Adult Thrips Research Articles

Phenology of greenhouse thrips (Heliothrips haemorrhoidalis) on kiwifruit vines, shelter trees and alternative host plants

The greenhouse thrips, Heliothrips haemorrhoidalis is a quarantine pest of kiwifruit. There is a need for reliable information on its phenology in kiwifruit orchards to inform the development of new management options. Numbers of larval, pupal and adult greenhouse thrips were counted on leaves of the two main kiwifruit cultivars Actinidia chinensis var. deliciosa (‘Hayward’) at two sites at different times and A. chinensis var. chinensis ‘Zesy002’ at one site. Greenhouse thrips were also counted on leaves of shelter tree species Cryptomeria japonica, and other plants present on kiwifruit orchards, blackberry (Rubus fruticosus s.l.), barberry (Berberis glaucocarpa), and wineberry (Aristotelia serrata) across a number of sites at different times. There was a strong seasonal pattern to the phenology of greenhouse thrips and it was relatively synchronous for all the host plants surveyed. In general, number of greenhouse thrips on foliage increased from January to peak in April or May before declining in late autumn or winter and remaining low until the following January or February. The phenology of greenhouse thrips followed the same seasonal pattern for a variety of host plants found on kiwifruit orchards at sites in the Bay of Plenty across two two-year time periods. Therefore, host species does not appear to be a factor affecting the phenology of thrips. Other, non-host factors such as microclimate may be important drivers of phenology but they require further study. The consistency of the seasonal pattern of relative abundance means that there is a well-defined window to target for thrips management.

Insidious flower bug, Orius insidiosus (Say) (Hemiptera: Anthocoridae), predation on western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), on Transvaal daisy, Gerbera jamesonii, cut flowers and chrysanthemum, Tanacetum × grandiflorum, plants under laboratory and greenhouse conditions

The insidious flower bug, Orius insidiosus (Say) (Hemiptera: Anthocoridae), is a generalist predator that feeds on western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), larvae and adults. Our study involved a series of experiments conducted under laboratory and greenhouse conditions from 2017 to 2020 to: 1) determine the number of insidious flower bug adults that should be released to manage western flower thrips populations below damaging levels, 2) assess if integrating the insidious flower bug with the insecticide spinosad (Conserve®) is a viable alternative plant protection strategy, and 3) determine if short (<12 h) or long (>12 h) day lengths/photoperiods affect insidious flower bug predation on western flower thrips under greenhouse conditions. We found that releasing three or four insidious flower bug adults was most effective in managing western flower thrips populations on chrysanthemum, Tanacetum × grandiflorum, plants with the mean number of western flower thrips adults and larvae per chrysanthemum plant < 10. We determined that spinosad can be used with the insidious flower bug to manage western flower thrips populations. Finally, we ascertained that insidious flower bug predation was not affected by short [10.5:13.5 (light:dark hours)] or long [14.5:9.5 (light:dark hours)] day lengths/photoperiods. Consequently, greenhouse producers can release the insidious flower bug anytime during the growing season, even from fall through winter, to manage populations of western flower thrips on chrysanthemum. In addition, greenhouse producers can integrate spray applications of spinosad with the insidious flower bug as long as the applications do not negatively affect insidious flower bugs.

Dynamic Distribution of Adult Thrips hawaiiensis Morgan During Banana Flowering Stage and Its Precise Chemical Control in Banana Plantation

Dynamic Distribution of Adult Thrips hawaiiensis Morgan During Banana Flowering Stage and Its Precise Chemical Control in Banana Plantation

Lethal and Sublethal Effects of Proteus, Matrine, and Pyridalyl on Frankliniella occidentalis (Thysanoptera: Thripidae).

