Thrip control

[Darkstarlive]

what is the most effective treatment for thrips?? I have gnatrol and BTK(Bacillus Thuringiensis Kurstaki), also NPS(No Pest Strips) will this combo do the trick??
Peace..

 

[Guest]

I hate those little shit’s. Killed the one’s that I hade with FUNGICIDE 3 good stuff kills mites too.

 

[MTF-Sandman]

Neem will take care of em for sure...NPS should work, but I've never tried it on them.

 

[sproutco]

Neem will take care of em for sure....

Interestingly, I read somewhere that neem will only control the larval stage and not the adults. Give it a try I guess. I use safer soap and aim for complete coverage of all surfaces.

 

[Grass_Lover]

I got safer soap from a website instead of just NEEM because neem only works on babies.

2x sprays whiped mine out. I spread the treatments apart and 2-3 treatments will whipe everything out, unless you have some critters in dirt

 

[Guest]

Stay on the look out ... once you think they are gone the lil bastards will pop back up. Neem has always worked for me for control not complete eradication. Never tried NPS, heard it will work also just never liked the things I read about them.

Good Luck

Mo,

 

[Guest]

Thrips

Thrips

They are hard to completely eradicate in a setup that has clones, vegging moms and a flowering girls all in one area. Many times they just spread all around the different areas by flying, hopping..Ideally you would just let whatever is flowering finish with minimum addition of sprays and crap that will stay on the buds.
Then hit the vegging plants and moms harder before switching the lights over because the flowers are not formed. Neem is a good deterrant in veg since it keeps the area free of larvae etc and won't leave a taste on buds, but if the bugs have already set in, you want to do something to kill the adults first. I heard the no pest strips are super toxic, but will kill most everything. I'd clear out the flower room also at harvest and spray it down with something, leave the no pest strips in there for a few days, maybe a pyrethrin gas fogger to get the hidden corners. Then once the flower room is "disinfected", make sure all the vegging plants have been hit well with something. I usually grow smaller numbers of plants, so many times I'll get each plant one by one and manually wash off the leaves with tap water in another room. It's messy and time consuming, but I hate pests and know how hard they are to get rid of. Then I'll dunk each one in a solution of some type of pesticide or another (like miticide for mites) or spray it with safer soap for thrips like sproutco said thoroughly. I'd say a full on plan of attack is really needed to fully eradicate pests, specially jumping, flying ones...Good luck

 

[irie-i]

ambelyseus cucumeris

ambelyseus cucumeris

these predators work everytime. they eat the mature thrips, then hang around and wait for the young 'uns to emerge from the soil and eat them! no messy toxic sprays, no wondering if the neem is still effective, no waiting for larva to emerge for another hit.

they are ultimately cheaper than sprays.

www.thebugfactory.ca

the people at the bug factory are super nice. theyre on vancouver island in bc canada. they wont ask what youre growing, and they dont care if youre growing the herb.

the cucumeris come in a little bucket. the bucket has bran in it and the cucumeris live on the bran. you spread it around your garden and sit back, realx, and let them do theyre thing. theyre best as a preventative, but with persisitence and perhaps reapplication will certainly rid you of thrips forever. when they are done working they simply dissapear. they wont harm your plants in anyway. they are not vegetarians!

 

[sproutco]

Interestingly avid could be used on thrips. This might be handy since it controls spider mites so well. I thought this article was interesting in that it mentions soaps, neem, and preditors we are talking about. If you skip down, I highlighted in bold the part about neem not controling adult thrips.

Greenhouse IPM: Sustainable Thrips Control
By Lane Greer and Steve Diver
NCAT Agriculture Specialist
© NCAT 2000
ATTRA Publication #IP148/63 The printable PDF version of the entire document is available at:
http://attra.ncat.org/attra-pub/PDF/ghthrips.pdf
18 pages — 304 kb
Download Acrobat Reader

--------------------------------------------------------------------------------
Abstract
This publication summarizes IPM for greenhouse thrips on both vegetable and ornamental crops. Monitoring, biological controls, biorational pesticides, and insect growth regulators are discussed. Supplemental tables include information on the newest biopesticides and biological control organisms.

