Epilachna borealis

(Fabricius, 1775)

Squash Lady Beetle, Squash beetle

Epilachna borealis, commonly known as the squash or squash , is a lady beetle to the eastern United States. Unlike most lady beetles that are predatory, this feeds exclusively on cucurbitaceous plants. and cause significant damage to squash, pumpkins, and related by skeletonizing leaves and feeding on fruit rinds. The species is frequently mistaken for 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 by its habits and association with plants. The combination of coloration with seven black spots per and four small spots on the separates it from most other North lady beetles. Resembles cucumber ( ) in general appearance but has the characteristic convex lady beetle body shape. Differs from the () by 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 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 feeding on cucurbitaceous plants. Both and consume leaf tissue between , creating 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 clusters of small on leaf surfaces of plants. 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 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 . Adults seek shelter in decaying vegetation or leaf litter for .

Ecological Role

and agricultural pest. Unlike predatory , does not contribute to of other . Serves as for and .

Human Relevance

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

Similar Taxa

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

Misconceptions

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

More Details

Taxonomic note

Member of Epilachninae, one of the few lineages of that evolved 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.