Spring beetles in truffle orchards
This spring we received a number of enquiries from truffle growers in Western Australia concerned about leaf feeding caused by spring beetle. These beetles are a native insect that occur mainly in Western Australia. As the name suggests spring beetles occur most often during spring. By the time you read this article in December, they will most likely have disappeared but may well return again next spring.
Spring beetles have a wide host range and apart from a range of native plants, they attack commercial crops such as deciduous fruit tree crops and avocados, and many ornamental plants such as roses. On apples they feed on leaves, petals and very occasionally fruitlets. They do not appear to feed on the growing tip of plants so unless plants being attacked have little foliage such as newly planted trees, the beetle is unlikely to be important. In truffle orchards, they usually feed on hazelnut trees but also French oak (Quercus Ilex).
The insect looks concerning because of their high level of activity during the day and very obvious feeding damage, however in most cases their feeding can be tolerated. They are not present in the orchard for long, most often leaving by late spring/early summer and healthy trees can tolerate feeding damage without any adverse long-term impacts. If you are concerned about their presence, keep an eye on numbers and level of damage, particularly if they are feeding on growing tips. We have not observed any damage to growing tips caused by spring beetle but they do have potential to do that and this could affect tree growth.