Table of Contents
Biology and Identification
Crop Scouting and Trapping
Sanitation
Screening
Cultural Controls
Biological Control
Biorational Pesticides
Insect Growth Regulators
Summary and Further Resources
References
Further Reading
Specialists in Thrips Control
Biological Control Suppliers
Appendix I: Monitoring and Scouting Techniques
Appendix II: Beneficial Organisms used in Greenhouses
Appendix III: Biorational Pesticides


Thrips are one of the most difficult pests to control in greenhouses. Thrips are tiny insects that reproduce rapidly, congregate in tight places that make pesticide coverage difficult, and feed with rasping-piercing-sucking mouth parts, resulting in deformation of flowers and leaves. Tolerance of thrips on floriculture crops is particularly low. In addition, when the Western flower thrips feed on plants infected with the tomato spotted wilt virus (TSWV) or impatiens necrotic spot virus (INSV), the insect vectors these diseases to other plants in the greenhouse. Once plants are infected, it is too late to do anything except dispose of diseased plants. Thus, the best way to prevent virus infection is to control thrips.

Biology and Identification
There are at least 6,000 species of thrips in the world. A few of the main species of thrips known to injure greenhouse crops are summarized in Table 1.

It is important to understand the life cycle and behavior of thrips in order to develop an ffective control strategy. Knowledge about the weak link in a pest's life cycle can help in choosing the most appropriate control strategy.

Table 2 summarizes the life cycle of adult thrips.

Table 1. Main Species of Thrips in Greenhouses
Common Name Species Name
Greenhouse thrips Heliothrips haemorrhoidalis
Banded greenhouse thrips Hercinothrips femoralis
Flower thrips Frankliniella tritici
Western flower thrips (WFT) Frankliniella occidentalis
Onion or tobacco thrips Thrips tabaci



Table 2. Life Cycle of Adult Thrips
Stage Duration of Temperatures Between 68° and 98°
Egg 2-4 days
1st instar 1-2 days
2nd instar 2-4 days
Pre-pupal 1-2 day
Pupal 1-3 days
Adult 30-45 days

As an aid to managing thrips species infesting your greenhouse, you may want to obtain positive identification. Because they are extremely small, the best way thrips can be identified is by a trained entomologist with the aid of a microscope. Plant diagnosis, or identification of insect and disease pests, is usually available through the Cooperative Extension Service.

Crop Scouting and Trapping
To detect early infestations, a crop scouting program that includes both sticky trap cards and visual inspection is critical. Scouting should be done once a week, and more often when an infestation is detected. Regular scouting is also necessary to monitor the efficacy of control measures. A hand lens is a useful tool to detect live thrips as well as signs of thrips activity—e.g., black feces and silvery, flecked areas on leaves. Lightly blowing on blossoms and growing points aids in visual inspection as it causes thrips to become mobile, apparently because of the carbon dioxide contained in exhalation.

Hot-pink sticky cards have been found to be the most attractive color for trapping thrips, though blue is often still used. Sticky traps should be placed 1 to 2 inches above the crop canopy so that the bottoms of the traps are just above the crop, at the rate of one or two per 1,000 square feet.

The economic threshold, or number of thrips found on each trap in relation to crop injury, is not yet available for every greenhouse crop. A threshold level of 20 WFT/trap/week was figured to be appropriate for chysanthemums in Switzerland.(1) In contrast, a greenhouse in New Mexico initiates pesticide application when just 5 thrips/trap/week are detected, and chrysanthemums make up 80% of its crop mix.(2) When biological control organisms are used to control thrips, they should be released as soon as the first adult thrips have been trapped.

