a1 Field Crop Insect Section, Science Service Laboratory, Lethbridge, Alberta
The superb plant bug, Adelphocoris superbus (Uhl.), is a serious pest in some alfalfa seed fields in southern Alberta. It feeds on the unopened bud clusters, causing them to whiten and die (bud-blasting). Under cages, it has also caused flower-drop, stunting of plants, and destruction of immature seed (Sorenson, 1954). When numerous it may prevent fields from producing enough bloom for the alfalfa pollinators in the vicinity, and in such numbers is of economic importance to the seed-growers. The number of bugs necessary for an economic population thus varies inversely with the pollinator population on the field.
(Received February 28 1956)
1 Contribution No. 3410 Entomology Division Science Service, Department of Agriculture, Ottawa, Canada; from a thesis suhditted by the senior author in partial fulfilment of the requirements for the M.Sc. degree, University of Alberta, 1953.
2 Assistant Entomologist and Senior Entomologist.