外来入侵害虫——西花蓟马在山东省不同地区主要花卉上的分布

【背景】外来入侵害虫西花蓟马于2003年首次在北京郊区被发现,并逐渐扩散蔓延,目前已在我国局部地区暴发成灾。【方法】于2008～2009年通过定点调查的方法对山东省115个地区258个样点的主要花卉上的蓟马种类进行了分析。【结果】山东省主要花卉上发生的蓟马有11种,包括花蓟马、黄胸蓟马、黄蓟马、西花蓟马、棕榈蓟马、烟蓟马、禾花蓟马、横纹蓟马、腹小头蓟马、黑白纹蓟马、油加律带蓟马等,其优势种为花蓟马。外来入侵害虫西花蓟马在山东省18个地区的花卉上被发现。其中,荣成市区发生最重,占蓟马采集总量的51.86%;德州市区和青岛市区发生次之,分别占蓟马采集总量的34.21%和33.88%;其他地区西花蓟马发生量占采集总量的1.39%～18.75%。【结论与意义】西花蓟马已在山东省定殖并广泛分布,相关部门应做好西花蓟马的预防与控制工作。     

Management of thrips (Thysanoptera: Thripidae) in Australian strawberry crops: within-plant distribution characteristics and action thresholds

Abstract  Management of thrips in a hydroponic strawberry crop near Sydney, New South Wales, was studied from 1999 to 2002. The main species present were western flower thrips, Frankliniella occidentalis (Pergande), plague thrips, Thrips imaginis Bagnall, and, occasionally, onion thrips, Thrips tabaci Lindeman. Their within- and between-plant distribution and the degree and type of damage caused are described, and used to recommend action thresholds. Flowers are identified as the primary monitoring site, and young green fruit as the key damage site. Action thresholds of approximately 45% of flowers with 5 or more adult western flower thrips, or 40% of flowers with 10 or more adult plague thrips are recommended. Alternative thresholds using all motile stages are given for flowers, and for young green and red berries. A higher tolerance is recommended during cool, wet periods.     

外来人侵害虫——西花蓟马在山东省不同地区主要花卉上的分布

【背景】外来入侵害虫西花蓟马于2003年首次在北京郊区被发现,并逐渐扩散蔓延,目前已在我国局部地区暴发成灾。【方法】于2008～2009年通过定点调查的方法对山东省115个地区258个样点的主要花卉上的蓟马种类进行了分析。【结果】山东省主要花卉上发生的蓟马有11种,包括花蓟马、黄胸蓟马、黄蓟马、西花蓟马、棕榈蓟马、烟蓟马、禾花蓟马、横纹蓟马、腹小头蓟马、黑白纹蓟马、油加律带蓟马等,其优势种为花蓟马。外来入侵害虫西花蓟马在山东省18个地区的花卉上被发现。其中,荣成市区发生最重,占蓟马采集总量的51．86％;德州市区和青岛市区发生次之,分别占蓟马采集总量的34．21％和33．88％;其他地区西花蓟马发生量占采集总量的1．39％～18．75％。【结论与意义】西花蓟马已在山东省定殖并广泛分布,相关部门应做好西花蓟马的预防与控制工作。     

Winter and spring abundance of Frankliniella spp. and Thrips tabaci Lindeman (Thysan., Thripidae) on weed host plants in Turkey

