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Cabbage Looper

Cabbage Looper

Trichoplusia ni

Insectalso: Looper

A smooth green caterpillar that loops its body like an inchworm as it crawls, chewing big holes in cabbage-family crops and many others. The cabbage looper is one of the common green caterpillars on cole crops, alongside the imported cabbageworm, and it skeletonizes leaves and bores into heads from midsummer on.

🔎 How to spot it

The caterpillar is smooth and pale green with a few thin white stripes down the back, up to about an inch and a half long, and it moves by arching its middle into a loop because it lacks the middle pairs of legs that smooth-crawling caterpillars have. Look for ragged holes chewed in leaves, dark green droppings, and young larvae skeletonizing leaf undersides. The night-flying gray moth has a small silver figure-eight mark on each forewing.

🥀 Damage it causes

Young loopers skeletonize the undersides of leaves, while older ones chew large ragged holes straight through leaves and into flower heads, and they bore into the heads of cabbage, broccoli, and cauliflower, contaminating them with droppings. Besides cole crops they feed on lettuce, beans, tomato, and many other plants.

🛡️ Prevent it

Cover cole crops with floating row cover from transplanting to keep the moths from laying eggs. Scout the undersides of leaves for the single round eggs and small loopers, and encourage the many natural enemies, parasitic wasps, predatory bugs, and birds, that usually keep loopers in check when broad-spray insecticides are avoided. Clean up crop debris after harvest.

🧯 If it is already here

Handpick the caterpillars, which is very effective on a few plants. For larger numbers, the organic sprays Bacillus thuringiensis (Bt) and spinosad work well on small loopers; aim for the leaf undersides and treat while larvae are young. Release or protect natural enemies, and tiny Trichogramma wasps are sold to parasitize the eggs before they hatch.

💡 Good to know

The looping crawl is the easy way to tell a cabbage looper from the velvety, smooth-crawling imported cabbageworm, which moves without arching. All the green cabbage caterpillars are controlled the same way, with row cover, scouting, and Bt. A healthy population of parasitic wasps usually keeps loopers from getting out of hand.

🌱 Plants it attacks

142 plants in the library can be attacked by this pest

Adirondack Blue PotatoAdzuki Bean🥔All Blue PotatoAmish Paste TomatoArugulaBarbara Karst BougainvilleaBeauregard Sweet Potato🍅Beefmaster TomatoBetter Boy Tomato🥬Bibb Lettuce🍅Big Beef TomatoBig Boy TomatoBlack BeanBlack Cherry TomatoBlack Krim Tomato🥬Black Seeded Simpson Lettuce🥕Black Spanish RadishBlack-Eyed PeaBloomsdale SpinachBlue Lake Green BeanBok Choy🍅Box Car Willie TomatoBrandywine TomatoBroad Windsor Fava BeanBroccoli RabeBrussels SproutsButtercrunch LettuceCalabrese BroccoliCannellini BeanCelebrity Tomato🥬Champion CollardsCheddar CauliflowerCherokee Purple TomatoCherry Belle RadishChicoryChinese BroccoliCollard GreensCranberry BeanCupani Sweet PeaDaikon RadishDandelionDe Cicco BroccoliDwarf Blue Curled Vates Kale🥬Dwarf Siberian KaleEarly Girl Tomato🌸Easter Egg RadishEndiveEnglish Shelling PeaField PeaFingerling PotatoFordhook 242 Lima Bean🥕French Breakfast RadishFriséeGerman Butterball Potato🍅German Queen TomatoGreen CabbageGreen Leaf LettuceGreen Zebra TomatoHakurei TurnipHorseradishIceberg LettuceIndigo Rose TomatoJanuary King CabbageJuliet Grape TomatoKellogg's Breakfast TomatoKennebec PotatoKentucky Wonder Pole BeanKidney BeanKohlrabi🍅La Roma IV TomatoLacinato KaleLamb's QuarterLemon Boy TomatoLincoln Pea🥬Little Gem Lettuce🥬Lollo Rossa LettuceMâcheMalabar SpinachMizuna🍅Mortgage Lifter TomatoMr. Stripey TomatoMung BeanMustard GreensNapa CabbageNavy BeanNew Zealand SpinachNorland Potato🥬Oakleaf LettuceOrachPineapple TomatoPinto Bean🌱Provider Bush Bean🥦Purple Cape Cauliflower🥔Purple Majesty PotatoPurple Sprouting BroccoliPurple Top TurnipPurslaneRadicchio🥕Rainbow Carrot MixRainbow Chard

For educational and informational purposes only. Pest control advice is general guidance drawn from university cooperative extension sources; always identify a pest positively and read and follow the label on any product before use, especially around food crops, children, and pets.