scholarly journals Alternative Means of Thrips Control in Greenhouse Crops

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 866E-866
Author(s):  
Julie A. McIntyre ◽  
Douglas A. Hopper ◽  
Whitney Cranshaw

Various cultural, biological, and low toxicity methods of pest control that can be used as part of an Integrated Pest Management program for greenhouse growers were tested. Experiments were conducted to analyze alternative methods to control western flower thrips (Frankliniella occidentalis) on greenhouse crops, including an insect growth regulator (IGR), aluminized mulches, medial surface treatments involving irrigation, and predaceous nematodes. Persistence of thrips was determined by immersing excised flowers in 70% ethanol solution and pouring the extract through filter paper; thrips on the filter paper were counted. Various experiments were conducted over a 4-month period to determine which means provided the best control. The repeated use of an IGR was effective in reducing thrips populations. Preliminary evaluations indicate nematodes may provide better control than soil treatments.

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 435D-435
Author(s):  
Douglas A. Hopper ◽  
Julie A. McIntyre

Research focused on alternative methods to control Western flower thrips (Frankliniella occidentalis Pergande), encompassing chemicals from varying classes, parasitic nematodes, microbial insecticides, and physical/mechanical deterrents. Chemical spray applications were applied weekly for 4 to 6 weeks. Experiment 1 made comparisons between fenoxycarb (Precision), bifenthrin (Talstar), and entomopathogenic nematodes (Biosafe). Experiment 2 compared abamectin (Avid), spinosyn A and D (Spinosad), azadirachtin (neem extract: Margosan-O), and diatomaceous earth (a physical control aimed at deterring pupation). Experiment 3 compared Spinosad, fipronil, and two microbial insecticides (Naturalis-O and Mycotrol). The number of thrips counted in flowers after treatments had been applied indicated that the strict chemical treatments (Avid, Spinosad, fipronil) provided quick knockdown and overall longer-term population control. Microbial insecticides, diatomaceous earth, and nematodes maintained populations at a lower level than the control, but were not as effective as strict chemical controls. Margosan-O, Precision, and Talstar controlled populations at medium levels. For periods when populations may cycle upward, more potent chemicals could be used (Spinosad, fipronil, and Avid) while still avoiding problems associated with more toxic chemicals.


2020 ◽  
Vol 49 (1) ◽  
pp. 73-87 ◽  
Author(s):  
Rafia A Khan ◽  
Dakshina R Seal ◽  
Shouan Zhang ◽  
Oscar E Liburd ◽  
Rajagopalbabu Srinivasan ◽  
...  

Abstract Tomato chlorotic spot virus (TCSV) is an orthotospovirus that causes a devastating disease in tomato (Lycopersicon esculentum Miller). TCSV emerged recently in South Florida. Studies were conducted in three commercial tomato fields in Miami-Dade County, Florida during the vegetable-growing seasons from October to April in 2015 through 2017. Each year, data were collected at 3, 6, and 9 wk after transplanting at various distances from the edges of each fields. Based on 3 yr total samples, three species of thrips were commonly observed melon thrips, Thrips palmi Karny (62.16 ± 0.79%), being the most abundant species followed by common blossom thrips, Frankliniella schultzei Trybom (21.55 ± 0.66%), and western flower thrips, Frankliniella occidentalis (Pergande) (16.26 ± 0.61%). Abundance of all thrips and TCSV infected plants was high at the edge of a tomato field 3 wk after transplanting with significantly fewer infected plants toward the center of the field. The distribution patterns of thrips and TCSV in various fields were mostly regular and aggregated across the sampling dates during the study period. Abundance of TCSV symptomatic plants and thrips species was high at the edge of the field and increased over time. The number of samples required to accurately determine population density of thrips was calculated by using three precision levels (0.10, 0.20, 0.30) at three predetermined densities of thrips (0.10, 0.20, and 0.40 per sample). This information will provide guidelines to growers, crop protection personnel, agricultural scouts, and researchers to develop a sustainable thrips and tospovirus management program.


