was found in all four Yponomeuta species. Within reared parasitoids, A. fuscicollis is new record for Slovenia and Austria, Baryscapus evonymellae (Bouché) (Hymenoptera: Eulophidae) and Diadegma armillatum (Gravenhorst) (Hymenoptera: Ichneumonidae) are new records for Slovenia and Agrypon canaliculatum (Ratzeburg) (Hymenoptera: Ichneumonidae), Dolichogenidea dilecta (Haliday) (Hymenoptera: Braconidae), Elasmus steffani Viggiani (Hymenoptera: Eulophidae), Herpestomus brunnicornis (Gravenhorst) (Hymenoptera: Ichneumonidae), Trieces tricarinatus (Holmgren) (Hymenoptera: Ichneumonidae) and Mesochorus nuncupator (Panzer) (Hymenoptera: Ichneumonidae) are new records for Serbia. Also, Yponomeuta cagnagella is a new host record for Pteromalus semotus (Walker) (Hymenoptera: Pteromalidae) and Y. padella for E. steffani. Finally, we reviewed parasitoids of European Yponomeuta species and their associated host plants. In total 154 species are recorded from nine hymenopteran and one dipteran family.  相似文献   

8.
The yellow‐legged hornet Vespa velutina nigrithorax du Buysson (Hymenoptera: Vespidae) is an Asian native species which has now established in parts of Europe. Since its detection in France in 2005 it has spread quickly across the country and also spread to the Iberian Peninsula. This paper compiles the most recent data about its spread and distribution on the Spanish mainland. The efficacy of using Véto‐Pharma© traps as a control method is also discussed.  相似文献   

9.
In general, it is difficult to evaluate host resource utilization of parasitoids by examining the biomass of concealed wood borers at parasitism, because the larval tissues of parasitized hosts observed in field surveys are often almost completely consumed. This work explored a precise and convenient method for evaluating the biomass of concealed wood-boring insect pests after they are parasitized. Allometric scaling laws were used to determine mathematical relationships between larval weight and other size variables in two host insects: the emerald ash borer [EAB], Agrilus planipennis Fairmaire, and the oak long-horned beetle [OLB], Massicus raddei (Blessig). These insects are hosts of the parasitoid Sclerodermus pupariae Yang et Yao (Hymenoptera: Bethylidae). Our results showed that body weight among different instars was significantly different for both host species, with greater overlap between neighboring instars. Mean larval weight had a highly significant exponential relationship with instar number. EAB larval weight showed a highly significant power relationship to body length and width, width of the prothoracic plate, peristoma width, urogomphus length, and anteriormost width of the urogomphus. Significant power relationships were also observed between OLB larval weight and body size parameters (including body length, length of the mesothoracic spiracle, width of the prothoracic plate, distance between the main ocelli, and mandible length). These findings indicated that host biomass could be easily calculated if any one size variable could be measured at the time of parasitism. Allometric methods provide a precise means of evaluating time-specific biomass of concealed wood borers.  相似文献   

10.
The most harmful hymenopteran pests of Pinus sylvestris L. are conifer sawflies from the family Diprionidae, including the widespread Diprion pini (L.). Natural enemies of this pest are still poorly known in many European areas where attacks occur. We studied the egg parasitoids of D. pini at four sites in two mountainous areas of Spain: the Sierra de Francia (western Spain) and the Sierra de Albarracín (eastern Spain). At all sites, the dominant egg parasitoid was Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae), whereas other three chalcidoid species were rare. All these species were previously recorded in association with D. pini, but we report here their first record in Spain. Neochrysocharis formosa attacked up to 32.3% of egg clusters of D. pini in the Sierra de Albarracín and 18.5% in the Sierra de Francia. In the attacked egg clusters, this species parasitized up to 35% of eggs in the Sierra de Albarracín and 23.7% in the Sierra de Francia, with a marked female-biased sex ratio. Contrary to the clustered pattern of parasitism observed for N. formosa while attacking other gregarious diprionids, the oviposition in egg clusters of D. pini followed a random pattern, probably due to the froth roof (spumous coating) that covers its eggs and interferes with the egg-searching behavior of females. Indeed, other parasitoid species of D. pini have been reported to behave similarly.  相似文献   

11.
Margosine-0®, a commercial preparation of neem seed extract, was tested for its effects as a toxicant, growth inhibitor, or repellent against six species of cockroaches —Blatta orientalis L.,Blattella germanica (L.),Byrsotria fumigata Guérin-Méneville,Gromphadorhina portentosa (Schaum),Periplaneta americana (L.), andSupella longipalpa (F.) (Orthoptera: Blaberidae, Blattidae, and Blattel-lidae). Last-instar nymphs of these species fed Lab-Chow® pellets impregnated with neem extract at a rate of 0.5 ml/pellet showed increased mortality and retarded development. All lst-instar nymphs ofB, orientalis, B. germanica andS. longipalpa died after consuming treated Lab-Chow pellets. Topical application of 2 μl of Margosine-0 to the abdomens of last-instarB. orientalis nymphs, as well as injection of 0.5 μl, resulted in reduction of growth and increased mortality. Placing lst-instarB. orientalis nymphs on a surface treated with the neem extract had no notable effect. In a choice test,P. americana adults immediately preferred the pellets treated with 0.5 ml of neem extract, but pint cardboard cartons treated with 1.5 ml extract repelled them.  相似文献   

