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Thrips pests are causing increasing damage to many crops, including vegetables, fruits, and ornamental plants. RNA interference (RNAi) has been recognized as a potential approach for thrips control. However, the RNAi of thrips is often restricted by the lack of efficient dsRNA delivery method. Here, we developed a nanocarrier-mediated dsRNA oral delivery system for efficient RNAi in the melon thrips, Thrips palmi. We first determined RPL17 and EF1α as the optimal reference genes among different developmental stages, tissues, adult ages, and starvation treatments. Two aminopeptidase N genes, TpAPN2 and TpAPN3, expressed at a relatively high level in the midgut, were selected as target genes for RNAi. In our delivery system, dsRNA solutions were absorbed by cucumber leaves and delivered to thrips by feeding. Naked dsRNAs exhibited no RNAi effect, whereas the nanocarrier SPc (star polycation)-loaded dsRNAs induced a 43.7% and 48.9% decrease in the expression levels of TpAPN2 and TpAPN3, respectively. Inhibited functions of TpAPN2 and TpAPN3 resulted in 36.0% and 53.9% reduction in the feeding amount and 28.5% and 35.5% decrease in egg production, respectively. Co-silencing of TpAPN2 and TpAPN3 led to a mortality of 48.3%, higher than the single-RNAi of TpAPN2 (23.3%) and TpAPN3 (30%). The newly developed dsRNA delivery system is easy to manipulate with improved RNAi efficacy, providing a powerful tool for gene functional study of thrips. [ABSTRACT FROM AUTHOR]

Melon thrips, Thrips palmi (Thysanoptera: Thripidae), is a serious insect pest in crop productions, and synthetic chemicals are frequently used to control them. However, this practice causes residual issue in nature and makes melon thrips acquire strong resistance. To overcome these problems, a group of entomopathogenic fungi could be used as an alternative for controlling melon thrips. In this work, a total of 100 fungal isolates from soil in four different regions of Korea were isolated and subjected to virulence assays against melon thrips. Twenty‐five highly virulent fungal isolates, which showed 100% mortality 6 days after treatment, were determined. Liquid‐cultured filtrates of the selected isolates were further used to investigate their insecticidal activity against melon thrips, and of the 25 selected isolates finally seven isolates including Metarhizium spp. and Fusarium spp. showed high insecticidal activity in a dose‐dependent manner. Under a thermal stress at 121°C, culture filtrates of the seven isolates still kept their insecticidal activities. When liquid‐cultured spores were exposed to 45°C, spores of Fusarium isolates were resistant to the thermal stress, but those of Metarhizium isolates were susceptible to the stress. The culture filtrates of Fusarium isolates did not show any phytotoxicity to the tomato plants, followed by no phytotoxicity of liquid‐cultured spores, although mycotoxins need to be further clearly characterized. This work suggests that entomopathogenic Fusarium isolates are competitive in virulence against melon thrips and production of insecticidal metabolites compared to Metarhizium, and particularly attractive in sporal resistance against thermal stress, significantly stronger than Metarhizium. [ABSTRACT FROM AUTHOR]

