Trichogramma brassicae – Egg Parasitoid Wasp for Caterpillar & Borer Control

Trichogramma brassicae is a minute parasitic wasp used to control caterpillar pests by attacking them at the egg stage—before they hatch and cause crop damage. Especially effective in cole crops and cool-climate plantings, this beneficial insect targets over 200 species of moths and butterflies, including armyworms, cabbage worms, loopers, borers, fruitworms, and hornworms. By preventing egg hatch, T. brassicae provides reliable, chemical-free protection for vegetables, orchards, vineyards, and field crops. How It Works Female wasps lay their eggs inside pest moth eggs. The developing larvae consume the contents, preventing caterpillar emergence. Parasitized eggs turn brown to black, serving as an indicator of success. Adults emerge in 7–10 days, continuing the cycle. Each female can parasitize up to 300 pest eggs during her 1–2 week lifespan. Effective control requires releasing T. brassicae at the first sign of moth flight, before larval feeding begins. Targets These Pest Species Armyworms (Spodoptera, Pseudaletia) Cabbage worms, loopers, moths Cutworms (Agrotis, Peridroma) Corn earworm & European corn borer (Ostrinia nubilalis) Codling moth, oriental fruit moth Tomato hornworm Squash vine borer Leafrollers, webworms, bollworms 200+ additional Lepidoptera pest species Ideal Conditions Best for low-growing crops (e.g., broccoli, cabbage, kale) Temperature range: 70–90°F ideal for rapid development Emergence: 2–5 days after receipt (from cards) Full lifecycle: ~10 days (temperature-dependent) Application Instructions Monitor pest flight using pheromone traps to time releases Release at first moth flight and continue every 7–10 days while moth activity persists Do not touch parasitized eggs on cards or tabs Place cards or tabs evenly throughout crop canopy; for bulk eggs, use release boxes or distribute in shaded areas Release Rates On cards (100,000 eggs per card, 30 tabs of ~3,300 eggs each): Greenhouse/low plants: 1 tab per 3,000 sq. ft. or per tree Field: ½–2 cards per acre weekly for 2–6 weeks Bulk eggs: Greenhouse: 1–2 per sq. ft. Field: 50,000–100,000 per acre Where to Use Cole crops (cabbage, broccoli, kale, etc.) Greenhouses Orchards and vineyards Outdoor vegetable beds and row crops Container plants Storage Storage: Keep at 80–90°F in a warm, shaded location until adults emerge Do not refrigerate; release immediately upon emergence Quick Tips ✔ Time releases carefully with pest flight patterns for best results ✔ Ideal for cool-season and cole crop protection ✔ Use alongside Bacillus thuringiensis (Bt) for layered caterpillar control ✘ Not effective once caterpillars have hatched—apply early