Field Identification
Datana larvae gang-rush rhododendrons and azaleas in late summer—black bodies with broken yellow stripes and a habit of rearing both ends when disturbed like a confused inchworm committee. One colony can skeletonize a branch before your coffee cools.
Early instars feed together in tight groups; later they spread. Yellow-and-black adults are nondescript hand-moth types you will never notice unless you are trapping lights.
How to Deal With It
Organic Control Methods
Bt kurstaki while larvae are small and actively feeding—spray leaf undersides; spinosad as a backup if they are nearing full size (mind pollinator rules on blooming plants).
Tachinid flies and ichneumonid wasps stitch up late instars; spiders and songbirds snack on stragglers.
Accept minor nibbles on native plantings; on specimen shrubs, scout the interior canopy where clusters hide from polite society.
Clip infested terminals into a bucket of soapy water—fast, smug, and chemical-free.
Walk lines in August; early removal of one cluster prevents headline defoliation.
Let Nature Handle It
Natural Enemies
- Tachinid Flies
- Ichneumonid Wasps
- Spiders
- Songbirds
Threat Map