We evaluated the effectiveness of vapor heat treatment on Thrips palmi Karny, Bemisia tabaci(Gennadius), and colonies of powdery mildew, Sphaerotheca fuliginea(Schlechtendal)Pollacci, on greenhouse melon seedlings. Air was gradually heated to a set temperature(48°C)over 45 min while the relative humidity was maintained at 95%. The set temperature was then held for 8 min. The numbers of T. palmi adults and larvae, B. tabaci adults, and colonies of powdery mildew were lower on seedlings held at 48°C for 8 min than on untreated seedlings. The hatchability of T. palmi and the ratio of emerged adults were lower on treated than on untreated seedlings. Treatment at 48°C for 8 min did not visibly damage the seedlings. These results suggest that vapor heat treatment at 48°C for 8 min can effectively reduce the population densities of T. palmi eggs, larvae, pupae, and adults, B. tabaci adults, and powdery mildew on greenhouse melon seedlings. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ultraviolet (UV) interferes with the vision, flight initiation, dispersal, host, and population dispersion of herbivorous insects. Hence, UV‐blocking film has recently been developed as one of the most potential tools to control pests under tropical greenhouse conditions. In this study, we investigated the effects of UV‐blocking film on the population dynamics of Thrips palmi Karny and the growth status of Hami melon (Cucumis melo var. reticulatus) in greenhouses. RESULTS: By comparing thrips populations in greenhouses covered with UV‐blocking films with those covered with ordinary polyethylene films, we found that the UV‐blocking film effectively reduced the thrips population within 1 week and continued to control the population, meanwhile the quality and yield of melon in UV‐blocking greenhouses also had a substantial increase. CONCLUSION: The UV‐blocking film remarkably inhibited the population growth of thrips and greatly improved the yield of Hami melon cultivated in UV‐blocking greenhouse compared with the control greenhouse. Overall, UV‐blocking film is a very powerful potential tool for green pest control in the field, enhancing the quality of tropical fruits, and providing a new wind vane for sustainable green agriculture in the future. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The present study was undertaken to determine distribution of thrips species from major tomato growing regions in South India (Tamil Nadu, Karnataka, Maharashtra, Telangana, Andhra Pradesh). The thrips species were identified using molecular techniques employing universal barcoding primer (mt-COI). These revealed the presence of six species viz., Thrips palmi Karny, Scirtothrips dorsalis Hood, Thrips tabaci Lindeman, Frankliniella schultzei (Trybom), Thrips apicatus Priesner and Tusothrips sumatrensis (Karny). Of these, T. palmi was found to be predominant in all the states surveyed followed by S. dorsalis, F. schultzei and T. tabaci. [ABSTRACT FROM AUTHOR]

The tomato industry in South Florida (USA) is seriously affected by recently emerging Tomato chlorotic spot virus (TCSV). Western flower thrips, Frankliniella occidentalis (Pergande), and common blossom thrips, Frankliniella schultzei (Trybom) (Thysanoptera: Thripidae), are the two known vectors of TCSV in Florida. In the present study, the presence of thrips vectors and TCSV in 24 flowering ornamental plant species was observed in South Florida. The two thrips vectors, as well as melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae), were abundant in the area; they were observed with a range from high (83.1 per sample of 10 flowers) in Hibiscus rosa‐sinensis L. to low (3.7 per sample of 10 flowers) in Catharanthus roseus (L.) G. Don in a nursery study. In a subsequent greenhouse study, we selected seven species of ornamentals, among which the species with the highest thrips abundance, and planted them next to tomato, to determine their effects on TCSV incidence and thrips abundance in tomatoes. Tomatoes with Portulaca oleracea L. next to them showed a higher number of TCSV‐infected plants (4.25 plants per plot in 2017, and 3.25 plants per plot in 2018) compared to tomatoes with some of the other ornamentals next to them. We report the presence of TCSV through reverse transcriptase polymerase chain reaction (RT‐PCR) analysis in Lantana camara L., H. rosa‐sinensis, Mandevilla spec., Gazania linearis (Thunb.) Druce, Hemerocallis spec., Agastache spec., and P. oleracea. Identification of alternative hosts of TCSV and thrips vectors can be helpful to evaluate the ongoing management programs and develop future programs in local tomato‐growing areas. [ABSTRACT FROM AUTHOR]

We evaluated the effectiveness of using an indigenous generalist predatory mite, Neoseiulus barkeri (Hughes) (Acari: Phytoseiidae), to control Thrips palmi Karny (Thysanoptera: Thripidae) in greenhouse melons. In a growth chamber experiment, the density of T. palmi was lower on plants exposed to 20 N. barkeri per plant than on plants grown without a biological control. In a greenhouse experiment, the density of T. palmi was lower in the N. barkeri release plots than in the no-release plots. These results suggest that N. barkeri is an effective biological control agent against T. palmi. [ABSTRACT FROM AUTHOR]