Abstract:  The species composition of thrips and abundance of three pestiferous thrips species, Frankliniella occidentalis (Pergande), Thrips tabaci Lindeman and Frankliniella intonsa (Trybom) (Thysan., Thripidae) on weed species during winter and spring time were studied in vegetable production and polycultured areas in the eastern Mediterranean region of Turkey in years 2002 and 2003. Of a total of 61 543 thrips extracted from 8933 samples collected, 77% were adults. F. occidentalis was collected from all of 49 weed species sampled and F. intonsa was detected on 18 plant species between May and June. T. tabaci was collected from 42 of a total of 49 weed species. Immature thrips were extracted from 42 of a total of 49 weed species. Four weed species of a total 35 weed species sampled between April and May in the sampling areas hosted 63% of larvae and approximately 50% of F. occidentalis collected. A total of 23 thrips species was recorded from weeds sampled in this study. F. occidentalis accounted for 83% of a total 47 640 adult thrips collected and followed by low rates of T. tabaci and F. intonsa (9 and 1%, respectively). Melanthrips spp. accounted for 3.54% of total numbers of adult thrips. Flower-inhabiting thrips species and T. tabaci were most abundant on weeds between April and May when the number of weed species in bloom was greatest, then decreased to low levels after May. Most pestiferous thrips on weeds species were collected from vegetable production areas. F. occidentalis was the predominant thrips comprising over 80% in most months in the vegetable grown area. In polycultured area, the composition of adult thrips shifted monthly. While Melanthrips was the more prevailing thrips by rates 53% in February and 81% in March, F. occidentalis was the predominant thrips with 60 to 62% in spring, respectively.     

Analysis of the thrips fauna (Thysanoptera) on flowers of herbs

Studies of Thysanoptera were realized at the Agricultural Experimental Station in Mydlniki near Cracow over the years 2003-2005. This research work covers the observations of the species composition of thrips and the periods of the occurrence of the particulars species of thrips and their numerousness. The thrips were collected from flowers of Valeriana officinalis L., Hypericum perforatum L. and Levisticum officinale Koch. Following thrips species dominated samples collected directly from plants: Frankliniella intonsa (Trybom), Thrips fuscipennis Haliday, Thrips tabaci Lindeman and Thrips major Uzel. The greatest number of thrips was noticed during flowering period on Valeriana officinalis L., and Hypericum perforatum L.     

Efficacy of entomopathogenic nematode Steinernema feltiae (Rhabditida: Steinernematidae) as influenced by Frankliniella occidentalis (Thysanoptera: Thripidae) developmental stage and host plant stage

Entomopathogenic nematodes were investigated as an alternative biological control strategy for western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), in ornamental greenhouse crops, by using potted chrysanthemum as a model crop. The susceptibility of various life stages of F. occidentalis to different concentrations of the nematode Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) was investigated in petri dish bioassays. This was followed with trials using potted chrysanthemums comparing the efficacy of nematode application to plants in vegetative (exposed habitat) versus flowering (cryptic habitat) stages. In both trials, the effect of the wetting agent Agral 90 (nonylphenoxy polyethoxyethanol), which is used in combination with the nematode spray, on F. occidentalis mortality was assessed. In petri dish trials, the prepupae and pupae were the most susceptible developmental stages of F. occidentalis to infection by S. feltiae. First and second instars were killed by very high rates of nematodes (> or =20,000 infective juveniles per milliliter), but corrected mortality was only approximately 28-37%. No significant mortality was observed for adult thrips. Results from the petri dish trials were confirmed on chrysanthemum plants. Foliar application of S. feltiae did not result in significant mortality in larvae or adults. No significant differences in efficacy were detected by application of nematodes on vegetative versus flowering chrysanthemum. Agral 90 had a significant impact on mortality on the first stage larvae and prepupae in the petri dish trials but not in the plant trials. Thrips control by S. feltiae in greenhouses may be partly or completely due to prepupal and pupal mortality.     

Transmission of Chrysanthemum Stem Necrosis Virus, a Recently Discovered Tospovirus, by Two Thrips Species

The biological transmission of a recently discovered tospovirus species, Chrysanthemum stem necrosis virus (CSNV), was studied. The transmission capacity of three thrips species ( Frankliniella schultzei , Frankliniella occidentalis and Thrips tabaci ) was tested using a leaf disc assay combined with DAS-ELISA. This capacity was tested with adults which were given an acquisition access period of 16 h on CSNV-infected plants as new-born larvae, up to 8 h old. The virus was efficiently transmitted by F. schultzei (78.1%) and F. occidentalis (65.1%), but not at all by T. tabaci (0.0%). Infection was confirmed in adult thrips; high virus titres were found in 75.9% of F. schultzei and 97.4% of F. occidentalis adults. Although T. tabaci did not transmit CSNV in this study, comparatively low amounts of virus were detected in 75.0% of the tested population. The results obtained showed that F. occidentalis and F. schultzei may be the major vectors of CSNV in Brazil.     

