Scirtothrips Species Research Articles

Taxonomic changes in Scirtothrips species (Thysanoptera: Thripidae) from México

The twelve species of Scirtothrips known from México are difficult to identify. We present new updates for defining Scirtothrips in that country. The species were re-evaluated using specimens from the National Insect Collection at IBUNAM, México. Visual comparisons of the Scirtothrips holotypes and paratypes were completed and contrasted to the current nomenclature of Central and North America taxa. We proposed synonymy of seven species, but the genus retains the twelve species officially reported in México herein. Scirtothrips citri, Scirtothrips perseae and Scirtothrips dorsalis are crop pests usually recorded. An updated key was developed to identify the Scirtothrips spp. in México.

A new species of the genus Scirtothrips (Thysanoptera, Thripidae) from India.

A new species of Scirtothrips is described from India, S. donumdei, collected on leaves of Senegalia pennata (Fabaceae). Partial mitochondrial cytochrome c oxidase subunit 1 (mtCOI) gene sequence of the species was sequenced and the annotated sequence was submitted to NCBI GenBank.

Preventive releases of phytoseiid and anthocorid predators provided with supplemental food successfully control Scirtothrips in strawberry

Thrips of the subtropical genus Scirtothrips are emerging as important pests in several crops. Scirtothrips dorsalis has been increasingly invading new areas outside of its native region of South and East Asia causing economic damage to several crops. Scirtothrips inermis is another polyphagous species with worldwide distribution. Both species are polyphagous, and in recent years have emerged as key pests in strawberry. In this study, we first evaluated the predation and oviposition rate of commercially available phytoseiid predatory mites Amblyseius swirskii, Amblydromalus limonicus, Transeius montdorensis, and Neoseiulus cucumeris on larval stages of both Scirtothrips species, and oviposition rates of predatory mites on the supplementary food source Artemia franciscana cysts were also assessed. Predatory mites equally accepted both thrips species as prey and showed stable oviposition rates on these diets. Amblyseius swirskii and A. limonicus were the most voracious, also exhibiting the highest oviposition rate of the predators tested. We further evaluated the biological control potential of predatory mites and anthocorid predators Orius laevigatus and Orius limbatus in a greenhouse experiment. Predators were released preventively and supported with Artemia cysts before the introduction of S. inermis. Both Orius predators achieved good control of the pest, with O. limbatus developing higher numbers than O. laevigatus. Regarding phytoseiids, A. swirskii and A. limonicus both controlled the pest and built higher populations than T. montdorensis and N. cucumeris. Our results show that a preventive strategy based on phytoseiid or anthocorid predators in strawberry can be effective in suppressing S. inermis.

A new genus and species of Scirtothrips genus-group (Thysanoptera, Thripidae), with two new species of Scirtothrips, from Dipterocarp Forest canopy in Malaysia.

A new genus and three new species are described from the canopy of Dipterocarp forest in Pasoh Forest Research in Malaysia: Daunothrips gen. n., D. striatus sp. n., Scirtothrips convexum sp. n. and Scirtothrips longifacies sp. n. The morphological characters of these new members of the Scirtothrips genus-group are discussed and illustrated.

Endemism among Lord Howe Island Thysanoptera, with new species of Baenothrips (Phlaeothripidae) and Scirtothrips (Thripidae)

The Thysanoptera diversity of Lord Howe Island comprises 39 known species, of which 13 are considered likely to be endemic to this tiny remnant of an ancient submarine volcano. Three new species are described in Baenothrips, a small but widespread genus of wingless, fungus-feeding species in the Old World tropics. Two new species of Scirtothrips are described that are members of a species-group breeding on the youngest fronds of tree ferns.

