scholarly journals Efficacy of Binary Pesticide Mixtures Against Western Flower Thrips

2014 ◽  
Vol 24 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Raymond A. Cloyd ◽  
Amy L. Raudenbush
Keyword(s):  
Ammonium Chloride ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Production Cycle ◽  
Labor Costs ◽  
Pesticide Mixtures ◽  
Horticultural Crops ◽  
Flower Thrips ◽  
Dimethyl Ammonium Chloride ◽  
Dimethyl Ammonium

This study was designed to determine the efficacy of binary pesticide mixtures against one of the most important insect pests of greenhouse-grown horticultural crops, western flower thrips (Frankliniella occidentalis). Two separate experiments were conducted under greenhouse conditions to simulate a greenhouse production cycle using yellow transvaal daisy (Gerbera jamesonii) cut flowers, which were artificially infested with a known number of western flower thrips. The pesticides used in the two experiments were spinosad, pymetrozine, abamectin, pyridalyl, fluvalinate, chlorfenapyr, bifenazate, azadirachtin, petroleum oil, tolfenpyrad, fenhexamid, azoxystrobin, and spirotetramat. Pesticide mixtures were evaluated at the recommended labeled rates (Expt. 1) and assessments were made to determine if adding didecyl dimethyl ammonium chloride enhanced the efficacy of the pesticide mixtures (Expt. 2). Results from Expt. 1 indicated that many of the binary pesticide mixtures provided ≥80% mortality of western flower thrips although this was a baseline population without previous exposure to pesticides. In Expt. 2, the addition of didecyl dimethyl ammonium chloride failed to increase the efficacy of most of the designated pesticide mixtures compared with the pesticides applied separately. Furthermore, none of the binary pesticide mixtures were phytotoxic to the transvaal daisy flowers. Although there are issues associated with using pesticide mixtures such as the potential for resistance developing to different pesticides in mixtures, greenhouse producers combine pesticides together to reduce labor costs and expand the spectrum of activity against insect and mite (Tetranychidae) pests. Therefore, the relevance of this information is that greenhouse producers now understand which pesticide mixtures may be used and those that should be avoided when suppressing populations of western flower thrips thus minimizing feeding damage to greenhouse-grown horticultural crops.

Effect of Pesticide Mixtures in Controlling Western Flower Thrips (Thysanoptera: Thripidae)

2005 ◽  
Vol 40 (1) ◽  
pp. 54-66 ◽  
Author(s):  
Daniel F. Warnock ◽  
Raymond A. Cloyd
Keyword(s):  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
The Other ◽  
Labor Costs ◽  
Laboratory Bioassay ◽  
Eustoma Grandiflorum ◽  
Pesticide Mixtures ◽  
Greenhouse Experiments ◽  
Flower Thrips ◽  
Plant Feeding

Greenhouse managers mix together pesticides to broaden the spectrum of pest control and to reduce pesticide and labor costs. However, the efficacy of pesticide mixtures has not been well-documented. This study assesses how mixtures of commercially available insecticides and miticides in two, three, and four-way combinations affected the control of western flower thrips, Frankliniella occidentalis Pergande, in greenhouse experiments and in a laboratory bioassay. The pesticides screened in the greenhouse experiments and laboratory bioassay were spinosad, abamectin, bifenazate, azadirachtin and imidacloprid. Each pesticide was applied at the maximum label-recommended rate. In the greenhouse experiments, transvaal daisy (Gerbera jamesonii H. Bolus ex Hook. f) and lisianthus (Eustoma grandiflorum G. Don ex Sweet) flowers were infested with 25 adult western flower thrips (mixture of females and males). Flowers were then sprayed with the designated treatments. After 72 h, flowers were dissected to assess the numbers of live and dead western flower thrips. In the laboratory bioassay, chrysanthemum (Dendranthema grandiflora Tzvelev) leaf sections, treated with solutions of each pesticide and all possible combinations, were exposed to 15 adult western flower thrips. The numbers of live and dead western flower thrips were assessed after 48 h. For all three experiments, we were not able to identify any antagonistic pesticide combinations. All treatments with spinosad, including the individual application and pesticide mixtures, resulted in high mortality of western flower thrips. Our data suggest that combinations of spinosad with the other pesticides tested do not affect the efficacy of spinosad in controlling western flower thrips. This information is important to greenhouse managers who wish to mix pesticides and still control western flower thrips in addition to the other plant-feeding arthropods found in greenhouses.

scholarly journals Complexity and local specificity of the virome associated with tospovirus-transmitting thrips species.

