Thursday, August 20, 2020

Controlling Pest Caterpillar in The Field

Trichogramma wasp parasitizing lepidoptera egg.
Lepidoptera species are one of the top pests of hemp and cannabis production and may appear anytime from early spring well into fall.

Types of Lepidoptera

Species such as Eurasian Hemp Borer, European Corn Borer, Corn Earworm, and many others cause significant damage when left unchecked.

Types of Damage

Damage from these pests commonly takes two forms: stem boring or leaf chewing. Stem boring refers to when the insect eats its way into the plant, while leaf chewing refers to defoliation.




Understanding and controlling the lifecycles of these pests is key to season-long damage protection. Lepidoptera typically go through four main stages: egg, larval, pupal, and adult stage. The larval stage is represented by caterpillars. The pupal is the cocoon stage when they are often dormant. The adult stages appear as moths, flies, or butterflies. Different control strategies target different life stages, so timing control activities is very important.

Cultural management can help growers handle the larval and adult life-stages and generally follows these two focuses.  

·       Environmental Cleanup - Through the vigilant season-long reduction of weeds and plant debris, growers remove the preferred habitat, potential food sources, or breeding areas. This is effective at combating all four stages

·       Traps - The use of UV light traps and pheromone lures helps manage the population of adult moths when properly positioned and employed.

Spray treatments can be added to cultural control strategies and are highly effective for the larval stage, however they may not be approved for all locations or all crops.

Biological Control Agent (BCA) Options

Various species of Trichogramma wasps target the egg stage of many Lepidoptera. These biological control agents (BCAs) can be released either in a loose bulk carrier throughout the crop or as eggs on cards that can be hung on plants. As the Trichogramma eggs hatch, the wasps emerge and hunt down Lepidoptera eggs to parasitize. Once eggs have been attacked by wasps, the pest life cycle halts. Weekly applications should begin in early June to catch the first generation of eggs and continue throughout production through August. 

Different species of Trichogramma prey on different Lepidoptera species. Contact your GGSPro BCA specialist for help determining which species is most appropriate for your operation.



Griffin Lepidoptera Control Products

Product NameSupplierSpeciesSizeItem Number
Tricholine
Bioline
T. Brassicae
20K or 10K pupae
SB0451-04, SB0451-01
TRICHOforce B
Beneficial Insectary
T. Brassicae
10K pupae
30TBH
Trichogramma
Beneficial Insectary
Mixed
100k pupae
30TBH

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