伊朗粉虱寄生蜂种类记述(膜翅目:广腹细蜂科、姬小蜂科、蚜小蜂科)

本文报道了伊朗寄生粉虱的25种寄生蜂,分别隶属于膜翅目的广腹细蜂科、姬小蜂科和蚜小蜂科,其中15种寄生蜂种类为伊朗的分布新纪录(标有*号者)。     

Morphometric and molecular analysis of the Encarsia inaron species-group (Hymenoptera: Aphelinidae), parasitoids of whiteflies (Hemiptera: Aleyrodidae)

Several series of host-reared specimens of an Encarsia species, initially thought to be the cosmopolitan Encarsia inaron (Walker), were collected in the Azores Islands (Portugal). Subsequent morphometric analysis supported the presence of two species: E. inaron and a new species, described herein as Encarsia estrellae Manzari & Polaszek sp. n. Encarsia estrellae was reared from Aleyrodes singularis Danzig, A. ?singularis, and Bemisia sp. afer-group on several host plants. In addition, the D2 region of the 28S rDNA gene was sequenced in eight individuals belonging to these species, as well as single representatives of two closely related and one distantly related species. Phylogenetic analysis of these DNA sequences, together with 23 additional Encarsia sequences retrieved from the European Molecular Biology Laboratory (EMBL) and GenBank databases, further supported the specific status of E. estrellae, and the placement of E. dichroa (Mercet) in the E. inaron species-group. Additionally, E. inaron is redescribed and some taxonomic problems in the E. inaron species-group are discussed.     

Migration, trapping and local dynamics of whiteflies (Homoptera: Aleyrodidae)

1 The ability to quantify whitefly migration provides a tool that can contribute to an improved understanding of the epidemic development of whitefly‐transmitted viruses. 2 In an attempt to develop a protocol for estimating whitefly immigration and emigration rates in an annual crop, new traps and sampling devices were tested in the field and models for population dynamics were developed. 3 An estimate of immigration rate was derived from the growth of a natural population of Trialeurodes vaporariorum (Westwood) in the beginning of a crop cycle before offspring of immigrants contributed to population growth. 4 A model for changes in whitefly density during an entire bean (Phaseolus vulgaris L.) crop cycle, including an immigration parameter, was also developed. 5 Non‐attractant window traps surrounding an annual field crop were assumed to intercept whiteflies immigrating into and emigrating away from the crop. Captures on these traps could not categorically be identified as immigrants or emigrants, but the cumulated captures nevertheless explained 66% of the variation in population density found within the field. Hence, window traps may be used as an efficient and reliable alternative to yellow sticky traps, aspirator methods and leaf‐turn methods, etc., for estimating whitefly densities in field crops.     

Cladistic analysis of morphological characters in the eulophine tribe Cirrospilini (Hymenoptera: Eulophidae)

A total of 56 morphological characters were analyzed for 53 cirrospiline species that represent all of the 17 described genera of the tribe. The other taxa of the Eulophinae included in the analysis were six species of six representative genera in the tribe Eulophini, a species of Elasmus (the only genus comprising the tribe Elasmini), and a species of Trichospilus (unplaced). Trichospilus and two of the six genera of Eulophini examined were placed within Cirrospilini. Monophyly of Cirrospilini (when these two genera of Eulophini and Trichospilus are included) and of the cirrospiline genera for which more than one species were examined was supported, but the relationships between the genera were poorly resolved. An exception was Cirrospilus, the largest genus in the Cirrospilini, monophyly of which was not supported to any extent.     

