Insect Identification
Insect Identification

Three Lined Potato Beetle - (Lema trilinea)

Authored By Staff Writer | Last Updated: 2/7/2014

The multicolored Three-Lined Potato Beetle loves to eat a wide array of food plants making them a real pest.

Picture of Three Lined Potato Beetle

This species larvae feed on the leaves of potato plants, nightshades like peppers, eggplant and tomatoes as well as tomatillos, the green 'tomatoes' used to make salsa verde. The larvae are grayish in color and are grub-like in form. Newly hatched Three-Lined Potato Beetles will congregate on a food plant and eat the leaves until only the middle vein remains. They secrete a frothy substance over themselves as they eat. Once the leaves of the plant have been completely devoured, the plant dies without bearing any edible vegetables.

They can be found in meadows, garden beds or cultivated fields. Three-Lined Potato Beetles resemble Striped Cucumber Beetles, but the potato beetle has a narrow 'waist' and the cucumber beetle does not.

Females will lay yellow eggs on leaves of the food plant. After hatching and eating the plant leaves, the larvae move to ground level and pupate in the dirt, emerging as adults. Up to two generations can be produced a year and adults can survive the winter. This makes the population growth somewhat rapid and destructive to food plants.

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Category: Beetle
Common name: Three Lined Potato Beetle
Scientific Name: Lema trilinea
Other Names: Potato Beetle, Potato Bug

  Kingdom: Animalia
   Phylum: Arthropoda
    Class: Insecta
     Order: Coleoptera
      Family: Chrysomelidae
       Genus: Lema
        Species: trilinea

Adult Size (Length): 5mm to 8mm (0.20in to 0.31in)

Identifying Colors: black; yellow; red; orange

Additional Descriptors: striped, multicolored, flying, harmful

North American Reach (Though Not Limited To*): Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Hawaii; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming; Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Nova Scotia; Ontario; Prince Edward Island; Quebec; Saskatchewan; Mexico

* Keep in mind that insect reach is not governed by lines on a map and therefore may appear in areas/regions/states beyond those listed above.