A crawler is the newly hatched first-instar nymph of a mealybug 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 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.
Soft-bodied sap-sucking insects of the family Pseudococcidae, covered in white waxy filaments, that hide in stem joints and roots and excrete honeydew.Integrated pest management: preventing and controlling pests by combining monitoring, prevention, cultural, biological and, as a last resort, chemical tools against set action thresholds.A developmental stage between two moults of an insect larva or nymph; control tactics often work only on early instars.The sugary liquid excreted by sap-feeding insects such as aphids, whiteflies, mealybugs and soft scales; it makes leaves sticky and feeds sooty mould.
