Thrips Research Articles

Two new species and two new records of fungus-feeding Phlaeothripinae from China (Thysanoptera, Phlaeothripidae)

Two new species of fungivorous Phlaeothripinae, Mystrothrips levis sp. n. and Urothrips lancangensis sp. n., are described from China. Pentagonothrips antennalis Haga & Okajima and Plectrothrips bicolor Okajima are newly recorded in China.

Partial inventory of the insect species introduced in Puerto Rico from 1980 to 2015

The development of a biological inventory is a common tool in biodiversity and conservation studies. There is some information related to a biological inventory in Puerto Rico compiled from academic journals and regulatory agencies; however, there is no document that contains all the information. Accordingly, we reviewed literature and documents regarding introduced insects over a period of 35 years, from 1980 to 2015; however, there is still data to be collected and corroborated. For each species, we describe the classification, distribution by hosts, taxa and detection date. Included as introduced species are insects detected on the island, whether introduced deliberately, accidentally or by natural phenomena. Official sources of information were used to complement the data from our inventory. The fundamental purpose of the study is to establish the presence of species of the insect fauna listed by state and federal agencies, and to describe, in an integral way, the composition of biotic elements. Among the most relevant data found is the fact that most of the introduced insect species are from the orders Hemiptera, Thysanoptera, Coleoptera, Diptera and Hymenoptera. The order Hemiptera was the most prevalent in this study, with 12 families represented. Another significant finding is that the largest number of insect species was introduced into the island in the years 2006, 2008, 2010 and 2012.

Novel insights into mitochondrial gene rearrangement in thrips (Insecta: Thysanoptera) from the grass thrips, Anaphothrips obscurus

We sequenced the mitochondrial (mt) genome of the grass thrips, Anaphothrips obscurus, which is highly rearranged and differs from the four thrips species reported previously in the arrangement of both tRNA genes and a protein-coding gene, nad3, and in the copy number of the control region (CR). We reconstructed the phylogeny of the thrips with mt genome sequences, and used it as a framework to gain insights into mt genome evolution in thrips. It is evident that A. obscurus is less rearranged in mt genome organization than the other four known thrips. nad3 is in its ancestral location in A. obscurus but was translocated in other four thrips. Also, A. obscurus has one CR, which is ancestral to hexapods whereas other thrips have two or three CRs. All of the five thrips whose mt genomes have been sequenced to date are from the subfamily Thripinae, which represents about a quarter of the species richness in the order Thysanoptera. The high variation in mt genome organization observed in a subfamily challenges our knowledge about animal mt genomes. It remains to be investigated why mt genomes evolved so fast in the subfamily Thripinae and how mt genomes evolved in other lineages of thrips.

Combate químico de THRIPS TABACI (thysanoptera: thripidae) en el cultivo de cebolla, en Morelos, México

El cultivo de cebolla presenta altas poblaciones del trips (Thrips tabaci Lindeman), lo que ocasiona marchitez prematura, retarda el desarrollo de la hoja y distorsiona los brotes vegetativos. Los agricultores han usado diferentes plaguicidas para el manejo del trips, sin tener en cuenta la rotación de grupos químicos y dosis adecuadas, lo que ocasiona contaminación ambiental por el uso excesivo de agroquímicos. Por lo que el objetivo de este estudio, fue evaluar seis grupos de plaguicidas para el manejo de trips, los cuales fueron rotados durante el ciclo del cultivo, así como también se identificó la especie de trips presente en el cultivo de la cebolla. El estudio inició en octubre de 2013, en un cultivo de cebolla, ubicada en Ayala, Morelos. Cada tratamiento consistió en la aplicación de los siguientes insecticidas: T1: Testigo (sin producto); T2: Movento, Velcefate, Muralla, Tracer; T3: Regent, Muralla, Movento, Seizer+ Agromectin; T4: Tracer, Movento, Curacron, Muralla; T5: Actigard, Tracer, Colt, Agromectin; T6: Evisect-s, Curacron, Tracer, Calypso. Para determinar el control de los insecticidas, se contabilizó el número de ninfas y adultos de trips. Con los datos del número de ninfas y adultos de trips en los diferentes tratamientos, se realizó un análisis de varianza y separación de medias con la prueba Tukey (? 0.05). Para determinar las especies de trips presentes, se tomó una muestra en las hojas de las plantas de cebolla. Los insecticidas que lograron un control de las ninfas de trips en el cultivo de cebolla, fueron el Tracer, Acefate, Curacron y la combinación de Seizer+ Agromectin. Los insecticidas Tracer y Muralla, fueron los que mantuvieron las poblaciones más bajas de adultos de trips en el cultivo de cebolla. La especie de trips predominante en el cultivo de cebolla durante el estudio fue Thrips tabaci L.

