94 B.C. Entomological Society. 



baited area or in the non-baited area. Further, there was no indication that 

 the maggot attack was more severe in any one part of the field over any 

 other. 



The first male flies appeared in the field on May loth ; the first females 

 a few days later. The height of the oviposition period was not passed 

 until June 6th. Eggs were laid in the field on May 19th, and continually 

 from this date until August. The length of the larval period varied from 

 sixteen to twenty-nine days and the pupal period from fourteen to twenty- 

 six days. The earliest pupa formed was found on June 14th. Second- 

 generation adults appeared on July 7th. The first generation of flies 

 extended over a period between May loth and July 7th ; the second genera- 

 tion until August 23rd, after which time third-generation flies might be 

 expected. Two generations occur and doubtless a third, but the life-history 

 notes on the last generation have not been obtained with accuracy. A great 

 many notes have been obtained on the habits of the fly and particular atten- 

 tion has been paid to temperatures and weather conditions. 



OBSERVATIONS ON THE CONTROL OF THE ONION- 

 MAGGOT (HYLEMYIA ANTIGUA). 



BV M. H. RUHMAN. 



Onions have been extensively grown in British Columbia for a number 

 of years, particularly in the Okanagan Valley. In the year 19 14 growers 

 began to complain that cutworms were destroying their young plants. On 

 investigation it was found that the onion-maggot was present and respon- 

 sible for most of the trouble. This was most evident in small kitchen- 

 gardens, the large commercial plantings not suffering sufficiently to attract 

 attention. The few short gaps that did occur in the rows of onions were 

 attributed to faulty seeding or cutworms. In the year 191 5 growers began 

 to get alarmed, as extensive injury was being done by the onion-maggot. 

 The recommendations for control — i.e., the removal of infested plants in 

 the middle of June and their destruction by boiling or burning, and the 

 destruction after harvest of onion-tops and undersized onions, usually left 

 on the field to be ploughed under — did not appeal to them and compara- 

 tively little was done to control the pest. The onion-maggot" has now 

 become so serious a menace that control measures must be undertaken or 

 the growing of onions commercially must soon be discontinued. 



The adult of the onion-maggot is a fly somewhat resembling the 

 the common house-fly, a little smaller and more slender, but with propor- 

 tionally larger wings, and is grey in colour. The life-history of the fly 

 in British Columbia is not well known; the insect passes the winter in the 

 pupal stage in the ground and occasionally in stored onions, in which they 

 may have pupated. The adult fly emerges in the spring; the earliest 

 Canadian record is of an adult captured in the third week in May at 

 Ottawa (i). The number of eggs laid at one deposition may vary from 



