Pest profile

Pickleworm

Diaphania nitidalis · Lepidoptera: Crambidae[2]

Pickleworms invade much of the Southeast each summer and tunnel into squash and cucumber blossoms and fruit.[1]

Pickleworm moth with brown wings and a yellowish translucent central patch, resting with wings spread
Pickleworm moth with brown wings and a yellowish translucent central patch, resting with wings spread. Photo: kcthetc1, public domain (CC0), via iNaturalist

How to identify it

  • Eggs are tiny and white turning yellow, laid in small clusters on buds and flowers.[1]
  • Moths fly at night, most around midnight.[1]

Where it lives

A tropical insect, it overwinters only in south Florida and perhaps south Texas, then disperses across the Southeast each summer; the Carolinas regularly see crop damage.[1]

US map: public records from 18 states since 1990 (GBIF).

Biology and life cycle

The life cycle takes about 30 days, with two to four overlapping generations in Georgia and the Carolinas.[1]

Damage and signs

  • It damages summer and winter squash, cucumber, cantaloupe and pumpkin; blossoms are a favored site, and larvae often burrow into fruit.[1]

Health risk

It feeds on cucurbits; UF/IFAS mentions no risk to people.[1]

Control

Prevention

Plant early so part of the crop is harvested before pickleworms arrive.[1]

Keep them out

Screens or row covers keep moths off; uncover plants by day for bee pollination, since moths fly at night.[1]

Common questions

What's boring into my squash blossoms in late summer?
In the Southeast, pickleworm larvae are a common cause.[1]
How can I avoid pickleworms?
Plant early, or cover plants at night with row covers.[1]

Sources

  1. University of Florida IFAS Extension (Featured Creatures), “Pickleworm, Diaphania nitidalis (EENY-164).” edis.ifas.ufl.edu/publication/IN321 (accessed 2026-10-06)
  2. iNaturalist, “Diaphania nitidalis taxon page (order and family).” www.inaturalist.org/taxa/126218 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.