Cross-striped cabbageworm
The cross-striped cabbageworm is the caterpillar of a small night-flying moth related to the European corn borer. Unlike the other cabbage caterpillars, the moth lays its eggs in clusters, so the caterpillars feed in a group on one plant. They riddle the young leaves and terminal buds with holes and can skeletonise that plant while its neighbours are untouched. The caterpillars are bluish-grey with numerous black bands across the back and a yellow line along each side, and grow to ¾ inch. The pest was once mainly southern, but UMass now calls it a serious problem on brassicas in southeastern New England. Numbers generally reach damaging levels only in late summer, and are highest on late plantings.
Evergestis rimosalis larvae feeding together in the terminal bud of a collard plant. Photo: pending.
Identification
The caterpillars are light bluish-grey on top and green underneath, with many black stripes running across the back. Along each side, below the cross-bands, runs a yellow line; Kentucky describes it as a black-and-yellow stripe. They grow to ¾ inch (19 mm) in two to three weeks. The markings separate this from every other cabbage caterpillar: the imported cabbageworm is velvety green, the cabbage looper is smooth green with white side lines and arches as it walks, and the diamondback moth caterpillar is tiny and wriggles when touched. Finding several caterpillars together is itself a clue.
The eggs are flattened, scale-like and light yellow, laid in overlapping clusters on leaf undersides. UMass counts 3 to 25 per cluster and Kentucky 20 to 30. The moth is straw-coloured to brown, with a little purple and wavy or zigzag lines, and a wingspan of about 1 inch. It flies at night, so most gardeners see only the caterpillars. Mature larvae drop to the soil and pupate in a tight cocoon just below the surface.
Easily confused with
- Imported cabbagewormAlso a pestVelvety green and sluggish, with often a faint yellow-orange stripe down the back and four pairs of prolegs in the middle of the body, so it crawls flat rather than looping.
- Cabbage looperAlso a pestSmooth, pale green with a white line along each side, and fewer legs in the middle of the body (two pairs of prolegs, against four on the cabbageworm): it walks by arching its middle into a loop, like an inchworm.
- Diamondback moth caterpillarAlso a pestUnder ½ inch when full grown, tapered, with a forked tail end. Disturb it and it wiggles vigorously and may drop off the plant on a silk thread.
Damage symptoms
The caterpillars feed on all the tender parts of the plant and prefer the terminal buds. Young leaves and buds end up riddled with holes, like buckshot. Larvae also feed on sprouts and burrow into heads. Because a whole cluster of eggs hatches on one plant, damage is patchy: a heavily infested plant is often completely skeletonised while the plants next to it are left undamaged.
- Young leaves and buds riddled with small holes
- Terminal buds and sprouts eaten; heads bored into
- Individual plants skeletonised to the veins beside clean plants
- Groups of banded caterpillars on the same plant
- Flat yellow egg clusters on leaf undersides
Lifecycle & degree days
There are two to three generations a year, but numbers generally do not reach damaging levels until late summer, so late-season plantings suffer most. The pest does not generally overwinter in New England. UMass saw one very early infestation that suggested caterpillars had overwintered in a high tunnel. Mature larvae pupate just below the soil surface. None of the sources checked gives degree-day or stage-length figures beyond the two to three weeks of larval growth.
- Generations / yr
- 2–3
- Larval growth
- 2–3 weeks to ¾ inch
- Pupates
- In a cocoon just below the soil surface
- Damaging from
- Late summer, on late plantings
- Overwinters
- Not generally in New England; possibly in high tunnels
Host crops
It feeds on cabbage, broccoli, cauliflower and other brassicas. UMass advises controlling wild mustard and shepherd's purse to help keep numbers down. In a Missouri organic cabbage study (Shrestha et al. 2019), red Russian kale planted as a trap crop carried 154 times more cross-striped cabbageworms per plant than the cabbage, and glossy collards 54 times more. That strong preference is the basis for trap-cropping it.
Monitoring & action thresholds
This is the UMass commercial threshold. It is much lower than the 10–35% UMass uses for the other cabbage caterpillars, because this pest is so destructive. No source sets a home-garden figure. In practice, check every plant in late summer and act on the first infested plants.
From midsummer, turn over leaves and look for flat yellow egg clusters and for groups of small banded caterpillars, paying most attention to the terminal buds. Late-season plantings are the ones to watch. The moths fly at night and are seldom seen, and because infestations are clumped you need to check many plants, not a few.
Biological control
The braconid wasp Cotesia orobenae parasitises cross-striped cabbageworms. In the Missouri study, parasitism rose when sweet alyssum and buckwheat were planted with the trap crop, and eggs and larvae of the spotted lady beetle Coleomegilla maculata were also more common there. UMass reports that the purchased egg parasitoid Trichogramma brassicae attacks all the brassica caterpillars, and passes on a supplier's view that Trichogramma work better against moths that lay eggs in clusters, like this one; that is a supplier's claim, not a trial result. The evidence on flowers is mixed. In a two-year collard trial (Ghani & Bilbo 2026), plots with sweet alyssum and Bt sprays had the least diamondback moth, but the damage and yield results suggested alyssum was a drawback for cross-striped cabbageworm. In that trial, both Bt and bifenthrin sprays effectively managed a 2023 cross-striped cabbageworm outbreak.
Cultural controls
Hygiene and a trap crop reduce the late-summer build-up.
- Plough under or remove crop debris after harvest
- Control wild mustard and shepherd's purse in and around the garden
- Plant red Russian kale or glossy collards as a trap crop, and treat or remove the caterpillars that gather on it
- Check late plantings closely from midsummer for egg clusters and groups of caterpillars
Chemical, last resort
- Bt kurstakiREI 4 h
- SpinosadREI 4 h
- ChlorantraniliproleREI 4 h
Sources
Univ. of Kentucky ENTFACT-300, Cabbage Pests (Bessin, rev. 1/26)
UMass Extension Vegetable Program, Cross-Striped Cabbageworm (2013)
UMass Extension, Caterpillars in Brassica Crops (Hazzard, Scheufele & McKeag, 2022)
Shrestha, Finke & Piñero, The 'Botanical Triad', Insects 10: 181 (2019)
Ghani & Bilbo, Sweet alyssum and selective insecticides for DBM biocontrol, J. Econ. Entomol. 2026
UC IPM Cole Crops PMG, Imported Cabbageworm treatment table (REIs, 12/20)
UC IPM, Relative Toxicities of Insecticides Used in Cole Crops to Natural Enemies
DiPel DF label, EPA Reg. 73049-39 (2022)
Bonide Thuricide concentrate label, EPA Reg. 4-226 (2016)
Page status
Drafted from the sources below, then checked claim by claim against those sources on 23 September 2026.
Suggest a correction →Cross-striped cabbageworm by crop
The same pest behaves differently on different hosts. Each page below gives the host-specific control, rate and threshold.