12.
The Citrus Leafminer (CLM) Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) is considered an important pest of citrus, damaging mainly nursery plants. In Greece it was first recorded on the island of Rhodes in 1995 and rapidly spread to all citrus growing areas of the country. Due to its wide expansion and damage, efforts were initiated to control this pest with biological control agents. For this purpose, a number of exotic parasitoids, such as Citrostichus phyllocnistoides (Narayanan), Quadrastichus sp. Girault and Semielacher petiolata (Girault) (Hymenoptera: Eulophidae), were introduced, reared in insectaries and released in several regions of Greece. The species composition and the seasonal abundance of the native parasitoids, as well as the recovery of the released parasitoids, were investigated in weekly samplings during 1998 and 1999 in a citrus orchard in Argolis district. Results showed that among the released parasitoids, only C. phyllocnistoides was recovered. Among the native parasitoids, Neochrysocharis formosa (Westwood), Pnigalio pectinicornis (L.) and Cirrospilus sp. Westwood (Hymenoptera: Eulophidae) were identified. The most abundant parasitoid species was the exotic C. phyllocnistoides. The highest percent of parasitism in 1999 increased approximately by 46% compared with that of the previous year. The percent of parasitism increased to its maximum level during November, at the end of the sampling period in both years, when the population density of C. phyllocnistoides was high.  相似文献   

13.
The citrus mealybugPlanococcus citri (Risso) and the vine mealybugPlanococcus ficus (Signoret) (Hemiptera: Pseudococcidae) are two worldwide polyphagous pests of citrus, vineyards and ornamental plants in greenhouses. Biological control of these pests may rely on the combined release of parasites and predators, which can be affected by intraguild predation (IGP). This study investigated the feeding behavior of different stages ofCryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) on mealybugs parasitized byAnagyrus pseudococci (Girault) (Hymenoptera: Encyrtidae) 2, 4, 6, 8 and 10 days. The study was conducted in a climate-controlled room at 28±1° C, 16L:8D, and 65±10% r.h. The highest consumption values for all stages ofC. montrouzieri occurred with 2- and 4-day parasitized mealybugs, whereas the predator did not feed on either species of mealybug parasitized for longer periods, due to the onset of mummification. http://www.phytoparasitica.org posting August 4, 2008.  相似文献   

14.
以血球计数板较系统地考查了菜粉蝶和柑桔凤蝶雌雄蛹被蝶蛹金小蜂寄生后浆血细胞和颗粒血细胞数量的时间动态变化,以明确该蜂寄生对其寄主血细胞数量和组成的影响.结果表明,菜粉蝶蛹被寄生后,其血细胞总数除寄生后2天外均极显著高于同期未寄生蛹,最多的约高出20倍;除被寄生后0.5和5天的寄生蛹的血细胞组成与同期未寄生蛹无显著差异外,寄生后1～ 4 天雌雄寄生蛹的浆血细胞所占比例均显著低于同期未寄生蛹,而颗粒血细胞所占比例则反之.玉带凤蝶寄生蛹的血细胞总数在寄生后0.5 ～ 3天与同期未寄生蛹相比均无显著差异,但寄生后4 ～ 5天却显著升高,最多的约高出3倍;寄生后0.5 ～ 5天的寄生蛹浆血细胞所占比例均显著低于同期未寄生蛹,而颗粒血细胞所占比例恰反之.可见,该蜂寄生在一定时间内不仅能引起其两种寄主血细胞总数和颗粒血细胞所占比例明显增高,而且能导致浆血细胞所占比例明显下降.  相似文献   

15.
Z. Mendel 《Phytoparasitica》1988,16(2):101-108
The occurrence of nests of the pine processionary caterpillar (PPC),Thaumetopoea wilkinsoni Tarns (Lepidoptera: Thaumetopoeidae), was recorded in two 9-year-old plots planted withPinus halepensis, P. brutia andP. eldarica in a randomized block design. Nest density was highest inP. eldarica and lowest inP. halepensis. The mean number of nests per tree and their frequency distribution indicate that the preference of the PPC is in the order P.eldarica >P brutia >P. halepensis;it is believed to be related to shape of the tree. Planting ofP. eldarica in camping sites is not recommended, due to its high susceptibility to colonization by the PPC.  相似文献   

