How to recognize beetles

Beetles belong to the order of Coleoptera, which is a large order inside the insects. More than 300.000 species are known worldwide and they can vary in size from less than half a milimeter to giant beetles of up to 15 cm. Beetles can be recognized by their hard, often colourful covershields that protect the membranous hind wings. Beetles undergo methamorphosis and, in Europe, they usually have one generation per year. 

The lifestyle varies heavily between the different beetle species. Some species are mostly nocturnal and hide during the day. Other species are mainly observed during the day. Plant feeding beetles can cause major damage, while other species, like ladybirds, are beneficial and can be useful in pest control.  

Beetle damage

Beetles mainly cause damage in outdoor ornamental crops, but also in ornamental- and vegetable gardens. Adults and larvae of harmful beetles often feed on leaves causing growth reduction and cosmetic damage. 

Some larvae are known to feed on roots, which causes entire plants to die. A well-known example of such a beetle is the black vine weevil. Adult black vine weevils individuals take round ‘bites’ out of the leaves during the night causing cosmetic damage. The larvae cause heavy damage by feeding below-ground on roots, causing entire plants to die.