The western flower thrips (WFT), Frankliniella occidentalis (Pergande) is one of the most harmful pests of crops in greenhouses and fields. Considering the need for studies that introduce new insecticides for control of the WFT, the leaf dip method was carried out to study the acute toxicity of Proteus, matrine, and pyridalyl to adult thrips, and life tables were constructed to assess the impacts of sublethal concentrations (LC25) of these insecticides on the development and reproduction of the F1 generation. Bioassays showed that the toxicity of matrine (LC50: 45.9 µl ml-1) and Proteus (LC50: 54.5 µl ml-1) was higher than pyridalyl (LC50: 176.5 µl ml-1). At LC25 concentration, both Proteus and matrine prolonged the development period and reduced the survival rate of eggs, larval stages, and pupae in the F1 generation. Also, the adults' longevity, oviposition duration, and the cumulative number of eggs laid per female (fecundity) were decreased significantly. Sublethal concentrations of Proteus and matrine inhibited the population growth rate relative to the control based on the predicted number of offspring. The lowest net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) were estimated for Proteus (7.02 offspring/individual, 0. 0838 d-1, and 1. 08 d-1, respectively). In contrast, the WFT F1 generation that resulted from parent adults treated with pyridalyl was neither affected in their developmental time, nor fecundity, or the intrinsic rate of increase. According to our findings, all tested insecticides, especially Proteus, showed good potential for use in integrated pest management strategies against F. occidentalis.

Spontaneous vegetation in the horticultural belt of La Plata as host of Thripidae (Thysanoptera) vectors of Tospovirus: Relative risk as an epidemiological component

Black Death is a virosis caused by the Tomato Spotted Wilt Virus (TSWV), transmitted by thrips, and represents a complex problem since weed hosts for thrips vectors and the virus is accentuated as virus reservoir and vector sustenance. The objective was to generate, from a list of weeds that act as hosts for the four vector thrips species in the horticultural belt of La Plata, a relative risk categorization as an epidemiological component. Between 2000 and 2003, three sites were selected within the horticultural belt of La Plata (Buenos Aires, Argentina) where flowers of 21 weed hosts of Frankliniella occidentalis, Frankliniella schultzei, Frankliniella gemina and Thrips tabaci were sampled monthly (60 in total). For analysis, the sampling results were grouped into three annual seasons, corresponding to the phenology of greenhouse crops in the region. For the four thrips vectors, the abundance of adult thrips and the presence of their larvae were considered using an unsupervised hierarchical cluster analysis and the DGC multivariate mean comparison test to obtain the number of significant groups. From this base grouping, three risk groups (RG) were defined as a source of inoculum for these vectors: high (H), medium (M) and low (L) according to the status of the reproductive host (RH). The groups that emerged were: (H): RH of F occidentalis, (M): RH of F. schultzei and T. tabaci, and (L): RH of F. gemina or non-vector thrips. Periodic survey and early flowering suppression of nine weed species categorized as high risk is proposed. This implies the continuous monitoring of three weed species, to which other companion weeds are added according to the growing season.

Role of digestive enzymes in the adaptation of Frankliniella occidentalis to preferred and less‐preferred host plants

AbstractThe western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is an important invasive pest that causes serious damage to vegetables in China. Changes in digestive enzyme activities (α‐amylase, trypsin, and tryptase) and gene expression levels of F. occidentalis were examined after they were transferred to kidney bean, a preferred host, or broad bean, a less‐preferred host. The results showed that α‐amylase and trypsin activities initially decreased in both nymphs and adults after transfer to kidney bean or broad bean plants and they were the lowest in the F1 generation. The α‐amylase and trypsin activities were significantly different among the tested generations. The tryptase activities in the second instars fed on kidney bean plants were not significantly different from those of the controls in nymphs at all three generations, whereas they increased when fed on broad bean plants. Most digestive enzyme genes in both the nymph and adult thrips showed similar changes, decreasing with transfer to kidney bean plants and increasing on broad bean plants. However, the expression levels of the trypsin gene FoTRYP‐1 and the tryptase gene FoTPSB2 in the second instars fed on broad bean and kidney bean plants, respectively, were not significantly different from those of the controls. The expression levels of the four digestive enzyme genes were significantly higher in broad bean than in kidney bean plants. These results indicate that F. occidentalis can adjust its digestive enzyme activities and gene expression levels after being transferred to host plants for which its preference differs and that the changes depend on the specific enzyme, thrips generation, and developmental stage. Findings from this study would provide a basis for further studies to reveal the physiological and ecological bases of the wide host range and strong host adaptability of F. occidentalis.

