Epilachna borealis

(Fabricius, 1775)

Squash Lady Beetle, Squash beetle

Epilachna borealis, commonly known as the squash lady beetle or squash , is a phytophagous lady beetle native to the eastern United States. Unlike most lady beetles that are predatory, this feeds exclusively on cucurbitaceous plants. and larvae cause significant damage to squash, pumpkins, and related crops by skeletonizing leaves and feeding on fruit rinds. The species is frequently mistaken for beneficial lady beetles or cucumber beetles due to its similar appearance.

Epilachna borealis by (c) skitterbug, some rights reserved (CC BY), uploaded by skitterbug. Used under a CC-BY license.

Histoire physique, politique et naturelle de l'ile de Cuba (Tab. 11) BHL34893042 by Orbigny, Alcide Dessalines d'; Richard, Achille; Sagra, Ramón de la. Used under a Public domain license.

Field book of insects (6244370848) by Lutz, Frank Eugene. Used under a Public domain license.

Pronunciation

How to pronounce Epilachna borealis: /ɛpɪˈlæknə bɔːriˈælɪs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from predatory lady beetles by its phytophagous habits and association with cucurbit plants. The combination of yellow coloration with seven black spots per and four small spots on the pronotum separates it from most other North American lady beetles. Resembles cucumber beetles ( Chrysomelidae) in general appearance but has the characteristic convex lady beetle body shape. Differs from the (Epilachna varivestis) by plant association and subtle spot pattern differences.

Images

Habitat

Found in agricultural settings, gardens, and natural areas where cucurbitaceous plants grow. Associated with cultivated and wild squash, pumpkins, gourds, and related plants. Requires moist conditions favorable to plant growth.

Distribution

Eastern United States. Records include Vermont and surrounding regions.

Seasonality

Active during spring through fall, with in protected locations. Adults emerge in spring to resume feeding and . Later in the season, adults feed on pumpkin and squash rinds.

Diet

Specialized herbivore feeding on cucurbitaceous plants. Both and larvae consume leaf tissue between , creating skeletonization damage. Adults have been observed feeding on pumpkin and squash rinds later in the growing season.

Host Associations

Cucurbitaceae - of plants including squash, pumpkins, cucumbers, melons, and gourds

Life Cycle

Females deposit clusters of small yellow on leaf surfaces of plants. Larvae hatch and feed on leaf tissue, creating semi-circular trenches around feeding areas before consuming enclosed tissue. Larvae complete development and pupate, with emerging to continue feeding. Adults overwinter in protected locations and resume activity in spring. Multiple per year likely in favorable climates.

Behavior

and larvae feed by producing a semi-circular trench around their intended feeding area before consuming the enclosed leaf tissue. Gregarious feeding observed, with multiple individuals feeding on same plant. Adults seek shelter in decaying vegetation or leaf litter for .

Ecological Role

Herbivore and agricultural pest. Unlike predatory lady beetles, does not contribute to of other insects. Serves as prey for and .

Human Relevance

Significant agricultural pest of squash, pumpkins, and related crops. Damage includes leaf skeletonization and direct feeding on fruit rinds, reducing yield and marketability. Often mistaken for beneficial lady beetles, leading to delayed management. Control methods include hand removal, , , and using such as Pediobius faveolatus.

Similar Taxa

Epilachna varivestis is congeneric and shares phytophagous habits, but feeds on legumes rather than cucurbits and has slightly different spot patterns
Acalymma vittatumStriped cucumber beetle resembles E. borealis in coloration and shares cucurbit , but has more elongated body and different elytral pattern
Diabrotica undecimpunctata howardiSpotted cucumber beetle has similar spotted appearance but more elongated body shape and different spot arrangement
Coccinella septempunctataSeven-spotted lady beetle is predatory and beneficial, with similar spot count but red/orange coloration and different spot arrangement; does not damage plants

Misconceptions

Frequently mistaken for beneficial predatory lady beetles due to resemblance, leading to failure to control . Also confused with cucumber beetles (family Chrysomelidae) due to similar coloration and shared plants.

More Details

Taxonomic note

Member of Epilachninae, one of the few lineages of Coccinellidae that evolved herbivory rather than . This subfamily includes several agricultural pests across the Americas.

Defensive secretions

Like other Epilachna , likely produces defensive alkaloidal compounds when disturbed, though this has been more thoroughly documented in E. varivestis.