1920 ENTOMOLOGICAL SOCIETY. KH 



Diamoxd-Back ^Iotji {FlulelJa, inacnlipennis) was very coi)>piciioiis in 

 fields of cabbage. 



Corn" Eak \Voi;m {IJelioilds ohsolcta). This insect attacked the ea:s of 

 sweet and field corn in many localities this fall. Infested ears were received by 

 the writers from Welland, l^incoln, Wellington and Lanibton Counties. Injury 

 was practically confined to late planted corn. In Welland County it was observed 

 that Dent corn was injured more tlian Flint. 



Tomato or TotoAcco Worm (Pklegethoniius qu'mqiieinacicla-ta). Tlii- 

 s])ecies was present in exceptionally large numbers in tomato and tol)acco (iclds 

 in the Leamington district and other parts of western Ontario. It was al-n e<,ni- 

 mon in Xorfolk County. 



Pea Aphis {Macrosiphum pisi). This plant louse was again very destrneri\e 

 to peas grown for the canning factories in Prince Edward County and to a U's>cr 

 extent in Norfolk County. Field jieas were also injured in Lincoln County. 



Cutworms. Quite a few complaints were received regarding cutworm injury 

 to cabbage, tomato and corn. AVhat we took to be the dingy cutworm Feltia diiccnti 

 was injurious to cabbage at Yineland about mid-May. The variegated cutworm was 

 moderately abundant throughout tlu> Burlington district and was apparently the 

 cause of most of the holes eaten in tomatoes in September. 



Asparagus Beetles (Crioceris asparagi and C. 1^- punctata.) The two 

 species were very common and injurious in the Niagara district. At A'inehind 

 the chalcid parasite {Tctrasticlius asparagi) was again observed. 



Colorado Potato Beetle (Lrptinotar.m Jecenilinruta). The beetles came 

 through the winter in large numbers and caused much danuige early in the year 

 to potatoes and tomatoes. According to reports received, the " Friendly Perillus " 

 was unusually effective as a check. 



Cabbage Aphis (Aphis hrassicac). This louse was very abundant in late 

 summer and fall on cabbage, cauliflower and turnips and caused consideral)lo 

 injury. However, due to the effective Avork of the parasitic and predaceous enemies, 

 the outbreak did not reach the alarming proportions we anticipated. It is of 

 interest to note that one of the most important insect checks of this species w^as 

 the larva of Aphidoletes julva. 



Ked Headed Flea-p.eetle (Sgstena frontatis). This si)ecies wa« uinisually 

 prevalent on beans. 



Black Stixk-bug (Cosmopepla himaculaia) was remarkably almndant Tliis 

 year on grains but so far as we could see caused no injury. Air. AlaeLelhin, 

 Ontario Vegetable Specialist, reports that during the summer this species killed 

 the tips of asparagus plants in a truck garden at London. 



Potato Leaf-iiopper (Empoasca mall) was reniarkal)ly abundant on pota- 

 toes and beans throughout the Province. It was generally credited with being 

 responsible for all the leaf burn which was so ])i'evalcnt on early potatoes. However, 

 we are not at all sure that this claim was wholly correct. 



In this connection the following ])reliminary exi»eriments conducted at the 

 Dominion Entomological Laboratory, Yineland Station, by Mr. Eobinson are of 

 interest. Three cheesecloth cages each large enough to cover three plants were 

 put over potatoes growdng in the field in June befoi'c theiv were any signs of leaf- 

 bui"n. Large numbers of l(>af-ho])]>ers weri^ inlroduced into tAvo cage.- and ihe 

 third Avas used as a check. Xon(^ ol' tlie jilanis were watered. Tip-burn developed 

 on the potatoes in all three cages, and, strange to say. jn-1 as ra])idly on the check 

 plants as on the infested ones. These cx|)eriments Avei'e (hiplieatt'd in the insectary 



