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.

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 Sugar-based Compounds in Enhancing the Efficacy of Insecticides against the Western Flower Thrips

2012 ◽  
Vol 22 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Raymond A. Cloyd ◽  
Joshua D. Gillespie
Keyword(s):  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
High Rate ◽  
Water Control ◽  
Brown Sugar ◽  
Greenhouse Experiments ◽  
Flower Thrips ◽  
Significant Difference ◽  
Percent Mortality ◽  
The Individual

It has been proposed by greenhouse producers that adding sugar to a stomach poison insecticide enhances the efficacy of the insecticide in controlling western flower thrips (Frankliniella occidentalis). As such, a series of laboratory, including no-choice and multiple-choice assays, and greenhouse experiments were conducted to determine if adding sugar-based compounds to insecticides enhances efficacy against western flower thrips. The sugar-based compounds evaluated were Mountain Dew, Diet Mountain Dew, white sugar, and brown sugar at two rates [initial (0.18 mL/100 mL and 0.12 g/100 mL) and high (0.36 mL/100 mL and 0.24 g/100 mL)]. A water control was also included in all the assays. In the laboratory experiments, western flower thrips adults and nymphs were not attracted to any of the sugar-based compounds with <60 s (out of 300 s total) spent in any of the treatments, and ≤29 s (out of 300 s total) spent in the treatments when the sugar-based compounds were mixed with three insecticides (tau-fluvalinate, pyridalyl, and spinosad). In the greenhouse experiments, the addition of the high rate of Mountain Dew (0.36 mL/100 mL) and brown sugar (0.24 g/100 mL) did not enhance the efficacy (based on percent mortality) of the insecticides against western flower thrips. There was no significant difference between the individual insecticide treatments and the mixtures with either Mountain Dew or brown sugar. This study is the first to quantitatively demonstrate that western flower thrips adults and nymphs are not attracted to sugar-based compounds and that it is not warranted to add these types of materials to spray solutions targeted for control of western flower thrips.

Effect of Integrating the Entomopathogenic Fungus (Hypocreales: Cordycipitaceae) and the Rove Beetle (Coleoptera: Staphylinidae) in Suppressing Western Flower Thrips (Thysanoptera: Thripidae) Populations Under Greenhouse Conditions

2019 ◽  
Vol 112 (5) ◽  
pp. 2085-2093
Author(s):  
Yinping Li ◽  
Raymond A Cloyd ◽  
Nora M Bello
Keyword(s):  
Entomopathogenic Fungus ◽  
Frankliniella Occidentalis ◽  
Production Systems ◽  
Insect Pest ◽  
Western Flower Thrips ◽  
Life Stages ◽  
Water Control ◽  
Greenhouse Production ◽  
Flower Thrips ◽  
Rove Beetle

Abstract Western flower thrips, Frankliniella occidentalis (Pergande), is a destructive insect pest in greenhouse production systems. Therefore, integrating the entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin, with the soil-dwelling rove beetle, Dalotia coriaria (Kraatz), targeting different aboveground and belowground life stages may help effectively manage western flower thrips populations. Two greenhouse experiments were conducted evaluating five treatments: 1) insecticides (spinosad, pyridalyl, chlorfenapyr, and abamectin), 2) B. bassiana, 3) D. coriaria, 4) B. bassiana and D. coriaria combination, and 5) water control. The estimated mean number of western flower thrips adults captured on yellow sticky cards was significantly lower for the insecticide treatment (mean range: 0–46 western flower thrips adults per yellow sticky card) than the B. bassiana and D. coriaria combination (0.3–105.1 western flower thrips per yellow card) over 8 wk. There were no significant differences in the final foliar damage ratings of chrysanthemum, Dendranthema × grandiflorum (Ramat.) Kitam., plants among the five treatments in experiment 1, but there were significant differences in experiment 2. In experiment 2, chrysanthemum plants across all treatments were not marketable due to western flower thrips feeding damage. Therefore, using B. bassiana and D. coriaria early in production should suppress population growth by targeting both foliar-feeding and soil-dwelling life stages of western flower thrips simultaneously.

