EXPERIMEJ^T STATIOX EEPORT. 581 



The eggs liateh very soon after being laid, and the young appear 

 as small, footless maggots, tapering toward the month end and 

 squarely cut otf or truncate behind. They attack the young onion, bare 

 into the tissue, and decay begins around them almost at once. The 

 young plant is very sensitive to this kind of injury and the leaves wilt 

 and droop. 



If -we examine the half-grown maggot more closely we will note 

 that it has no distinct head, no feet and no other obvious organs of 

 locomotion ; but it is ringed or wrinkled and moves along by extending 

 its body forward, holding its position by the anterior wrinkles and 

 drawing the hinder part of the body forward. 



The posterior, or cut-off, portion of the body is set with little 

 hillocks or conic tubercles, and there are two well-protected spiracles 

 or breathing holes. 



The pointed or head-end is furnished with a small mouth opening, 

 with a pair of fleshy lips or jaws and two pointed, curved, hook-like, 

 corneous structures. By means of these sharp-pointed jaws the larva 

 scrapes and punctures the surface of the onion, and by means of the 

 fleshy, lip-like structures it gets the exuding plant juices into the 

 mouth and so on through the gullet into the stomach. The dark 

 framework seen within the enlarged anterior rings of the larva in 

 Figure 23, shows the chitinous support for the muscles that work 

 the sucking or pumping structures of the gullet. Without biting mouth 

 structures, then; the insect is nevertheless able to get into a young 

 onion, and, once in, progress is even more rapid, because of the aid 

 given by the organisms favoring decay. Earely there is a single mag- 

 got in a small bulb; more commonly there are half a dozen or more. 

 The first brood comes to maturity about the middle of June, and 

 perhaps the most serious part of the early injury has been done at 

 that time. When the larva is full grown it begins to contract, be- 

 comes shorter, more regularly oval and cylindrical and changes to a 

 dull brown color. In this — the pupal— stage it is inactive and is really 

 only a cover to the real pupa which develops within the dried larval 

 skin. In this condition it remains for a few days only before changing 

 to the adult or fly stage already described. 



It is said that there are three broods during the season, and that is 

 indicated by the dates at which larvae have been found, but the later 

 broods are not so numerous in specimens as the earlier, or at least seem 

 to do much less mischief. 