16.
Coccinella septempunctata L. (Coleoptera: Coccinellidae) is a natural enemy of several important pests. This biocontrol agent is also a host for different parasitoids. Little is known about the parasitoid complex of C. septempunctata in Pakistan. The authors identified Oomyzus scaposus (Thomson, 1878) (Hymenoptera: Eulophidae) as a larval-pupal parasitoid of C. septempunctata in the district of Sargodha, Punjab, Pakistan. Out of 36 C. septempunctata pupae collected, 58.3% were parasitized by O. scaposus. This study documents the first record of O. scaposus parasitizing C. septempunctata in Pakistan.  相似文献   

17.
A new species of Anagyrus Howard (Hymenoptera: Encyrtidae), A. pseudofuscus Zu sp. nov., is described from China as a parasitoid of the mealybug, Phenacoccus solani Ferris (Hemiptera: Pseudococcidae).  相似文献   

18.
The response of three soft scales: the pyriform scale —Protopulvinaria pyriformis (Cockerell), the mango shield scale —Protopulvinaria mangiferae (Green), and the capparis soft scale —Coccus capparidis (Green), to paiasitization by the parasiteMetaphycus swirskii Annecke & Mynhardt (Hymenoptera:Encyrtidae), was studied. Although the parasite was able to complete its development in any of these three host species, different rates of mortality of parasite immatures were recorded in the various hosts. Parasite mortality inP. pyriformis was due to egg encapsulation only and was higher in the field than under laboratory conditions (53.1%vs. 27.7%, respectively). InP. mangiferae a total of 55.4% mortality was observed, while inC. capparidis it reached only 14.0%, rendering the latter the most suitable of the three soft scales tested, for successful development ofM. swirskii.  相似文献   

19.
黑绒鳃金龟甲成虫对不同单色光和光强的趋光行为   总被引：3，自引：0，他引：3  
为筛选高效光源以提高灯光对黑绒鳃金龟甲的诱杀效果,在室内采用昆虫行为学方法测试了黑绒鳃金龟甲成虫对14种单色光及不同白光光强的趋光行为。结果显示:14种单色光刺激下,黑绒鳃金龟甲成虫表现出不同的趋光行为,在紫光区400 nm和420 nm处趋光率最高,为39.72%;其次为绿光区498、524、562 nm处,趋光率分别为38.61%、38.05%和37.22%。该虫雌、雄成虫对14种单色光的趋光率存在差异,在460、483、524、605 nm处,雌虫的趋光率显著高于雄虫,分别达到38.89%、41.11%、41.67%和38.34%,雄虫则为28.33%、32.78%、34.45%和31.11%。不同白光光强刺激下该虫也表现出不同的趋光行为,最高趋光率出现在弱光强区域,雌、雄成虫分别达到51.67%和44.44%,随着光强增加趋光率下降,但最强光强时趋光率又有所增加。表明紫光和绿光为黑绒鳃金龟甲的敏感光源,且对弱光强更敏感;雌虫对光谱和光强的敏感性高于雄虫。  相似文献   

20.
Insecticidal tests using diazinon showed that the mortality of Plutella xylostella larvae parasitized by Cotesia plutellae was reduced by 4.6-fold compared to that of the nonparasitized hosts. The use of chemicals with synergistic effect to insecticides in toxicity assay helps to elucidate the kind of enzyme involved in lowering insect mortality. Synergism of diethyl maleate and piperonyl butoxide with diazinon resulted to 2.4- and 1.9-fold increase, respectively, in susceptibility of parasitized larvae compared to those of nonparasitized larvae. These results indicated the possibility that the decrease in susceptibility to diazinon was due to the elevated activities of glutathione-S-transferase (GST) and cytochrome P450 monooxygenase (CYP), respectively. The GST activities in parasitized larvae were significantly higher than those of nonparasitized ones starting from three days post-parasitization until emergence of parasitoid larva. High GST activities during late parasitism could be attributed to both enzyme activities toward diazinon of parasitized P. xylostella larva itself and C. plutellae larva inside larval host. High GST activity one day after parasitization, although statistical significance was not detected, was caused by polydnavirus (PDV) and the venom of C. plutellae not by parasitoid larvae. Artificial injection of PDV plus venom demonstrated that the resulting increase in GST activity is similar to the increase brought by parasitization. High CYP activity after 3 days post-parasitization in parasitized larva was attributed mainly to the activity of parasitoid larva. Carboxylesterase activity in the parasitized host remained at a high level, while that in the nonparasitized host decreased slightly as pupation approaches. On the other hand, acetylcholinesterase activity also remained constant after parasitization until larval emergence, while that of the nonparasitized hosts decreased gradually as the host larvae approach pupation. These results were supported by inhibition tests using diazoxon in vitro.  相似文献   

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