Bioactivity of carvacrol and thymol against Frankliniella occidentalis and Thrips tabaci

Abstract: Two constituents of essential oils, carvacrol and thymol, were tested for their effects on the feeding activity, oviposition preference and oviposition rate of Frankliniella occidentalis and Thrips tabaci . Given a choice between treated and untreated leaf discs, F. occidentalis avoided ovipositing on leaf discs treated with 1 or 0.1% thymol. In no-choice experiments, 1 and 0.1% thymol and 1% carvacrol resulted in a reduced oviposition rate of F. occidentalis compared with the control. Both constituents caused a slight reduction of the feeding damage of F. occidentalis . 1 and 0.1% carvacrol had a pronounced deterrent effect on the oviposition site selection of T. tabaci . Both constituents served as anti-ovipositants for both thrips species, albeit F. occidentalis was more affected than T. tabaci .     

Predatory effect of Orius niger (Wolff) (Hem., Anthocoridae) on Frankliniella occidentalis (Pergande) and Thrips tabaci Lindeman (Thysan., Thripidae)

The predatory effect of adult female Orius niger (Wolff) (Hem., Anthocoridae) on the larvae I–II and adults of two injurious thrips , Frankliniella occidentalis (Pergande) and Thrips tabaci Lindeman (Thysan., Thripidae), was examined in June 1997, in controlled environment chambers (temperature 22 ± 0.2°C, 65 ± 3% RH, a 16 h light : 8 h dark photoperiod and light intensity 9000 Lux). This study took place on sweet pepper leaves ( Capsicum annuum L.) in transparent small plastic cages at proportions of 1/5, 1/10, 1/20 and 1/30 predator/number of thrips for larvae I–II and adults separately for each thrips species. O. niger was proved an effective predator for the immature stages (larvae I–II) and for the adults of the two thrips species. We concluded that O. niger could be used with success for the biological control of thrips in greenhouses crops.     

Variation in preference and performance of Frankliniella occidentalis (Thysanoptera: Thripidae) on three strawberry cultivars

Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a major pest of strawberry, causing substantial yield loss through direct feeding on the flowers and fruit. Insecticides are the main method used for its control; however, F. occidentalis has developed resistance to insecticides from all major chemical classes. Chemical control is not a long-term strategy and integrated pest management is required. This study determined whether F. occidentalis damage could be reduced by host plant resistance or tolerance in three commercial strawberry cultivars (Fragaria X ananassa [Rosaceae]: 'Albion', 'Camarosa', and 'Camino Real'). Determination of resistance or tolerance to F. occidentalis was based on olfactory response, feeding damage, ovipositional preference, and host suitability for reproduction on leaves. F. occidentalis adults preferred to feed on Camarosa; however, if leaves had been fed on previously by conspecifics, there was no difference in feeding preference. Camarosa was the most preferred cultivar for oviposition, and more eggs were laid by F. occidentalis on Camarosa than either Albion or Camino Real. More larvae hatched and adults were reared from Camarosa than either Albion or Camino Real. The percentage of unhatched eggs, larvae, and pupae that died was highest on Camino Real. Survival rate was highest on Camarosa. Egg incubation, prepupation, pupation, and total developmental periods were shortest on Camarosa, but the larval period was longest on Camarosa. Camarosa was the most favorable cultivar for F. occidentalis population growth on leaves.     