Abundance and Species of Thrips1 in Cotton on the South Plains of Texas

Thrips (Thysanoptera: Thripidae) are the major insect pest of seedling cotton, Gossypium hirsutum L., on the Texas South Plains. The western flower thrips, Frankliniella occidentalis Pergande (Thysanoptera: Thripidae), has historically been the most abundant thrips species in cotton in the region. A field survey during the 2017 and 2018 growing seasons collected thrips from small-plot insecticide seed treatment research experiments at multiple locations across the Texas South Plains. Species composition of adult thrips from cotyledon to four true-leaf stages cotton was determined by morphological identification with the aid of a microscope. Of the species collected during 2 years of study, 64% were onion thrips, Thrips tabaci Lindeman, followed by F. occidentalis (23%), Frankliniella exigua Hood (10%), and tobacco thrips, Frankliniella fusca Hinds (1%). Relative abundance of species varied significantly across growing seasons. In 2017, T. tabaci was the most abundant species in cotyledon to four true-leaf stages of cotton. In 2018, F. occidentalis was more prevalent than other thrips species. The percentage of adults was significantly greater than that of immatures at the cotyledon stage while immature thrips were significantly more abundant during one to four true-leaf stages of cotton. The study indicated T. tabaci and F. occidentalis were the most prevalent thrips species on seedling cotton on the South Plains of Texas.

Evaluation of The Predatory Efficiency of Orius Albidipennis Reuter for Two Prey Species Myzus Persicae (Sulzer) and Thrips Tabaci Lind. on The Carrot Plant in Laboratory

The study aimed to investigate the effect of different densities of M.persicae and T. tabaci on the predatory ability of the predator O. albidipennis and determine the preference for one of the two prey, in addition to assessing the in vitro predator's efficiency in reducing the number of aphids on the carrot plant. The results indicated that the rates of predated adult and nymph thrips were significantly higher than that of predated aphids. The highest rate of predation for nymphs and adults thrips was 33.2 and 25 preys per day, respectively, at a density of 60prey/container, while the highest rate of predation of adults and nymphs of aphids was 19 and 13.2prey/day, respectively, at a density of 60prey/container. The food preference experiment showed that the adults of the predator O. albidipennis feed on the immature stages thrips and aphids when introduced together and have no clear preference for one of the prey. The results of evaluating the efficiency of predator adults on reducing different densities of aphids showed that the predator was effectively able to reduce the population increase of aphids when the insect densities were 10, 20 or 30 insect. however, the predator was not effective when introduced to aphids at starting density of 40, no significant difference was found due to predator presence or absence as the aphids population density were 118.4 and 135.2 insects/cage after four days, respectively.

Relationship between Colonization by Onion Thrips (Thrips tabaci Lind.) and Leaf Colour Measures across Eight Onion Cultivars (Allium cepa L.)

Thrips tabaci Lindeman is a global pest and also represents a serious threat to onion production in Poland. In 2 years (2015–2016) of field studies, 8 onion cultivars were evaluated to characterize their susceptibility to onion thrips and to determine if leaf colour is associated with thrips preference. The actual count and the proportional abundance of adult thrips collected from onion leaves during plant colonization by insects were both used to express the preference of thrips for different onion cultivars. At the same time, the colour measurements were analysed by considering the CIELAB (CIE 1976 L*a*b*) and CIE L*C*h* colour spaces. There were distinct differences in the susceptibility of onion cultivars to colonization by onion thrips. Leaf colour coordinate values were correlated with attractiveness to thrips; typically, higher lightness (L*), yellowness (b*), chroma (C*), hue (h*), and lower redness (a*) attracted more thrips. We concluded that the vivid, intense green-yellowish leaf colour of susceptible varieties might have been the cause of the thrips preference observed. We also identified useful genotypes, Tęcza and Wenta, for host plant resistance to thrips and suggest a link between colour and antixenotic resistance. The resistant cultivars had darker, green-grey-yellowish leaves.