2021 ◽  
Author(s):  
M. Chiapello ◽  
Lara Bosco ◽  
M. Ciuffo ◽  
S. Ottati ◽  
N. Salem ◽  
...  
Keyword(s):  
Frankliniella Occidentalis ◽  
High Throughput Sequencing ◽  
Western Flower Thrips ◽  
Thrips Tabaci ◽  
Model Systems ◽  
Horticultural Crops ◽  
Flower Thrips ◽  
Thrips Species ◽  
Repeated Sampling ◽  
Neohydatothrips Variabilis

Frankliniella occidentalis (western flower thrips=WFT) and Thrips tabaci (onion thrips=OT) are insect species that greatly impact horticultural crops through direct damage and their efficient vectoring of tomato spotted wilt virus and iris yellow spot virus. In this study we collected thrips of these species from 12 field populations in various regions in Italy. We also included one field population of Neohydatothrips variabilis (soybean thrips=ST) from the U.S.A. Total RNAseq from high-throughput sequencing (HTS) was used to assemble the virome and then we assigned putative viral contigs to each thrips sample by qRT-PCR. Excluding plant and fungal viruses, we were able to identify 61 viral segments, corresponding to 41 viruses: 14 were assigned to WFT, 17 to OT, one from ST and 9 viruses could not be assigned to any species based on our stringent criteria. All these viruses are putative representative of new species (with only the exception of a sobemo-like virus that is 100% identical to a virus recently characterized in ST) and some belong to new higher-ranking taxa. These additions to the viral phylogeny suggest previously undescribed evolutionary niches. Most of the Baltimore’s classes of RNA viruses were present (positive- and minus- strand and dsRNA viruses), but only one DNA virus was identified in our collection. Repeated sampling in a subset of locations in 2019 and 2020 and further virus characterization in a subset of four thrips populations maintained in laboratory allowed us to provide evidence of a locally persistent thrips core virome that characterizes each population. IMPORTANCE Harnessing the insect microbiome can result in new approaches to contain their populations or the damage they cause vectoring viruses of medical, veterinary, or agricultural importance. Persistent insect viruses are a neglected component of their microbiota. Here for the first time, we characterize the virome associated with the two model systems for tospovirus-transmitting thrips species, of utmost importance for the direct and indirect damage they cause to a number of different crops. The thrips virome here characterized includes several novel viruses, that in some cases reveal previously undescribed clades. More importantly, some of the viruses we describe are part of a core virome that is specific and consistently present in distinct geographical locations monitored over the years, hinting at a possible mutualistic symbiotic relationship with their host.

scholarly journals Effect of Tank Mixing Pesticides in Controlling Western Flower Thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 767D-768
Author(s):  
Daniel Warnock* ◽  
Raymond Cloyd
Keyword(s):  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
The Other ◽  
Labor Costs ◽  
Laboratory Bioassay ◽  
Eustoma Grandiflorum ◽  
Greenhouse Experiments ◽  
Flower Thrips ◽  
Plant Feeding ◽  
The Individual