Colour sticky traps are used in several crops for monitoring and mass trapping. This study evaluated coloured sticky traps for mass trapping of thrips Scirtothrips dorsalis (Hood), Thrips tabaci (Lindeman) and Thrips palmi (Karny) in cotton. The attractiveness of six colours viz., blue, yellow, orange, green, red and white in traps was evaluated during 2018 to 2020. Number of thrips captured in differed coloured traps was significantly different, with the blue-coloured sticky trap attracting more thrips followed by yellow. These observations reveal that blue and yellow- coloured traps can be used for monitoring and mass trapping of thrips as a component of IPM programme in cotton. [ABSTRACT FROM AUTHOR]

Putative mechanisms underlying spinosyn resistance have been identified in controlled studies on many species; however, mechanisms underlying field-evolved resistance and the development of a molecular diagnostic method for monitoring field resistance have lagged behind. Here, we examined levels of resistance of melon thrips, Thrips palmi Karny (Thysanoptera:Thripidae), to spinetoram as well as target site mutations in field populations across China to identify potential mechanisms and useful molecular markers for diagnostic and quantifying purposes. In resistant populations, we identified the G275E mutation, which has previously been linked to spinosyns resistance, and F314V mutation, both located in the α 6 subunit of the nicotinic acetylcholine receptor. There was a strong correlation between levels of spinetoram resistance and allele frequency of G275E mutation in field-collected populations (r 2 = 0.84) and those reared under laboratory conditions for two to five generations (r 2 = 0.91). LC50 ranged from 0.12 to 0.66 mg/liter in populations without G275E mutation, whereas it ranged from 33.12 to 39.91 mg/liter in most populations with a G275E mutation frequency more than 90%. Our results indicate that the field-evolved resistance of T. palmi to spinetoram in China is mainly conferred by the G275E mutation. The frequency of the G275E mutation provides a useful diagnostic for quantifying resistance levels in field populations of T. palmi. [ABSTRACT FROM AUTHOR]

Different species of thrips can occur in the same location and on the same plant. However, variation among dominant thrips species in their susceptibility to insecticide remains unclear. In this study, we evaluated the susceptibility of Frankliniella occidentalis, Thrips palmi and Frankliniella intonsa, three common thrips on vegetables, to spinetoram, from 12 geographical areas across China. Thrips palmi showed the lowest susceptibility to spinetoram (LC50 ranged from 0.1192 to 117.6707 mg L−1), while F. intonsa showed the highest susceptibility (LC50 ranged from 0.0044 to 0.6476 mg L−1). Field-evolved resistance to spinetoram was found for T. palmi and F. occidentalis, resulting in 987.17-fold and 323.77-fold differences in toxicity within each of these species, respectively. The Shouguang populations of T. palmi and F. occidentalis had the highest overall levels of resistance, with LC50 values of 117.6707 mg L−1 and 11.4290 mg L−1, respectively. Levels of susceptibility in southern populations of F. intonsa were low compared to northern populations of this species in China. In conclusion, our study highlighted variation in susceptibility of thrips to spinetoram, both among species and among geographical areas. The results should help the implementation of management tactics, and they provide insights into the displacement of thrips species in fields. [ABSTRACT FROM AUTHOR]

The behaviour of 5th 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 5th instar nymphs and adult females. First encounter of prey was shortest for 5th instar nymphs but not significantly different from that of adult females. The distance travelled to 1st prey by 5th instar nymphs was significantly shortest compared to both adult male and female O. insidiosus. However, speed of arrival to 1st prey did not significantly differ among the three stages of O. insidiosus examined. Mean time spent by O. insidiosus 5th instar nymphs and adult females on 1st, 2nd, 3rd and 4th prey encounters was not significantly different. However, adult males of O. insidiosus spent significantly less time on 4th prey encounter compared with 1st - 3rd prey encounters. [ABSTRACT FROM AUTHOR]