Development, Survival, and Reproduction of Orius insidiosus (Hemiptera: Anthocoridae) Reared on Frankliniella invasor (Thysanoptera: Thripidae).

The minute pirate bug Orius insidiosus (Say) is an important predator in mango agroecosystems. It attacks several species of thrips, particularly Frankliniella invasor Sakimura, which is considered a species of economic importance in mango. We investigated the effect of six diets on the development, survival, and reproduction of O. insidiosus: 1) first instars of F. invasor, 2) second instars, 3) adults, 4) pollen, 5) pollen plus thrips larvae, and 6) water. Individuals fed on thrips larvae, with or without pollen, completed their immature development significantly faster. Nymphs of O. insidiosus were able to complete their development feeding on pollen only, while individuals that received water as a diet were unable to reach the adult stage. The highest intrinsic growth rate was obtained when O. insidiosus were fed on pollen plus thrips larvae, and the lowest when individuals were fed on thrips adults. Our studies show that a diet of pollen plus F. invasor larvae is optimal for O. insidiosus development and population growth.

Thrips (Insecta: Thysanoptera) Species Infesting Garlic (Batanes Red) in Selected Farms in Batanes, Philippines

The study aimed to determine the species of thrips infesting garlic (Batanes Red) in the Department of Agriculture–Batanes Experiment Station (DA-BES) in Ihubok 1, Basco; DA-BES Dibtung, Radiwan, Ivana; and in the Calderon Farm in Radiwan, Ivana, Batanes. Sampling was done in February 2020. A total of 950 adult female thrips were collected from all study sites. The majority of the thrips were collected from DA-BES Farm in Ihubok 1, Basco with 89.89%, followed by the Calderon Farm in Ridawan, Ivana with 5.16%, and DA-BES Farm in Dibtung, Ridawan, Ivana with 4.95%. Thrips were represented by two terebrantian species, namely: Thrips tabaci Lindeman (Thripidae) with 97.37%, Anaphothrips sudanensis Trybom (Thripidae) with 2.32%, and a tubuliferan species Haplothrips gowdeyi (Franklin) (Phlaeothripidae) with 0.31%. T. tabaci was the dominant species in all study sites. A. sudanensis was found in all the study sites but in low number, while H. gowdeyi was present in two DA-BES study sites but absent in the Calderon Farm. This is the first report of A. sudanensis and H. gowdeyi infesting garlic in the Philippines.

Exploring species composition and population dynamics of thrips (Thysanoptera: Thripidae) in peanut crops in Argentina

Thrips (Thysanoptera: Thripidae) are major pests of peanut (Arachis hypogaea L.). They cause feeding damage and indirect injuries transmitting plant viruses. In Argentina, peanut is commonly affected by thrips. The crop also is infected by groundnut ringspot orthotospovirus, a virus transmitted by thrips vectors. However, in the country, information about thrips in peanut is very scarce. A 3-yr study was conducted to characterize the species composition and thrips population dynamics in the main peanut-producing area in Argentina. Frankliniella schultzei (Trybom), followed by Caliothrips phaseoli (Hood) were the most abundant species. Together the two species accounted for ~ 95-99 % of the total adult thrips captured in each season. Significant different abundances were observed among these two thrips species throughout each peanut growing season. Nevertheless, the temporal dynamics of F. schultzei and C. phaseoli showed a similar trend in the three study years. In general, the colonization by F. schultzei started in late December and their population increased from the second half of January peaking around the first half of February. The highest densities of F. schultzei occurred simultaneously in foliage and flowers during the warmer months of the year. The C. phaseoli population inhabited on foliage and peaked in late February or mid-March. Other species collected were Frankliniella occidentalis (Pergande), Frankliniella gemina Bagnall, and Thrips tabaci (Lindeman). This study mentions F. gemina in peanut for the first time. Results show that F. schultzei and C. phaseoli are common thrips pests in peanut in Argentina and provide new information about the population dynamics of these thrips species in peanut crops.