Parasitoids of whiteflies (Hymenoptera: Aphelinidae,Eulophidae, Platygastridae; Hemiptera: Aleyrodidae) from the Macaronesian archipelagos of the Canary Islands,Madeira and the Azores

Data on the whitefly parasitoid species known from the Macaronesian archipelagos of the Canary Islands, Madeira and the Azores are presented, based largely on recently collected material. A total of 26 species are treated, including six new species, six new records for the Canary Islands, two new records for Madeira, and two new records for the Azores. All species are fully described and illustrated. New species described are: Encarsia atlantica Polaszek & Hernández; Encarsia levadicola Polaszek & Hernández; Encarsia melanostoma Polaszek & Hernández; Encarsia noahi Polaszek & Hernández; Euderomphale gomer LaSalle & Hernández; Euderomphale insularis LaSalle & Hernández. A fully illustrated identification key based on females is provided for recognition of whitefly parasitoids in these archipelagos. Data on the known distribution and hosts are provided, as well as references to biology and use in biological control.     

Impact of Bemisia whiteflies (Homoptera: Aleyrodidae) on alfalfa growth, forage yield, and quality

A 3-yr project was initiated in 1993 to examine the effects of insecticides and sustained whitefly, Bemisia argentifolii Bellows & Perring [aka. B tabaci Gennadius (Strain B)], feeding on alfalfa plant growth and vigor in greenhouse cage studies, and to determine the impact of natural Bemisia whitefly populations on alfalfa forage yields and quality in a large-plot field experiment. Alfalfa plant growth and vigor after exposure to imidacloprid and a mixture of fenpropathrin and acephate insecticides did not differ from untreated plants in the greenhouse. Consequently, foliar and soil applied insecticides were used to manipulate whitefly densities on alfalfa plants to measure whitefly feeding effects on plant growth and forage yield. Heavy whitefly densities on untreated alfalfa plants in the greenhouse resulted in significant reductions in relative growth rates and net assimilation rates as compared with imidacloprid-treated plants that were maintained relatively whitefly-free. Reductions in alfalfa plant growth measured between infested and treated plants were proportional to whitefly densities. Field plot results derived from three crop seasons were relatively consistent with our greenhouse trials. Both experimental approaches clearly showed that alfalfa plants exposed to high densities of whitefly immatures and adults grew at a significantly slower rate and produced less foliage. As a result of reduced growth rates, alfalfa maturity in the naturally infested plots was estimated to be approximately 7-10 d behind managed plots. Delays in maturity resulted in significant reductions in forage yields of 13-18% during August-September harvests when whitefly populations reached peak abundance. Whitefly feeding stresses also effected hay quality through the reduction of crude protein content and contamination of foliage with honeydew and sooty mold. The status of the Bemisia whiteflies as an economic pest to alfalfa is clearly evident from these studies, but the damage potential of whiteflies in the southwestern United States appears to be restricted to one or two harvest periods during the summer coinciding with peak adult populations and their dispersal from alternate host crops.     

潜蝇姬小蜂属寄生蜂对潜叶蝇的控害特性及应用

潜蝇姬小蜂属Diglyphus寄生蜂是潜叶蝇类害虫的重要天敌。本文对其种类、 分布、 田间发生和优势度、 优势种的控害特性和生态适应性, 以及优势种的人工繁殖和田间应用等进行总结和展望, 以期为更好地应用该属寄生蜂防控我国潜叶蝇的研究和应用提供指导。迄今已鉴定该属寄生蜂36种, 全为抑性外寄生蜂, 其中针对豌豆潜蝇姬小蜂D. isaea、 贝氏潜蝇姬小蜂D. begini和中带潜蝇姬小蜂D. intermedius的研究较多。雌蜂不仅可通过繁殖型的寄生方式而且还可通过非繁殖型方式（取食寄主和产卵器插入直接杀死）致死寄主。雌蜂偏好寄生大个体寄主和取食相对较小个体的寄主, 且雌蜂对寄主幼虫的偏好具有“寄主大小依赖型性别分配”现象（host-size-dependent sex allocation）。从温度适应范围和控害潜力首推为豌豆潜蝇姬小蜂。优势种的规模饲养技术已经被研发并得到了较广泛的田间应用。未来研究可主要集中于： （1）加强优势种尤其是温度适应范围广或较为耐热的种群或地理品系的研究, 以增加对三叶草斑潜蝇Liriomyza trifolii和美洲斑潜蝇L. sativae的控效; （2）加强雌蜂寄主取食行为特性及其生理机制的研究, 以更高效利用; （3）因地制宜研发规模化饲养技术和释放技术; （4）加强潜蝇姬小蜂同其他潜叶蝇寄生蜂的协同控害及竞争共存机制的研究, 已提升对潜叶蝇的生防控制效果。     

Application technique and irrigation method affect imidacloprid control of silverleaf whiteflies (Homoptera: Aleyrodidae) on poinsettias.