Colored sticky traps for monitoring phytophagous thrips (Thysanoptera) in mango agroecosystems, and their impact on beneficial insects

The capture efficiency of six colored sticky traps (blue, green, orange, purple, white, and yellow) was tested in mango agroecosystems of Mexico with the purpose to: (i) document the diversity of Thysanoptera; (ii) determine the attraction of phytophagous thrips; (iii) assess the impact of these traps on beneficial insects; and (iv) assess the relationship between the density of Frankliniella thrips captured on traps and those found in the inflorescences. The use of colored sticky traps has revealed a great diversity of thrips and beneficial insects in the mango agroecosystem. A total of 16,441 thrips were caught on sticky traps throughout the sampling period, of which 16,251 (98.8%) were thrips adults and 190 (1.2%) larvae. Forty one species of thrips were collected either from sticky traps or from inflorescences. Of these, 32 species feed either on leaves or flowers. Frankliniella cephalica, F. gardeniae and F. invasor, were the most abundant species. Scirtothrips citri and S. manihoti were also captured among other phytophagous thrips. The white trap captured significantly more Frankliniella species and also had the smallest capture of beneficial insects. Yellow traps were the most attractive for Scirtothrips species, with low detrimental effects on insect pollinators, although high impact on natural enemies. Thrips species captured on sticky traps showed a low and non-significantly correlation with respect to the density of thrips in mango inflorescences. Although sticky traps did not predict the density of Frankliniella populations in mango inflorescences, the study represents a substantial progress in the use of color traps in mango agroecosystems. Colored sticky traps would be a good option for monitoring mango thrips to detect them at earlier stages of infestation to implement management tactics and avoid the building-up of thrips populations.

DNA barcoding of selected Scirtothrips species (Thysanoptera) from India

The members of the genus Scirtothrips are highly polyphagous, including major pest and vector species. We applied both morphology and molecular approaches to delimit the selected Scirtothrips species from India. Out of 43 generated barcode sequences, six sequences of three species (S. hitam, S. mangiferae, and S. malayensis) are the novel contribution in global database. The Bayesian (BA) phylogeny clearly distinguishes all the studied species with reciprocal monophyletic criteria and represents multiple clades in S. dorsalis and S. oligochaetus. The high Kimura-2-Parameter (K2P) genetic divergences were observed between the multiple clades of S. dorsalis (4.5–8.8%) and S. oligochaetus (6.4%), which indicating possible existence of cryptic diversity. The current study also provided the morphological keys for six Scirtothrips species including S. hitam as a new record to India.

Phylogenetic relationships among Scirtothrips species and related genera (Thysanoptera, Thripidae) based on morphology

Scirtothrips, one of the largest genera of Thripinae, includes several species that are important pests for agricultural and horticultural plants. Scirtothrips genus-group comprises 11 genera, but phylogenetic relationships among these are unclear, as are the interspecific relationships within Scirtothrips. We used 61 morphological characters to study the morphological variation and phylogenetic relationships among the members of this genus-group. Phylogenetic analysis supported the inclusion of eight genera in Scirtothrips genus-group but excluded Ajothrips and Scirtidothrips, although the monophyly of Scirtothrips was not well-supported. Our analysis strongly supported two different species-groups both comprising species associated with Acacia in Australia, suggesting the occurrence of at least two separate radiations onto this plant genus. The monophyly of Scirtothrips perseae species-group was not supported; members of this group are involved in damage to avocado in the New World. The Scirtothrips aurantii species-group was recognised as comprising S. aurantii, Scirtothrips dodonaeae and Scirtothrips mugambii, based on one synapomorphic character, male hind femora with a comb of setae. We demonstrated that the conspicuous drepanae that occur in males of some Scirtothrips species evolved separately in New and Old World species. We discussed the relationships among Scirtothrips species together with data on geographic distributions and host plants, and noted inconsistencies that presumably result from homoplasy.

Scirtothrips genus-group in Iran with an unusual new species of Scirtothrips (Thysanoptera: Thripidae)

A new species of Scirtothrips Shull from leaves of Tamarix sp. is described and illustrated from southern Iran. Among Scirtothrips species, it is unusual in having two pairs of long pronotal posteroangular setae, and ocellar setae III unusually long. A key is provided to distinguish members of the Scirtothrips genus-group in Iran: Drepanothrips reuteri Uzel, Scirtothrips dorsalis Hood, S. hafezi sp. n. and S. mangiferae Priesner.

