Help wanted in spotting the Oak Jewel Beetle

Published: 14 May 2012

Calling all entomologists... your help is wanted in spotting the oak jewel beetle Agrilus biguttatus across Britain.

Tree and forestry charity the Sylva Foundation has set up an online survey on their TreeWatch website. They want volunteers to help record the presence or absence of the oak jewel beetle on oak trees, indicated by 'D'-shaped holes in their bark, and if the adult beetle is sighted then this can be recorded too.

The oak jewel beetle lays its eggs in the bark of oak trees. The larvae that hatch then tunnel through the bark to feed underneath, occasionally girdling the trees. Sometimes the presence of feeding Agrilus larvae is marked on the outside of the bark by tarry spots or bleeding of a dark fluid. When the larvae pupate, the emerging young adult beetles make very characteristic 'D'-shaped exit holes. Although Agrilus is not considered to be capable of attacking healthy oaks, the beetle is thought by scientists to be one of the factors in acute oak decline.

Prior to the Winter storm of 1987 Agrilus biguttatus was thought by conservationists to be rare (listed in the British Red Data Book as "vulnerable"), meaning that extinction was thought likely if no change occurred. Many oak trees in England in the early 1990s suffered significant decline and it was noted that there was the highly visible evidence of Agrilus attack on many of the declining trees.

Please help with this important survey. Your scientific data will be shared with scientists from Forest Research, and the National Biodiversity Network, to help gain better understanding of this insect.

To complete the survey please visit:

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