Pest profile

Potato/Tomato Psyllid

Bactericera cockerelli · Hemiptera: Triozidae[2]

The potato/tomato psyllid is the most damaging insect of tomatoes and potatoes in Colorado, mostly through its toxic saliva.[1]

Potato/tomato psyllid adult, a tiny cicada-like insect with clear wings and white bands, on a green leaf
Potato/tomato psyllid adult, a tiny cicada-like insect with clear wings and white bands, on a green leaf. Photo: Jesse Rorabaugh, public domain (CC0), via iNaturalist

How to identify it

  • Adults look like tiny cicadas about 2 mm long, dark gray with prominent white bands on the abdomen and stripes on the thorax; they jump.[1]
  • Nymphs are flat, oval and wingless, yellowish or orange at first and greener as they grow, mostly under lower leaves.[1]
  • Feeding nymphs leave 'psyllid sugar,' wax-covered pellets that look like granulated salt or sugar on leaves below.[1]

Look-alikes

Look-alikeHow to tell them apart
Potato flea beetlesThey also jump and often turn up in the same sweep-net samples on potato.[1]

Where it lives

It overwinters mainly in southern Texas and northern Mexico and migrates north, usually reaching Colorado in May or early June.[1]

US map: public records from 6 states since 1990 (GBIF).

Biology and life cycle

Eggs are tiny, orange-yellow and on stalks; they hatch in about a week, and nymphs mature in two to three weeks.[1]

Four or more generations can occur in a growing season; in greenhouses it can persist year-round.[1]

Damage and signs

  • Psyllid yellows causes yellow or purple leaves, stunted and curled new growth, and small, misshapen potato tubers.[1]
  • Tomato fruit stays smaller, duller and less flavorful; the psyllid also carries the bacterium behind zebra chip of potato.[1]

Health risk

It feeds on plants; CSU Extension mentions no risk to people.[1]

Control

Prevention

Survey every year: check leaf undersides for nymphs and psyllid sugar, or sweep larger plantings, especially in June and early July.[1]

Biological control

Damsel bugs and minute pirate bugs are its most important predators.[1]

Pesticides

Spinosad is the most commonly available effective insecticide; horticultural oils give some control of nymphs.[1]

Common questions

Why are my tomato plants turning yellow-purple and stunted?
Psyllid yellows from potato/tomato psyllid saliva is one cause.[1]
What is the white sugary stuff on my tomato leaves?
It may be psyllid sugar excreted by feeding potato/tomato psyllid nymphs.[1]

Sources

  1. Colorado State University Extension, “Potato or Tomato Psyllids (Fact Sheet 5.540).” extension.colostate.edu/resource/potato-or-tomato-psyllids/ (accessed 2026-10-06)
  2. iNaturalist, “Bactericera cockerelli taxon page (order and family).” www.inaturalist.org/taxa/372093 (accessed 2026-10-06)

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