蔬菜花期蓟马的种群动态与空间分布研究

西花蓟马是近年来在我国局部地区暴发成灾的重要外来入侵害虫,有关西花蓟马入侵对本地蓟马种群动态、空间分布及优势种影响的报道较少。对云南省昆明市近郊蔬菜花期的蓟马种群动态和空间分布研究表明,蔬菜上的蓟马种类主要是西花蓟马Frankliniella occidentalis(Pergande)、花蓟马F.intonsa(Trybom)、棕榈蓟马T.palmi(Karny)和端大蓟马Megalurothrips distalis(Karny);不同蔬菜上的蓟马优势种存在一定差异,其中辣椒和茼蒿上的蓟马优势种为西花蓟马;韭菜、茄子和四季豆上的蓟马优势种分别为花蓟马、棕榈蓟马和端大蓟马。各蔬菜上的蓟马种群数量以花期为多,盛花期达最大值,其中茄子花上的蓟马成虫平均虫口密度最高,为14.93头/朵。利用聚集度指标进行空间分布检测表明,不同蔬菜上蓟马成虫的空间分布型均为聚集分布,且聚集程度随密度的增加而增大。本研究可为深入探讨西花蓟马对本地蓟马的竞争取代机制积累资料,同时为西花蓟马的综合治理奠定理论基础。     

Notes on Thysanoptera found on flax (Linum usitatissimum L.) in the British Isles

The following eighteen species of Thysanoptera Terebrantia have been found on flax in the British Isles: Melanthrips fuscus (Sulzer), Aeolothrips fasciatus (L.), Anaphothrips obscurus (Müler), Aptinothrips rufus (Gmelin), Chirothrips manicatus Hal., Limothrips cerealium Hal., L. denticornis Hal., Stenothrips graminum Uzel, Taeniothrips atratus (Hal.), T. vulgatissimus (Hal.), Thrips angusticeps Uzel, T. discolor Hal., T. flavus Schrank, T. fuscipennis Hal., T. major Uzel, T. minutissimus L., T. physapus L., T. tabaci Lindeman. Each species is described briefly with notes on habits of adults and larvae, place of pupation, number of generations in the year, hibernation, time of occurrence on plants, plants and objects on which found, host plants of larvae and adults, importance to flax, record of locality and collector on flax, distribution, including altitudes, in the British Isles. More species occur in the south than in the north of Great Britain, and species common to both regions usually occur in greater numbers in the south. The insects breed on certain species of crop plants, weeds or trees of arable land. No damage of economic importance to flax by Thysanoptera has been proven in the British Isles, and the flax thrips, Thrips lini Ladureau, has not been found. Taeniothrips vulgatissimus (Hal.) may breed on flax and its adults, and those of T. atratus (Hal.) may cause superficial damage to petals of flowers. Thrips angusticeps Uzel and T. tabaci Lindeman will probably breed on flax.     

Ecological studies on Thrips imaginis Bagnall (Thysanoptera) in flowers of Echium plantagineum L. in Australia

Aspects of the ecology of Thrips imaginis Bagnall in flowers of Echium plantagineum L. are described and subjected to experimental analysis. Thrips eggs were mostly laid in plant parts that were not lost when the short-lived flowers abscissed. The abundance of adults and larvae in flowers from the bud stage through to abscission was determined. Larvae usually required more than one flower to complete development and so had to migrate between flowers to survive. Larvae generally remained between the bases of the stamen filaments when in direct sunlight, but moved along the filaments to the anthers for rapid pollen feeding during low light intensity, especially at night. There was little spatial and temporal overlap between thrips larvae and honeybees in the flowers. Ants can cause much damage to the flowers and can feed on thrips. Pollen feeding of T. imaginis is described. The species of pollen grain affects feeding, and this may influence breeding success. Low u.v.-reflecting white, blue and yellow water traps caught more T. imaginis that green, red, black and high u.v.-reflecting white. These results agree well with the numbers of adults in several native and non-native flowers of various colours. Adult female thrips colour variation is correlated with for ewing length, and hence reflects factors acting on a pre-adult stage.     

