Cucurbit-specialist
Guides
Acalymma
striped cucumber beetles, cucumber beetles
Acalymma is a genus of leaf beetles in the family Chrysomelidae comprising approximately 72 described species in the Western Hemisphere. The genus is primarily distributed in the New World, with most species occurring in North America including Mexico. Two species, A. vittatum (striped cucumber beetle) and A. trivittatum (western striped cucumber beetle), are major agricultural pests of cucurbit crops. Acalymma species are specialists on plants in the family Cucurbitaceae, with adults feeding on leaves, flowers, and fruit, and larvae feeding on roots.
Acalymma trivittatum
Western Striped Cucumber Beetle
Acalymma trivittatum, the western striped cucumber beetle, is a specialist leaf beetle native to western North America. It is a key agricultural pest of cucurbit crops including melons, cucumbers, squash, and pumpkins. The species is closely related to the eastern striped cucumber beetle (Acalymma vittatum), with which it shares similar biology and damage potential. Both adults and larvae cause significant economic injury through direct feeding damage and transmission of bacterial wilt pathogen Erwinia tracheiphila.
Acalymma vittatum
striped cucumber beetle
Acalymma vittatum, the striped cucumber beetle, is a chrysomelid beetle native to eastern North America and a serious agricultural pest of cucurbit crops. Adults and larvae both feed on host plants, with adults damaging foliage, flowers, and fruit while larvae feed on roots. The species is a vector of Erwinia tracheiphila, the causal agent of bacterial wilt, which can destroy susceptible crops. Males produce an aggregation pheromone, vittatalactone, that attracts both sexes to host plants and facilitates mate finding. The species is replaced west of the Rocky Mountains by the western striped cucumber beetle, Acalymma trivittatum.
Anasa tristis
Squash Bug
Anasa tristis is a significant agricultural pest native to North America, specializing in cucurbit crops including squash, pumpkins, and zucchini. Adults are greyish-brown, flattened insects approximately 1.5 cm long with distinctive alternating brown and gold spots along the abdominal margin. The species is a phloem-feeding sap sucker that physically damages plant xylem and leaves, causing wilting, darkening, and death. It also vectors the bacterial pathogen Serratia marcescens, which causes cucurbit yellow vine disease—a condition particularly prevalent in Oklahoma and Texas but spreading to other regions. When disturbed, adults emit an unpleasant odor.
Diabrotica
cucumber beetles, corn rootworms
Diabrotica is a large, widespread genus of leaf beetles (Chrysomelidae) comprising approximately 400 species native to the Americas. The genus includes several economically significant agricultural pests, particularly species affecting corn, cucurbits, and other crops. Three informal species groups are recognized—fucata (354 species, multivoltine), virgifera (24 species, univoltine), and signifera (11 species, univoltine)—based on life history traits rather than molecular phylogeny. The genus exhibits a unique evolutionary relationship with cucurbitacin-producing plants, with beetles attracted to these bitter, toxic compounds for chemical defense.
Diaphania nitidalis
pickleworm, pickleworm moth
Diaphania nitidalis is a significant agricultural pest of cucurbit crops, particularly damaging to squash, cucumbers, and melons. Adults are nocturnal moths with iridescent brown wings marked by yellow bands and white borders. Larvae feed voraciously on reproductive tissues, flowers, and fruits, often burrowing into fruit flesh. The species is tropical in origin and intolerant of cold temperatures, limiting its permanent range to southern North America and tropical regions, though it migrates northward seasonally.
Peponapis pruinosa
eastern cucurbit bee, squash bee, hoary squash bee
Peponapis pruinosa is a solitary ground-nesting bee specialized on cucurbits (squash, pumpkins, and gourds). It is an oligolege, collecting pollen exclusively from Cucurbita species. The species expanded its range dramatically following human cultivation of squash throughout North America. It is an effective pollinator of cultivated cucurbits and often completes its entire life cycle within agricultural fields.