The melon thrips, Thrips palmi, is an increasingly important pest of vegetables in northern China. Some populations have developed resistance in the field to the insecticide spinetoram. Understanding the origin and dispersal of insecticide‐resistant populations can shed light on resistance management strategies. In this study, we tested susceptibility of seven greenhouse populations of T. palmi to spinetoram collected from a small area of about 300 km2 in Shandong Province and examined population genetic structure across the area based on a segment of mitochondrial cox1 gene and 22 microsatellite loci to infer the possible origin and dispersal of insecticide resistance. Levels of resistance to spinetoram differed among seven populations, which included one population with high resistance (LC50 = 759.34 mg/L), three populations with medium resistance (LC50 ranged from 28.69 to 34.79 mg/L), and three populations with low resistance (LC50 ranged from 7.61 to 8.97 mg/L). The populations were genetically differentiated into two groups unrelated to both levels of resistance and geographic distance. The molecular data indicated high levels of gene flow between populations with different levels of resistance to spinetoram and low gene flow among populations with the same level of resistance, pointing to a likely separate history of resistance evolution. Resistance levels of two tested populations to spinetoram decreased 23 and 4.6 times after five generations without any exposure to the pesticide. We therefore suspect that resistance of T. palmi most likely evolved in response to local applications of the insecticide. Our study suggests that the development of resistance could be avoided or resistance even reversed by reducing usage of spinetoram. [ABSTRACT FROM AUTHOR]

In order to contrast the fitness of Thrips palmi Karny reared on two of its hosts plants, Brassica oleracea L. leaves and Phaseolus vulgaris L. beans, life tables were constructed for T. palmi individuals reared on the two hostplants at 25°C using the age–stage, two-sex life table. The durations of the egg, first instar larva, pupa, and total immature stages of T. palmi reared on P. vulgaris were significantly longer than those reared on B. oleracea , whereas the adult preoviposition period, female adult longevity, and number of oviposition days of T. palmi reared on B. oleracea were significantly longer/greater than those on P. vulgaris. The fecundity (F) of T. palmi reared on B. oleracea (159.71 offspring/female) was significantly higher than in females reared on P. vulgaris (F = 122.98 offspring/female) despite the higher proportion of female adults that emerged on P. vulgaris. Although there were no significant differences in the intrinsic rate of increase (r), finite rate (λ), net reproductive rate (R 0), and mean generation time (T) between the two populations, computer projection showed that the T. palmi population will increase faster when reared on B. oleracea than on P. vulgaris. Our results demonstrate that population projection based on life table data is potentially an important tool in pest management. Furthermore, we used the bootstrap technique to demonstrate the variable effect that survival rate and fecundity at different ages can have on population parameters. [ABSTRACT FROM AUTHOR]

Thrips are tiny insects from the order Thysanoptera (Hexapoda: Condylognatha), including many sap‐sucking pests that are causing increasing damage to crops worldwide. In contrast to their closest relatives of Hemiptera (Hexapoda: Condylognatha), including numerous sap‐sucking species, there are few genomic resources available for thrips. In this study, we assembled the first thrips genome at the chromosomal level from the melon thrips, Thrips palmi, a notorious pest in agriculture, using PacBio long‐read and Illumina short‐read sequences. The assembled genome was 237.85 Mb in size, with 1,324 contigs and a contig N50 of 567 kb. All contigs were assembled into 16 linkage groups assisted by the Hi‐C technique. In total, 16,333 protein‐coding genes were predicted, of which 88.13% were functionally annotated. Among sap‐sucking insects, polyphagous species (e.g., T. palmi and Bemisia tabaci) usually possess more detoxification genes than oligophagous species (e.g., Diaphorina citri). The polyphagous thrips genomes characterized so far have relatively more detoxification genes in the GST and CCE families than polyphagous aphids, but they have fewer UGTs. HSP genes, especially from the Hsp70s group, have expanded in thrips compared to other hemipterans. These differences point to different genetic mechanisms associated with detoxification and stress responses in these two groups of sap‐sucking insects. The expansion of these gene families may contribute to the rapid development of pesticide resistance in thrips, as supported by a transcriptome comparison of resistant and sensitive populations of T. palmi. The high‐quality genome developed here provides an invaluable resource for understanding the ecology, genetics, and evolution of thrips as well as their relatives more generally. [ABSTRACT FROM AUTHOR]

