Cereal leaf beetle in 33.3% of fields in southern Alberta. Locally, adults spread to the exterior of fields during their overwinter. Larvae tend to stay on the outside of crop fields, but are also found in the center. Local populations are never homogenously distributed, hotspots and empty places occur in each field. "O. melanopus" consumes nearly all cereal crops, but has a strong affinity for oats, barley, and rye, and its favorite host is wheat. Alternatives are corn, sorghum, and sudangrass for adults, and wild oats, quackgrass, timothy, canary grass, reed canary grass, annual and perennial ryegrass, foxtail, orchard grass, wild rye, smooth
Cover crop ("Sinapis alba") and radish ("Raphanus sativus"). They can be grown after a main (cereal) crop and trap nematodes, for example the beet cyst nematode and Columbian root knot nematode. When grown, nematodes hatch and are attracted to the roots. After entering the roots they cannot reproduce in the root due to a hypersensitive resistance reaction of the plant. Hence the nematode population is greatly reduced, by 70-99%, depending on species and cultivation time. Other cover crops are used to attract natural predators of pests by providing elements of their habitat. This is a form of biological control known as habitat