Subirrigation systems are increasingly used to water and fertilize greenhouse crops. They also appear to be well suited for the application of systemic pesticides. We conducted two studies to look at interactive effects ofimidacloprid application technique and irrigation method on plant uptake of imidacloprid and whitefly control. Drench applications of imidacloprid resulted in much higher concentrations in the leaves than applications to the bottom of pots after 14 d. However, imidacloprid efficacy in subirrigated plants was better if the imidacloprid was applied to the bottom of the pot than when an equal amount was applied as a drench. In drip-irrigated plants, imidacloprid efficacy was greater after a drench than after an application to the bottom of the pots. A second study showed that drench applications to drip-irrigated plants result in high imidacloprid concentrations in the bottom of the canopy, whereas bottom applications to subirrigated plants result in a more even distribution of imidacloprid throughout the plant. Surprisingly, the high leaf imidacloprid concentrations in the bottom layer of drip-irrigated plants did not result in improved whitefly control. Imidacloprid efficacy was better in subirrigated, bottom-treated plants than in drip-irrigated, drenched plants. Overall, results from these studies indicate that imidacloprid is very effective when applied to the bottom of subirrigated pots.     

Effects of planting pattern of collards on resistance to whiteflies (Homoptera: Aleyrodidae) and on parasitoid abundance

Fourteen collard entries, Brassica oleraceae L., Acephala group, were evaluated for resistance to natural populations of Bemisia argentifolii Bellows & Perring in replicated field plots in Charleston, SC. Glossy-leaf phenotypes ('SC Glaze', 'SC Landrace,' 'Green Glaze') were the most resistant collard entries and had fewer whiteflies than the nonglossy, open-pollinated cultivars. Also, two F1 hybrid cultivars with normal, nonglossy leaves ('Blue Max' and 'Top Bunch') were resistant. In laboratory experiments, there were no differences in the intrinsic rate of growth (rs) of B. argentifolii populations on either glossy or nonglossy collard phenotypes. Over a 2-yr period, there were no differences in the abundance of whiteflies on the glossy phenotype of Green Glaze when it was planted in solid 20-plant plots or when it was alternated (every other plant) with the nonglossy phenotype of Green Glaze. In a similarly designed experiment, there was no difference in the resistance of Blue Max in either solid or mixed planting scheme compared with the susceptible 'Morris Heading'. Higher numbers of whiteflies and parasitoids (primarily Eretmocerus spp.) were collected on yellow sticky cards in the solid plantings of the nonglossy phenotype of Green Glaze than were collected in the solid plantings of the glossy Green Glaze phenotype. Counts on sticky cards in the mixed plots were intermediate. These data show that planting pattern of collard entries is relatively unimportant in the deployment of these sources of host plant resistance. The data also suggest that nonpreference is the primary mode of resistance to whiteflies for certain collard entries.     

