Estigmene acrea
Pest description and crop damage "Woolly bear" caterpillars up to 2 inches long, covered by long, red-brown hairs. They are seen especially in late season but rarely are an economic problem.
Scouting and thresholds No formal economic thresholds exist for saltmarsh caterpillar insecticide treatment decisions.
Management-biological control
- Bacillus thuringiensis aizawai (XenTari - live spores of an insect-killing bacterium)-See label for rates. PHI 0 days. Biological insecticide most effective against newly hatched larvae. No contact action; larvae must eat treated leaves. Use a spreader-sticker. REI 4 hr. Some formulations are OMRI-listed for organic use.
- Bacillus thuringiensis kurstaki (Biobit HP, Crymax, Deliver, Dipel DF, Javelin WG, and others - live spores of an insect-killing bacterium)-See label for rates. PHI 0 days. REI 4 hr. Biological insecticide most effective against small, newly hatched larvae. No contact action; larvae must eat treated leaves. Use a spreader-sticker. Some formulations are OMRI-listed for organic use.
- GS-omega/kappa-Hxtx-Hv1a (Spear LEP - peptide derived from spider venom)-See label for rates. Tank mix with Bacillus thuringiensis products (Bts) to enhance control. PHI 0 days
Management-chemical control
- azadirachtin/pyrethrins (Azera, Azera Pro) at 0.0125 to 0.025 lb ai/A, and up to 0.044 lb ai/A under extremely heavy infestation. Dilution in a minimum of 30 gal water per acre is recommended for conventional equipment. May be applied by air at the rate of 0.0125 to 0.025 lb ai/A in a minimum of 25 gal water. Do not repeat more than every 5 to 7 days. OMRI-listed for organic use.
- esfenvalerate, (Asana XL, S-fenvaloStar, Zyrate) at 0.03 to 0.05 lb ai/A. PHI 21 days. Apply as necessary but not more than 0.15 lb ai/A per season. Apply with ground or air equipment using enough water (at least 2 gal/A) to cover uniformly.
- methoxyfenozide (Inspirato 2F, Intrepid 2F, Invertid 2F, Troubadour, Vexer, Withstand, Zylo) at 0.12 to 0.25 lb ai/A. Apply at egg hatch or when signs of feeding occur. PHI 7 days.
- methoxyfenozide and spinetoram (Intrepid Edge) at 0.11 to 0.28 lb ai/A. Apply at egg hatch or first signs of feeding. PHI 7 days.
- pyrethrins (Lynx EC 1.4, Lynx EC 5.0, PyGanic EC 1.4, Tersus)-See label for rates. REI 12 hr. PHI 0 days. Some formulations are OMRI-listed for organic use.