# Crawler

> The mobile first-instar nymph of a mealybug or scale insect; the only stage without protective wax, so the stage contact sprays hit best.

- Canonical: https://genetixbay.com/knowledge/glossary/crawler.html
- Also written: crawlers, mealybug crawler
- Glossary category: Pests and diseases · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

A crawler is the newly hatched first-instar nymph of a [mealybug](https://genetixbay.com/knowledge/glossary/mealybug.md) or scale insect. Crawlers are tiny, mobile and largely free of the wax that later protects the insect; they walk or are carried by wind, people and ants to new feeding sites. UC [IPM](https://genetixbay.com/knowledge/glossary/ipm.md) describes crawlers as the stage that disperses.

## In practice

Timing matters: contact classes such as soaps and oils work far better on crawlers than on waxy adults and egg sacs. Because mealybug generations take about four weeks at 25 C, crawler emergence comes in waves, and treatments are aimed at each wave rather than on a fixed weekly calendar. Follow the label and local law.

## Don't confuse with

- **Ovisac**: the cottony egg sac that crawlers hatch from.
- **Instar**: any stage between moults, not only the first.

## Related terms

[Mealybug](https://genetixbay.com/knowledge/glossary/mealybug.md), [Instar](https://genetixbay.com/knowledge/glossary/instar.md), [Honeydew](https://genetixbay.com/knowledge/glossary/honeydew.md)

## Read more

- [Mealybugs and root mealybugs on cannabis: ID, life cycle in numbers and IPM](https://genetixbay.com/knowledge/pests/mealybugs.md)

## Sources

1. Flint, M.L. Pest Notes: Mealybugs. UC ANR Publication 74174. https://ipm.ucanr.edu/PMG/PESTNOTES/pn74174.html