Independent cytoplasmic incompatibility induced by Cardinium and Wolbachia maintains endosymbiont coinfections in haplodiploid thrips populations.

Cardinium and Wolbachia are common maternally inherited reproductive parasites that can coinfect arthropods, yet interactions between both bacterial endosymbionts are rarely studied. For the first time, we report their independent expression of complete cytoplasmic incompatibility (CI) in a coinfected host, and CI in a species of the haplodiploid insect order Thysanoptera. In Pezothrips kellyanus, Cardinium-induced CI resulted in a combination of male development (MD) and embryonic female mortality (FM) of fertilized eggs. In contrast, Wolbachia-induced CI resulted in FM together with postembryonic mortality not previously reported as a CI outcome. Both endosymbionts appeared to not influence fecundity but virgins produced more offspring than mated females. In coinfected individuals, Wolbachia density was higher than Cardinium. Wolbachia removal did not impact Cardinium density, suggesting a lack of competition within hosts. Maternal transmission was complete for Wolbachia and high for Cardinium. Our data support theoretical predictions and empirical detection of high endosymbiont prevalence in field populations of the native range of this pest thrips. However, previous findings of more frequent loss of Wolbachia than Cardinium, particularly in field populations of the host's invasive range, suggest that genetic diversity or varying environmental factors between field populations also play a role in shaping host-endosymbiont dynamics.

Trapping effect of three color sticky traps on thrips in soybean fields

Trapping effect of three color sticky traps on thrips in soybean fields

One Genus and Two Species of Thripinae Newly Recorded from China (Thysanoptera: Thripidae)

In this paper, Biltothrips minutus (Bhatti) and Taeniothrips tigris Bhatti are newly recorded from China and illustrations of these two species are provided.

Greenhouse Whitefly and Thrips Management Model Using Natural Enemies in Semi-forcing Culture of Tomato

Greenhouse Whitefly and Thrips Management Model Using Natural Enemies in Semi-forcing Culture of Tomato

FIRST REPORT OF TOMATO SPOTTED WILT VIRUS INFECTING PUMPKIN IN CHINA

In August 2015, symptomatic pumpkin (Cucurbita moschata Duch.) plants were observed in Linyi, Shandong province, China. Plants exhibited symptoms of leaf mottling, crinkling and mosaic which appeared similar to symptoms caused by Tomato spotted wilt virus (TSWV) (Karavina et al., 2016). Twenty field samples, two symptomatic and 18 asymptomatic, were collected. A high incidence of thrips (Thrips palmi) was also observed in the field and on the sampling plants. Given the symptoms observed and the prevalence of thrips, TSWV infection was suspected. Total RNA was extracted from symptomatic and asymptomatic plants and analyzed by RT-PCR using specific primer pair TSWV-F1 (5’-CACACTAAGCAAGCACA-3’)/TSWV-R1 (5’-TCAGTCTTACAAATCATC-3’), designed for this study, corresponding to a highly conserved region including the complete nucleocapsid protein (N) gene. Fragments of the expected size (976 bp) were amplified from the symptomatic but not from the asymptomatic samples, and one of them was cloned and sequenced (KX185153). No other viruses were detected. The incidence of TSWV in the four acres pumpkin field surveyed was 0.45%. Sequence comparisons revealed that the N gene of this isolate shared the highest nucleotide identity of 99.9% with an isolate of TSWV from an asparagus lettuce sample from China (KP330473) indicating the pumpkin plants were infected with TSWV. Phylogenetic analysis showed that this isolate and other isolates from China clustered together with those from South Korea and Japan as a separate group. TSWV (genus Tospovirus, family Bunyaviridae) has an extensive host range (Cho et al., 1987) of which tomato, pepper, peanut and tobacco are common susceptible host crops. TSWV has been reported to infect tomato, tobacco and other plants (Dong et al., 2010) in China. To our knowledge, this is the first report of TSWV infecting pumpkin in China.

The Confused Identity ofFrankliniella williamsi(Thysanoptera: Thripidae)

Abstract Details of the variation in the pronotal chaetotaxy among the type specimens of Frankliniella williamsi Hood and Frankliniella spinosa Moulton (Thysanoptera: Thripidae) are provided. We reject the recent revalidation of F. spinosa and conclude that the corn thrips, F. williamsi, is a single, variable species.

