Life Cycle

September
Adult beetles may start to emerge from winter shelter. If too early they will likely die from lack of food (elm leaves). In heavily infested areas the beetle can be a pest inside houses, sheds and caravans.
October
Most adult beetles emerge from shelter during October, fly to nearby elm trees and start to feed on the newly emerged leaves. The beetle is small and usually hard to spot however the "shot hole" damage to the leaves from their feeding is easily seen.
ELBELB
November
The beetles mate and eggs resembling a double row of yellow lemons are laid on the elm leaves. The eggs hatch after 7-10 days
December
From late November the larvae (grubs) hatch from the eggs. Growing from about 1mm to 10mm in three stages they feed on and skeletonise the elm leaves. Where there are heavy infestations the trees are rapidly defoliated. The larvae move down the branches and trunk to pupate. About 5mm long, oval and bright yellow, the pupae can be seen on the ground at the base of the tree and in the textured bark. After about 10 days new adults emerge.
ELB
January - March
Depending on environmental conditions a second generation may occur. By January it is possible to see all life stages present on a single tree. By mid March the beetles will disappear to sheltered sites to hibernate.
 ELB