Sideways... Wjich strain of BT are you using? BT israelisis is suited for controlling fly family pests while BT kurstaki which is found in Safer Caterpillar Killer and Dipel DF is suited to controlling caterpillars. Lots more white butterflies in the garden this year. Just started the Dipel and have been doing monthly Spinosad treatments.
Also, what time of day did you apply the BT? It doesn't last long in sunlight. I hope you have better success this year controlling the pest.
Also, what time of day did you apply the BT? It doesn't last long in sunlight. I hope you have better success this year controlling the pest.