SIDE EFFECTS OF TWO PLANT INSECTICIDES ON NATURAL ENEMIES OF INSECTS IN ALFALFA (MEDICAGO SATIVA L.) SEED PRODUCTION

During the period 2012-2014, in the experimental field of the Institute of Forage Crops, Pleven, Bulgaria, the side effect of neem and pyrethrum products on banded thrips, Aeolothrips ntermedius Bagnall (Thysanoptera: Thripidae) and the seven-spot ladybird Coccinella septempunctata L. (Coleoptera: Coccinellidae) adults was defined. Treatments were carried out at the beginning of the flowering stage of alfalfa ( Medicago sativa L.) in the second intercut. Sweeping with an entomological net was used to collect specimens. It was found that the biological insecticides NeemAzal and Pyrethrum were nontoxic with respect to Coccinella septempunctata adults, and in almost 70% of cases were harmless to Aeolothrips intermedius . Analysis of variance (ANOVA) regarding product toxicity on predatory species demonstrated that the factor B (type of insecticide) had the strongest effect – 89.1 and 82.5% of the total variance for C. septempunctata and A. intermedius , respectively. Tested plant insecticides showed no negative impact on the predatory species and they can be applied in organic seed production of alfalfa.

Meniscus ascent by thrips (Thysanoptera)

Meniscus climbing using a fixed body posture has been well documented for various aquatic and neustonic insects, but is not known from small flying insects that inadvertently become trapped on water surfaces. Here, we show that thrips (order Thysanoptera) can ascend a meniscus by arching their non-wetting bodies to translate head-first and upward along a water surface; if initially oriented backwards, they can turn by 180° to ascend head-first, and climb upward on a surrounding boundary. Using variable-concentration sucrose solutions, we show that translational and climbing speeds during meniscus ascent vary inversely with fluid viscosity. Becoming trapped in water is a frequent event for flying insects, and given that most of them are very small, dedicated behaviours to escape water may be commonplace among pterygotes.

The Genus Tospovirus: Emerging Bunyaviruses that Threaten Food Security.

The genus Tospovirus is unique within the family Bunyaviridae in that it is made up of viruses that infect plants. Initially documented over 100 years ago, tospoviruses have become increasingly important worldwide since the 1980s due to the spread of the important insect vector Frankliniella occidentalis and the discovery of new viruses. As a result, tospoviruses are now recognized globally as emerging agricultural diseases. Tospoviruses and their vectors, thrips species in the order Thysanoptera, represent a major problem for agricultural and ornamental crops that must be managed to avoid devastating losses. In recent years, the number of recognized species in the genus has increased rapidly, and our knowledge of the molecular interactions of tospoviruses with their host plants and vectors has expanded. In this review, we present an overview of the genus Tospovirus with particular emphasis on new understandings of the molecular plant-virus and vector-virus interactions as well as relationships among genus members.

A TaqMan real-time RT-PCR assay for detection of Groundnut ringspot virus.

Groundnut ringspot virus (GRSV) is a tospovirus species transmitted in a circulative propagative manner by several thrips species. Traditionally, GRSV is detected by enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR), so this paper describes a rapid diagnostic system for the reliable detection of GRSV in plants and individual thrips by real-time RT-PCR. Watermelon GRSV infected leaves and fruits, and individual thrips (Frankliniella schultzei) collected from flowers on infected watermelons were used in the test. We designed a GRSV TaqMan assay to efficiently detect GRSV in all samples. The method had high specificity and could distinguish GRSV from the other tospovirus species, like Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV) and Zucchini lethal chlorosis virus (ZLCV). The test will help us to collect epidemiological data for GRSV in plants and thrips worldwide.

Advances in Controlling Thrips Using Predatory Mites

Advances in Controlling Thrips Using Predatory Mites

Developing lure and kill systems for thrips pest management

Some thrips species (Thysanoptera) are important pests of crops in New Zealand and are vectors of several important plant tospoviruses Lure and kill could provide an alternative or complementary control to the current practice that relies on the unsustainable use of insecticides The efficacy of a lure and kill device was tested on thrips in a grass field The thrips olfactory lure used was methyl isonicotinate the visual cue was yellow and the kill component in the trap was an organophosphate insecticide applied to an absorbent material The control device was yellow but did not contain the lure or insecticide The device allowed thrips to freely enter and leave but limited the access of nontarget organisms The devices were left out for three days The ratio of dead thrips in the control devices relative to those with insecticide was 1344 Addition of the olfactory lure to the insecticide devices increased the ratio to 1475 The results highlight the need for an effective olfactory lure component to ensure the insects enter and explore the trap to be exposed to a lethal dose of the kill component Results are discussed in relation to thrips pest management

Natural history of G ynaikothrips uzeli (Thysanoptera, Phlaeothripidae) in galls of Ficus benjamina (Rosales, Moraceae)

ABSTRACT Galls induced by thrips are simple structures when compared to those of other groups of arthropods, and little is known regarding many of their aspects. This study aimed to investigate aspects of the natural history of Gynaikothrips uzeli Zimmermann, 1900 in galls of Ficus benjamina L., 1753 using seasonal sampling (summer and winter). Twenty trees were sampled and divided into quadrants. From each of them, five galls were collected, forming a total of 400 galls per collection. Thrips showed greater abundance at higher temperatures (25.7°C) and no precipitation. Sex ratio was biased towards females (0.022 males per female), pointing to an inbred mating structure. Arthropod fauna associated with galls was more abundant (N=798) in winter, and it included representatives of the orders Hemiptera, Hymenoptera, Araneae, Coleoptera, Neuroptera, Psocoptera, Thysanoptera, Diptera and Blattodea.

