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The main open-field producer regions of cucurbits (watermelon, squash, melon and cucumber) in Panama (Los Santos, Herrera and Coclé provinces) were surveyed for molecular identification, occurrence and distribution of Thrips palmi (the most important pest thrip species on cucurbits in Panama), Frankliniella intonsa and Frankliniella cephalica during the growing seasons of 2009 to 2013 and 2017 to 2018. Forty plots were surveyed and DNA extracts of 186 thrips (larvae and adults) were analyzed by multiplex PCR, using a set of T. palmi-specific primers in combination with a set of insect-universal primers. DNA extracts corresponding to 174 individual thrips (93.5%) rendered both PCR products of expected size with T. palmi-specific and insect-universal primers, whereas the remaining DNA extracts corresponding to 12 individual thrips (6.5%) only rendered the product of the expected size with insect-universal primers. Sequencing of those PCR products and BLAST analysis allowed for the identification of F. intonsa and F. cephalica. Thrips palmi was detected in all three provinces, while F. intonsa and F. cephalica were detected in Herrera and Los Santos provinces. To our knowledge, this is not only the first detection of F. intonsa in Panama, but also the first detection of F. cephalica in Panamanian cucurbit crops.

The behaviour of 5 th instar nymphs and adult males and females of anthocorid bug, Orius insidiosus preying on adult Thrips palmi was studied. Adult O. insidiosus males spent longest time in motion compared with 5 th instar nymphs and adult females. First encounter of prey was shortest for 5 th instar nymphs but not significantly different from that of adult females. The distance travelled to 1 st prey by 5 th instar nymphs was significantly shortest compared to both adult male and female O. insidiosus . However, speed of arrival to 1 st prey did not significantly differ among the three stages of O. insidiosus examined. Mean time spent by O. insidiosus 5 th instar nymphs and adult females on 1 st , 2 nd , 3 rd and 4 th prey encounters was not significantly different. However, adult males of O. insidiosus spent significantly less time on 4th prey encounter compared with 1 st - 3 rd prey encounters.

Thrips palmi (Thysanoptera: Thripidae) is an important pest of vegetables, ornamentals, and legumes worldwide. Besides damage caused by feeding, it transmits several tospoviruses. Identification of T. palmi at an early stage is crucial in implementing appropriate pest management strategies. Morpho-taxonomic identification of T. palmi based on the adult stage is time-consuming and needs taxonomic expertise. Here, we report a rapid, on-site, field-based assay for identification of T. palmi based on recombinase polymerase amplification (RPA), its first application in insects. RPA primers designed based on 3′ polymorphisms of the Internal Transcribed Spacer 2 region efficiently discriminated T. palmi without any cross-reactivity to other predominant thrips species. RPA was performed with crude DNA, extracted from single T. palmi simply by crushing in sterile distilled water and could be completed within 20 min by holding the reaction tubes in the hand. The assay was further simplified by using fluorescent as well as colorimetric dyes thus eliminating the gel-electrophoresis steps. The presence of T. palmi was visualized by a change in color from dark blue to sky blue. The assay was validated with known thrips specimens and found to be effective in diagnosing the presence of T. palmi in natural vegetation. This on-site, rapid assay for diagnosis of T. palmi can be used by non-expert personnel in the field of quarantine and pest management.

Plant viruses can modify the performance and behavior of insect vectors to maximize their transmission rates. Whether viruses can evolve to mediate their insect vectors’ interspecific competition is poorly understood. Here, we used two vectors of tomato zonate spot virus (TZSV), one native species (Thrips palmi) and one exotic species (Frankliniella occidentalis), to investigate this in laboratory and field experiments. TZSV infection increased the population growth of its insect vectors when the thrips species were isolated from one another. When both species coexisted, F. occidentalis displaced T. palmi on both TZSV-infected and uninfected plants. However, on TZSV-infected plant, F. occidentalis completely displaced T. palmi more rapidly (within 14 days) than on uninfected plants. Our results also revealed that reproductive interference occurred between the two thrips species, whereas TZSV-infected pepper significantly decreased the reproductive interference of T. palmi to F. occidentalis. When F. occidentalis and T. palmi co-occurred in Jinning County, Yunnan Province, we found a rising trend of natural proportions of F. occidentalis in the TZSV-infected pepper fields, suggesting that TZSV-infected pepper enhanced the competitive advantage of F. occidentalis over T. palmi in the field. Together, our findings demonstrate a plant virus that plays an important role in the competitive displacement of its insect vectors.

Capsicum species are commercially grown for pepper production. This crop suffers severely from thrips damage and the identification of natural sources of thrips resistance is essential for the development of resistant cultivars. It is unclear whether resistance to Frankliniella occidentalis as assessed in a specific environment holds under different conditions. Additionally, other thrips species may respond differently to the plant genotypes. Screening for robust and general resistance to thrips encompasses testing different Capsicum accessions under various conditions and with different thrips species. We screened 11 Capsicum accessions (C. annuum and C. chinense) for resistance to F. occidentalis at three different locations in the Netherlands. Next, the same 11 accessions were screened for resistance to Thrips palmi and Scirtothrips dorsalis at two locations in Asia. This resulted in a unique analysis of thrips resistance in Capsicum at five different locations around the world. Finally, all accessions were also screened for resistance to F. occidentalis in the Netherlands using a leaf disc choice assay, allowing direct comparison of whole plant and leaf disc assays. Resistance to F. occidentalis was only partially consistent among the three sites in the Netherlands. The most susceptible accessions were consistently susceptible, but which accession was the most resistant differed among sites. In Asia, one C. chinense accession was particularly resistant to S. dorsalis and T. palmi, but this was not the most resistant accession to F. occidentalis. Overall, resistance to F. occidentalis correlated with S. dorsalis but not with T. palmi resistance in the C. annuum accessions. Damage inflicted on leaf discs reflected damage on the whole plant level. Our study showed that identifying broad spectrum resistance to thrips in Capsicum may prove to be challenging. Breeding programmes should focus on developing cultivars suitable for growing in defined geographic regions with specific thrips species and abiotic conditions.

To develop an augmentative biological control programme for Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and Thrips palmi Karny (Thysanoptera: Thripidae) using Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae), we studied the life history traits of a Japanese strain of N. tenuis reared on B. tabaci and T. palmi in controlled environments. The lower developmental threshold during the nymphal period was far higher than those estimated for Spanish, Moroccan, and Iranian strains, indicating that the Japanese strain is better adapted to higher temperatures than the other three strains tested. The intrinsic rate of increase rm was highest at 30 °C and lowest at 20 °C. The rm value for individuals reared on T. palmi at 25 °C was lower than that for individuals reared on B. tabaci at the same temperature. Implications of these results for the biological control of B. tabaci and T. palmi in greenhouses are discussed.