First Report of Tomato spotted wilt virus in Eustoma grandiflorum in Korea

HomePlant DiseaseVol. 101, No. 3First Report of Tomato spotted wilt virus in Eustoma grandiflorum in Korea Previous DISEASE NOTES OPENOpen Access licenseFirst Report of Tomato spotted wilt virus in Eustoma grandiflorum in KoreaJ. Y. Yoon, G. S. Choi, and S. K. ChoiJ. Y. YoonSearch for more papers by this author, G. S. ChoiSearch for more papers by this author, and S. K. ChoiSearch for more papers by this authorAffiliationsAuthors and Affiliations J. Y. Yoon G. S. Choi S. K. Choi , Virology Unit, Department of Horticultural and Herbal Environment, National Institute of Horticultural and Herbal Science, RDA, Wanju, Jeollabuk-Do, 55365, Republic of Korea. Published Online:13 Dec 2016https://doi.org/10.1094/PDIS-10-16-1514-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae) was first reported in Korea in 2004 (Choi et al. 2004) and the virus is currently widespread in the country, infecting pepper, tomato, potato, and wild plant species (Choi et al. 2014). TSWV is transmitted by at least 11 species of thrips (e.g., Frankliniella occidentalis), one species of Ceratothripoides, and one species of Scirtothrips. Transmission can also be archived through infected plant sap. Lisianthus (Eustoma grandiflorum) is an herbaceous annual and an emerging flower for weddings, producing eight million cutting flowers in 2014 in Korea. In January 2016, virus-like symptoms including mosaic and wilting followed by necrosis on leaves and branch were observed in lisianthus plants in a greenhouse in Tae-An-gun, Korea. Approximately 10% of lisianthus plants (about 3,000 plants) in the greenhouse showed virus-like foliar symptoms, based on visual estimates. To identify a causal virus, four symptomatic leaf samples of lisianthus plants were analyzed by transmission electron microscopy (TEM) of leaf dip-preparations. Tospovirus-like particles (about 80 to 100 nm in diameter) were observed from all the samples of lisianthus plants. To confirm TEM result, the symptomatic leaf samples were further analyzed using double-antibody sandwich (DAS)-ELISA kits (Agdia, Elkhart, U.S.A.) for the presence of three lisianthus-infecting viruses, such as Bean yellow mosaic virus, Cucumber mosaic virus, and TSWV, as our preliminary survey on flowers. A positive control and a negative control (leaves of healthy a lisianthus plant) were used. DAS-ELISA clearly showed that TSWV was only detected serologically from the naturally infected lisianthus plants. The single infection of TSWV in the symptomatic lisianthus plants was further confirmed by a TSWV-Immunostrip kit (Agdia). To confirm the presence of TSWV alone, RT-PCR products were synthesized for L, M, and S RNA segments using Tospovirus-specific primers and TSWV-specific primers (Batuman et al. 2014; Choi et al. 2014). The expected fragments of 445, 868, and 777 bp were amplified and sequenced (LC191920, LC191921, LC168751). The sequences of each fragment were identical to a consensus sequence, showing 97, 98, and 99% identity with TSWV-L, M, and S RNA (KC494520, HM581941, and KC494482), respectively. These results clearly showed that the results of DAS-ELISA and the TSWV-Immunostrip kit were not due to interspecies cross-reactivity of the virus-specific antibodies. The results of sequence comparisons showed no reassortment between TSWV and another tospovirus. Taken together, a distinct TSWV isolate is the causal agent in the diseased lisianthus plants. To our knowledge, this is the first report of TSWV in lisianthus in Korea. The epidemic nature of TSWV, along with lisianthus production in Korea, warrants monitoring for TSWV in greenhouse production in Korea.

Scirtothrips coccolobaesp. nov. (Thysanoptera: Thripidae), a Leaf-Feeding Thrips on Sea Grape Known from Florida and the Cayman Islands

A new species of Scirtothrips, S. coccolobae sp. nov. (Thysanoptera: Thripidae), is described from the state of Florida in the United States of America, and from the Cayman Islands. This species appears to be native to the Caribbean region. Present evidence indicates it to be specific to a single host plant, Coccoloba uvifera L. (Caryophyllales: Polygonaceae).