Greenhouse managers tank mix pesticides to broaden the spectrum of pest control, and reduce pesticide and labor costs. However, the effect of tank mixing an assortment of pesticides on efficacy to control pests has not been documented. This study assessed how tank mixing commercially available insecticides and miticides in two-, three-, and four-way combinations impacts the control of western flower thrips (WFT), Frankliniella occidentalis in greenhouse experiments and a laboratory bioassay. The pesticides screened were spinosad, abamectin, bifenazate, azadirachtin, and imidacloprid. Each pesticide was applied at the label-recommended rate. In the greenhouse experiments, transvaal daisy (Gerbera jamesonii) and lisianthus (Eustoma grandiflorum) flowers were inoculated with 25 adult WFT, and then flowers were sprayed with the designated treatments. After 72 hours, flowers were emasculated to assess the numbers of live and dead WFT. In the laboratory bioassay, chrysanthemum (Dendranthema grandiflora) leaf disks, treated with each pesticide and all tank mixes, were exposed to 15 adult WFT. The numbers of live and dead WFT were assessed after 48 hours. For all three experiments, no antagonistic tank mixes were identified. All treatments with spinosad, including the individual application and tank mixes, resulted in high mortality of WFT based on the numbers of live and dead WFT recovered. Our data suggest that tank mixes of spinosad with the other pesticides tested do not affect the efficacy of spinosad in controlling WFT. This information is important to greenhouse managers who want to tank mix pesticides and still control WFT in addition to the other plant-feeding arthropods found in greenhouses.

scholarly journals Effects of Spray Volume and Application Frequency on Insecticide Efficacy Against Adult Western Flower Thrips (Frankliniella Occidentalis) under Greenhouse Conditions

HortScience ◽  
2020 ◽  
Vol 55 (10) ◽  
pp. 1708-1714
Author(s):  
Devin L. Radosevich ◽  
Raymond A. Cloyd ◽  
Nathan J. Herrick
Keyword(s):  
Frankliniella Occidentalis ◽  
Insect Pest ◽  
Western Flower Thrips ◽  
Economic Losses ◽  
Horticultural Crops ◽  
Flower Thrips ◽  
Insecticide Efficacy ◽  
Percent Mortality ◽  
Application Frequency ◽  
Spray Volume

The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a major insect pest of greenhouse-grown horticultural crops. Western flower thrips causes direct and indirect damage by feeding on plant leaves, flowers, and fruits, and by transmitting viruses that can result in greenhouse producers experiencing substantial economic losses. Consequently, insecticides are used to suppress western flower thrips populations. However, issues associated with applying insecticides may affect the suppression of western flower thrips populations. Therefore, experiments were conducted under greenhouse conditions to determine the effects of the spray volume applied and application frequency on insecticide efficacy against western flower thrips adults located in transvaal daisy, Gerbera jamesonii, cut flowers. Four spray volumes (5.0, 10.0, 12.5, and 25.0 mL), two application frequencies (one or two spray applications), and three insecticides [spinosad (Conserve), chlorfenapyr (Pylon), and flonicamid (Aria)], each with a different mode of action, were tested. The insecticide treatments had the greatest effects on the mean percent mortality of western flower thrips adults regardless of spray volume or application frequency. However, in Expt. 3, the 5.0- and 10.0-mL spray volumes resulted in a higher mean percent mortality of western flower thrips adults than the 2.5-mL spray volume. Spinosad and chlorfenapyr resulted in a mean percent mortality of more than 72% for western flower thrips adults, whereas flonicamid resulted in mean percent mortality between 40% and 91%. Our study demonstrates that certain insecticides are more effective against western flower thrips adults located in transvaal daisy flowers than others, which will help greenhouse producers effectively manage western flower thrips populations.

Frankliniella occidentalis (western flower thrips).

2021 ◽  
Author(s):  
Stuart Reitz
Keyword(s):  
Plant Material ◽  
Frankliniella Occidentalis ◽  
Plant Protection ◽  
Western Flower Thrips ◽  
Agricultural Pests ◽  
Fruit Crops ◽  
Horticultural Crops ◽  
Flower Thrips ◽  
Rapid Spread ◽  
The World

Abstract Since the 1970s Frankliniella occidentalis has successfully invaded many countries to become one of the most important agricultural pests of ornamental, vegetable and fruit crops globally. Its invasiveness is largely attributed to the international movement of plant material and insecticide resistance, both of which have combined to foster the rapid spread of the species throughout the world (Kirk and Terry, 2003; Reitz et al., 2020). Individuals are very small and they reside in concealed places on plants; thus are easily hidden and hard to detect in transported plant material. They reproduce rapidly and are highly polyphagous, breeding on many horticultural crops that are transported around the world. F. occidentalis is species no. 177 on the list of A2 pests regulated as quarantine pests in the European Plant Protection Organisation (EPPO) region (version 2005-09). It has now reached many countries, and remains a serious threat to crops in those countries that it has not yet reached.