Melon thrips (Thrips palmi) is the principal insect pest of vegetable and ornamental plants worldwide. In addition to inflicting feeding injuries on host plants, they act as vectors of economically damaging tospoviruses. Application of insecticides and host plant resistance has proven largely ineffective in the management of T. palmi. However, increasingly, genetic knowledge is being successfully utilized to manage insect pests. A number of recent studies have enriched the genetic database of T. palmi. In this review, we report on genetics of T. palmi for species identification and to study its populations structure. For example, a DNA polymorphism analysis of global T. palmi populations has revealed the existence of 29 haplotypes. The T. palmi population can be divided into three lineages based on phylogenetic analysis. A high maximum intraspecific distance is indicative of cryptic species within T. palmi populations. Regarding climate adaptability, the upregulation of trehalose biosynthesis genes, and genes encoding several heat-shock proteins is expected to enable T. palmi thermal adaptation to both cold and hot conditions. Genetics of T. palmi has shown that resistance to conventional insecticides like cypermethrin appears to be linked to mutations in the sodium channel. On the other hand, resistance to imidacloprid appears to be a result of cytochrome P450-mediated detoxification. T. palmi genes potentially involved in tospovirus transmission are also reviewed and new molecular tools for genetic study presented. Molecular modeling and docking analyses of groundnut bud necrosis virus glycoprotein demonstrated protein–protein interactions with T. palmi vacuolar ATP synthase E subunit, cathepsin, clathrin, adaptor protein 2, and enolase. Overall, a better knowledge of T. palmi genes will assist elucidation of thrips identification, means of adaptation in diverse ecological niches, mechanisms of insecticide resistance, and transmission of plant viruses. This data will be an invaluable tool for integrated thrips management.

A model was developed to improve pest risk assessments and to better advise risk managers and policy makers on the relative importance of the pathways of pest entry and the strength of measures to be taken on each. The model computes the probability of the transfer of insect or mite pests from traded commodities to hosts at sites suitable for establishment. The probability is calculated from arrival of the pest on imported produce (cut flowers/branches, fruits or vegetables), up-to-and-including first egg laying, and taking into account any necessary development of the pest to a suitably mobile stage. Three case studies, Helicoverpa armigera on Rosa cut flowers, Thrips palmi on Solanum fruit and Rhagoletis mendax on Vaccinium fruit, are explained in detail. Probabilities were estimated for nine variables from which a joint probability, the probability of transfer, was calculated for each of the species–product combinations and trade chain scenarios. Although the probabilities were expressions of expert belief, rather than empirically derived, the resulting large differences in outcomes between the cases gave greater discrimination of relative risk than more qualitative approaches. The model helps to identify pest and trade-chain characteristics that are most limiting to transfer and so highlights the importance of these characteristics for future assessments. For pests that arrive as immature stages that are relatively immobile, development into an adult was identified as an important limiting factor especially for pests with a long lifecycle in relation to the shelf life of the product. For pests that have a limited dispersal ability the proximity to a suitable site was an important factor. Pests that arrive as adults, or can rapidly attain adulthood, and that can establish close to the destination of the produce are therefore a particular biosecurity concern.

Watermelon bud necrosis orthotospovirus (WBNV), is a distinct virus species in the genus Orthotospovirus, family Tospoviridae and order Bunyavirales. Orthotospovirus is the only genus in the family whose members infect plants, while viruses in other genera infect invertebrates. WBNV is prevalent in most of the watermelon growing Indian states and therefore, its prevalence in the Indian subcontinent cannot be ignored. Quasi-spherical enveloped virions are 80–110 nm in size. Virion composed of genomic RNAs with nucleoprotein, viral polymerase, and a lipid envelope with glycoprotein (GN/Gc) spikes. WBNV shares common genomic features with other orthotospoviruses. The tri-segmented genome is referred to as the small (S) (3.4 kb), the medium (M) (4.7 kb), and the large (L) (8.9 kb) RNAs. S RNA uses ambisense coding strategy and codes for non-structural (NSs) protein in the viral (v) sense and nucleocapsid (N) protein in the viral complementary (vc) sense. Similarly, M RNA uses ambisense coding strategy and codes for a precursor for the GN/GC in vc sense and movement (NSm) protein in v sense. L RNA is of negative polarity and codes for the RNA-dependent RNA polymerase (RdRp). WBNV is known to be transmitted by Thrips palmi (Order: Thysanoptera; Family: Thripidae; melon thrips) in a persistent propagative manner. WBNV is sap transmitted to various experimental hosts belonging to several families viz., Amaranthaceae, Asteraceae, Chenopodiaceae, Cucurbitaceae, Fabaceae, Pedaliaceae, and Solanaceae. WBNV has limited natural host range, predominantly confined to bitter gourd (Memordica charantia), chrysanthemum (Chrysanthemum indicum), chilli (Capsicum annum), cucumber (Cucumis sativus), muskmelon (Cucumis melo), pumpkin (Cucumis sativus), ridge gourd (Luffa acutangula), tomato (Solanum lycopersicum), and watermelon (Citrullus lanatus). Besides these main hosts, Abutilon indicum, Amaranthus spp., Euphorbia heterophylla, Malvastrum coromandelium, and Parthenium hysterophorus serve as green-bridge for virus perpetuation. WBNV symptoms include mottling, yellowing, necrotic streaks on vines, shortened internodes, stunted plant growth, severe stem and bud necrosis and dieback of the buds. Late season infection results in deformed fruits with necrotic local lesions. In India, WBNV resistant watermelon varieties are not available. A wild relative of watermelon, Citrullus colosynthis, has recently been identified as a resistant source, which is used in the breeding program as part of integrated disease management (IDM) strategies. IDM strategies include clean crop cultivation, border cropping, intercropping, use of plastic mulches, crop rotation, and control of thrips can alleviate the effect of WBNV in the Indian subcontinent. Recently, non-conventional management option of development of putative transgenic resistance has been worked out and found WBNV N gene is effective in conferring resistance in watermelon.

BACKGROUND Rapid genetic on-site identification methods at points of entry, such as seaports and airports, have the potential to become important tools to prevent the introduction and spread of economically harmful pest species that are unintentionally transported by the global trade of plant commodities. This paper reports the development and evaluation of a loop-mediated isothermal amplification (LAMP)-based identification system to prevent introduction of the three most frequently encountered regulated quarantine insect species groups at Swiss borders, Bemisia tabaci, Thrips palmi and several regulated fruit flies of the genera Bactrocera and Zeugodacus. RESULTS The LAMP primers were designed to target a fragment of the mitochondrial cytochrome c oxidase subunit I gene and were generated based on publicly available DNA sequences. Laboratory evaluations analysing 282 insect specimens suspected to be quarantine organisms revealed an overall test efficiency of 99%. Additional on-site evaluation at a point of entry using 37 specimens performed by plant health inspectors with minimal laboratory training resulted in an overall test efficiency of 95%. During both evaluation rounds, there were no false-positives and the observed false-negatives were attributable to human-induced manipulation errors. To overcome the possibility of accidental introduction of pests as a result of rare false-negative results, samples yielding negative results in the LAMP method were also subjected to DNA barcoding. CONCLUSION Our LAMP assays reliably differentiated between the tested regulated and non-regulated insect species within

The effect of Groundnut bud necrosis virus (GBNV) infection on the life history traits of its vector, Thrips palmi, and its feeding preference on GBNV-infected plants were studied. A significant difference was observed in the developmental period (first instar to adult) between the GBNV-infected and healthy thrips, wherein the developmental period of GBNV-infected thrips was decreased. However, there was no effect on the other parameters such as preadult mortality, adult longevity, and fecundity. Further investigation on a settling and feeding choice assay of T. palmi to GBNV-infected and healthy plants showed that T. palmi preferred GBNV-infected cowpea plants more than the healthy cowpea plants. This preference was also noticed for leaf disks from GBNV-infected cowpea, groundnut, and tomato plants.