An economic comparison of biological and conventional control strategies for whiteflies (Homoptera: Aleyrodidae) in greenhouse poinsettias

The objective of this study was to evaluate the costs of biologically controlling infestations of silverleaf whitefly, Bemisia argentifolii Bellows & Perring, in New England greenhouse operations on poinsettia, Euphorbia pulcherrima Wild, ex Koltz, using the parasitic wasp Encarsia formosa Gahan (Nile Delta strain). Partial budget analysis was used to compare costs for conventional verses biological control regimens. Four alternative whitefly control budgets are developed; two conventional chemical-based control budgets formulated with and without the use of imidacloprid, and two biological control budgets which demonstrate the impact of possibly greater pest monitoring efforts necessary to implement this type strategy successfully. The analysis shows that biological whitefly control costs were > 300% greater than conventional chemical-based control strategy costs. Most of this increase is caused by the higher costs of Encarsia formosa as the material control input. If monitoring costs are held constant across different strategies, labor costs actually decline for biological control. This is because of a significant reduction in the number of control applications made and the relatively lower cost of applying E. formosa. If more extensive monitoring efforts are required to implement biological control successfully, labor costs increase by 56% over the conventional pre-imidacloprid regimen. Based on these results, the authors conclude that cheaper and more reliable means of producing E. formosa must be developed before this strategy will become economically viable for commercial poinsettia greenhouse production.     

Aphelinidae parasitoids [Hymenoptera: Chalcidoidea] of whiteflies [Hemiptera: Aleyrodidae] in Israel,with description of three new species

Fifteen aphelinidae species, belonging to the generaEncarsia Foerter andEretmocerus Haldeman, are recorded as new whiteflies parasitoids from Israel. Three new species are described and recorded for the first time from Israel. A key to the Israeli species is given.     

Interactions between Spathius agrili (Hymenoptera: Braconidae) and Tetrastichus planipennisi (Hymenoptera: Eulophidae), larval parasitoids of Agrilus planipennis (Coleoptera: Buprestidae)

Three hymenopteran parasitoids native to China are being released in the United States as biological control agents for the emerald ash borer (EAB), Agrilus planipennis Fairmaire, an Asian buprestid species responsible for mortality of ash trees (Fraxinus spp.) in North America. Two of these hymenopterans, Spathius agrili Yang (Braconidae), a larval ectoparasitoid, and Tetrastichus planipennisi Yang (Eulophidae), a larval endoparasitoid, prefer late-instar EAB larvae. This overlapping host preference raises concerns that interspecific competition following field releases may compromise establishment of one or both species. In a series of laboratory and field experiments, we found S. agrili and T. planipennisi exhibited similar parasitism rates when presented alone with EAB larvae for 12–14 days. However, S. agrili was more efficient at locating and parasitizing hosts within the first 27 h, possibly explaining why S. agrili excluded T. planipennisi in the laboratory trials and nearly excluded T. planipennisi in field trials when the two species were presented together with EAB larvae. We found that S. agrili parasitized larvae previously parasitized by T. planipennisi but not the reverse. However, S. agrili offspring failed to complete development on hosts that were previously parasitized by T. planipennisi. We recommend releasing these species separately in time or space to avoid the antagonistic interactions observed in this study.     

Biology of a thelyotokous biotype of Eretmocerus mundus (Hymenoptera: Aphelinidae) on Bemisia tabaci (Homoptera: Aleyrodidae)

Abstract Thelyotokous biotype of Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae), a parasitoid of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), was recently recorded in northern Iran. Reproductive biology of this biotype was studied as part of an evaluation of its potential for biological control of B. tabaci. The parasitoid deposited more eggs under 2nd and 3rd nymphal instars than 1st or 4th instars. Adult females fed honey, with no access to whitefly nymphs, lived significantly longer (13.6 ± 4.7 d) than those given access to nymphs, but not fed honey (7.6 ± 2.21 d). Lifetime fecundity averaged 81.7 ± 26.9 female progeny per female parasitoid, ranging from 11–132. Daily fecundity, measured as the number of whitefly nymphs parasitized by per female each day for 10 d, averaged 18.06 ± 3.95 for the first 6 d of life, and then declined to < 11. Developmental time from oviposition to parasitoid emergence was significantly shorter in the 3rd instar of the host (15.9 ± 1.06 d) than in the 1st instar (18.7 ± 2.3 d), but not in the 2nd instar (16.4 ± 1.3 d).     

