Thrips are one of the earliest insect pests of peanuts. These small flying insects have bristly wings and can fly or ride the air currents over long distances. There are several species of thrips found on peanuts, most commonly being tobacco thrips and western flower thrips.
Adults thrips lay eggs on peanut stem terminals. These eggs hatch into small, yellow immature thrips that start a fresh generation (two to three week life cycle). Thrips are capable of reproducing parthenogenetically (reproduction by development of an unfertilized usually female gamete). For this reason, thrips populations can increase rapidly over few weeks and overcome peanut seedlings.
Effects on Peanuts
Adults thrips are good at finding host plants as they migrate to peanut fields. Once on a host plant, they start feeding on the terminal leaves of peanut seedlings with their rasping mouthparts. This extensive feeding can cause severe leaf deformation and death of small plants that may exacerbated by drought or unfavorable growing conditions for peanuts. Thrips can also transmit the spotted wilt disease in peanuts.
Many peanut producers use phorate (Thimet) as an in-furrow treatment. This treatment protects plants when adequate levels of soil moisture is present. Extension professionals have tested other in-furrow products and found them to be effective at labelled rates in a single-row planting system. These products include imidacloprid (Admire Pro 4.6F and Velum Total pre-mix) and acephate. Foliar applications of Orthene can also be applied.
A word of caution. If a producer applies peanuts as twin rows, then they are splitting application over two rows. That definitively reduces the effectiveness of in-furrow insecticides.
Producers should watch out for high thrips populations this summer and apply rescue foliar insecticides for thrips control as needed. Some excellent foliar materials include spinetoram (Radiant 1 SC), novaluron (Diamond 0.83EC), and others.
Radiant is an excellent rescue insecticide against thrips and is also effective against small caterpillars and other pests that may visit peanut plants.
Consult the Peanut IPM Guide for all insecticide choices. Before applying, make sure to read the chemical’s label and follow application rates and directions. Producers should plan to include insecticides from different chemical classes in their integrated pest management strategies (IPM) to avoid insecticide resistance.
Alabama Extension agronomic crops regional agents and specialists are available to assist producers with insect identification and IPM planning that is suitable for their location. For more information, contact Ayanava Majumdar or Scott Graham.
The following resources can also assist producers in thrips management:
- Sucking Pests of Peanuts in Alabama: Thrips
- Using the Thrips Infestation Predictor for Cotton
- Tobacco Thrips
Trade names are used only to give specific information. The Alabama Cooperative Extension System does not endorse or guarantee any product and does not recommend one product instead of another that might be similar.