Thrips palmiandFrankliniella occidentalis(order Thysanoptera) are thrips species that represent major plant pests. They are polyphagous insects capable of adversely affecting crop production. As such, in the European Union, these thrips species should be regulated as quarantine organisms.T. palmiandF. occidentaliscan cause considerable damage to susceptible plants by feeding on them and transmitting several viruses responsible for serious plant diseases. Successful pest control strategies are based on an early, fast, and reliable diagnosis, which precedes the selection of appropriate steps to limit the effects of harmful organisms. We herein describe a novel diagnostic approach that enables the sensitive and species-specific detection (and differentiation) of these pests in a duplex polymerase chain reaction assay, which was adapted for both standard and real-time quantitative assays. Our method is based on the amplification of a 5.8S-internal transcribed spacer 2 ribosomal DNA fragment that is conserved betweenT. palmiandF. occidentalis.

Grain legumes are the important source of dietary protein in tropical regions and insect pests are the major biotic constraints in the production of the grain legumes throughout the country. About 150 species of insects are known to attack pulse crops in India. Among the insect pests, the sucking pests like aphid, Aphis craccivora Koch; jassid, Empoasca kerri Pruthi; whitefly, Bemisia tabaci Gennadius, thrips,Thrips palmi Karny and flower thrips, Megalurothrips usitatus Bagnall are known to cause significant damage to the pulse crops and also indirectly acting as a vectors in transmitting the deadly diseases resulting in severe loss in grain yields of the legume crops. The present review highlights the losses caused by the sucking pests and critically review the literature generated on the bio efficacy of conventional and novel groups of chemical insecticides for the management of sucking pests infesting grain legumes at different locations in India.

In February 2013, an ornamental waxflower (Hoya calycina Schlecter) with leaves displaying concentric chlorotic and necrotic rings surrounding sunken, necrotic lesions typical of tospovirus infection was observed at a community garden in Honolulu, HI. Symptomatic leaf tissue tested negative for Tomato spotted wilt virus (TSWV), a common tospovirus in Hawaii, using a TSWV ImmunoStrips (AgDia, Elkhart, IN) assay following the manufacturer's instructions. Double-stranded RNAs were isolated from a symptomatic leaf and reverse transcribed using random primers (2). The cDNA was then used as template in a universal tospovirus PCR assay using primers gL3637 and gL4435c, which amplify sequences of the L segment encoding the RNA-dependent RNA polymerase of tospoviruses (1). An ~800-bp product was amplified and cloned using pGEM-T Easy (Promega, Madison, WI). Three clones were selected and found to be identical by dye-terminator sequencing performed at the University of Hawaii's Advanced Studies in Genomics, Proteomics, and Bioinformatics laboratory. Following primer sequence trimming, the 773-bp sequence (GenBank Accession No. KF030938) was found to be 97, 88, and 87% identical to Capsicum chlorosis virus (CaCV; a tentative species in the family Bunyaviridae, genus Tospovirus) strains Ch-Har (GU199334), TwTom1 (HM021140), and AIT (DQ256124), respectively. To confirm the presence of CaCV, the cDNA was also used as template in a universal tospovirus PCR assay with primers 3′T12 and TsMCR2 which amplify a region of the S segment of tospoviruses (3). The amplification product from this assay was cloned and sequenced as described above and found to be 93 to 98% identical to CaCV nucleotide sequences present in GenBank. Attempts to detect the CaCV strain in waxflower using a watermelon silver mottle virus and groundnut bud necrosis virus triple antibody sandwich ELISA (AgDia) were unsuccessful. No other plants in the community garden had typical tospovirus-like symptoms; however, samples from tomato (Solanum lycopersicum L.; two samples), chili pepper (Capsicum spp.; four samples), eggplant (Solanum melongena L.; one sample), and passionfruit (Passiflora edulis Sims; one sample) with virus-like symptoms were collected from the garden and had RNA isolated using a NucleoSpin RNA II kit (Macherey-Nagel, Bethlehem, PA). No tospoviruses were detected in any of these samples with the RT-PCR assay using primers gL3637 and gL4435. The waxflower plant infected with CaCV was immediately removed by community garden members and destroyed, preventing any additional serological or biological assays to be performed. CaCV is transmitted by several species of thrips, including Thrips palmi, which is present in Hawaii. Waxflower is not native to Hawaii and it is unclear whether CaCV entered Hawaii in this plant or whether it was infected by viruliferous thrips. A survey for CaCV in known hosts is essential to determine the geographic distribution of CaCV in Hawaii, as this virus poses a considerable threat to tomato, chili pepper, and phalaenopsis orchid production in Hawaii and the United States. References: (1) F.-H. Chu et al. Phytopathology 91:361, 2001. (2) M. J. Melzer et al. Virus Genes 40:111, 2010. (3) M. Okuda and K. Hanada. J. Virol. Methods 96:149, 2001.

Thrips palmi Karny and Frankliniella schultzei Trybom (Thysanoptera: Thripidae) are serious pests of various crops of economic importance across the globe. Two species of phytoseiid mites were evaluated as potential predators of T. palmi and F. schultzei in the laboratory, a shade house and a commercial cucumber production field. In a no-choice lab bioassay, both Amblyseius swirskii (Athias-Henriot) and Neoseiulus cucumeris Oudemans (Mesostigmata: Phytoseiidae) preyed in equal measure on larvae of T. palmi and F. schultzei placed on leaf disks. In the shade house, mites were only recovered from leaf samples and not in flowers. Consequently, they were only effective in controlling T. palmi on leaves. Two rates of mites (20 and 40 mites/plant) were tested in the field. Neither species nor rate suppressed F. schultzei in blooms. In contrast, both rates of A. swirskii suppressed T. palmi on leaves, although the high rate acted more rapidly and therefore had a greater overall effect over the course of the 22-day study. These results suggest that A. swirskii can serve as an effective alternative to conventional insecticide-based management of T. palmi in commercial open field cucumber production in Florida.

