Orangedog Caterpillars on Lemon Tree: Hand-Pick or Bt

Large, ugly worms on lemon leaves in Mobile, AL with forked red "tongue" (osmeterium) when poked—orangedog caterpillars (Papilio cresphontes larvae), immature giant swallowtail butterflies.

Control

• Hand-pick or shake off small trees.
• Bt (Bacillus thuringiensis): Dipel or Thuricide—biological, caterpillar-specific.
• Neem oil ineffective (user tried).

Perspective

They mimic bird droppings. Damage usually minor on mature trees. Butterflies are beneficial pollinators.