HortScience ◽  
2005 ◽  
Vol 40 (1) ◽  
pp. 146-149 ◽  
Author(s):  
Rebecca L. Loughner ◽  
Daniel F. Warnock ◽  
Raymond A. Cloyd

Western flower thrips (Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)] collected from greenhouse, laboratory, and native populations were evaluated for resistance to the insecticide spinosad. Individual cut stems of transvaal daisy (Gerbera jamesonii H. Bolus ex Hook. f.) were inoculated with 25 adults from 1 of 9 thrips populations and maintained in isolation chambers. Treatments of no spray, water spray, spinosad at one-half label rate (0.41 mL·L-1) and spinosad at the recommended label rate (0.81 mL·L-1) were applied to the flowers. Three days after treatment, the number of live and dead thrips was recorded. Significantly more thrips were recovered from the control treatments than the spinosad treatments. Thrips survival varied by treatment and insect population. Based on an odds ratio analysis, the likelihood of recovering live thrips was greater in the IL-GH1 (Illinois greenhouse) population than in the NV-N1 (Nevada native) reference population for both spinosad treatments, suggesting resistance to spinosad in the IL-GH1 population. The IL-GH1 population was collected from a greenhouse regularly sprayed with spinosad whereas the NV-N1 population was collected in Incline Village, Nev., on wildflowers with no history of exposure to spinosad. This is the first documented indication of spinosad resistance in a thrips population. In comparison to the NV-N1 reference population, none of the populations collected from laboratory or native nonagricultural environments exhibited evidence of resistance to spinosad. Resistance to an insecticide with a novel mode of action, such as spinosad, indicates the necessity of rotating insecticides and implementing alternative methods of managing western flower thrips. Chemical names used: spinosad including spinosyn A and spinosyn D (Conserve SC).


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 569e-570 ◽  
Author(s):  
P.A. Stack ◽  
L.B. Stack ◽  
F.A. Drummond

A mail survey of greenhouse growers was conducted in 1994 and 1995 to determine the presence and importance of western flower thrips (WFT), Frankliniella occidentalis Pergande, in Maine greenhouses in growing years 1993 and 1994. Respondents were licensed growers with at least 1000 ft2 (93 m2) of greenhouse growing area. The survey objectives were to develop a grower demographic profile; determine the incidence of WFT and two WFT-vectored plant viruses, tomato spotted wilt (TSWV) and impatiens necrotic spot (INSV); and identify current WFT management strategies. The survey shows that Maine greenhouse growers are seasonal, experienced and retail oriented. Their growing area averages less than 10,000 ft2 (929 m2) and they produce a diverse crop mix and choose to import production stock as much as propagate it themselves. Both WFT and TSWV/INSV have increased in severity in Maine greenhouses over the past 10 years. Larger, year-round greenhouses are more likely to experience infestations of WFT and higher virus incidence. An integrated pest management (IPM) strategy is employed by the majority of growers surveyed. Insecticide application is the primary tactic used to control WFT. Fewer than 4% of the growers use natural enemies to control thrips. However, 63% responded that future research in pest management should focus on biological control.


2006 ◽  
Vol 16 (4) ◽  
pp. 633-636 ◽  
Author(s):  
Brian K. Hogendorp ◽  
Raymond A. Cloyd

Sanitation, which includes removing plant and growing medium debris, is an important component of any greenhouse or nursery pest management program. However, there is minimal quantitative information on how sanitation practices can reduce pest problems. In this study, conducted from May through Nov. 2005, we evaluated plant and growing medium debris as a source of insect pests from four greenhouses located in central Illinois. Two 32-gal refuse containers were placed in each greenhouse with a 3 × 5-inch yellow sticky card attached to the underside of each refuse container lid. Each week, yellow sticky cards and plastic refuse bags were collected from the containers and insects captured on the yellow sticky cards were identified. Insects captured on the yellow sticky cards were consistent across the four greenhouses with western flower thrips (Frankliniella occidentalis), fungus gnats (Bradysia spp.), and whiteflies (Bemisia spp.) the primary insects present each week. Insect numbers, in order of prevalence on the yellow sticky cards, varied across the four locations, which may be related to the type of plant debris discarded. For example, extremely high numbers of adult whiteflies (range = 702 to 1930) were captured on yellow sticky cards in one greenhouse each month from August through November. This was due to the presence of yellow sage (Lantana camera), bee balm (Monarda didyma), garden verbena (Verbena × hybrida), common zinnia (Zinnia elegans), sage (Salvia spp.) and fuchsia (Fuschia spp.) debris that was heavily-infested with the egg, nymph, pupa, and adult stages of whiteflies. High western flower thrips adult numbers in the greenhouses were generally associated with plant types such as marguerite daisy (Dendranthema frutescens) and pot marigold (Calendula officinalis) disposed while in bloom with opened yellow flowers, which contained adult western flower thrips. Based on the results of this study, it is important that greenhouse producers timely remove plant and growing medium debris from greenhouses or place debris into refuse containers with tight-sealing lids to prevent insect pests from escaping.


