Threecornered Alfalfa Hopper in Alfalfa
Crop Injury: Threecornered alfalfa hopper (Spissistilus festinus) is a pest of alfalfa in the southern United States. Injury to alfalfa occurs when nymphs and adults use piercing-sucking mouthparts to consume sap from plants, leading to reduced alfalfa quantity and quality. Feeding activity of adults and later-stage nymphs can appear as a series of small holes girdling stems and petioles. Leaf yellowing and purple stem discoloration result if feeding reduces nutrient uptake. Feeding injury can kill stems, lead to lodging, and provide pathogen entry points. Egg laying can also kill stems.
Pest Description: Adult hoppers are greenish with a triangle shaped plate on the back. At rest, the wings are folded beneath the plate. Adults fly quickly when disturbed. Tan to green nymphs have 12 spines running along the body and are typically stationary.
Threecornered alfalfa hopper
Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org
Threecornered alfalfa hopper
Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org
Life Cycle: Threecornered alfalfa hoppers overwinter as adults or eggs, depending on regional climate. Eggs are laid in alfalfa stems and in soil. Eggs hatch and nymphs begin feeding, developing through five instars before reaching adulthood. Multiple generations can occur per year.
Scouting: Use a sweep net to determine presence and number of threecornered alfalfa hoppers. Seedling year stands are at higher risk.
Management: Threecorneded alfalfa hoppers can be managed using an insecticide application based on insect numbers as determined through sweep net sampling (1.5 to 2 adults/sweep) or stem damage (10% girdled) coinciding with insect presence. Early harvest can help to avoid damage.
Using a Sweep Net in Alfalfa
Prepared and reviewed by the Alfalfa Pest Management Working Group.
Threecornered alfalfa hopper. Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org.
Threecornered alfalfa hopper. Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org.
Threecornered alfalfa hoppers. Gerald J. Lenhard, Louisiana State University, Bugwood.org.
Threecornered alfalfa hoppers. Gerald J. Lenhard, Louisiana State University, Bugwood.org.
Threecornered alfalfa hopper. Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org.
Gallery images courtesy Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org and Gerald J. Lenhard, Louisiana State University, Bugwood.org.
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