Certain plants are especially appealing to thrips and can be used as "biological indicators" to detect the presence of thrips in the greenhouse. Majestic, Blue Magic, and Calypso petunias are recognized as thrips indicators because they will exhibit viral symptoms of TSWV within just a few days after feeding. Fortunately, the virus remains localized in the plants and does not become systemic, so that spread of this disease from infected petunias to other plants in the greenhouse is not a problem. Symptoms of thrips-vectored TSWV on petunias include a distinct brown rim at the feeding site within three to four days after feeding. This is followed by a localized circular lesion in about a week. Flowers should be removed from the petunias to discourage adult thrips from feeding on the flowers instead of the foliage, because viral lesions will not show up on flowers.(3)

Leanne Pundt, Extension Greenhouse IPM specialist with the University of Connecticut, provided the following suggestions on effective integration of sticky cards and indicator plants (4):

Place sticky cards throughout your operation to detect where thrips are located and to monitor their numbers.
Place indicator plants among crops at bench or floor level. One plant every 20 to 30 feet seems to work well.
Place incoming plant material with indicator plants and isolate for at least three to four days to allow thrips scars to develop and show viral lesions.
Dr. Wayne Allen, research pathologist with Agriculture Canada, provided these additional points on use of sticky cards and indicator plants (5):

Indicator plants are not intended as a substitute for sticky cards, but rather they're an additional component to an effective monitoring system.
While sticky cards monitor only flight activity and relative population of thrips, indicator plants monitor feeding activity and the presence of virus-carrying thrips near those plants.
Studies show that attraction to indicator plants can be significantly increased if hot pink or blue insect-monitoring cards, without adhesive, are attached to the petunia pots. In addition to increased attractiveness to thrips, the colored cards serve as location markers, and reminders that the plants should be examined frequently.
See Appendix I for a summary of monitoring and scouting techniques for greenhouse insects.

Sanitation
Sanitation is key for controlling pests in greenhouses. The goal of sanitation is to eliminate all possible sources of the pest. Weeds inside and near the outside of the greenhouse can harbor pests. It's best to pull weeds inside the greenhouse rather than spray them, since insects may survive the spray and migrate onto crops. Bag all weeds and dispose of them outside the greenhouse.

In addition, a 10-30 foot vegetation-free zone around the outside perimeter of the greenhouse—especially near vents and openings—can provide a dramatic decrease in pests. A heavy-duty geotextile weed barrier (e.g., DeWitt Sunbelt® Weed Barrier) covered with bark mulch or gravel can provide a pleasant vegetation-free zone, and eliminate the need for herbicides.

Plant debris from previous crops can also be a source of both immature and adult pests. Clean up all debris from previous crops and dispose of infested plants, or any infested growth. Ideally, the greenhouse should be thoroughly cleaned and left empty for one week prior to beginning the next crop. This enables removal of all pest stages, and starves any remaining adults. Closing up the greenhouse when it is empty in summer will increase the temperature and help eradicate pests.

Inside the greenhouse, a clean stock program should be in place. This includes temporary quarantine and inspection of all plants upon arrival from other greenhouses, and regular monitoring of stock plants used for propagation. If a separate section of the greenhouse can't be dedicated to this purpose, flag all incoming plants. All new plant material should be thoroughly inspected (with a 10X hand lens) for the presence of pests to ensure that no infested plants are introduced into the greenhouse. Workers in the greenhouse should avoid wearing yellow clothing, since many pests are attracted to this color and may hitch a ride on the fabric from one greenhouse to the next.

