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How to identify it
- Females are oval and grayish, almost 3/16 inch long, and covered with a thin white waxy coat, with small tufts of wax in three parallel rows down the back.[1]
- It is a short-tailed mealybug: the wax filaments at the rear are no more than a quarter of the body length, and the ones along the sides are short too.[1]
- Each female makes a dense, narrow white egg sac that eventually grows longer than she is.[1]
- Males are tiny two-winged, gnat-like insects with long white waxy tails; they usually fly after dark. Nymphs are small and yellowish, gradually gaining the adults' white wax.[1]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Madeira mealybug (Phenacoccus madeirensis) | A close relative that is hard to separate even under the microscope: specialists tell them apart by counting tiny wax pores on the back of the thorax.[2] |
| Citrus mealybug and other mealybugs | Several mealybugs infest the same houseplants. NC State notes that Mexican mealybug is less damaging than the citrus mealybug. Look for the Mexican mealybug's three rows of small wax tufts and its short tail filaments.[1] |
Where it lives
In the United States, ScaleNet's catalog records it from Florida, and NC State describes it as common on ornamentals and a minor pest of lima beans in warmer parts of the country. Elsewhere it is recorded from Baja California Sur in Mexico, the Caribbean (including Puerto Rico, Haiti and the Bahamas), Colombia, Spain, Sicily and the Canary Islands.[2][1]
Biology and life cycle
A female lays up to 400 eggs, which hatch in 6 to 14 days. Females pass through three nymphal stages; males have two, then a prepupa and pupa before becoming winged adults.[1]
In a greenhouse, development from egg to adult female takes about 47 days.[1]
Its hosts span at least 13 plant families, from aralia, English ivy, geraniums, chrysanthemums, gynura, hollyhock, lantana and poinsettia to coleus, primrose, loquat, peppers, tomato, beans and cotton.[1][2]
Natural enemies recorded on it include the mealybug destroyer (Cryptolaemus montrouzieri) and other lady beetles, plus parasitic wasps such as Leptomastix dactylopii.[2]
Damage and signs
Health risk
The sources treat it only as a plant pest; none mentions bites or other risk to people or pets.[1][2]
Control
Traps and physical control
On a few lightly infested plants, dab the mealybugs off with a cotton swab dipped in rubbing alcohol, then wash the plant with mild soapy water (soap, not detergent) to remove leftover wax and honeydew. Keep watching for a few weeks and remove new mealybugs as they appear.[1]
Pesticides
Insecticidal soaps and houseplant sprays or granules labeled for mealybugs can work. Because the egg sacs shield the eggs, treat at weekly intervals at least twice and probably three times so newly hatched mealybugs are hit too.[1]
Imidacloprid is one systemic insecticide NC State lists for homeowner mealybug control.[1]
Common questions
- What are the gray, waxy bugs with white tufts on my English ivy or geranium?
- Oval grayish mealybugs about 3/16 inch long with three rows of small white wax tufts and short tails are likely Mexican mealybugs, which are common on ivy, geraniums and other ornamentals.[1]
- Why do mealybugs keep coming back after I spray?
- Their dense egg sacs keep sprays from reaching the eggs, so new mealybugs keep hatching. Repeat treatments weekly two or three times.[1]
Sources
- NC State Extension, “Mexican Mealybug (PDIC factsheet).” content.ces.ncsu.edu/mexican-mealybug-1 (accessed 2026-11-09)
- ScaleNet (scale insect database begun at the USDA ARS Systematic Entomology Laboratory), “ScaleNet catalogue: Phenacoccus gossypii Townsend & Cockerell.” scalenet.info/catalogue/Phenacoccus%20gossypii/ (accessed 2026-11-09)
- iNaturalist, “Phenacoccus gossypii taxon page (order and family).” www.inaturalist.org/taxa/1476786 (accessed 2026-11-09)