Melon yellow spot orthotospovirus (MYSV, genus Orthotospovirus, family Tospoviridae) is naturally transmitted by Thrips palmi (Kato et al. 1999). It was initially identified from a melon (Cucumis melo) plant in Shizuoka Prefecture, Japan (Kato et al. 2000). To date, MYSV has been identified to infect several cucurbits such as watermelon, melon, balsam pear, cucumber, pumpkin, wax gourd, and luffa. The virus has also been detected in pepper (Supakitthanakorn et al. 2018). In May 2018, a viral-like disease was observed on broad beans (Vicia faba L.) in a ∼0.4-ha field in Shangyu County, Zhejiang Province, China. Diseased plants were dwarf, and numerous necrotic spots appeared on the upper leaves. To identify viral agents potentially associated with this disease, a sRNA library from a symptomatic sample was generated and sequenced. Total RNA was extracted using RNAiso Plus (TaKaRa, Tokyo, Japan). Libraries were constructed using a TruSeq Small RNA Library preparation kit (Illumina, San Diego, CA). Approximately 21 million raw reads were obtained from the Illumina MiSeq platform. After removing the adapters and low-quality reads, the clean reads within the range of 18 to 26 nt were analyzed using VirusDetect, a program that can efficiently identify plant viruses and viroids from deep siRNA sequences (Zheng et al. 2017). Contig assembly and BLASTn analysis against the reference virus genomes in the NCBI database led to the identification of 117 contigs with high (94.4 to 100%) nucleotide identity to the genome of MYSV. These contigs mapped to the MYSV genomic RNAs (L, M, and S) with 62.2 to 86.5% coverage. Besides MYSV, no other viruses or viroids were found in the sample. Based on the assembled contigs and the reference MYSV genome, we designed eight primer pairs to obtain the sequence of MYSV Zhejiang (MYSV-ZJ) isolate L, M, and S segments. Briefly, total RNA from MYSV-infected broad bean was extracted using RNAiso Plus. Reverse transcription was conducted using avian myeloblastosis virus reverse transcription (TaKaRa) with random primers N6 (TaKaRa). Segments of MYSV were amplified using high-fidelity DNA polymerase KOD-Plus-Neo (Toyobo, Osaka, Japan). PCR products were cloned into the pLB vector (Tiangen, Beijing, China) and Sanger sequenced. The obtained sequences were assembled into three near-complete sequences of MYSV-ZJ genomic L (8,869 nt; MN550994), M (4,870 nt; MN550995), and S (3,208 nt; MN550996). Pairwise sequence comparison revealed that the MYSV-ZJ shared the highest nucleotide sequence identities of 97.3 to 98.3% with the genome segments of Hainan isolate (MH734110 to MH734112). We performed reverse transcription PCR detection on all collected samples using primers MYSV-N-F and MYSV-N-R designed on the sequence of MYSV-ZJ to amplify the MYSV N gene. Seven of 20 randomly collected samples (symptomatic = 9, asymptomatic = 11) were positive for MYSV. None of the asymptomatic samples tested positive for the virus. In addition, MYSV was also not detected from two symptomatic samples, and it is not known the cause of the symptom. To the best of our knowledge, this is the first report of MYSV infecting broad bean. With the widespread presence of T. palmi in broad bean fields, MYSV may be an underlying threat to the cultivation of broad beans in China.

BACKGROUND This study was aimed at assessing the fumigant toxicity to adult Thrips palmi (a serious insect pest) and Orius strigicollis (a beneficial predator insect) of basil (Ocimum basilicum) essential oil compounds and structurally related compounds using vapour-phase toxicity bioassays. RESULTS Against adult T. palmi, linalool (LD50 0.0055 mg cm−3) was the most toxic fumigant and was 15.2-fold more effective than dichlorvos (0.0837 mg cm−3). Strong fumigant toxicity was also observed in pulegone (0.0095 mg cm−3), (±)-camphor (0.0097 mg cm−3) and 1,8-cineole (0.0167 mg cm−3). Moderate toxicity was produced by camphene, 3-carene, (−)-menthone, (+)-α-pinene, (+)-β-pinene, α-terpineol and (−)-α-thujone (0.0215–0.0388 mg cm−3). Against adult O. strigicollis, dichlorvos (LD50 9.0 × 10−10 mg cm−3) was the most toxic fumigant, whereas the LD50 values of these compounds ranged from 0.0127 to >0.23 mg cm−3. Based upon the selective toxicity ratio, the compounds described are more selective than dichlorvos. CONCLUSION The basil oil compounds described merit further study as potential insecticides for control of T. palmi in greenhouses because of their generally lower toxicity to O. strigicollis and their greater activity as a fumigant than dichlorvos. © 2014 Society of Chemical Industry

To examine the resistance mechanisms of Thrips palmi against spinosad, we cloned partial nucleotide sequences of the nicotinic acetylcholine receptor α6 subunit (TPα6) gene from susceptible (OK) and resistant (TS1 and TS5) strains and compared the deduced amino acid sequences among the three strains. The OK, TS1, and TS5 strains respectively showed LC50 values of 3.4mg/L, 2838.5mg/L, and 6655.5mg/L. The deduced amino acid sequence of TPα6 gene showed 96% identity with that of Frankliniella occidentalis. Comparison of the deduced amino acid sequences of TPα6 gene among the three strains showed that the TS1 and TS5 strains had a resistant amino acid, Glu, at amino acid position 275. On the other hand, a susceptible amino acid, Gly, was encoded at the corresponding amino acid position for the OK strain. The synergist, piperonyl butoxide, respectively caused 1.1-fold , 5.8-fold , and 9.0-fold decreases in the resistance ratios of the OK, TS1, and TS5 strains. These results suggest that spinosad resistance of T. palmi is conferred by reduced sensitivity of TPα6 and cytochrome P450-mediated detoxification.

Melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae), is a significant pest of vegetable crops and ornamental plants due to feeding and oviposition injury to vegetative and reproductive tissues. As an integrated approach, we evaluated the efficacy of a phytoseiid mite, Amblyseius swirskii Athias-Henriot, and different colored and UV-reflective plastic mulches for managing T. palmi in snap bean (Phaseolus vulgaris L.), cucumber (Cucumis sativus L.), yellow squash (Cucurbita pepo L.), eggplant (Solanum melongena L.), Jalapeno pepper (Capsicum annuum L.), and tomato (Solanum lycopersicum L.). The five mulch treatments evaluated were: “Shine N′ Ripe” (Metalized top and black bottom), “Can-Shine” (Metalized top and white bottom), “Black” plastic black-on-black (Can-Grow-XSB), black-on-white (Can-Grow XSB), “White” plastic; white-on-black (Can-Grow XSB), and bare soil with no mulch. The number of T. palmi adults and larvae in leaf samples collected from the middle third (stratum) of plants in each treatment was determined. In 2015 at 49 days after planting (DAP), curative release of 40–50 A. swirskii per plant did not suppress T. palmi effectively when the thrips population was high. There were no significant interactions between A. swirskii and crop or A. swirskii and mulch type on the number of T. palmi. However, in 2016 at 15 DAP, preventive release of A. swirskii, reduced the number of T. palmi in each of the mulch and crop treatments. Metalized mulch reduced the number of T. palmi early in the season when plants’ canopy did not shade the mulched area. These results suggest that use of metalized reflective mulch and A. swirskii, each have the potential to manage T. palmi at low population densities.

A field experiment was conducted to explore the activity of insect herbivores in linseed, their natural enemies, and population dynamics, on variety BRLS-102 at Sabour (Bhagalpur), Bihar during rabi, 2016–17. A total of nine insect herbivores were observed of which the two thrips viz., Thrips palmi and Frankliniella schultzei are new records. Four natural enemies (predators)-Coccinella septempunctata and Menochilus sexmaculata belonging to Coccinellidae, spider (Oxyopes sp.), and Paederus sp (Staphylindiae) were observed. The linseed pests were active from mid-January to mid-March from vegetative to bud formation stage. Maximum population of Agrotis ipsilon and thrips were observed during 52nd and 9th SMW, respectively; and that of aphids, Helicoverpa armigera, Oxyopes sp., coccinellids and bud fly was on the 8th SMW. Correlation coefficients of the population/infestation of these with the weather factors are given herein to explain their population dynamics.