Screening
In the spring, adult thrips migrate from host plants and relocate to new host plants. Though thrips are not strong fliers, they are easily borne by the wind, which facilitates their movement. Prevention of airborne entry of thrips into greenhouses can be greatly aided with the use of an insect screen. Growers in New York, North Carolina, and Florida estimated a 30-70% reduction in pest problems after installation of insect screening.(6)

Thrips are so tiny and elusive, that the brand of insect screening you choose can make a big difference in how well it excludes thrips. In 1995, researchers from North Carolina reported that 27 types of insect screens were evaluated for thrips exclusion. Only 3 brands (FlyBarr®, BugBed®, No-Thrips®) were effective in preventing the entry of thrips into greenhouses.(7)

Cultural Controls
One option to consider is a fallow period in summer. To perform this operation successfully, the grower should first remove all plants, then all weeds, and then heat the greenhouse (either artificially or naturally) until soil temperatures reach 60°F. This temperature should be maintained for three weeks. During this time, any thrips eggs will hatch and the nymphs will starve for lack of food. Depending on fuel source and heating systems, the fallow period treatment could cost from five to fifteen cents per square foot, with floor heating being the least costly system.

This strategy has worked for Western flower thrips. Researchers found that an air temperature of 104° F with a relative humidity of 10% was sufficient to kill WFT (an environment that was fatal to plants within 4 days). However, when sufficient water was made available to keep plants alive in the greenhouse (whether weeds or crop plants), mortality of WFT was only 50%.(8)

Another recommended strategy for controlling thrips is to remove all flowers and buds, if not crucial to the crop. The flowers and buds should be put into plastic bags, sealed, and disposed of outside the greenhouse.

Plants that Repel Thrips
A large greenhouse grower in The Netherlands found that garlic plants are an effective way to repel thrips. He uses three potted garlic plants for every 30 square feet of bench area.(9)

Biological Control
Biological control of greenhouse thrips can be achieved through release of biocontrol agents such as predatory mites, lady beetles, and soil-dwelling mites. See Appendix II for a detailed summary of beneficial organisms used in greenhouse IPM. Please note that thrips are listed as target pests for each product in the table. A list of suppliers is also provided.

Certain crops are better adapted to biological control of thrips than others. Greenhouse vegetables, bedding plants, and tropical houseplants are better adapted to biological control than are floriculture crops. Thrips preferentially feed on flowers and leaves and cause little or no damage to fruits themselves. Thus, while fruit-bearing vegetable crops like tomatoes, cucumbers, and peppers are well suited to low populations of prey food (i.e., thrips), tolerance in floriculture crops is greatly reduced because feeding results in cosmetic injury on the marketable portion of the crop. When TSWV or INSV are present, tolerance is nil in either case.

A recent study showed that beneficial insects can control Western flower thrips on bedding plants, even though bedding plants have such a short turnaround time.(10) Treatments consisted of BotaniGard™ (a Beauveria bassiana-based product) applied at 1 lb./acre, Neoseiulus cucumeris mites applied weekly at a rate of 12,000 mites per 3,000 sq. ft. of growing area, and a combination of the two. Plants treated with B. bassiana had between .16 and .5 thrips/plant, while plants treated with predatory mites had a maximum of .15 thrips/plant. The untreated control plants had .75 to 1.25 thrips per plant.

Notes on biological control of thrips:
Release of biocontrol agents should begin as soon as thrips are detected on sticky traps, or even before detection, as part of a planned biocontrol release program on sensitive crops.
Adult female predatory mites (Neoseiulus) consume from 1 to 10 young thrips per day and have a 30-day lifespan. They can also survive on pollen and spider mites in the absence of thrips. Repeat applications of predators must be made to establish a 1:2 ratio of predators to prey. Neoseiulus attacks first instar (very young) thrips only and does not move long distances from where it is first placed. They are most often applied in small piles at the base of plants, or in paper bags. Usually, a small hole is made in the bag, and mites move out of the bag slowly.
Adult pirate bugs (Orius) consume 5-20 thrips (all stages) per day. They can survive on pollen in the absence of prey. Both adults and nymphs are predacious. Orius is the only predator that attacks thrips in tight places like flower buds. Since Orius is a strong flyer, it moves easily throughout the greenhouse.
Soil-dwelling predacious mites (Hypoaspsis) attack thrips in their pre-pupal and pupal stages when they inhabit the soil or growing medium. Hypoaspis mites are usually applied only once per crop or season.
Thripobius semiluteus is a parasitoid of greenhouse thrips nymphs.

