Pear Psylla

family: psyllidae
species: psylla pyricola
common name: pear psylla
antennae characters: 10-segments
specialties: notorious honeydew producer. small (2-5 mm) and lo
hosts: pears
natural enemies: minute pirate bug, green lacewing
cultural control methods: french rootstocks are resistant to pear decline good sampling strategies forecast treatments
physical control methods: chemical control is a primary means of defense.
pesticides used: dormant oil and pyrthroids
notes: Without guthion sprays (for CM) psylla are less of a problem since natural enemies exert some control; pear psylla may vector MLO for pear decline; feeding alone may cause economic damage. Overwinters as adults on the bark: in February it becomes active and lays eggs on/in bark near leaf buds. Each nymph lives in/under a drop of honeydew. The final instar does coat itself with this honeydew. 3-5 generation per year.

Agriculture and Agri-Food Canada Insect Identification Sheet No. 46 March 1981

Pear Psylla

Psylla pyricola Foerster

The pear psylla is believed to have been introduced into North America in 1832. It has since spread to all pear producing regions in Canada. In addition to pears, it also attacks quince.

Injury:

Damage to pear trees is threefold: first, the nymphs excrete large quantities of honeydew, an excellent medium for the growth of a black sooty mold. The presence of this mold on fruit renders it unsalable. Second, heavy infestation can cause trees to wilt and lose their leaves as the psyllas feed and inject their toxic saliva. Third, the pear psylla can transmit the disease "pear decline".

Life History:

Pear psyllas overwinter in the adult stage in cracks of tree bark or under plant debris. Adults are small (2 mm), dark brown, with reddish or green markings. Early in the spring females lay up to 500 pear shaped yellow eggs in cracks or on ridges of pear trees. Subsequent generations of eggs are laid on new foliage, usually along the mid rib. Nymphs begin to emerge in the middle of May. They are extremely small (0.5 mm), yellow, and wingless. In the next month they undergo 4 molts.

While in their second through fourth instar, they are characteristically covered with a honeydew drop. In the final instar, called the "hardshell" stage, their wing pads become prominent and their color changes to dark brown. There are three or four generations per year, depending on locality.

Pest Management:

Consult representatives of your provincial Department of Agriculture for control recommendations.