Effect of Pesticide Mixtures on the Survival of the Predatory Mite Neoseiulus cucumeris (Acarina: Phytoseiidae)

2007 ◽  
Vol 42 (3) ◽  
pp. 311-319 ◽  
Author(s):  
Heather E. Lash ◽  
Daniel F. Warnock ◽  
Raymond A. Cloyd
Keyword(s):  
Fungal Pathogens ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Predatory Mite ◽  
Water Control ◽  
Neoseiulus Cucumeris ◽  
Thiophanate Methyl ◽  
Pesticide Mixtures ◽  
Control Programs ◽  
Flower Thrips

This study was conducted to determine the effect of 2 insecticides/miticides, spinosad and abamectin, and 2 fungicides, thiophanate-methyl and fenhexamid, when applied alone or mixed in all combinations, on the survival of Neoseiulus cucumeris (Oudemans). Neoseiulus cucumeris is a predatory mite utilized in greenhouses for managing western flower thrips, Frankliniella occidentalis Pergande. The deutonymph and adult stages of N. cucumeris were directly exposed to the pesticide treatments or a water control. Overall, the deutonymphs were more susceptible to the pesticide treatments, based on percent survival 24 h after treatment, than the adults. Five of the 7 pesticide mixtures containing spinosad and 4 of the 7 mixtures containing abamectin resulted in deutonymph mortality values between 50 and 69%. Thiophanate-methyl alone and in combination with either spinosad or abamectin resulted in >35% mortality of the deutonymphs. Based on the results of this study, spinosad and abamectin, when used alone or in mixture with thiophanate-methyl will reduce N. cucumeris populations by killing the deutonymphs. This information is important to greenhouse managers who want to use pesticide mixtures to manage arthropod pests and fungal pathogens without disrupting biological control programs for western flower thrips.

scholarly journals Getting Mixed-Up: Are Greenhouse Producers Adopting Appropriate Pesticide Mixtures to Manage Arthropod Pests?

2009 ◽  
Vol 19 (3) ◽  
pp. 638-646 ◽  
Author(s):  
Raymond A. Cloyd
Keyword(s):  
Frankliniella Occidentalis ◽  
Insect Pests ◽  
Life Stage ◽  
Western Flower Thrips ◽  
Pesticide Mixture ◽  
Pesticide Mixtures ◽  
Flower Thrips ◽  
Wide Range ◽  
Arthropod Pests ◽  
Arthropod Pest