Biorational Pesticides
While the practices of inspection, sanitation, physical exclusion, and biological control will go a long way towards managing thrips, there may still be instances when pesticides are necessary. Biorational pesticides—also known as least-toxic or "soft" pesticides—are emphasized in biologically intensive IPM programs and by growers depending on organic pest management (OPM) as part of certified organic production.

Thrips control can still be difficult even with the use of biorational pesticides. During much of their life cycle thrips exist as eggs, as pupae in the soil, or as extremely mobile adults. Once thrips infest a crop, the adult females begin feeding and laying their eggs. Thrips usually concentrate on rapidly growing tissues such as young leaves, flowers and terminal buds. This affinity for tight places makes thorough coverage with a pesticide difficult. Just prior to pupation, the larvae move down the plant to pupate in the soil or leaf litter. They are most vulnerable just after hatching and before pupation.

Dr. Richard Lindquist (11), entomologist at Ohio State University, demonstrated biorational control of flower thrips with either: a) M-Pede® insecticidal soap mixed with an emulsified crop oil, or b) weekly applications of neem seed oil (NSO) for four straight weeks. He also found that the fungus Paecilomyces fumosoroseus (PFR), the predatory mite Neoseiulus cucumeris, and an azadirachtin insecticide (neem) could be used alone or in combination for control of WFT in greenhouses.(12)

New Research with Thrips:
In laboratory trials and caged rose trials, Beauveria bassiana sprays killed up to 82% of the thrips on rose foliage.(13) Mortality increased along with humidity. Oil formulations of B. bassiana worked more quickly than wettable powders.
BotaniGard™ and Naturalis-O™, both of which use Beauveria bassiana, have been effective on a schedule of three to five applications at three to five-day intervals. The addition of Azatin™ (a neem product) may increase effectiveness.(14)
Dr. Richard Lindquist at Ohio State University found that four applications of Naturalis-O™ over a period of 15 days controlled thrips well on gerbera.(15)
In another study, Lindquist found that Conserve® (a new biopesticide formulated from the soil-inhabiting actinomycete Saccharopolyspora spinosa) was significantly better than Orthene™ at controlling Western flower thrips.(16) Plants treated with Conserve also had higher numbers of beneficial insects and mites—such as minute pirate bugs, predatory mites, and green lacewing larvae.
Neem extracts (trade names Azatin™, Neemazad™, and Neemix™ ) prevent development of flower thrips in the early larval stages, but have no effect on adults. Repeat applications are most effective.
In 1999, Dr. Dan Gilrein of Cornell Extension tested several biopesticides for their effect on Western flower thrips, including Avid (contains abamectin), Conserve (spinosad), Sanmite (the synthetic chemical pyridaben), BotaniGard (Beauveria bassiana), a combination of BotaniGard +Azatin (neem) + M-Pede (insecticidal soap), and Alsa (a garlic product).(17) Although Conserve performed best, other treatments also provided control. The table below is excerpted from an article in the September, 1999 issue of GMPro.
Researchers at Ohio State University are currently testing combinations of B. bassiana with the biorationals Azatin, Adept (an insect growth regulator), Conserve, Fulex SO-2000, Hot Pepper Wax, Garlic Barrier, yeast extract, and white sugar.(18) So far, they have shown that spray mixes combining B. bassiana with Adept, sugar, yeast extract or Azatin produce higher levels of infection and mortality in Western flower thrips. Specifically, white sugar at a rate of 1 lb./100 gallons and yeast extract at a rate of 0.25% wt/volume increased mortality by about 20 percent, presumably due to their ability to induce feeding. The opposite was true for plants treated with Hot Pepper Wax, an insect repellent and antifeedant. BotaniGard + Azatin showed excellent results: "Inclusion of Azatin at 1/10 or 1/4 the recommended rate led to a 50 and 100% increase, respectively, in infection and mortality."(18)
Biorational pesticides for greenhouse pests are summarized in Appendix III. Please note that thrips are listed as target pests for each product in the table.