Specificity of accumulation and transmission of tomato spotted wilt virus (TSWV) in two genera, Frankliniella and Thrips (Thysanoptera: Thripidae)

The accumulation and transmission of tomato spotted wilt virus (TSWV) was examined in second instar larvae and adults of two thrips genera, Frankliniella and Thrips. The species tested were F. occidentalis (Pergande), F. intonsa (Trybom), T. tabaciLindeman, T. setosus Moulton, T. palmi Karny and T. hawaiiensis (Morgan). In a standard petunia leaf disc assay, the efficiencies of TSWV transmission by two species of Frankliniella were higher than those of any Thrips species in the adult stage. A triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA) showed that large amounts of the TSWV-nucleocapsid (N) protein were present in the ELISA-positive larvae of each species, with the exception of T. palmi. The ELISA titre of and the proportion of virus-infected individuals of the two Frankliniella species increased or did not significantly change from the larval to the adult stages, whereas those of the four Thrips species decreased significantly. These results show that the specificity of virus transmission by adult thrips is probably affected by the amount of viral N protein accumulation in the adults and that the accumulation pattern from the larval to the adult stages is in between the two genera tested in the present study.     

Aggregation and mating of thrips in flowers of Calystegia sepium

Abstract. 1. Aggregation and mating of Thrips major Uzel and Thrips fuscipennis Haliday (Thysanoptera: Thripidae) in the 1-day flowers of Calystegia sepium (L.) R.Br. are described.
2. The number of thrips per flower increased rapidly after flower-opening at dawn and decreased during the evening and following morning.
3. Males patrolled the corolla, attempting to copulate with any females that landed. Their movement was affected by the density of thrips on the corolla. Most females were among the stamens and style, apparently feeding on pollen.
4. These thrips were also abundant in flowers of Filipendula ulmaria (L.) Maxim. They fed on pollen, and grains adhered to them. They may be significant pollinators because of their high frequency of flights.
5. The aggregations appear to be a simple consequence of general flower-finding responses to colour and scent that are particularly elicited by flowers of C.sepium and F.ulmaria. The ecological significance of male aggregations is discussed.     

The role of floral structure and biotic factors in determining the occurrence of florivorous thrips in a dystilous shrub

Elucidating the factors determining the occurrence of florivorous organisms is an essential step for comprehending arthropod–plant interactions, especially when considering florivores that use flowers/inflorescences as microhabitats. In this study, we characterize the interaction between florivorous thrips (Thysanoptera) and Palicourea rigida (Rubiaceae), a distylous hummingbird-pollinated shrub. We investigated the relative role of different factors in determining thrips occurrence in the flower and inflorescence microhabitats. Furthermore, we experimentally examined the protective role of corolla influencing thrips exploration of floral buds. Frankliniella musaeperda (Thripidae) was the only species recorded on P. rigida, feeding on floral tissue, pollen and nectar. Thrips occurrence was not related to distyly, but rather to floral stage. Open flowers presented the highest abundance of thrips, followed by senescent flowers and then buds. The experimental opening of buds translated in increased thrips occurrence, indicating that F. musaeperda manage to explore the microhabitat offered by the floral chamber, as long as there is an opening in the corolla. In inflorescences, thrips abundance was negatively related to the number of ants visiting extrafloral nectaries. We found that the marked difference between floral morphs of distylous plants is not necessarily reflected in the abundance of florivores. Thrips seek for floral cavities, preferentially those with fresh tissue, which may confer nutrient-rich food and protection. Buds also provide this; however, the enclosed petals are an effective barrier against F. musaeperda entrance. At inflorescence scale, presence of mutualistic ants in high numbers can drive away these flower-feeding insects. Despite the abundance of thrips in the flowers, there was no evidence of any functional relationship, either of pollination for flowers or of breeding for insects. We demonstrate here that in the flower/inflorescence microhabitat, structural and biotic factors play a key role in the exploitation and occupation by insect florivores.     