HortScience ◽  
2019 ◽  
Vol 54 (5) ◽  
pp. 890-895 ◽  
Author(s):  
Yinping Li ◽  
Raymond A. Cloyd ◽  
Nora M. Bello

Western flower thrips, Frankliniella occidentalis, is one of the most destructive insect pests of greenhouse-grown horticultural crops. The primary method of managing western flower thrips populations involves applications of insecticides; however, there is no information associated with the effect of the insect growth regulator, pyriproxyfen, or the entomopathogenic fungus, Isaria fumosorosea, on western flower thrips pupae in growing media. Therefore, four laboratory experiments were conducted to determine the effect of pyriproxyfen and I. fumosorosea applied as a drench to growing media on western flower thrips pupae. Expt. 1 evaluated the efficacy of pyriproxyfen and I. fumosorosea on western flower thrips pupae. Based on the results from Expt. 1, Expt. 2 assessed the effect of pyriproxyfen in two growing media (LC1 and BM1) on western flower thrips pupae. Expts. 3 and 4 determined the residual activity of pyriproxyfen in growing media on western flower thrips pupae 3, 5, 7, and 14 days after treatments were applied. The pyriproxyfen treatment resulted in a significantly lower estimated mean probability of western flower thrips adults captured on yellow sticky cards (17%) compared with the water control (59%), untreated check (88%), and two I. fumosorosea treatments (46% for 1.0 g and 41% for 2.0 g of Ancora) in Expt. 1. However, for the two growing media in Expt. 2, the estimated mean probability of western flower thrips adults captured on yellow sticky cards was not significantly different between the pyriproxyfen treatment (LC1 = 15%; BM1 = 12%) and the water control (LC1 = 41%; BM1 = 24%). For either the pyriproxyfen treatment or the untreated check, there was no evidence of a significant difference between the two growing media on the estimated mean probability of western flower thrips adults captured on yellow sticky cards. Furthermore, there was no evidence of any residual activity 3 days after drench applications of pyriproxyfen. The results of the study have demonstrated that drench applications of pyriproxyfen are not affecting survival of western flower thrips pupae.


BioControl ◽  
2021 ◽  
Author(s):  
Fatemeh Pirayeshfar ◽  
Seyed Ali Safavi ◽  
Hamid Reza Sarraf Moayeri ◽  
Gerben J. Messelink

AbstractAstigmatid mites can be used as prey for mass rearing of phytoseiid predators, but also as a supplemental food source to support predator populations in crops. Here we evaluated the potential of six species of astigmatid mites (living or frozen) as alternative food for the predatory mite Amblyseius swirskii Athias-Henriot in greenhouse crops. All prey mites tested were suitable for predator oviposition. In general, oviposition was greater when prey mites were reared on dog food with yeast than when they were reared on wheat bran with yeast. Amongst prey items provided as frozen diet, larvae of Thyreophagus entomophagus (Laboulbene), Acarus siro L. and Lepidoglyphus destructor (Schrank) that had been reared on dog food with yeast, resulted in the highest oviposition rates of A. swirskii. T. entomophagus larvae as frozen diet resulted in the shortest preimaginal developmental time of A. swirskii. On chrysanthemum plants, we found that the greatest increase in predator density occurred when living mites of T. entomophagous were used as a food source. This increase was greater than when predators were fed cattail pollen, a commonly used supplemental food. Effects on predators of providing living A. siro and L. destructor, or frozen larvae of T. entomophagous as food, were comparable with provision of pollen. Use of supplemental food in crops can be a risk if it is also consumed by omnivorous pests such as western flower thrips, Frankliniella occidentalis Pergande. However, we showed that both frozen and living mites of T. entomophagous were unsuitable for thrips oviposition. Hence, we believe that provision of prey mite species increases A. swirskii density, supporting biological control of thrips and other pests in greenhouse crops.