Table 3.
Control of Western flower thrips on Chrysanthemum 'Linda' after four weekly applications.(17)
Treatment Thrips/plant Flower damage*
Avid 19.3 0.6
Conserve 3.6 0.6
Sanmite 17.3 0.8
BotaniGard ES 51.4 3
BotaniGard + Azatin + M-Pede 25.2 2.6 neem + soap did not do as well as avid
Alsa drench 4x rate 43 2.7
Alsa drench 1x rate 43.4 3
Water (control) 47.9 3.7
*Flower damage was based on a 0-5 scale, 0 = no damage and 5 = all flowers entirely brown.

Insect Growth Regulators
Insect growth regulators (IGRs) are another least-toxic pesticide control option for pests. IGRs typically kill insects by disrupting their development. They have a complex mode of action that precludes insects from rapidly developing resistance. IGRs can work in one of several ways:

they can mimic juvenile hormones, so that insects never enter the reproductive stage of development;
they can interfere with the production of chitin, which makes up the shell of most insects; or
they can interfere with the molting process.
IGRs usually work through ingestion, so good spray coverage is essential. They generally don't affect non-target species—such as humans, birds, fish, or other vertebrates. For most IGRs there are minimal re-entry restrictions. IGRs typically take several days to have an effect on pest populations. Because IGRs do not affect mature insects, adult beneficials released into the greenhouse after an IGR application are not likely to be affected. Use of IGRs is generally prohibited by organic certification organizations because the products are synthetic. IGRs can sometimes be used in conjunction with biological control efforts and may provide growers with a "safety net" should beneficials fail to keep the pests below economically damaging levels. The table below lists some well-known insect growth regulators.

Table 4. Selected Insect Growth Regulators
Brand Name Supplier Active Against
Adept Uniroyal Chemicals Not specifically labeled for thrips, but does seem to be effective when used in combination with B. bassiana
Azatin Hydro-Gardens, Olympic Horticultural Products whiteflies, leafminers, thrips, mealybugs, fungus gnats, aphids, cabbage loopers, diamondback moths, armyworms
Neemazad Thermo Trilogy whiteflies, leafminers, thrips, mealybugs, fungus gnats, aphids, cabbage loopers, diamondback moths, armyworms
Neemix Thermo Trilogy whiteflies, leafminers, thrips, mealybugs, fungus gnats, aphids, loopers, diamondback moths, armyworms, cabbage loopers
Precision Novartix thrips, whiteflies, fungus gnats
Preclude Whitmire Micro-Gen whiteflies, thrips, scales, aphids

Summary and Further Resources
Greenhouse thrips are tiny insects, but they demand serious attention on the part of the greenhouse grower. Integrated pest management offers a sustainable approach for dealing with greenhouse thrips, and safer pest control products facilitate the adoption of least-toxic control measures that dovetail very nicely with the IPM philosophy.

Related ATTRA Materials

Organic Greenhouse Vegetable Production
Integrated Pest Management for Greenhouse Crops
Greenhouse IPM: Sustainable Aphid Control
Greenhouse IPM: Sustainable Whitefly Control


For an overview of greenhouse IPM, please see the complementary ATTRA publication Integrated Pest Management for Greenhouse Crops. It contains an extensive listing of resources and publications on greenhouse IPM which support many of the concepts and practices outlined in this publication on greenhouse thrips.

In the Resources sections below, growers are provided with a list of key articles on thrips; contacts for IPM specialists in thrips control; biological control suppliers; and tables that summarize monitoring and scouting techniques, biocontrol agents, and biorational pesticides that help to control thrips.

References
1) Parella, Michael P. 1995. Thrips management guide—Part 1: Prevention and control. GrowerTalks. April. p. 30, 32, 34, 36, 38.