Thrips palmi is a major pest of several economically important food crops. The mirid Orius insidiosus is an important predator of T. palmi in Trinidad and several other Caribbean islands. Its biocontrol effectiveness is hampered by frequent insecticide applications. Contact and leaf residual bioassays were conducted on both T. palmi and O. insidiosus with eleven commonly applied insecticides to determine the least and most toxic insecticide(s) to O. insidiosus and T. palmi, respectively. This information forms part of an Integrated Pest Management programme for T. palmi. Cypermethrin+ profenaphos and chlorfenapyr were observed to be the most toxic while imidacloprid was the least toxic to O. insidiosus adults. Fipronil, diafenthiuron and λ-cyhalothrin were the most toxic to T. palmi. Orius insidiosus survived for the longest period when exposed to chlorfenapyr but not significantly longer when exposed to acetamiprid, α-cypermethrin, or dimethoate. Alpha (α)-cypermethrin caused the fastest mortality in T. palmi while diafenthiuron took significantly longer to cause 50% mortality compared to α-cypermethrin and abamectin. The calculated Selectivity Ratios indicated that only fipronil, λ-cyhalothrin, acetamiprid, diafenthurion and imidacloprid favoured the predator. Leaf residue bioassays indicated that abamectin had the lowest LT50 for both O. insidiosus and T. palmi emphasizing the fact that abamectin degraded fastest and the residues left after application had the least effect on the predator/prey. Fipronil, λ-cyhalothrin, acetamiprid, diafenthurion, imidacloprid and abamectin might be incorporated into an IPM programme using O. insidiosus as a predator of T. palmi

Wollastoniella rotunda Yasunaga et Miyamoto is an effective predator of Thrips palmi Karny and a potential biological control agent for this pest of Japanese greenhouse vegetables. To determine alternative sources of prey for the mass rearing of W. rotunda used for T. palmi augmentative biocontrol, we examined the life history parameters of this predator as reared on two different prey species: Tyrophagus putrescentiae (Schrank) and Ephestia kuehniella Zeller eggs. When the predator nymphs were reared on T. putrescentiae and E. kuehniella at 25°C, their developmental times were 21.0 and 16.7 days, respectively, and their survival rates on T. putrescentiae and E. kuehniella at 25°C were 43% and 91%, respectively. The longevity of the predator females was 13.1 days on T. putrescentiae and 19.2 days on E. kuehniella, and their total fecundity was 15.0 eggs on T. putrescentiae and 56.5 eggs on E. kuehniella. The intrinsic rate of natural increase per day of W. rotunda on E. kuehniella (rm = 0.087) was greater than that on T. putrescentiae (rm = 0.031). We thus concluded that E. kuehniella is more suitable than T. putrescentiae as food for the mass rearing of W. rotunda.

Al analizar datos provenientes de poblaciones de plagas agricolas, regularmente se detecta que no cumplen los requerimientos teoricos para la aplicacion del ANDEVA clasico. El uso de transformaciones Box-Cox y de metodos estadisticos no parametricos resulta la alternativa mas utilizada para resolver este inconveniente. En el presente trabajo se exponen los resultados de la aplicacion de estas tecnicas a datos provenientes de Thrips palmi Karny muestreadas en plantaciones de papa (Solanum tuberosum L.) en el periodo de incidencia de la plaga. Se utilizo la docima X2 para la bondad de ajuste a la distribucion binomial negativa y de independencia para investigar la relacion entre los estratos de las plantas y los estados del insecto, se aplicaron siete transformaciones a los datos para satisfacer el cumplimiento de los supuestos basicos del ANDEVA, con las cuales no se logro eliminar la relacion entre la media y la varianza, por lo que se aplico el ANDEVA no parametrico de Kruskal-Wallis para comparar las densidades poblacionales del insecto. Los resultados permitieron seleccionar el estado larval del insecto y el estrato medio de la planta como elementos claves para disenar planes de muestreo para esta plaga.

BACKGROUND: Predatory mites (Amblyseius swirskii Athias-Henriot, Typhlodromips montdorensis Schicha, Neoseiulus cucumeris (Oudemans) and Iphiseius degenerans Berlese) were investigated for their potential to act as control agents for Thrips palmi Karny. Prey consumption rates and compatibility with pesticides were assessed. RESULTS: Second-instar larvae were the preferred life stage. Typhlodromips montdorensis consumed the most larvae (2.8) and also an average of 1.2 adult T. palmi per 5 day period. Both 24 and 48 h assessments following application of abamectin, spinosad and imazalil demonstrated mortality of predatory mites (across all species), which was significantly higher than with the other treatments (P < 0.001). Spraying with pymetrozine did not provide any increased mortality when compared with the water control. Application of thiacloprid proved detrimental only to I. degenerans. Following indirect exposure of predatory mites to pymetrozine and imazalil, no significant differences in mite mortality were obtained. Indirect exposure to spinosad was identified as the most detrimental treatment (P < 0.001) to all mites. Abamectin also proved detrimental, with only T. montdorensis showing any potential tolerance. CONCLUSION: All predatory mites investigated offer potential for controlling T. palmi. Compatibility with chemicals varied between the mites. The potential of incorporating the mites into eradication strategies for T. palmi is discussed. Copyright © 2012 Society of Chemical Industry

Surveys conducted in Melon yellow spot virus (MYSV)-affected cucumber greenhouses revealed that the incidence of MYSV disease on cucumber plants varied by crop management conditions. Because of temporal and spatial dispersal of viruliferous Thrips palmi in two greenhouses, MYSV was detected in 21.2% of the cucumber plants growing in a weedy greenhouse and in only 1.3% of the cucumber plants growing in a thoroughly weeded greenhouse at the end of the cropping period. MYSV was also detected in 13 weed species found outside the cucumber greenhouses. Viruliferous T. palmi adults were often found on Acalypha australis, Cerastium glomeratum and Lamium amplexicaule. T. palmi reared on MYSV-infected cucumber plants transmitted MYSV to C. glomeratum and L. amplexicaule. Moreover, T. palmi reared on MYSV-infected C. glomeratum rarely transmitted MYSV to cucumber seedlings. These results suggest that weed control is important for managing MYSV since weeds provide a habitat for the vector thrips and also serve as an initial inoculum source of the virus.

