Adult bay sucker psyllids (or Jumping Plant Lice as they’re sometimes called), are 2mm in length and resemble greenish-brown, winged aphids.

During spring, they emerge from amongst the leaf litter below a bay tree where they have remained dormant throughout winter. Ascending the tree to the tender new growth areas, the psyllids push their stylets into the edges of young leaves and begin feeding on the sap. Whilst doing so, a chemical in their saliva causes the leaf edges to curl and blister, which creates a protected environment on the leaf for the psyllids to mate and lay their eggs within.

Eggs that hatch into little nymphs continue to feed on the leaf sap and cause further deformity and yellowing of the leaves, secreting a fluffy white wax from their bodies that repel rainwater from the infested areas. Throughout the summer months, up to three generations of bay sucker psyllids can occur on an infested bay tree, before the adults descend to the ground to hibernate over winter amongst leaf litter and detritus.

Although the leaf damage caused by bay sucker psyllids can be unsightly, it rarely harms the tree and even on heavily infested trees, many leaves can remain unaffected throughout the year. 

However, infestations can be managed if the trees are not too large, simply by picking off or pruning out as many of the affected deformed leaves as possible and disposing of them away from the tree. Thorough spraying of the whole tree at regular intervals with the non-toxic, soap-based product SB Plant Invigoratorwill then help prevent re-infestations. Finally, during autumn, rake out and remove leaf litter from under the tree where any adult Psyllids could be preparing to hibernate.