The adult psyllid resembles a small cicada about 3 mm long. The body is brown-green and has white or yellowish markings on the thorax and lines on the abdomen. The wings are transparent and held vertically over the body.
The eggs are white when first laid and turn yellow to orange in a few hours. They are laid singly on small stalks on the undersides of leaves. Use a 10x hand lens to detect eggs.
The nymphs appear scale-like and oval, initially yellowish green to orange with a pair of red eyes and three pairs of short legs. Older nymphs are greenish and fringed with hairs, and wing buds are visible. Do not confuse these nymphs with greenhouse whitefly nymphs.
Distribution and host range
Tomato-potato psyllid was first discovered in Auckland, New Zealand in 2006, and has spread to other areas in the North Island, and Nelson in the South Island. It is a pest of tomato and capsicum on both indoor and outdoor crops, and potato.
Tomato-potato psyllid is also found in the United States, New Mexico and Southern Canada. Although tomato-potato psyllid is known to infest host plants from 20 plant families, its preferred hosts are plants from the family Solanaceae.
Besides tomato, capsicum, egg plant and potato, known wild hosts in New Zealand include black nightshade (Solanum nigrum), cape gooseberry (Physalis sp), common morning glory (Ipomoea purpurea) and field bind weed (Convulvulus arvensis). Tomato-potato psyllid will infest kumera.
Signs and symptoms
Tomato-potato psyllids cause injury to plants by feeding with piercing-sucking mouth parts. Both adults and nymphs cause injury. The nymphs inject a ‘salivary toxin’ into the plant while feeding.
The signs and symptoms of tomato-potato psyllid include:
Life history and habits
Female tomato-potato psyllids mate 3-4 days after emerging as adults, and may mate more than once in their life time of approximately 40 days. Females can produce up to 500 eggs, most of which are laid over a period about 21 days.
Eggs hatch 3-9 days after being laid and nymphs pass through five scale-like stages in 12-21 days, depending on temperature. In greenhouses, tomato-potato psyllid development proceeds rapidly between 15-32 °C, and the lower temperature threshold for development is about 7 °C.
At an average temperature of 18 °C, one life cycle is completed in approximately 33 days. In the United States there are thought to be 4-5 generations per year on outdoor host plants.
Tomato-potato psyllids adults are strong fliers and will disperse readily on the wind. They will spread from outdoor crops or weeds to indoor cops when host plants are no longer suitable. Psyllids may also be moved on plant material from one location to another.
Like greenhouse whitefly adults, tomato-potato psyllid will fly readily when disturbed, and so will spread rapidly through a greenhouse crop when people are working in the crop.
Tomato-potato psyllid has the potential to severely reduce the yield and quality of tomato and potato crops. In the United States, losses of tomato production have exceeded 80% in unprotected crops.
Damage to capsicum is usually less severe. Variation between the susceptibility of tomato cultivars occurs, but the relative susceptibility of New Zealand cultivars is unknown.
Tomato-potato psylid are readily attracted to yellow sticky traps, and will indicate the presence of this pest. Traps alone will not control tomato-potato psyllid.
In greenhouse crops, hang yellow sticky traps close to top of the plant canopy to catch adults. Traps can be placed close to vents and doors to check psyllid entry into greenhouses. Inspect plants weekly for signs eggs, nymphs and psyllid honeydew. Monitor plants for early signs of yellowing and leaf curling.
In outdoor crops, place yellow sticky traps on the margins of crops to monitor the entry of adults. Inspect plants for psyllids, honeydew, psyllid yellows and stunted growth.
Research in the United States indicates as few as 15 nymphs per plant for 5 days can cause psyllid yellows.
Our product, Orius, predates on psyllids in the laboratory, however its use in the field is currently untested. It is possible that Orius will provide some control of psyllids on your crop if it is already established feeding on other prey, such as thrips, aphids or spider mites, as well as pollen.
Tomato-potato psyllid is attacked by a range of predators and parasitoids, however, no natural enemies have been used to date in New Zealand to control this pest. A parasitoid and disease-causing micro-organsims have been evaluated, and may be available in the future.
Sound crop hygiene practices are essential is to minimise the buildup of tomato-potato psyllid. Infested leaves and plants, and old crops should be removed from greenhouse, placed in sealed container and destroyed. Alternate hosts, such as solenaceous weeds should be removed from outside greenhouses.
Chemicals vary in their effectiveness against tomato-potato psyllid. In the United States, products containing, abamectin, spiromesifen and spinosad are recommended.
Thorough spray coverage on the undersides of leaves is essential, and several applications may be needed. For pesticide resistance management, care should be taken to not exceed the recommended number of applications in a crop cycle or year.
Care should be taken to consider the effect of insecticides on beneficial insects and mites that may be being used in integrated pest management programmes. Consult with BioForce Ltd before applying any insecticide when beneficial insects or mites are being used.
If you are uncertain about the identity of any pest in your crop, or need advice on the management of pests contact BioForce Ltd, firstname.lastname@example.org .