Transmission mode of watermelon silver mottle virus by Thrips palmi.

Thrips and thrips-transmitted tospoviruses cause significant losses in crop yields worldwide. The melon thrips (Thrips palmi) is not only a pest of cucurbit crops, but also a vector that transmits tospoviruses, such as the watermelon silver mottle virus (WSMoV). Vector transmission of tospoviruses has been well studied in the tomato spotted wilt virus (TSWV)-Frankliniella occidentalis model system; however, until now the transmission mode of WSMoV by T. palmi has not been sufficiently examined. The results of the transmission assays suggest that T. palmi transmits WSMoV in a persistent manner, and that the virus is mainly transmitted by adults, having been ingested at the first-instar larval stage. Complementary RNAs corresponding to the NSm and NSs genes of WSMoV were detected in viruliferous thrips by reverse transcription-polymerase chain reaction; NSs protein was also detected in viruliferous thrips by western blotting, verifying the replication of WSMoV in T. palmi. Furthermore, we demonstrated that in thrips infected with WSMoV at the first-instar larval stage, the virus eventually infected various tissues of the adult thrips, including the primary salivary glands. Taken together, these results suggest that T. palmi transmits WSMoV in a persistent-propagative mode. The results of this study make a significant contribution to the understanding of the transmission biology of tospoviruses in general.

Species Composition of Thrips (Thysanoptera: Thripidae) in Strawberry High Tunnels in Denmark.

Simple SummaryOne of the main insect pests in protected strawberry production are thrips, but little is known about which species of thrips are present in the production system. In this study, we identified the thrips species of adults and larvae present in two strawberry cultivars at a commercial strawberry farm in Denmark. The most abundant species found were Frankliniella intonsa, followed by Thrips tabaci. The abundance of thrips peaked in July (temperature range 18–23 °C, mean humidity 65%, mean precipitation 5 mm). More thrips were found in the earlier flowering cultivar. In order to optimize control of thrips, a fundamental first step is knowing which species are present on the target crop.Thrips are a major pest in protected strawberry production. Knowledge of thrips species composition could be instrumental for improved thrips management, but very little is known about which species are present in strawberries grown in high-tunnels in Denmark. Thrips (adults and larvae) were sampled in two strawberry tunnels of the cultivars Murano and Furore from May to August 2018, in the middle and in the edges of the tunnels. The most abundant thrips species found in the tunnels were Frankliniella intonsa and Thrips tabaci adults. Frankliniella intonsa were also the most frequently found species of the immatures sampled, followed by T. tabaci larvae, and other species. The number of thrips differed between the two cultivars, sampling times and location in the tunnel. Frankliniella intonsa was more abundant in the middle of the tunnels, while T. tabaci was more abundant in the edge of the tunnels adjacent to the field margins. The number of thrips peaked by the end of July. Both chemical and biological control should consider species composition and occurrence; hence, a fundamental first step for thrips management is to identify the species present on the target crop.

Management of Onion Thrips (Thrips tabaci) in Organic Onion Production Using Multiple IPM Tactics.

