26 THE REPORT OF THE No. 36 



retroflexus L.), yellow fox-tail (Setaria glauca Beauv.) Lamb's quarters (Cheno- 

 podium album L.), tumble weed or Eussian thistle (Salsola var. tenuifolia 

 G.F.W. Mey), green fox-tail (Seteria viridis Beauv.), Lady's thumb (Polygonum 

 persicaria L.), wild buckwheat (Polygonum convolvulus L.) ground cherry (Phrysa- 

 lis heterophylljn Nees.) ; other weeds present but not infested were : purslane, Canada 

 thistle, bitter sweet, milkweed and crab grass. However, throughout, the district 

 of the weeds found to be infested in addition to the above the following can be 

 listed: orchard grass (Dactylis glomerata L.), Canada thistle (Cirsium arvense 

 Scop.) wild sunflowers (Helianthus sp.),blue weed or vipor's bugloss (Echium vul- 

 gare L.), ragweed (Ambrosia artem'isiifolia L.) ; mullein (Verbascum tliapsus L.), 

 goldenrod (Solidago sp.), old witchgrass (Panicum capillare L.), yarrow (Achillea 

 millefolium L.), burdock (Arctium minus Bernh.). 



In cultivated crops and flowers larva? have been secured in the field feeding on 

 dahlia, geranium, aster, golden glow, beets, mangolds, tomatoes (fruit), beans, oats, 

 squash, vines, broom corn, sudan grass, early amber sugar cane, Hungarian grass 

 and Mann's Wonder sorghum. 



No success was achieved in establishing larva? upon a long series of common 

 weeds by attaching eggs laid upon a slip of corn ]eaf. The eggs hatched but the 

 larva? rarely were able to infest the plant. In a series of experiments with paired 

 adults caged over 35 common cultivated vegetables and flowers the larva? in very 

 small numbers established themselves upon mangels, potatoes, celery, cauliflower, 

 peas, beans, peppers, eggplant, radish (gone to seed) salvia and aster. Summing 

 up, however, the entire infestation in the open of plants other than corn, with 

 the exception of the dahlias, and possibly barnyard grass and Mann's Wonder 

 sorghum was due entirely to the migrating larva?. These larva?, particularly in the 

 weeds, together with those in corn stalks, stubble and refuse have gone into the 

 winter in very large numbers with every prospect of coming through successfully 

 and giving rise to an increased infestation in 1922. 



THE SPREAD OF THE EUROPEAN CORN BORER IN 

 SOUTHERN ONTARIO. 



L. S. McLaxe, Entomological Bbanch, Ottawa. 



When the European Corn Borer was realized to be a serious pest, that is, in 

 the summer of 1918, the Canada Department of Agriculture took steps to warn the 

 general public of the danger of introducing this insect into Canada, and also 

 carried on investigations to determine the amount of corn, and other products 

 likely to harbour the borer, that had been imported into the Dominion from the 

 infested districts in Massachusetts. As a result of these investigations scouting 

 for the pest in the maritime provinces was carried on during the summer of 1919. 



With the discovery of the insect in western New York in the fall of that 

 year, the attention of the Department was directed to the possibility of the pest 

 having spread into the province of Ontario. Some scouting was done in Welland 

 County and along the Niagara River that fall, but was soon discontinued on ac- 

 count of the lateness' of the season and the unfavourable climatic conditions. 

 Plans were made, however, to resume the scouting in this territory the following 

 summer. 



On August 10th, 1920, the first infestation was found near Lorraine Station. 

 Humberstone township, Welland county. The larva? were small in size and were 

 collected in a field of ensilage corn. A preliminary survey of the infestation showed 



