Last year, the focus of the Beneficial Insect of the Week was crop pests. This year, we’re changing things up and highlighting the many natural enemies that help you out, silently and efficiently killing off crop pests. [note: featured Insects of the Week in 2015 are available on the Insect of the Week page]
You can't tell by looks whether an insect is a good bug (beneficial) or a bad bug (pest). And while you might recognize the adult, the immature form might appear quite alien. This is definitely the case with the ladybird beetle (aka lady beetle). This cute, orange, nearly round beetle with varying number of spots depending on species appears harmless but is a voracious eater, consuming up to 100 aphids a day (and other soft bodied insects). The larvae (slate blue, elongated body with varying black and yellow patterns) can be just as hungry.
One of the exciting projects at Agriculture Canada is looking at how natural enemies like ladybird beetles control cereal aphids in wheat, oat, barley and rye, preventing them from causing economic damage without you having to lift a finger (or hook up a sprayer). Of course, there are times when there aren't enough free helpers/natural enemies and we're developing an app that will help growers figure out if and when they need to control cereal aphids. (Refining and making accessible to growers a validated dynamic action threshold for cereal aphid control in cereal crops).
For more information about these natural enemies, other pests they control and other important crop and forage insects, see the new Field Crop and Forage Pests and their Natural Enemies in Western Canada - Identification and Management Field Guide for identification, life cycle and conservation options (download links for field guide available on the Insect of the Week page).
Ladybird beetle larva eating aphids
Mike Dolinski, MikeDolinski@hotmail.com