2) Aylsworth, Jean. 1994. Taking care of number one. Greenhouse Grower. February. p. 52, 54, 56.

3) Anon. 1993. Indicator plants give TSWV warning signs. Greenhouse Manager. March. p. 70.

4) Pundt, Leanne, John Sanderson, and Margery Daughtrey. 1992. Petunias are your tip-off for TSWV. GrowerTalks. November. p. 69, 71-72.

5) Allen, Wayne R. 1991. Get the jump on thrips and TSWV. Greenhouse Grower. July. p. 78, 80, 82.

6) Gill, S.A. and D.S. Ross. 1994. Insect microscreening: Its time has come. Greenhouse Grower. May. p. 77-82.

7) Grossman, Joel. 1996. Conference notes: Screening out greenhouse pests. The IPM Practitioner. September. p. 12.

8) Anon. 1992. Informed sources. Greenhouse Manager. August. p. 12.

9) Shipp, J.L. and T.J. Gillespie. 1993. Influence of temperature and water vapor pressure deficit on survival of Frankliniella occidentalis (Thysanoptera: Thripidae). Environmental Entomology. August. p. 726-732.

10) Gill, Stanton et al. 2000. Biological thrips control on bedding. GrowerTalks. February. p. 84-86.

11) Dr. Richard Lindquist
Department of Entomology
OARDC
Wooster, OH 44691
330-263-3736

12) Grossman, Joel. 1997. Conference Notes. The IPM Practitioner. September. p. 13.

13) Murphy, B.C. et al. 1998. Fungal pathogen controls thrips in greenhouse flowers. California Agriculture. May-June. p. 32-36.

14) Sanderson, John. 1999. Thrips tips. GrowerTalks. July. p. 128.

15) Gilrein, Dan. 1999. Control thrips from the start. Greenhouse Management and Production. January. p. 72-74.

16) Lindquist, Richard K. 1999. Evaluation of Conserve® for Western flower thrips control. Ohio Florists' Association Bulletin. March. p. 8.

17) Gilrein, Dan. 1999. Tips on controlling western flower thrips populations. GMPro. September. p. 81-82.

18) Brownbridge, Michael, Margaret Skinner, and Bruce L. Parker. 2000. Enhancing the activity of insect-killing fungi for floral IPM. Ohio Florists' Association Bulletin. January. p. 14-16.

Further Reading
Casey, Christine. 1997. Biological control of poinsettia pests. Greenhouse IPM Update. July 31. p. 1-3.

Casey, Christine. 1997. Biological control of thrips in retail greenhouses. Greenhouse IPM Update. August 14. p. 1-2.

Casey, Christine. 1997. Use of temperature and moisture extremes to manage Western flower thrips in greenhouses. Greenhouse IPM Update. February 13. p. 1-2.

Cloyd, Raymond. 1997. Western flower thrips: Biological controls can be effective if you know what, when & how to use them. Greenhouse Management & Production. April. p. 28-30.

Cloyd, Raymond A., Michael Brownbridge and Clifford S. Sadof. 1998. Greenhouse biological control of Western flower thrips. The IPM Practitioner. August. p. 1-9.

Gill, Stanton. 1994. Thrips management and biological control. GrowerTalks. October. p. 36-40.

Gilrein, Dan. 1999. Control thrips from the start. GMPro. January. p. 72-74.

Hsu, Cynthia, and Willam Quarles. 1995. Greenhouse IPM for Western flower thrips. The IPM Practitioner. April. p. 1-11.

Parella, Michael. 1995. Thrips management guide - Part 1: Prevention and control. GrowerTalks. April. p. 30, 32, 34, 36, 38.

Parella, Michael P. 1995. Thrips management guide - Part II: Proper identification. GrowerTalks. July. p. 82, 84, 86, 88, 91-92, 94.