Simple SummaryOnion thrips (Thrips tabaci) is a major pest in organic onion production and effective integrated pest management strategies are lacking. Our objective was to evaluate pest management programs consisting of several different tactics: (1) two onion plant cultivars with semi-glossy leaves (“Rossa di Milano” and B5336AxB5351C) and one with waxy leaves (“Bradley”), (2) silver reflective and white plastic mulches, and (3) with or without an application of a biopesticide (spinosad + neem oil tank mix). Thrips densities were counted weekly and bulbs weighed at harvest. The application of the biopesticide had the most significant reduction in thrips densities and increase in yield. The cultivar “Rossa di Milano” had lower thrips densities compared with “Bradley” and B5336AxB5351C, but also had the lowest yield. Reflective mulch had lower thrips densities than white mulch but had no effect on yield. None of the other tactics provided any significant additional benefits to thrips management. While biopesticides will still be a key component to onion thrips management programs, their application frequency should be further optimized.Onion thrips (Thrips tabaci Lindeman) is a major pest in organic onion production and effective integrated pest management strategies are lacking. Our objective was to evaluate combinations of semi-glossy (“Rossa di Milano” and B5336AxB5351C) and waxy (“Bradley”) onion cultivars with reflective mulch, with or without biopesticides (spinosad + neem oil tank mix), to manage T. tabaci in organic onion production. Thrips densities were assessed weekly and bulbs graded and weighed at harvest. Onions sprayed with spinosad + neem oil had fewer T. tabaci (adults: 74% (2019); larvae: 40% (2018), 84% (2019) and produced higher yields (13% (2018), 23% (2019)) than onions that were unsprayed, regardless of mulch type or onion cultivar. “Rossa di Milano” had relatively fewer adult and larval thrips populations compared with “Bradley” (21% (2018), 32% (2019)) and B5336AxB5351C. However, “Rossa di Milano” had the lowest marketable yield in both years. Reflective mulch reduced densities on certain dates in both years compared to white mulch, but the largest and most consistent reduction only occurred in 2019. Reflective mulch had no impact on bulb yield. While spinosad + neem oil reduced thrips numbers and increased yield alone, none of the treatment combinations were effective at suppressing populations of thrips. Future T. tabaci management in organic onions will require optimization of the available effective biopesticides.

Frankliniella occidentalis facilitate Salmonella enterica survival in the phyllosphere.

The human enteric bacterial pathogen Salmonella enterica causes approximately 1.35 million cases of food borne illnesses annually in the United States. Of these salmonellosis cases, almost half are derived from the consumption of fresh, raw produce. Although epiphytic S. enterica populations naturally decline in the phyllosphere, a subset of phytophagous insects have recently been identified as biological multipliers, consequently facilitating the growth of bacterial populations. We investigated whether tomato leaves with macroscopic feeding damage, caused by infestation of adult Western flower thrips (Frankliniella occidentalis), support higher S. enterica populations. To explore this hypothesis, we assessed S. enterica populations in response to thrips feeding by varying insect density, plant age, and the gender of the insect. As a reference control, direct leaf damage analogous to thrips feeding was also evaluated using directed, hydraulic pressure. In a supplementary set series of experiments, groups of F. occidentalis infested tomato plants were later inoculated with S. enterica to determine how prior insect infestation might influence bacterial survival and persistence. Following an infestation period, leaves visibly damaged by adult F. occidentalis supported significantly higher S. enterica populations and resulted in greater amounts of electrolyte leakage (measured as electrical conductivity) than leaves lacking visible feeding damage. Plant age did not significantly influence S. enterica populations or estimates of electrolyte leakage, independent of initial infestation. Additionally, the gender of the insect did not uniquely influence S. enterica population dynamics. Finally, applications of aggressive water bombardment resulted in more electrolyte leakage than leaves damaged by F. occidentalis, yet supported comparable S. enterica populations. Together, this study indicates that F. occidentalis feeding is one of the many potential biological mechanisms creating a more habitable environment for S. enterica.