Species of the genus Scirtothrips from Africa (Thysanoptera, Thripidae)

A key is provided to 14 species of Scirtothrips recorded from Africa south of the Sahara, including Cape Verde Islands. S. dodonaeae sp. n. is described from Dodonaea in South Africa, and the possibility is discussed that South African populations here referred to as S. aff. dorsalis represent a new species. Type specimens of the six Scirtothrips species described by J.C.Faure have been re-examined, and brief diagnoses are provided for all 14 species.

A new genus and species of Scirtothrips genus-group (Thysanoptera: Thripidae) from Kenya, intercepted by Australian quarantine

The thrips species described here has been taken repetitively in recent years by the Australian Quarantine and Inspection Service on fresh leaves imported from Kenya. The leaves involved are of Catha edulis (Celastraceae), a plant that is used as a mild stimulant, particularly in countries near the Horn of Africa between Kenya and the Yemen. The leaves are either chewed fresh or made into a beverage, and the plant is commonly known as “khat” or “qat”. Leaves of this plant imported into Australia have been found commonly to bear larvae and pupae, and more rarely adults, of an interesting species of Thripinae. Although clearly a member of the Scirtothrips genus-group (Masumoto & Okajima, 2007), the species represents a previously undescribed genus. The host range of this species is at present unknown, however Dr Subramanian Sevgan of ICIPE, Kenya, kindly e-mailed photomicrographs of this thrips (19 May 2009) and confirmed that the species had been collected from Catha edulis in that country. Although possibly host specific, this new species must continue to be considered a potential hazard by Australian quarantine, because so many species of Scirtothrips are highly polyphagous and pestiferous. Moreover, on the same imported leaves larvae and adults of a Scirtothrips species also have been taken several times, but this species remains unidentifiable due to the absence of any modern information on the African fauna of Scirtothrips. This article describes the new genus and species, with comparisons to related taxa. Nomenclatural details of all taxa mentioned here are given in the web-available world catalogue of Thysanoptera (Mound, 2009). The new names reflect the Kenyan origin of the specimens studied, and the contribution of Katarina Graljuk who first intercepted the species in Australia, and who with her colleagues at the Australian Quarantine and Inspection Service help prevent invasive organisms from entering and harming Australian agriculture and ecosystems.

Relationships Among Species of <I>Scirtothrips</I> (Thysanoptera: Thripidae, Thripinae) Using Molecular and Morphological Data

Results of analyses of molecular sequence (COI, 28S-D2) and morphology (21 character states) data, both alone and combined, were used to determine relationships between 18 species of Scirtothrips (Thysanoptera: Thripidae, Thripinae). Two species of Neohydatothrips from Panama were used as the outgroup. Five major pest Scirtothrips were included in these analyses: S. aurantii, S. citri, S. dorsalis, S. kenyensis, and S. perseae. Trees generated from a parsimony analysis of molecular data and Bayesian analysis of molecular and morphology data combined showed high levels of congruence. The morphology-only tree had several differences in species groupings when compared with trees derived using molecular data. Both parsimony and Bayesian analyses using molecular data indicated that Scirtothrips species associated with avocados were monophyletic, a result not observed with morphological analyses. No support was found for a monophyletic S. dorsalis clade when sampled from six different countries. The S. dorsalis complex may be comprised of at least three separable groups identifiable at the molecular level, but indistinguishable morphologically. The implications of this finding for S. dorsalis, a thrips pest of global significance with high invasion potential, are discussed.

Synonomy of Five Scirtothrips Species (Thysanoptera: Thripidae) Described from Avocados (Persea americana) in Mexico

Abstract The holotypes of Scirtothrips aguacatae, S. kupandae, S. manihotifloris, S. tacambarensis, and S. uruapaniensis were examined and compared with specimens of Scirtothrips perseae from Mexico, Guatemala, and California. The chaetotaxy of the pronotum and head of each of these 5 holotypes was found to fall within the range observed on specimens identified as S. perseae based DNA analyses and subsequent slide mounting and morphological examination of the body surface of specimens from which analyzed DNA was extracted. As a result of morphological examination and complementary DNA analyses, these 5 species are considered synonyms of S. perseae. This synonomy should reduce potential quarantine disputes over avocado imports from Mexico that could arise from concerns raised over the large number of Scirtothrips species previously considered as pests of avocados in Mexico that might inadvertently accompany imports.