2016 ◽  
Vol 56 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Nooshin Razavi ◽  
Kamal Ahmadi

AbstractThe western flower thrips, Frankliniella occidentalis (Pergande) attacks a large number of crop plants. The current insecticides have caused resistance in insects and have caused outbreaks of thrips. In many instances, alternative methods of insect management and natural products, offer adequate pest control and pose fewer hazards. Several species of minute pirate bugs of the genus Orius play a significant role in the biological control of a large number of thrips species, such as F. occidentalis. In this study, the insecticidal activity of four ethanolic plant extracts (Cercis siliquastrum L., Calendula officinalis L., Peganum harmala L., Melia azedarach L.) in integration with Orius horvathi (Reuter) were evaluated for controlling F. occidentalis. The present research aimed to find plant extracts with a good impact on F. occidentalis but which have fewer side effects on O. horvathi. The results showed that P. harmala extract can be considered compatible with the natural enemy for controlling thrips. When the predatory bugs O. horvathi, were released three days after P. harmala extract spraying, the integration was more effective. While the P. harmala plant extract plays an important role in thrips control, it is necessary to consider the specified time interval between the application of the P. harmala plant extract and the release of the O. horvathi predatory bugs. The ethanolic extract of M. azedarach caused a balance between the pest population and the natural enemy. This result is very important in an Integrated Pest Management (IPM) program because this ethanolic extract of M. azedarach had lower side effects on the natural enemy. This means that an integration of plant derived chemicals and the natural enemy, O. horvathi, can effectively control thrips.


1987 ◽  
Vol 119 (5) ◽  
pp. 501-503 ◽  
Author(s):  
A.B. Broadbent ◽  
W.R. Allen ◽  
R.G. Foottit

The western flower thrips, Frankliniella occidentalis (Pergande), occurs from sea level to subalpine altitudes in western North America (Bryan and Smith 1956). Until recently, it was assumed that this species was found primarily west of the Rocky Mountains and that Frankliniella tritici (Fitch), the eastern flower thrips, was the dominant flower thrips in both eastern Canada and United States. Beshear (1983) reported F. occidentalis on cotton, peas, beans, and peanuts in Georgia. The following year, in the Niagara Peninsula of Ontario, the tomato spotted wilt virus caused extensive crop losses to greenhousegrown tomatoes and ornamentals. The virus-vector was identified as F. occidentalis (Allen and Broadbent 1986). Previously, F. fusca was the only known vector of tomato spotted wilt virus in Ontario and the eastern provinces (Paliwal 1974, 1976).


HortScience ◽  
1991 ◽  
Vol 26 (8) ◽  
pp. 1073-1074 ◽  
Author(s):  
Richard L. Fery ◽  
James M. Schalk

A replicated greenhouse study was conducted to confirm the availability of resistance to western Rower thrips in pepper germplasm. Host-plant resistance ratings confirmed earlier observations that there is a considerable amount of variability within pepper germplasm for reaction to F. occidentalis. Plants of `Keystone Resistant Giant', `Yolo Wonder L', `Mississippi Nemaheart', `Sweet Banana', and `California Wonder' were resistant to the insect and exhibited only mild symptoms of damage. Plants of `Carolina Cayenne', `Santaka', and `Bohemian Chili', however, exhibited the symptoms of severe thrips damage, i.e., poorly expanded, deformed, and distorted leaves; greatly shortened internodes; and severe chlorosis. The resistance to F. occidentalis in pepper appears to be due to tolerance mechanisms, not antixenosis (nonpreference) or antibiosis mechanisms. Thrips-resistant cultivars could be used as a cornerstone in an integrated pest management program for greenhouse pepper production.


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