The effects of red-light irradiation and a reflective sheet cover on the population density of two thrips species（Thysanoptera: Thripidae）, the melon thrips（Thrips palmi Karny）and the onion thrips （Thrips tabaci Lindeman）, were investigated on eggplant and cucumber in a greenhouse in 2014 and 2015. Red fluorescent lamps were illuminated from above the plants and a light reflecting sheet was placed on the ridges of the treated plots. A greenhouse without either material was set up as a control plot. The population densities of the two thrips species on eggplant and T. palmi on cucumber were significantly lower in the treated plots than in the control plot. [ABSTRACT FROM AUTHOR]

Background: To date, four thrips vectors have been reported to transmit five different tospoviruses in India. Their identification at an early stage is crucial in formulating appropriate pest management strategies. Since morphometric key-based thrips identification based on the adult stage is time-consuming, there is a need to develop diagnostic tools which are rapid, accurate, and independent of developmental stages. Here, we report a multiplex PCR assay to identify four major thrips vectors viz. Thrips palmi, T. tabaci, Scirtothrips dorsalis, and Frankliniella schultzei present in India. Results: Cytochrome oxidase subunit III and internal transcribed spacer region 2 were utilized to design species-specific primers. Of 38 pairs of primers tested, primer pairs AG35F-AG36R, AG47F-AG48R, AG87F-AG88R, and AG79F-AG80R amplified 568 bp, 713 bp, 388 bp, and 200 bp products from the DNA templates of T. palmi, S. dorsalis, T. tabaci, and F. schultzei, respectively at same PCR conditions. The specificity of the primer pairs was validated with a large number of known specimens and no cross-reactivity was observed with other thrips species. The multiplex PCR assay with a cocktail of all the four primer pairs detected four thrips vectors efficiently and could discriminate all of them concurrently in a single reaction. Conclusion: The multiplex PCR reported in this study could identify the major thrips vectors reported in India. The assay will be useful in ascertaining distribution profile of major thrips vectors, disease epidemiology, screening large samples, and quarantine. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The study was conducted to evaluate the effect of bio-pesticides and chemical insecticides namely Novastar 56EC, Stargate 48SC, Confidor 70WG, Actara 25aWG, Tracer 45SC, Ecomec 1.8EC, Bioneem plus 1EC to control thrips infesting mung bean in the experimental field of Sher-e-Bangla Agricultural University during November 2017 to February 2018. An untreated control observation was also evaluated. Efficacy of the treatments differed significantly and showed effective results in reduction of thrips population and infestation on mung bean at vegetative and reproductive growth stages of the plant. Stargate 48SC (clothianidin) was the most effective insecticide against the thrips species Megalurothrips usitatus and Thrips palmi with the highest reduction of population on top trifoliate leaves and terminal shoots (100.00 and 89.40%, respectively) at vegetative stage and reduction on flower buds and flowers (86.04 and 85.95%, respectively) at reproductive stage of mung bean. The lowest flower bud and flower infestation (7.22 and 3.41%, respectively) and shedding (4.21 and 1.06%, respectively) by thrips with the highest number of pod (23.80 plant-1), seed (10.20 pod-1), 1000 seed weight (48.40 g) and yield (1026.91 kg ha-1) were also found in Stargate 48SC treated plots followed by Confidor 70WG and Actara 25WG treatments. [ABSTRACT FROM AUTHOR]

Melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae), is a serious pest of vegetable, ornamental, and fruit crops. As a potential component of an integrated pest management (IPM) program, different plastic mulches including white-on-black, black-on-white, black-on-black, two metalized ultraviolet (UV)-reflective mulches, and a no mulch control were evaluated for managing T. palmi on six field-grown vegetable crops (eggplant, cucumber, squash, snap bean, Jalapeno pepper, and tomato) during the Fall of 2015 and 2016. Metalized reflective mulch significantly reduced the number of T. palmi in all vegetable crops compared with the other treatments. The highest numbers of T. palmi were observed on the white-on-black mulch and control treatments. The numbers of adults and larvae were highest on eggplant followed by cucumber, snap bean, squash, and Jalapeno pepper. The lowest numbers of T. palmi were observed on tomato plants. This study indicated that growing vegetable crops on metalized mulch is an effective method of reducing T. palmi populations in vegetable crops and should be considered in IPM programs for this insect species. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study tested phenotypic changes in heat and cold tolerance of Thrips palmi. • Rapid heat hardening at 35 °C slightly increased CTmax but decreased it at 31 °C. • Heat acclimation for 2 and 4 days significantly increased CTmax at 35 °C. • Cold hardening and acclimation increased cold tolerance. • Space for heat stress induction is narrower than for cold stress induction. Extreme temperatures threaten species under climate change and can limit range expansions. Many species cope with changing environments through plastic changes. This study tested phenotypic changes in heat and cold tolerance under hardening and acclimation in the melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae), an agricultural pest of many vegetables. We first measured the critical thermal maximum (CT max) of the species by the knockdown time under static temperatures and found support for an injury accumulation model of heat stress. The inferred knockdown time at 39 °C was 82.22 min. Rapid heat hardening for 1 h at 35 °C slightly increased CT max by 1.04 min but decreased it following exposure to 31 °C by 3.46 min and 39 °C by 6.78 min. Heat acclimation for 2 and 4 days significantly increased CT max at 35 °C by 1.83, and 6.83 min, respectively. Rapid cold hardening at 0 °C and 4 °C for 2 h, and cold acclimation at 10 °C for 3 days also significantly increased cold tolerance by 6.09, 5.82, and 2.00 min, respectively, while cold hardening at 8 °C for 2 h and acclimation at 4 °C and 10 °C for 5 days did not change cold stress tolerance. Mortality at 4 °C for 3 and 5 days reached 24.07 % and 43.22 % respectively. Our study showed plasticity for heat and cold stress tolerance in T. palmi , but the thermal and temporal space for heat stress induction is narrower than for cold stress induction. [ABSTRACT FROM AUTHOR]

Phototactic behaviours and the toxic effects of certain light wavelengths have been used to control insect pests. However, in many species, little is known about this innate behaviour and the effects on physiological and biological traits related to the emission and/or reflection spectra of light. The present study investigated the phototactic behaviour and the effects on physiological and biological traits of a small insect, the melon thrips, Thrips palmi (Thysanoptera Thripidae). Using seven different lightemitting diode panels (355, 405, 470, 525, 590, 660 and 735 nm) under dark conditions, it was found that this species was attracted to a wide range of light from short to long wavelengths in all tested lights. Comparing the light intensities required to gather 50% of individuals to the panels revealed that the short wavelength region (λmax 470 nm) was more effective than longer wavelengths. None of the seven wavelengths examined affected biological traits such as adult emergence and oviposition in the melon thrips. Comparison with previous studies indicates that these results are species specific and provide data that will be helpful in developing future pestcontrol measures using lights. [ABSTRACT FROM AUTHOR]

Aggregation pheromones have been identified and tested in the field for Frankliniella occidentalis and Thrips palmi. These pheromones are produced by adult males and attract both males and females. They are likely to be widespread across the Thripidae and identification is in progress for several other pest species. Aggregation pheromones are used commercially for monitoring and activation. Field trials have shown they can be cost effective for mass trapping when used as part of an integrated pest management (IPM) programme. Use for other approaches, such as lure and kill and mating disruption have not yet been tested. A better understanding of the role of these pheromones in the mating behaviour of thrips is needed and this may suggest further ways of developing their potential for pest management. [ABSTRACT FROM PUBLISHER]