Population dynamics of banded thrips (Aeolothrips intermedius Bagnall, Thysanoptera, Aeolothripidae) and its potential prey Thysanoptera species on white clover

In 2002, the occurrence of banded thrips (Aeolothrips intermedius Bagnall) and some other Thysanoptera species on white clover (Trifolium repens L.) was monitored at two locations in the continental part of Slovenia. White clover presents in many countries important intercrop in integrated vegetable production. Light blue sticky boards were placed on grasslands (one parcel on each location) with high percentage of white clover. Sticky boards were changed in about 10-days intervals from the end of April till the beginning of October. Number of caught individuals on the boards was counted. They were classified in three different groups: 1. Aeolothrips intermedius, 2. representatives of Haplothrips, Odontothrips and Frankliniella genera, 3. representatives of Thrips genus. We stated that, compared with the other Thysanoptera species in the open, predatory thrips occurs in lower number. Predatory species Aeolothrips intermedius was the most numerous during the flowering of white clover. It was established that other Thysanoptera species (the most of them are facultative phytophagous species) were more numerous also in the periods of less favourable weather conditions and during the non-flowering growing stages of white clover. Based on the results of present research we concluded that A. intermedius has a potential to control onion thrips (Thrips tabaci Lindeman), especially in July and August, when in the open both species occur in high numbers.     

Impact of straw mulch on populations of onion thrips (Thysanoptera: Thripidae) in onion

Development of insecticide resistance in onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), populations in onion (Allium spp.) fields and the incidence of the T. tabaci transmitted Iris yellow spot virus have stimulated interest in evaluating alternative management tactics. Effects of straw mulch applied in commercial onion fields in muck areas of western New York were assessed in 2006 and 2007 as a possible onion thrips management strategy. In trials in which no insecticides were applied for thrips control, straw mulch-treated plots supported significantly lower T. tabaci populations compared with control plots. In both years, the action thresholds of one or three larvae per leaf were reached in straw mulch treatments between 7 and 14 d later than in the control. Ground predatory fauna, as evaluated by pitfall trapping, was not increased by straw mulch in 2006; however, populations of the common predatory thrips Aeolothrips fasciatus (L.) (Thysanoptera: Aeolothripidae) were significantly lower in straw mulch plots in both years. Interference of straw mulch in the pupation and emergence of T. tabaci was investigated in the lab and their emergence was reduced by 54% compared with bare soil. In the field the overall yield of onions was not affected by the straw mulch treatment; however, the presence of jumbo grade onions (>77 mm) was increased in 2006, but not in 2007. These results indicate that populations of T. tabaci adults and larvae can be significantly reduced by the use of straw mulch without compromising overall onion yield. The use of this cultural practice in an onion integrated pest management program seems promising.     

Transmission of Iris yellow spot virus by Frankliniella fusca and Thrips tabaci (Thysanoptera: Thripidae)

Thrips-transmitted Iris yellow spot virus (IYSV) (Family Bunyaviridae, Genus Tospovirus) affects onion production in the United States and worldwide. The presence of IYSV in Georgia was confirmed in 2003. Two important thrips species that transmit tospoviruses, the onion thrips (Thrips tabaci (Lindeman)) and the tobacco thrips (Frankliniella fusca (Hinds)) are known to infest onion in Georgia. However, T. tabaci is the only confirmed vector of IYSV. Experiments were conducted to test the vector status of F. fusca in comparison with T. tabaci. F. fusca and T. tabaci larvae and adults reared on IYSV-infected hosts were tested with antiserum specific to the nonstructural protein of IYSV through an antigen coated plate ELISA. The detection rates for F. fusca larvae and adults were 4.5 and 5.1%, respectively, and for T. tabaci larvae and adults they were 20.0 and 24.0%, respectively, indicating that both F. fusca and T. tabaci can transmit IYSV. Further, transmission efficiencies of F. fusca and T. tabaci were evaluated by using an indicator host, lisianthus (Eustoma russellianum (Salisbury)). Both F. fusca and T. tabaci transmitted IYSV at 18.3 and 76.6%, respectively. Results confirmed that F. fusca also can transmit IYSV but at a lower efficiency than T. tabaci. To attest if low vector competency of our laboratory-reared F. fusca population affected its IYSV transmission capability, a Tomato spotted wilt virus (Family Bunyaviridae, Genus Tospovirus) transmission experiment was conducted. F. fusca transmitted Tomato spotted wilt virus at a competent rate (90%) suggesting that the transmission efficiency of a competent thrips vector can widely vary between two closely related viruses.