Robb, Karen. 1996. Expand your thrips control arsenal, Part 2. Greenhouse Management & Production. June. p. 58, 60.

Sanderson, John P. 1997. Thrips in the greenhouse. Greenhouse IPM Update. Oct. 23. p. 1-2.

Sclar, D. Casey. 2000. An overview of Western flower thrips management: Insecticide sprays. Northeast Greenhouse IPM Notes. May. p. 1-3.

Willmott, James. 1998. Thrips control in vegetable transplants. Northeast Greenhouse IPM Notes. February. p. 1-2.

http://attra.ncat.org/attra-pub/gh-thrips.html

 

[Kenny Lingus]

I've found Bio Bizz' BUZZ-OFF to be quite efficient to thrip problems. Also No-pest strip helps a little to avvoid neew buggers coming in and such, but Buzz off is good.

Dillute 2ml/L of remedy in lukewarm water (ex: bodytemp).
-If the plants are small I would dip them in the solution for 5sec and make sure every crinkled leaf-pore was immerged. If I had larger plants I would just spray thoroughly untill dripping point.

The problem with thrips is the adults fly away immediately when you touch the plants (or even just enter the room!). Larvae/young thrips are also really fast, flat little critters. Some may just jump away and fall on the ground and others might attach themselves very strongly to the plants surface. They look similar to silverfish and seem to fit perfectly into small cracks and between tiny ridges on the leafs surface, thus making them extremely hard to rinse away.
-For these reasons it's quite neccessary with extreme measures. A vacuum cleaner to catch refugee thrips in the air when you approach your plants. You should also vac in the sphere around the foliage while you shake the bush vigorously. Keep the machine running for a while to make sure you trap them bugs within dust and dirt in the bag/bin.
-Next thing is rinsing/spraying. Use cold water with some preassure to flush as many creeps you can. After this you use your preffered mxture to poison any left over thrips. (dipping smaller plants in solution is very effective.)
-While you're fighting these creatures it's advicable to lower the temperature to around 20-22 dgr celsius and even lower nights temp to fuck up their breeding conditions.

You'll may have to repeat these procedures every 5th day for 3-4 weeks, and it is also important that you close any possible entrance for new pests to enter.

In a forum here at ICMAG I found the following suggestion.

http://www.icmag.com/ic/showthread.php?t=18473&highlight=lemon+juice

1/2 cup baking soda
1 cup food grade vinegar
3 tablespoons lemonjuice
2 drops of dishsoap

-Mix it in a 40Fl.OZ bottle and pour a cup of hot water into container and dillute to 40Fl.OZ.

This solution should be sprayed on plants and left to work for 20 minutes before you rinse it of thoroughly with clean tempered water. It is necessary that you cover the medium good because this mix is very alcaline.

The article claims this will dissolve eggs. larvae and insect bodies in genral and also kill off a large number of pests and some molds on various plants booth outdoors and indoors.

NB! WARNING
To blend alot of baking soda and vinegar in a closed container will cause an explosion and may damage skin and eyes when the caustic contents hit you.

-For this reason I am ot sure wether the article is an hoax or a serious gardening tip.

Edit: ^^^ You beat me with replieing to yourself there mate ^^^

And a very good post it was too.

 

[OGDread]

Necrotic Spot Virus

Necrotic Spot Virus

Hi,

with interest I read about the mention of Necrotic Spot Virus. Is this virus also capable of attacking canna?
I say this, because I think it may explain occurances of dark spots on my canna leafs, often after a thrip infestation has upped itself from low to medium..

ps, the only thing to seemingly somewhat control my thrips is neem oil.

 

[Babbabud]

Ive used neem successfully agains thrips twice. Spray three times over a period of 2 weeks. My understanding is the first spray strerilizes the adults and teh two continued sprays takes care of the rest. Worked for me just as it said.

 

[Berry_Coughin']

Does anyone else's Neem taste...err smell like Chinese food??

yeah right, that stuff is nasty, but does remind me of Oriental foods....