Molecular Identification Key for Pest Species of <I>Scirtothrips</I> (Thysanoptera: Thripidae)

Effective plant quarantine and biological control initiatives require rapid and accurate identification of exotic and potentially invasive taxa that may cause high economic losses or environmental damage. The genus Scirtothrips Shull includes several species that are serious agricultural pests, and, because of their minute size and cryptic behavior, prone to undetected transport through international trade of plant material. Although assigning specimens to the genus Scirtothrips is straightforward using traditional taxonomic methods, identification of species is much more difficult and requires expert knowledge of the genus. Furthermore, the validity of some Scirtothrips species is questionable. Therefore, an easy, accurate, and highly reliable technique is desirable for Scirtothrips identification. Here, we provide a simple molecular key based on the internal transcribed spacer regions 1 and 2 (ITS1 and ITS2) of nuclear ribosomal DNA. Individual specimens can be identified by amplification of their ITS1 and ITS2 regions with general primers and determining the size of the products by using standard agarose gel electrophoresis, followed in some instances by DNA digestion with the restriction enzymes SacII or PspOM I. The advantage of this identification system is that nonspecialists are able to quickly and cheaply identify individual specimens. Material analyzed for this work was collected in the United States (California), India, South Africa, Kenya, Mexico, Guatemala, Honduras, Nicaragua, Costa Rica, Panama, Australia, New Zealand and Raiatea (Society Islands French Polynesia). We have identified seven pest species with the molecular-based methods described here. It is hoped that this system can be extended to other members of the genus as their ITS1 and ITS2 sequences become available. We also provide molecular confirmation for two new Scirtothrips species, one species from Honduras and one species from New Zealand.

Scirtothrips aurantii, Scirtothrips citri, Scirtothrips dorsalis

<i>Scirtothrips aurantii</i>, <i>Scirtothrips citri</i>, <i>Scirtothrips dorsalis</i>

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California,USA,in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados,while adults were collected from 11 different plant species. As part of a management program for this pest,a ‘‘classical’’ biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae,to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico,Guatemala,Costa Rica,the Dominican Republic, Trinidad,and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic,Trinidad,or Brazil. In total,2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material � 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips,and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques,prospects for the importation of thrips natural enemies for use in a ‘‘classical’’ biological control program in California against S. perseae are not promising. 2002 Elsevier Science (USA). All rights reserved.

TheScirtothripsspecies of Australia and New Zealand (Thysanoptera: Thripidae)

Summary Nine species of Scirtothrips are here recorded from the Australasian region, eight from Australia and two including one endemic species from New Zealand. A key is provided for their identification, and diagnostic details and collection notes are given for each species. Two new species, S. casuarinae and S. helenae are described from Australia and one new synonym, S. gladiiseta Girault = Dendrothripoides ipomeae Bagnall, is recorded.

Identification, distribution and host-plants of the pest species of Scirtothrips (Thysanoptera: Thripidae)

AbstractNotes are given on the host range, distribution and recognition of the ten species of Scirtothrips recorded as pests: S. aurantii Faure on citrus in South Africa and bananas in Yemen; S. bispinosus (Bagn.) on tea in S. India; S. citri (Moult.) on citrus in California; S. dorsalis Hood on groundnuts in India, tea in Japan and strawberries in Queensland; S. inermis Priesn. on citrus in New Zealand; S. kenyensis Mound on tea in Kenya; S. longipennis (Bagn.) in glasshouses; S. mangiferae Priesn. on mango in Egypt and Israel; S. manihoti (Bondar) on cassava in Brazil; S. oligochaetus (Karny) on cotton in India. S. acaciae Moult, from Ghana is synonymised with S. aurantii Faure, and S. fragariae (Gir.) from Queensland is synonymised with S. dorsalis Hood. Drepanothrips reuteri Uzel, a grapevine pest from Europe and America which is very similar to Scirtothrips species, is newly recorded from Japan on Castanea.