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.

scholarly journals Ultraviolet radiation modulates both constitutive and inducible plant defenses against thrips but is dose and plant genotype dependent

2019 ◽  
Author(s):  
Rocío Escobar-Bravo ◽  
Charlotte Nederpel ◽  
Sofía Naranjo ◽  
Hye Kyong Kim ◽  
María José Rodríguez-López ◽  
...  
Keyword(s):  
Frankliniella Occidentalis ◽  
Opposite Effect ◽  
Plant Defenses ◽  
Plant Protection ◽  
Insect Pest ◽  
Western Flower Thrips ◽  
Flower Thrips ◽  
Affected Plant ◽  
Mother Plants ◽  
Uv Dose

Abstract Ultraviolet (UV) radiation has emerged as an environmental cue with potential uses to enhance plant protection against arthropod pests in agriculture. UV can augment constitutive and inducible plant defenses against herbivorous arthropods. Here we investigated whether application of supplemental UV to chrysanthemum (Chrysanthemum × morifolium Ramat) cuttings during their rooting phase enhanced plant resistance to an important insect pest, Western flower thrips (Frankliniella occidentalis). For this, we analyzed how several daily UV exposure times affected plant damage by thrips on three different chrysanthemum cultivars. The most effective UV dose and responsive cultivar were further used to determine the UV effects on host plant preference by thrips, leaf metabolome and the induction of jasmonic acid (JA)-associated defenses. Our results showed that while short UV daily exposure times increased chrysanthemum resistance to thrips, longer exposure times had the opposite effect. Furthermore, we showed that UV-mediated induction of chrysanthemum resistance to thrips was genotype dependent and can persist after the end of the of the UV treatment. Yet, this induction was not transferred to the next generation from mother plants to cuttings. Nontargeted metabolomic, enzymatic and hormone analyses further revealed that UV slightly affected the leaf metabolome of chrysanthemum plants, and it enhanced the induction of JA-associated signaling after thrips infestation. Taken together, our results suggest that supplemental UV might modulate both constitutive and inducible chrysanthemum defenses against thrips.

scholarly journals Technique for Collecting Thrips for Use in Insecticide Efficacy Trials

HortScience ◽  
2001 ◽  
Vol 36 (5) ◽  
pp. 925-926 ◽  
Author(s):  
Raymond A. Cloyd ◽  
Daniel F. Warnock ◽  
Keith Holmes
Keyword(s):  
Experimental Test ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Test Plant ◽  
Larval Stages ◽  
Flower Thrips ◽  
Efficacy Trials ◽  
Insecticide Efficacy ◽  
Vacuum Device ◽  
Copper Tubing

An affordable device comprised of off-the-shelf parts, initially called the “Small Insect Aspirator” was developed to gently collect western flower thrips, Frankliniella occidentalis (Pergande), from a rearing colony for use in insecticide efficacy trials. This device allows for a designated number of thrips to be placed onto any experimental test plant. The device is a battery-motorized driven aspirator comprised of two pieces of copper tubing (6.0 mm in diameter) attached to a copper housing, which contains a threaded plastic lid and glass vial (20-mL). The aspirator is fully portable when attached to a battery-driven vacuum device, which allows researchers to efficiently collect thrips in outdoor field situations. When turned on, the vacuum gently pulls western flower thrips (adult and larval stages) through the copper tubing and deposits them into the collection vial. The vial is then detached and sealed with a threaded lid until the collected thrips are deposited onto experimental test plants.

scholarly journals Biological control of thrips pests (Thysanoptera: Thripidae) under greenhouse conditions in Transylvania, Romania

2020 ◽  
Vol 1 (2) ◽  
pp. 147-154 ◽  
Keyword(s):  
Biological Control ◽  
Frankliniella Occidentalis ◽  
Plant Protection ◽  
Western Flower Thrips ◽  
Economic Losses ◽  
Vegetable Production ◽  
Climate Data ◽  
Greenhouse Climate ◽  
Flower Thrips ◽  
Beneficial Organisms

In present, vegetable cultivation faces significant challenges for two reasons: (i) cultivators have to produce healthy, first-class goods, and (ii) vegetables are allowed to contain only a specified pesticide residue. Development of insecticide resistance as a result of repeated insecticide treatments is causing difficulties to cultivators, who have paid attention to biological control methods over recent years. In Romania, pepper sprouting represents a prominent place in greenhouse vegetable production. Under greenhouse conditions, one of the most dangerous pests of peppers is the western flower thrips (Frankliniella occidentalis), which can trigger high economic losses. In recent years, several populations have been found resistant to insecticides and other active compounds, therefore, in our experiments, performed under greenhouse conditions, we used the predatory mite Amblyseius swirskii and the pirate bug Orius laevigatus against the western flower thrips. In addition to thrips, we monitored the growth and spread of introduced beneficial organisms based on collected flower samples. We also evaluated the relationships between beneficial organisms and greenhouse climate data. Introduction of natural enemies has proven a success of biological plant protection, as thrips did not cause economic losses in our experiment.

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.

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