Bean dip bioassay was performed with six insecticides on the mortality response in tomato thrips- Thrips palmi Karny and Scirtothrips dorsalis Hood. The LC50 values ranged from 1.591 to 17.018 ppm, and spinosad with the least LC50 value of 1.591 ppm at 95% confidence limit was the most toxic. It was followed by cyantraniliprole (2.425 ppm), diafenthiuron (2.396 ppm), imidacloprid (5.110 ppm), fipronil (13.560 ppm) and dimethoate (17.018 ppm). Thus, spinosad, diafenthiuron and cyantraniliprole were observed to be more toxic. [ABSTRACT FROM AUTHOR]

Generally, the densities of phytophagous insects decrease in the field after an intense rain. For evaluating this assumption and demonstrating the coexistence of pests in the bean crop, the insect pests present in the common bean variety BAT 306 were sampled from December 2015 to March 2016. The samples were always taken the day after a rainy day. A five fixed quadrant design was used. Population density was monitored from the day 32 after planting by counting the leafhoppers, thrips, and whiteflies on five random plants in each quadrant. Taylor’s power law was used to determine the spatial pattern distribution of the insects with the highest incidence; population dispersion per sampling was graphed. Inter-specific competition was evaluated using mathematical models, and an analysis of principal components was made to determine the relationships between the populations and some climatic factors. The average density of whiteflies was less than 0.28 individuals by sample. The leafhopper was identified as Empoasca kraemeri and the thrips as Thrips palmi. These two species populations were shown to coexist with an aggregate pattern distribution and an intrinsic rate (rm) of 0.11 and 0.09, respectively, once the crop reached the reproductive stage. Despite the inverse relationship between the accumulated precipitations and the population levels, rainfall values over 60 millimeters did not achieve density zero. Wind speed, deficit of saturation, and sunshine were directly related to the densities of these vector insects. [ABSTRACT FROM AUTHOR]

Cold tolerance of the palm thrips, Thrips palmi Karny, was investigated to predict its survival in field during winter. Supercooling points of T. palmi were varied among the developmental stages and ranged from -26.4 to -18.4°C. However, the cold injuries occurred above supercooling points in terms of higher mortality. The exposure to subzero temperatures (-5° to -15°C) resulted in significant mortalities to all developmental stages of T. palmi. A preexposure to a low temperature (4°C) for 7 h significantly increased the cold tolerance of all stages of T. palmi with respect to survival at - 10°C and supercooling capacity. The rapid cold hardening (RCH) was dependent on the duration of the preexposure period at 4°C in adult stage. Polyol and sugar analysis using an high-performance liquid chromatography analysis showed that 4°C preexposure caused accumulation of glycerol, trehalose, mannitol, and mannose in the adults. The increase in trehalose levels was more significant than the others. This study suggests that all stages of T. palmi are able to become cold-hardy by RCH, in which several polyols and sugars may play crucial roles as cryoprotectants. [ABSTRACT FROM AUTHOR]

Thrips palmi Karny (Thysanoptera: Thripidae), invaded Miami Dade-county in 1990 and caused significant economic damage by defoliating various vegetable crops. It commonly occurs on the abaxial surface of host leaves where eggs are deposited individually inside the leaf tissues. Highest abundance of T. palmi was recorded on bean and eggplant in 1991-1994 in Tropical Research and Education Center research plots and commercial fields in Miami- Dade County. Density of T. palmi decreased significantly in subsequent years after the use of spinosad and other effective chemical insecticides. Thrips palmi populations increased in 2008 in spite of use of spinosad and showed increasing pattern causing crops loss at economic level. Orius insidiosus Say population was low in both TREC research fields and commercial fields due to harsh chemical management program, where insecticides belonging to various chemical classes were used alone (TREC fields) or in combination (commercial fields) to control T. palmi and other insect pests. None of the commonly used available insecticides alone or in combination provided satisfactory control of T. palmi in the early stage of invasion. Amongst various insecticides tested spinosad provided significant control of T. palmi on the crops until 2008 after which there was reduced effect of the chemical due to frequent use for managing multiple pests. [ABSTRACT FROM AUTHOR]