Thrips are among the most important agricultural pests globally because of the damage inflicted by their oviposition, feeding, and ability to transmit plant viruses. Because of their invasiveness, a number of pest species are common to both China and the United States and present significant challenges to growers of a wide range of crops in both countries. Among the pest thrips common to both countries are four of the major global thrips pests, Frankliniella occidentalis (Pergande), Scirtothrips dorsalis Hood, Thrips palmi Karny, and Thrips tabaci Lindeman. This review addresses characteristics that enable thrips to be such damaging pests and how biological attributes of thrips create challenges for their management. Despite these challenges, a number of successful management tactics have been developed for various cropping systems. We discuss some of these tactics that have been developed, including the use of cultural controls, biological controls, and judicious use of insecticides that do not disrupt overall pest management programs. The exchange of this type of information will help to facilitate management of pest thrips, especially in regions where species have recently invaded. A prime example is F. occidentalis, the western flower thrips, which is native to the United States, but has recently invaded China. Therefore, management tactics developed in the United States can be adapted to China. Because further success in management of thrips requires a thorough understanding of thrips ecology, we discuss areas of future research and emphasize the importance of collaboration among different countries to enhance our overall understanding of the biology and ecology of thrips and to improve management programs for these widespread pests.

The effects of prey species [ Thrips palmi Karny (Thysanoptera: Thripidae) and Tetranychus kanzawai Kishida (Acari: Tetranychidae)] and their densities per plant on the olfactory responses of females of the anthocorid predator Wollastoniella rotunda Yasunaga and Miyamoto (Hemiptera: Anthocoridae) to volatiles from plants that were either intact or infested by prey were investigated using a Y-tube olfactometer. W. rotunda females preferred the volatiles from intact eggplants ( Solamum melongena ) to clean air. The females preferred volatiles from eggplants infested with either of the two prey species at different densities (200 and 800 female prey species) over intact eggplant volatiles. The females also preferred volatiles from plants infested with 800 females to those from plants infested by 200 females of the same species. W. rotunda females preferred the odor from eggplants infested with 200 T. kanzawai to that from eggplants infested with 200 T. palmi . When the number of prey per plant was increased to 800, the predators showed equal preference for eggplants infested by either of the two prey species. W. rotunda females preferred the odor from the eggplants infested with 800 T. palmi to that from the eggplants infested with 200 T. kanzawai , and the odor from eggplants infested with 800 T. kanzawai to that from eggplants infested with 200 T. palmi. The preferences of W. rotunda for infested eggplants were discussed from the viewpoints of using this predator for the biological control of T. palmi and T. kanzawai .

A quick and developmental-stage non-limiting method of the identification of vectors of tospoviruses, such as Thrips tabaci and T. palmi, is important in the study of vector transmission, insecticide resistance, biological control, etc. Morphological identification of these thrips vectors is often a stumbling block in the absence of a specialist and limited by polymorphism, sex, stage of development, etc. Molecular identification, on the other hand, is not hampered by the above factors and can easily be followed by a non-specialist with a little training. The mitochondrial cytochrome oxidase I (mtCOI) exhibits reliable inter-species variations as compared to the other markers. In this communication, we present the differences in the mtCOI partial sequence of morphologically identified specimens of T. tabaci and T. palmi collected from onion and watermelon, respectively. Species-specific markers, identified in this study, could successfully determine T. tabaci and T. palmi, which corroborated the morphological identification. Phylogenetic analyses showed that both T. tabaci and T. palmi formed different clades as compared to the other NCBI accessions. The implication of these variations in vector efficiency has to be investigated further. The result of this investigation is useful in the quick identification of T. tabaci and T. palmi, a critical factor in understanding the epidemiology of the tospoviruses, their management and also in quarantine.

Thrips palmi Karny, the melon thrips, has spread widely and rapidly in tropical and subtropical regions, but despite a number of outbreaks (all successfully eradicated) and regular interceptions, it remains absent from Europe. Considerable experience of managing this pest has been gained in different countries as it has spread around the world. Control measures for T. palmi are reviewed and discussed, primarily in the context of measures available in the UK for use against future outbreaks. Recent reports of successful control of T. palmi in countries, to which it has recently spread, are also reviewed. The emphasis is on chemical insecticides for eradication of this quarantine pest, although biological, cultural and physical measures are also covered.

Thrips palmi Karny, the melon thrips, is a polyphagous pest that has spread widely in tropical and subtropical regions. It is absent from Europe, although outbreaks have occurred in the Netherlands (1988–98), the UK (2000–01) and most recently Portugal (2004). An outbreak of T. palmi occurred in Sussex in 2000. It was already well established when the UK Plant Health Service first notified. High populations were discovered in two glasshouse sites on the same nursery, growing all-year-round chrysanthemums. An intensive, largely chemically based eradication programme was carried out, with applications of aerosol ‘space’ treatments, systemic and foliar insecticides. Other measures included the use of sticky yellow sheets, methyl bromide fumigation of flowerbeds and plastic mulches. Together, these controls resulted in the collapse of the outbreak, within 7 months. Eradication was subsequently declared after freedom from the pest had occurred over two complete cropping cycles.

Monthly plantings conducted over 4 years in a rainfed triple maize cropping system in southern Mindanao, Philippines, revealed the Asian corn borer (ACB) Ostrinia furnacalis (Guenee) as the most important insect pest. Of minor importance and being restricted to one crop stage were rice seedling maggot Atherigona oryzae Malloch, thrips Thrips palmi Karny and Megalurothrips usitatus (Bagnall), corn leafhopper Cicadulina bimaculata (Evans), corn earworm Helicoverpa armigera (Hubner), and corn leaf aphid Rhopalosiphum maidis (Fitch). Farmers escape damage from ACB, seedling maggot, and thrips by planting the first crop in April. Planting of the second crop should be shifted from August to September to avoid ACB damage. Pest damage was low during the third crop, thus planting time is not an important consideration. Additional information on ACB bionomics was revealed in the study. Mean egg mass size was 36 eggs (range 1 – 169). Oviposition was found to be positively correlated with cumulative rainfall...

Thrips palmi is a major pest of many crops in the tropics and sub-tropics, and is a serious threat within the protected horticulture industry in other parts of the world including the UK. Widespread use of insecticides against T. palmi throughout the world coupled with the restricted range of products available makes it essential to find alternative systems for control. The scattered information on its natural enemies, particularly predators and parasitoids, is reviewed and their potential for use in the control of T. palmi as part of IPM strategies in the UK is considered. Natural enemies selected for detailed examination include: Amblyseius spp., Anthocoris nemoralis, Atheta coriaria, Bilia spp., Campylomma spp., Ceranisus spp., Deraeocoris spp., Franklinothrips spp., Hypoaspis spp., Orius spp. and Phytoseius spp. Recommendations for further investigations are made, including screening and efficacy testing of candidate predators and parasitoids, using semiochemicals to enhance their effectivene...

The predation potential of Haplothrips brevitubus (Karny) for thrips was evaluated in the laboratory. When second stage larvae of Pseudodendrothrips mori (Niwa) were presented to an adult H. brevitubus at densities of 10, 20, 30, and 40 larvae per cage at 25 °C over 24 h, the number of larvae consumed per day increased with an increasing density up to 30. Predation of H. brevitubus exhibited the type II functional response. The mean development time of the egg, larva, and pupa of H. brevitubus were 4.5, 9.6, and 4.8 days, respectively, at 25 °C. The survival rate from egg to adult emergence was 94.7%. One H. brevitubus larva consumed 41.6 P. mori larvae on average during the total larval period. Adult longevity was 35.2 days in females and 34.6 days in males. The pre-oviposition period was 2.7 days and the oviposition period was 31.5 days. The lifetime fecundity was 120.1 eggs and the mean daily oviposition rate was 3.6 eggs. Calculated mean generation time (T) was 29.5 days, intrinsic rate of natural increase (rm) was 0.162, and net reproductive rate (R0) was 56.5. The rm value of H. brevitubus was higher than that of Thrips palmi Karny and almost equal to that of Frankliniella occidentalis (Pergande). These results indicate that H. brevitubus has good potential as a predator of P. mori and is likely to be useful for controlling thrips.

