Arborjet Revolutionary Plant Health Solutions

Thrips

Thrips are slender, tiny insects that often have fringed wings and are generally 1 mm or less in size. Nymphs are elongate, lack wings and range in color from off-white or yellow to brown or black. Most thrips feed by sucking out cell contents of leaves or flowers, but some can cause leaf distortions or “galls” where they continue to feed and lay eggs. Thrips can have several generations (egg to adult) per year so these pest outbreaks can be very damaging. Although they are not good flyers they can be carried great distances by the wind. Given certain conditions, many species can amass a large population and travel in swarms.

 

Print PDF

 

Symptoms

Initial feeding symptoms on leaves appear as pale spots or stipples from the piercing- sucking mouthparts. At times, black feces will be present next to whitish feeding scars, and this sign will help distinguish damage caused by aphids that do not leave hard fecal matter. Certain species that cause galls, such as Myoporum and Cuban Laurel Thrips, can cause all of the new growth to appear tightly rolled or pod-like at branch tips.

 

   

 
 
 
 
 
 
 
A: Onion thrip (nymphs).
B: Pear thrip (adult).
C: Onion thrip damage.
 
Photo A taken by: Louis-Michel Nageleisen, Département de la Santé des Forêts,
Bugwood.org
Photo B taken by: Pennsylvania Department of Conservation and Natural Resources -
Forestry Archive, Bugwood.org
Photo C taken by: Whitney Cranshaw, Colorado State University, B B ugwood.org

Treatment

Thrips infestations can be swift and fleeting in landscape situations and may not always require an insecticide unless feeding activity is prolonged. Begin treatment with IMA-jet or ACE-jet as soon as thrips damage is positively confirmed and consider a sequential application with MIN-jet Iron or PHOSPHO-jet to assist with tree recovery.

When to Treat

An IMA-jet treatment early in the lifecycle of thrips is very effective and provides season-long control. Later season infestations or higher populations that require rapid control respond well to ACE-jet unless growing conditions extend more than 60 days, in which case a combination of ACE-jet followed by a low- medium rate of IMA-jet will provide good control. In the case of chemical-sensitive areas, the use of Eco-Mite Plus™ and AzaSol™ will provide suppression on a two-week application schedule. Generally, the best seasons for injection are spring and fall, since uptake occurs when trees are transpiring. The environmental conditions that favor uptake are adequate soil moisture and relatively high humidity. Soil temperature should be above 40°F for trunk injection. Hot weather and/or dry soil conditions may slow translocation of product into foliage so water trees before and after treatment application. The addition of a soil surfactant, such as NutriRoot, as a drench or sub-surface soil injection will encourage water to move deeper into the soil and increase moisture availability to the tree over time. If treating trees in the summer, inject in the morning for the quickest uptake.

What to Expect After Treatment

IMA-jet treatment will stop feeding activity within one to two days for common leaf-feeding thrips. For gall-forming thrips, use the highest rate of IMA-jet as soon as possible in the spring to encourage thinning to assist in the removal of infestation centers.

Related Videos

Video Library

Uploaded: 10/12/2015

More videos about Thrips »

Treat Now, It's Easy!

Hire a Professional



Find a Distributor


Don't wait until spring!

Current Pest Warnings

Emerald Ash Borer

Threatening over 20 states in the U.S. Learn More

Pine Bark Beetles

Threatening pines in Southern and Western U.S. Learn More

Rugose Spiraling Whitefly

Nuisance pest affecting trees in S. Florida Learn More