Pesticide mixtures are commonly used by greenhouse producers to deal with the array of arthropod (insect and mite) pests encountered in greenhouses. Greenhouse producers tank mix pesticides due to convenience because it is less time consuming, costly, and labor intensive to mix together two or more pesticides into a single spray solution and then perform one spray application compared with making multiple applications. Pesticide mixtures may also result in improved arthropod pest control. However, there has been no quantitative assessment to determine what pesticide mixtures (two-, three-, and four-way combinations) are being adopted by greenhouse producers and why. As such, a survey was conducted by distributing evaluation forms in conjunction with three sessions at two greenhouse producer conferences (two in 2007 and one in 2008) to obtain data on the types of pesticide mixtures used by greenhouse producers and determine if there are any problems associated with these pesticide mixtures. The evaluation form requested that participants provide information on the four most common pesticide mixtures (insecticides and/or miticides) used and for what specific arthropod pests. The response rate of the evaluation forms was 22.5% (45/200). The two-way pesticide mixture that was cited most often (n = 8) was the abamectin (Avid) and bifenthrin (Talstar) combination. The two pesticides typically included in a majority of the two-way and three-way mixtures were spinosad (Conserve) and abamectin. Spinosad was a component of 17 two-way and 7 three-way combinations, while abamectin was cited in 15 two-way and 9 three-way combinations. Both products are labeled for control of the western flower thrips (Frankliniella occidentalis), which is one of the most important insect pests in greenhouses. One pesticide mixture that was difficult to interpret involved the fungicides, thiophanate-methyl (Cleary's 3336) and metalaxyl (Subdue). This mixture was cited twice, and the arthropod pest listed was thrips (Thysanoptera). However, both fungicides have no insecticidal activity. Two of the mixtures listed in the survey used pesticides with similar modes of action: acephate (Orthene) + methiocarb (Mesurol), and pyrethrins (Pyreth-It) + bifenthrin (Talstar). A number of the pesticide mixtures listed for spider mites (Tetranychidae) were questionable due to similar life stage activity of the a.i. as indicated on the label including fenpyroximate (Akari) + clofentezine (Ovation), abamectin + chlorfenapyr (Pylon), and bifenazate (Floramite) + etoxazole (TetraSan). In fact, 38% of pesticide mixtures cited for twospotted spider mite (Tetranychus urticae) control should have been avoided due to analogous life stage activity. The data obtained from the survey clearly demonstrates that greenhouse producers implement a wide-range of pesticide mixtures to deal with the multitude of arthropod pests in greenhouses. However, the basis by which greenhouse producers decide the types of pesticides to mix together is not known. As such, the survey data can be used to direct future multistate or multiregional extension (outreach) efforts in developing programs specifically designed to educate greenhouse producers on which pesticides should and should not be mixed together.

scholarly journals Morphological and Chemical Factors Related to Western Flower Thrips Resistance in the Ornamental Gladiolus

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1384
Author(s):  
Dinar S. C. Wahyuni ◽  
Young Hae Choi ◽  
Kirsten A. Leiss ◽  
Peter G. L. Klinkhamer
Keyword(s):  
Host Plant ◽  
Plant Resistance ◽  
Host Plant Resistance ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Resistance Breeding ◽  
Breeding Programs ◽  
Triterpenoid Saponins ◽  
Flower Thrips ◽  
Highly Correlated

Understanding the mechanisms involved in host plant resistance opens the way for improved resistance breeding programs by using the traits involved as markers. Pest management is a major problem in cultivation of ornamentals. Gladiolus (Gladiolus hybridus L.) is an economically important ornamental in the Netherlands. Gladiolus is especially sensitive to attack by western flower thrips (Frankliniella occidentalis (Pergande) (Thysanoptera:Thripidae)). The objective of this study was, therefore, to investigate morphological and chemical markers for resistance breeding to western flower thrips in Gladiolus varieties. We measured thrips damage of 14 Gladiolus varieties in a whole-plant thrips bioassay and related this to morphological traits with a focus on papillae density. Moreover, we studied chemical host plant resistance to using an eco-metabolomic approach comparing the 1H NMR profiles of thrips resistant and susceptible varieties representing a broad range of papillae densities. Thrips damage varied strongly among varieties: the most susceptible variety showed 130 times more damage than the most resistant one. Varieties with low thrips damage had shorter mesophylls and epidermal cells, as well as a higher density of epicuticular papillae. All three traits related to thrips damage were highly correlated with each other. We observed a number of metabolites related to resistance against thrips: two unidentified triterpenoid saponins and the amino acids alanine and threonine. All these compounds were highly correlated amongst each other as well as to the density of papillae. These correlations suggest that papillae are involved in resistance to thrips by producing and/or storing compounds causing thrips resistance. Although it is not possible to distinguish the individual effects of morphological and chemical traits statistically, our results show that papillae density is an easy marker in Gladiolus-breeding programs targeted at increased resistance to thrips.

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