In recent years, the polyphagous pest Thrips palmi Karny has become a species of major quarantine concern, often intercepted on plant material in international trade. The ability to rapidly identify the species is a critical factor that will determine the success of any campaign to prevent its establishment in Europe or elsewhere. However, the immature stages cannot currently be identified to the species level with certainty by morphological methods. In this study, random amplified polymorphic DNA analysis was performed to identify putative markers, which were then screened by Southern blot analysis. One marker was sequenced and a real-time polymerase chain reaction assay developed. The assay was screened against 21 thrips species including 10 other species of the genus Thrips and were found to be specific to T. palmi. The assay is rapid, could be completed in as little as 45 min and can be used to aid the identification of T. palmi.

Since Thrips palmi became a regulated pest for most European countries, inspections at points of entry into Europe and monitoring in Europe have intensified not only for T. palmi but also for thrips as a whole. Morphological identification of thrips is performed on adults and to a lesser extent on second-stage larvae only, because no adequate identification keys for the separation of species based on the characteristics of eggs, first-stage larvae, pre-pupae or pupae are available. We have developed a real-time PCR assay based on TaqMan. A T. palmi-specific set of primers and probe were selected within the mitochondrial cytochrome oxidase I (COI) gene. The specificity of the assay was assessed using 15 specimens of Thrips palmi and 61 specimens of 23 other thrips species commonly occuring in Europe. All T. palmi specimens were detected, and no cross reactions with other thrips were observed. The method was tested on single larvae and adults and proved to be applicable for both those stages of T. palmi

Thrips palmi has not become established in England, yet its potential introduction represents a continuous threat to glasshouse ornamental and vegetable crops. The first outbreak of T. palmi in England occurred at a site of chrysanthemum production in southern England during 2000. The statutory eradication of the pest imposed significant financial costs on both the producer and Defra Plant Health Service. The use of additional insecticides, methyl bromide soil sterilisation, imidacloprid-treated compost, plastic sheeting to cover the growing media and associated additional labour costs during the eradication campaign resulted in a six-fold increase of expenditure on pest control. The estimated eradication costs for the grower exceeded £56,000 for the period April 2000 to July 2001. If eradication had not been achieved, T. palmi may have spread to establish in protected cultivation throughout England. The net present value of the economic impact of T. palmi over 10 years is estimated to be between £16.9 and £19.6 M depending upon the rate of pest spread. Impacts include yield and quality losses, additional research, plant health certification costs and loss of exports. Although there is uncertainty as to whether revenue from exports liable to carry T. palmi would be lost, if they were lost they would be the most significant contributor to the overall economic impact. Without loss of exports, impacts fall to between £0.6 and £3.3 M over 10 years. Benefit:cost ratios for eradicating the outbreak and maintaining an exclusion policy towards T. palmi range from 4:1 to 19:1 if there is no loss of exports, and from 95:1 to 110:1 if significant export losses did result from T. palmi establishment.

The tospoviruses Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV), Groundnut ringspot virus (GRSV) and Chrysanthemum stem necrosis virus (CSNV) are well-known pathogens on tomato in Brazil. The thrips species Frankliniella occidentalis, F. schultzei, Thrips tabaci and T. palmi were studied for their competence to transmit these tospoviruses. Frankliniella occidentalis transmitted all four tospoviruses with different efficiencies. Frankliniella schultzei transmitted TCSV, GRSV and CSNV. Although F. schultzei has been reported as a vector of TSWV, the F. schultzei population in the present study did not transmit the TSWV isolate used. A population of T. tabaci known to transmit Iris yellow spot virus (onion isolate) did not transmit any of the studied tospoviruses, and nor did T. palmi. Replication of these tospoviruses could be demonstrated by ELISA, not only in the thrips species that could transmit them, but also in those that could not. The results strongly suggest that competence to transmit is regulated not only by the initial amount of virus acquired and replication, but also by possible barriers to virus circulation inside the thrip's body.

To evaluate the effectiveness of the predatory bug, Wollastoniella rotunda Yasunaga et Miyamoto, against Thrips palmi Karny on eggplants in greenhouses, we conducted experiments over two growing seasons. In the first experiment, 71 adults of W. rotuuda were released in Novernber 1997, and the release ratio was 1:4 (adult bug: thrips) for prey density of 0.06 thrips per leaf. This release was successful in controlling a T. palmi population that had such a low density at the release time. In the second experiment, a total of 180nymphs of W. rotuuda were released three times in October and November 1998. These releases were also effective in controlling a T. palmi population that had a low density (0.15 thrips per leaD on the first release, and the release ratio of nymphal bugs to thrips was 1:2. Based on these results, we conclude that W. rotuuda could be effective as a biological control agent against T. palmi in winter greenhouses.

Mass rearing techniques are essential elements in developing a reliable and economic biological control method for Orius sauteri, a promising indigenous Orius species for biological control of Thrips palmi in greenhouses. Orius sauteri was reared on Ephestia kuehniella eggs and life history parameters and the minimum number of E. kuehniella eggs for rearing O. sauteri individuals were measured at 25°C and L16:D8. Developmental time during the nymphal stages was about 14 days for both sexes. Total fecundity and female longevity were 103.9 and 27.9 days, respectively. The intrinsic rate of natural increase per day was 0.115. An individual requires at least 30 eggs for nymphal development and survival and 20 eggs for adult oviposition and survival per four days.

Melon thrips (Thrips palmi Karny) is one of several Risk Group 2 pests on New Zealand MAF Biosecurity Authority’s list of unwanted pests. Its wide host plant range, and its presence world-wide, including several countries in the Pacific region, underpin its biosecurity status. In this case study we used CLIMEX, a climate matching software program, to determine likely locations in New Zealand where melon thrips could establish once introduced. Possible establishment was based on climate match with overseas locations where melon thrips is present, and on a range of biological parameters specific to the response of melon thrips to climatic conditions. The upper North Island is predicted to be most suited to melon thrips establishment. This also matches the known New Zealand distribution of Hercinothrips bicinctus, banana thrips, a species found worldwide in locations similar to that of melon thrips .