The whiteflies (Hemiptera: Aleyrodidae) of Europe and the Mediterranean Basin

The whitefly fauna of Europe and the Mediterranean Basin comprises 56 species that are considered to be native or naturalized, accommodated within 25 genera. Presented here are a check-list, an identification key to puparia, and a brief account of each species including its distribution and host-plant range. The puparium of each species is illustrated. One new nomenclatural combination (Aleuroclava similis, from Aleurotuberculatus) and two new synonymies (Parudamoselis kesselyaki with Ceraleurodicus varus, Asterobemisia nigrini with A. paveli) are proposed. Three nominal species (Aleurodes capreae, A. fraxini, and Aleyrodes campanulae) are here treated as nomina dubia. Species which, in the study area, have only been recorded from glasshouses are discussed. Four additional species, not yet recorded from the region, are included in the discussion, two of them because a particular quarantine risk is perceived and two because they are notifiable pests in European Union quarantine legislation.     

Use of CC traps with different trap base colors for silverleaf whiteflies (Homoptera: Aleyrodidae), thrips (Thysanoptera: Thripidae), and leafhoppers (Homoptera: Cicadellidae)

During 1996, 1997, and 1999, studies were conducted in cotton, sugar beets, alfalfa, yardlong bean, and peanut fields to compare insect catches in CC traps equipped with different trap base colors. The studies were conducted in southwestern United States, China, and India. The nine colors, white, rum, red, yellow, lime green, spring green, woodland green (dark green), true blue, and black, varied in spectral reflectance in the visible (400-700 nm) and near-infrared (700-1050 nm) portions of spectrum. Lime green, yellow, and spring green were the three most attractive trap base colors for silverleaf whitefly, Bemisia argentifolii Bellows & Perring, and leafhopper, Empoasca spp. adults. The three trap base colors were moderately high in the green, yellow, and orange spectral regions (490-600 nm), resembling the spectral reflectance curve of the abaxial (underleaf) surfaces of green cotton leaves. True blue and white were the most attractive trap base colors for western flower thrips, Frankliniella occidentalis (Pergande), adults. The true blue and white trap bases were moderately high in the blue spectral region (400-480 nm).     

Effect of pesticides on Colpoclypeus florus (Hymenoptera: Eulophidae) and Trichogramma platneri (Hymenoptera: Trichogrammatidae), parasitoids of leafrollers in Washington.

Pesticides were evaluated for their effect on two parasitoid species, Colpoclypeus flouts and Trichogramma platneri, that are potential biological control agents of leafrollers in apple orchards. Organophosphate and carbamate insecticides were highly toxic to both parasitoids in topical applications, but foliar residues of some products were nontoxic after 7 d. At reduced rates, topically applied pyrethroids were low in toxicity to C. florus were highly toxic to T. platneri, and foliar residues were nontoxic after about 7 d. Imidacloprid and abamectin were highly toxic when applied topically to both parasitoids but were not toxic as 1-d-old residues. Insect growth regulators did not cause mortality either as topical applications or residues; however, diflubenzuron caused severe sublethal effects, completely blocking the production of C. florus offspring. Biorational pesticides, such as soap, oil, and B. thuringiensis products, caused no toxicity to C. florus but had a direct impact on T. platneri as topical applications through physical immobilization. The potential to integrate different pesticides with biological control of leafrollers and the need for a step-wise approach to evaluate the impact of pesticides against natural enemies is discussed.     