The role of plant physiology and cultivar of chrysanthemum in the resistance against Western flower thrips

AbstractWestern flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is an economically important pest insect in vegetable and ornamental cultivation worldwide. Little is known about host plant resistance in the vegetative and generative phases of chrysanthemum [Chrysanthemum × morifolium (Ramat.) Hemsl. (Asteraceae)] and the role of resistance factors such as flavonols, flower color, and flower shape. We screened a broad range of chrysanthemum cultivars across two seasons to quantify resistance against Western flower thrips. Resistance was based on silver damage on the leaves, and relative flavonol content was measured using a Dualex Scientific 4 hand‐held sensor. There was significant variation in silver damage between cultivars, indicating different levels of resistance. There was no correlation between the relative flavonol content in middle leaves and plant silver damage. A clearer resistance level discrimination by flavonols in resistant and susceptible cultivars would be possible in the future by comparing multiple leaf positions during the ontogenetic phases of plant development. Moreover, the influence of flower color and shape on resistance to thrips was investigated by counting the adult thrips and larvae on flowers. The results showed significant differences in flower color preference by adults, but not by larvae. Flower shape influenced thrips larvae and females, but not males. The importance of the results for resistance determination is discussed.

Scirtothrips dorsalis (Thysanoptera: Thripidae) Is a Pest of Celery, Apium graveolens (Apiales: Apiaceae): First Report and Diagnostic Characters

Abstract Scirtothrips dorsalis (Hood), the chilli thrips, is reported for the first time as a pest of celery, Apium graveolens L. Infested celery plants in a polyhouse at Kalahalli village (13°05′46.0′′N, 77°47′12.2′′E) in Hoskote taluk of Bengaluru Rural district, Karnataka, India, had light to dark brownish scars on various parts besides discolored and distorted leaves. Association of fungal or bacterial disease was dismissed based on microscopic analysis of tissue sections. Eggs, juveniles, and adults of thrips were abundant, especially on the leaves. Diagnostic characters of the adult S. dorsalis collected on celery are presented here along with photomicrographs. Juvenile and adult stages of S. dorsalis were also recorded on 27 other plant species in 18 families during the surveys conducted in 18 districts of Karnataka from 2015 to 2021. The possible role of S. dorsalis as a vector of tospoviruses in celery needs to be investigated.

Behaviour of Orius insidiosus Say (Hemiptera: Anthocoridae) towards its prey, Thrips palmi Karny (Thysanoptera: Thripidae)

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.

Olive Production Threatened by a Resurgent Pest Liothrips oleae (Costa, 1857) (Thysanoptera: Phlaeothripidae) in Southern Italy.

Simple SummaryLiothrips oleae (Costa, 1857) (Thysanoptera: Phlaeothripidae) is widespread in the Mediterranean area, and in all regions, it is reputed to be a secondary pest in olive crops, mainly associated with damage to leaves and secondarily with damage to drupes, for which this thrips pest has a marginal impact on olive production. Taking into account the increase in the frequency of extreme damage by this species in Southern Italy in the last decade, this research aimed to elucidate the real impact (i.e., damage to leaves and drupes) by feeding thrips’ activity in olive orchards. Our results revealed that the impact of thrips was significant in all monitored olive orchards and the estimated damage level on drupes and leaves was higher in organic olive than in integrated olive management. A detailed morphological description of the Italian specimens and their molecular characterization are also provided.This study investigated a resurgence of Liothrips oleae Costa (Thysanoptera: Phlaeothripidae), an insect pest of olive crops, in a focal Southern Italian olive-producing area (Calabria Region). The young and adult olive thrips feed on the leaves and fruits of wild and cultivated olive trees, producing distortions, necrosis, and premature dropping of fruit. In our study, organic and integrated olive groves were compared for two years in order to establish the relationship between leaf and fruit damage among olive groves managed under different phytosanitary conditions. Sampling techniques were used in order to collect and count leaves and fruits (on plants and dropped premature drupes) presenting symptoms of thrips’ feeding activity. The impact of the thrips was significant in all orchards, and the estimated damage level on drupes and leaves was higher in organic olive management in each year. A morphological description of the adult females of the species is provided, and the first molecular characterization of the Calabrian olive thrips population was performed by using three different genetic regions (cytochrome c oxidase subunit I (COI), 28S ribosomal subunit (28S), and internal transcribed spacer 2 (ITS2)).