Insect Pests of Shorea robusta Gaertn. f. : An Update

Shorea robusta Gaertn. f. (Dipterocarpaceae), commonly known as sal, is one of the most important timbers of India both ecologically and economically. It is of Indian origin, widely distributed in central and north India and constitutes an important ecosystem, which provides cool and calm environment rich in biodiversity. This tree species has a highest number of insect fauna among the forest trees. Of about 346 insects recorded on sal, about 155 species of insects belonging to the order Lepidoptera (105), Coleoptera (31), Thysanoptera (9), Hemiptera (4), Orthoptera (4), Ephemeroptera (1) and Isoptera (1) are associated with living tree. The major insect pests of sal are, ‘seed and seedling borer’ Pammene theristis Meyrick (Lepidoptera: Eucosmidae), feeding on seed while they are on the tree; Sitophilus rugicollis Casey (Coleoptera : Curculionidae), damage seed either on the forest floor or during storage; white grubs such as Holotrichia spp. (Coleoptera : Scarabaeidae), which feed on the root system of the plants in nurseries and beetles feed on the foliage; defoliators such as Caviria sericea Moore (Lepidoptera : Lymantriidae), Lymantria mathura Moore (Lepidoptera : Lymantriidae), Paectes subapicalis Walker (Lepidoptera : Noctuidae), Trabala vishnou Lefebvre (Lepidoptera : Lasiocampidae), which feed on the leaves; stem borer such as Hoplocerambyx spinicornis Newman (Coleoptera : Cerambycidae) and sap sucker, such as Drosicha stebbingi Green (Hemiptera : Coccidae). Termites, such as Coptotermes curvignathus Holmgren (Isoptera : Rhinotermitidae) and timber borers, such as Sinoxylon anale and S. crassum (Coleoptera : Bostrychidae), damage sal timber in dying, felled or stored logs in depots.

Phylogenetic analysis of Groundnut ringspot virus isolates from peanut and identification of potential thrips vectors in peanut crop in Argentina

Groundnut ringspot virus (GRSV), genus Tospovirus , is a thrips-transmitted virus infecting peanuts ( Arachis hypogaea L.) in Cordoba province, Argentina. Fourteen viral isolates were recovered from Tospovirus -like symptomatic plants from different peanut fields. Viral isolates as GRSV were identified by serological and molecular tests. Nucleotide and derived amino acid sequence analyses of the nucleocapsid ( N ) gene indicated a high degree of identity between the GRSV peanut isolates, indicating that there is no molecular variability in the N gene of the GRSV that infects peanuts in the cropping area of Cordoba. In this study, we determined the presence of thrips species in the crop, which can potentially transmit the virus. Thrips were observed in all the evaluated peanut fields. Frankliniella schultzei was the most frequently identified species followed by Caliothrips phaseoli and Frankliniella occidentalis . This work reports the presence of F. schultzei and F. occidentalis in peanuts in Argentina for the first time. These results along with the high degree of similarity between the GRSV peanut isolates suggest that the virus could be transmitted by F. schultzei , which has been cited as its most efficient vector.

COMPOSICIÓN QUÍMICA DE ACEITES ESENCIALES DE 10 PLANTAS AROMÁTICAS PERUANAS

Con el objetivo de encontrar aceites esenciales que puedan ser usados como atrayentes orepelentes de Thrips tabaci, una plaga que afecta al espárrago, en el presente trabajo seestudia la composición química de los aceites esenciales de 10 plantas aromáticas peruanas:Jungia paniculata (DC.) A. Gray, Piper hispidum Sw., Ambrosia arborescens Mill.,Ambrosia peruviana Willd., Luma chequen (Feuillée ex Molina) A. Gray., Minthostachyssetosa (Briq.) Epling, Lepechinia meyenii (Walp.) Epl., Ruta chalepensis L., Ruta graveolensL., Aristolochia silvatica Barb. Rod. Se reporta por primera vez la composición de los aceitesesenciales de J. paniculata (“matico de la sierra”), A. peruviana (“marco hembra”), L. meyenii(“pachasalvia”) y A. silvatica (“huampishcuna”).