Factors that affect the selection of tomato leaflets by two whiteflies,Trialeurodes vaporariorum and Bemisia tabaci (Homoptera: Aleyrodidae)

In Japan, although greenhouse whitefly, Trialeurodes vaporariorum (Westwood), and sweet potato whitefly, Bemisia tabaci (Gennadius), co-occur on tomato plants under greenhouse conditions, the two whiteflies are distributed differently with regard to leaf position. To elucidate the factors that determine the leaf position of these whiteflies, we investigated traits for leaflets collected from three positions on tomato plants. Furthermore, we examined leaflet selection by and fertility of the two whiteflies under choice and non-choice conditions. In addition, the effect on whitefly behavior of volatile compounds released from leaflets was evaluated by use of a Y-tube olfactometer test. Nitrogen and carbon content were highest for upper leaflets. In choice tests, more T. vaporariorum and B. tabaci adults selected upper and middle leaflets, respectively. Similarly, they oviposited more eggs on upper and middle leaflets. In non-choice tests, T. vaporariorum oviposited more eggs on upper leaflets, but B. tabaci oviposited equally on each leaflet. In Y-tube olfactometer tests, more T. vaporariorum adults moved to upper leaflets whereas more B. tabaci adults moved to middle leaflets. These results suggest that different leaflet selection by adults of these two whiteflies is likely to be associated with the different volatile compounds emitted by tomato leaflets at each position.     

Effects of selected insecticides on Diadegma semiclausum（Hymenoptera： Ichneumonidae） and Oomyzus sokolowskii （Hymenoptera： Eulophidae）, parasitoids of Plutella xylostella （Lepidoptera： Plutellidae）

Abstract Field doses of six selected insecticides were tested against the immature (pupae) and mature (adult) stages of Diadegma semiclausum (Hellén) and Oomyzus sokolowskii (Kurdjumov), parasitoids of the diamondback moth, Plutella xylostella (L.). Effects of contact toxicity (direct spraying) of the six insecticides on emergence of parasitoids were found negligible on both species except permethrin which caused 37.5% mortality. All adults of both parasitoid species died 24 hours after exposure to chlorfenapyr, emamectin benzoate and permethrin. In contrast, the three insect growth regulators (IGRs), chlorfluazuron, flufenoxuron and teflubenzuron, were found harmless to both species, and adult mortality of both parasitoid species was 0–16.7%. However, parasitism by the females of both parasitoid species was severely impaired when the females were offered the three IGR diluted solutions for 24 hours. Effects of oral toxicities of the IGRs on longevity of both parasitoids after 12 hours exposure were found to be significantly different between males and females. Compatibility of tested insecticides with D. semiclausum and O. sokolowskii and integration of compatible insecticides with these parasitoids in integrated pest management programs of crucifers are discussed.     

Interactions between Phaedrotoma scabriventris Nixon (Hymenoptera: Braconidae) and Diglyphus isaea Walker (Hymenoptera: Eulophidae), parasitoids of Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae)

Liriomyza leafminer flies represent a serious threat to horticultural production in East Africa. Total field parasitism rates recorded in Kenya are below 5%, with the indigenous ectoparasitoid Diglyphus isaea Walker being one of the key parasitoid species. The International Centre of Insect Physiology and Ecology (icipe), in collaboration with the International Potato Centre (CIP), imported into Kenya the endoparasitoid Phaedrotoma scabriventris Nixon to improve natural control of leafminers. The objective of this study was to investigate the interactions between D. isaea and P. scabriventris when used together for the biological control of Liriomyza species. These interactions were studied under laboratory conditions, using treatments that involved single, simultaneous and sequential releases of the different parasitoid species onto plants infested by L. huidobrensis larvae. While used separately, parasitism rates of D. isaea and P. scabriventris were 30.4 ± 10.9% and 63.6 ± 7.7% respectively. However, when used simultaneously, the total parasitism rate increased to 77.0 ± 5.3%. Although P. scabriventris had no effect on D. isaea, the presence of D. isaea reduced the specific parasitism rate of P. scabriventris. In addition, both parasitoids induced leafminer mortality through larval-feeding and stinging. However, feeding and stinging mortality induced by D. isaea (41.9 ± 9.1%) was significantly higher compared to P. scabriventris (11.9 ± 8.7). Similarly, pupal mortality due to feeding and stinging activity was 49.1 ± 6.5% and 21.6 ± 1.9% when exposed to D. isaea and P. scabriventris respectively. The implication for simultaneous use of both parasitoids in East Africa is discussed.