The Pest: Tomato Potato Psyllid

The tomato potato psyllid (TPP) was first found in New Zealand in 2006 and has spread throughout the country. It may transmit a bacterium, Candidatus Liberibacter solanacearum that causes a disease in its host plants. TPP breeds all year, especially in the warmer parts of the country and in greenhouses. It develops between 15C and 32C with optimum development at 27C.

Adult tomato potato psyllids are small insects, similar in size to aphids. They have wings and look like small cicadas with a distinctive white band on the abdomen. The two pairs of transparent wings are held over their abdomen. A female can lay up to 500 eggs over a 21-day period, but in the field it is more likely to be around 200 eggs.

TPP eggs are yellow and attached to leaves by a thin short stalk. The eggs may be laid on all parts of the leaf and plant stem, but are often found on the leaf edge where they are most easily seen.

Nymphs hatch from the eggs. They are flat and scale like, and have three pairs of legs and sucking mouthparts.

There are five nymphal stages, each is called an instar. Nymphs settle on young leaves, mainly on the underside. Although they can walk, they spend much of their time motionless with their stylets inserted into the plant feeding on the plant sap and they excrete the excess water and sugar, which is called honeydew.

Symptoms and signs of psyllids include:

• Stunting and distortion of the leaves and flowers

• Yellowing and wilting of leaves

• Honey dew and sooty mould present on the plants