The EPPO A1 and A2 quarantine lists (with corresponding specific quarantine requirements) and Annexes I and II of EU Directive 77/93 (with requirements in Annex IV) cover a number of important glasshouse quarantine pests: Liriomyza spp., Bemisia tabaci and the viruses it transmits, Frankliniella occidentalis, tomato spotted wilt tospovirus, Thrips palmi, Aculops fuchsiae, Helicoverpa and Spodoptera spp., Opogona sacchari and Radopholus similis. Most frequently, the requirements made to exporting countries for these pests centre on country or area freedom, place of production freedom (usually over the last growing season), treatment of plants immediately before dispatch. Because many of the plants concerned have a wide host range, there is some difficulty in deciding which plant species should be regulated, or whether cut flowers, fruits or vegetables should be regulated as well as plants for planting. The requirements for some of these glasshouse pests are among the broadest included in the EPPO and EU system (e.g. all plants for planting, except seeds and bulbs, for T. palmi). The recommended requirements are generally well harmonized between EPPO and the EU, except in respect of the categories of exporting countries considered. The EU requirements frequently put neighbouring non-EU European or Mediterranean countries on the same basis as the most remote continents. Such an approach does not seem justifiable to EPPO.

During inspections of consignments of ornamental plants (cuttings, bulbs, rhizomes, pot plants, cut flowers) imported into Poland in 1993/1998, the following quarantine pests were intercepted most frequently: Frankliniella occidentalis (32 consignments), Aphelenchoides fragariae (17), Steneotarsonemus laticeps (12) and Bemisia tabaci (11). These pests were found in plants for planting, pot plants and cut flowers imported mainly from The Netherlands. Thrips palmi (EPPO A1 list) was intercepted on orchid cut flowers from Thailand (2) and Cacoecimorpha pronubana on pot plants of Thuja occidentalis from The Netherlands. Ditylenchus destructor was intercepted on bulbs of Erythronium denscanis (not previously described as a host). The methods of inspection and identification of particular intercepted pests are presented.

Thrips palmi is a polyphagous, EU‐listed pest which has greatly expanded its geographic range in the last 18 years. Originating in south‐east Asia T. palmi is now found throughout the Pacific, in Florida, in the Caribbean and in South America. Direct feeding damage causes economic loss, but it has also been shown to be a vector of tospoviruses. Monoclonal antibodies (MAbs) were raised against T. palmi for use in a rapid detection system to facilitate measures to prevent its establishment in the UK. These were characterized through cross‐reactivity studies with other insects including the two species of thrips most commonly found under glass in the UK Frankliniella occidentalis and T. tabaci. Several promising cell lines secreting MAb that showed specificity to T. palmi were produced. Alongside this work antigen characterization studies through protein profiles produced by SDS PAGE were carried out. The purpose of these studies was to identify any protein bands that were specific for T. palmi and the other...

To explore the possibility of usingOrius tantillus (Motschulsky) as a control agent againstThrips palmi Karny in greenhouses in Japan during the winter months, the effects of temperature on the development of eggs and nymphs of this predator were determined by rearing individuals under eight constant temperatures ranging from 17.5–35.0°C. Estimates of lower developmental threshold temperatures for eggs, male nymphs and female nymphs were 13.7°C, 11.9°C and 13.4°C, respectively. These estimates were lower than the average winter temperature at night in greenhouses in Japan, suggesting thatO. tantillus could possibly be used for the control ofT. palmi in such greenhouses. Thermal constants were estimated at 52.6, 185.2 and 153.8 degree days for eggs, male nymphs and female nymphs, respectively. Egg survival at temperatures between 20°C and 30°C was higher (p=0.05) than at 17.5°C.

We examined the genomic organization of the sodium channel α-subunit gene in two strains of melon thrips, Thrips palmi, having differing sensitivity to cypermethrin. The nucleotide sequences of the strains included 18 or 16 putative exons which covered the entire coding region of the gene producing 2039 amino acid residues. Deduced amino acid sequences of both strains showed 80% homology with those of Periplaneta americana and Cimex lectularius. Comparison of deduced amino acid sequences of both strains showed no consistent amino acid difference. In addition to the previously reported resistant amino acid (Ile) at the T929I site, both strains encoded another resistant amino acids at two positions which are involved in pyrethroid resistance in other arthropods. These amino acids might also involve in the basal levels of resistance to pyrethroids of both strains.

SUMMARY Postharvest treatments, including insecticidal dips, isopropyl alcohol dips, insecticidal fogs and hot-water immersion, were evaluated to control mixed infestations of Western Flower Thrips (Frankliniella occidentalis) and Melon Thrips (Thrips palmi) on dendrobium orchid blossoms. The limiting factor for all postharvest treatments was phytotoxicity, characterised by a loss of vase life that differed among cultivars. Insecticidal dips and insecticidal fogs were less phytotoxic than hot-water immersion and isopropyl alcohol dips. Insecticidal fogs consisting of abamectin 2.0% e.c. and abamectin tank-mixed with Pyrenone e.c. (6% pyrethrins, 60% piperonyl butoxide) reduced the mean number of thrips per blossom by 93.8% and 92.3%, respectively and were nonphytotoxic. An insecticidal aerosol, Floragas (2% permethrin and 0.1% pyrethrum dissolved in high pressure liquified CO2) reduced thrips by 33% to 54% with no phytotoxicity. Insecticidal dips for 3 min with agitation reduced the mean number of thrips per blossom by 43.7% to 99.1%. Of the 12 insecticides and one surfactant tested, only chlorpyrifos 44.4% e.c., fluvalinate 22.3% f., and chlorpyrifos 50% d.f. were both effective and nonphytotoxic. Immersion in water at 49.5°C for 15 and 20 s reduced the mean number of thrips per blossom by 88.1% and 95.3%, respectively. A 70% solution of isopropyl alcohol applied as a postharvest dip did not kill all thrips and was extremely phytotoxic to blossoms.

The occurrence of the quarantine pest Thrips palmi in The Netherlands in 1992 and the difficulties encountered in enforcing legal eradication measures have stimulated discussion concerning a possible network of diagnostic services in Europe. Official services find it increasingly difficult to evaluate and adopt the latest diagnostic techniques produced by research institutes and universities. It is proposed to create international discipline-oriented working groups to prepare draft identification methods for the official EPPO and EU quarantine pests. These draft methods could be harmonized by the EPPO Panel on Diagnostics and approved by EPPO Council. This is a two-sided sword: internationally agreed identification methods are produced and a diagnostic network comes into being at the same time.

A brief introduction is given to Thrips palmi, a horticultural pest recently introduced to Australia. Methods developed in the Northern Territory to trap thrips with blue sticky-board traps and water-tray traps for monitoring purposes and the techniques used for rapid preparation and identification are described. A brief description of specific characters which may be used to differentiate between T. palmi and four other closely related, economic species found in Australia is provided.

A survey for natural enemies of Thrips palmi Karny was conducted in its native habitat, Thailand, in 1987 and 1988 to develop a classical biological control program for this exotic pest of vegetables in Japan. One egg parasitoid, one larval parasitoid, and six larval predators were found. Of these eight natural enemies, the eulophid larval parasitoid Ceranisus menes (Walker) was the most effective, based on a study in a test plot of eggplant in Bangkok and an extensive survey of eggplant fields in several districts of Thailand in 1988. Parasitism by C. menes was usually limited to home gardens which were not sprayed with insecticides, suggesting a detrimental effect of insecticide applications on the parasitoid. The anthocorid larval predator Bilia sp. was the second most effective natural enemy. Problems associated with the introduction of these two promising biological control agents in relation to the occurrence of native natural enemies of T. palmi in Japan are discussed.