Potato Psyllid
Beginner
Scientific Name
Bactericera cockerelli
Identification
Adults: Adults are about 2 mm long and resemble small cicadas. Their colour goes through gradual changes from light yellow to pale green when they first emerge, brown or green 2 or 3 days later, until they become grey or black with white markings when they are 5 days old. They jump rapidly when disturbed.
Eggs: The eggs are very small, football-shaped, yellow to orange and borne singly on very fine stalks.
Nymphs: Nymphs are flattened and scale-like, with a fringe of short spines. Younger nymphs are pale brown, turning green as they get older. Nymphs are usually found on lower leaves and move readily when disturbed. They secrete a white substance resembling granulated sugar or salt that collects on leaves beneath the feeding insects.
Symptoms of Psyllid yellows: Stunted plants form rosettes and the leaves roll upwards. Affected plants turn yellow; the leaflets of red varieties turn reddish or purple. Aerial tubers may form.
Often Confused With
Aphids
Period of Activity
It has not been found in potato fields in Ontario.
Scouting Notes
Yellow Sticky Cards to monitor adults only:
These cards must be placed within the field but towards the field edge. Sticky cards need to be checked and replaced at least weekly, if not more frequently, since many insects are attracted to the cards which makes finding psyllids on the cards difficult. Before transporting, individual cards should be handled in one of the following ways: placed in a thin, clear plastic bag; separated with a wooden rack; covered with wax paper; or covered with the paper covering that comes with the card. If using a plastic bag, the sticky face of the card should be carefully adhered to the inside face of the bag to allow observation of insects through the plastic.
Sweep Nets to monitor adults only:
Take 100 sweeps from around the field perimeter. Collect all insects from the sweep net into a plastic bag, jar, or vial, and freeze overnight. Freezing the sample immediately decreases the potential for sample degradation.
Leaf sampling to monitor adults, eggs, and nymphs:
Collect 10 leaves from 10 locations within 9 m of the edge of the field. Fully expanded leaves are collected from the middle section of the plant. A hand lens is needed to see psyllid nymphs and eggs.
Thresholds
No action threshold exists for psyllids on potatoes. Detection of psyllids at any level, in any life stage, is the threshold for action until more information is obtained on the impact of small populations of infected psyllids on the potato crop.
Advanced
Scientific Name
Bactericera cockerelli
Identification
Adults: Adults are about 2 mm long and resemble small cicadas. Their colour goes through gradual changes from light yellow to pale green when they first emerge, brown or green 2 or 3 days later, until they become grey or black with white markings when they are 5 days old. They jump rapidly when disturbed.
Eggs: The eggs are very small, football-shaped, yellow to orange and borne singly on very fine stalks.
Nymphs: Nymphs are flattened and scale-like, with a fringe of short spines. Younger nymphs are pale brown, turning green as they get older. Nymphs are usually found on lower leaves and move readily when disturbed. They secrete a white substance resembling granulated sugar or salt that collects on leaves beneath the feeding insects.
Symptoms of Psyllid yellows: Stunted plants form rosettes and the leaves roll upwards. Affected plants turn yellow; the leaflets of red varieties turn reddish or purple. Aerial tubers may form
Often Confused With
Aphids
Biology
Life stages: eggs, nymphs, adults.
This tiny insect could be carried north by winds from southern areas of the US.
The potato psyllid has an extensive host range, but reproduces mostly on the potato and nightshade family (Solanaceae).
Feeding by adults does not cause significant damage to potato plants. However, the nymphs inject inject toxins with their saliva that can cause leaf curling, yellowing or purpling, and small, misshaped tubers. This physiological condition is called psyllid yellows.
Potato psyllids are vectors of the Bacterium that causes Zebra Chip
Period of Activity
It has not been found in potato fields in Ontario.
Scouting Notes
Yellow Sticky Cards to monitor adults only:
These cards must be placed within the field but towards the field edge. Sticky cards need to be checked and replaced at least weekly, if not more frequently, since many insects are attracted to the cards which makes finding psyllids on the cards difficult. Before transporting, individual cards should be handled in one of the following ways: placed in a thin, clear plastic bag; separated with a wooden rack; covered with wax paper; or covered with the paper covering that comes with the card. If using a plastic bag, the sticky face of the card should be carefully adhered to the inside face of the bag to allow observation of insects through the plastic.
Sweep Nets to monitor adults only:
Take 100 sweeps from around the field perimeter. Collect all insects from the sweep net into a plastic bag, jar, or vial, and freeze overnight. Freezing the sample immediately decreases the potential for sample degradation.
Leaf sampling to monitor adults, eggs, and nymphs:
Collect 10 leaves from 10 locations within 9 m of the edge of the field. Fully expanded leaves are collected from the middle section of the plant. A hand lens is needed to see psyllid nymphs and eggs.
Thresholds
No action threshold exists for psyllids on potatoes. Detection of psyllids at any level, in any life stage, is the threshold for action until more information is obtained on the impact of small populations of infected psyllids on the potato crop.
Management Notes
Many of the products registered in Canada for management of other potato pests will also control the potato psyllid.
