ASPARAGUS INSECTS 209 



the ground. The e^g is elongate oval, slightly wider at one 

 end and somewhat pointed at the other. It is about gV 

 inch in length and when first laid is glistening white in 

 color. The eggs hatch in twelve to eighteen days and the 

 young maggot begins to mine just under the epidermis. At 

 first the larva works upward, following a more or less sinuate 

 course, but when nearly mature it turns downward towards 

 the base of the plant. In the case of the first brood, pupation 

 may take place aboveground but the maggots of the second 

 generation usually work down from one to seven inches below 

 the surface before transforming. The full-grown maggot is 

 creamy white in color and is ^ to ^^ inch in length. The maggots 

 attain their growth in two or three weeks and transform into 

 puparia within the mine. The puparium is ^ to -5^ inch in length 

 and brownish in color, becoming darker with age. The insect 

 remains in this stage for two to three weeks and the flies of 

 the second brood begin to emerge the latter part of July. The 

 maggots of the second brood are most abundant in their mines 

 during August but both maggots and flies are present until 

 frost. The winter puparia are formed in late August and 

 September. These are found under the epidermis of the 

 stems below ground. There are two generations annually. 



When, as is often the case, several maggots infest a single 

 stem, their mines cross each other, thus girdling the shoot. 

 Stems injured in this way take on a sickly yellowish appearance 

 and die prematurely, thus weakening the plants to a consider- 

 able extent. 



Methods of control. 



The asparagus miner rarely does enough damage to warrant 

 commercial growers making any serious efforts to control it, 

 and no remedial measures satisfactory for commercial condi- 

 tions have been devised. The insect causes little or no trouble 

 in beds that are being cut, its injuries being chiefly confined to 

 p 



