10 Annals Entomological Society of America [Vol. XI, 



On cutting the gall open a small dipterous puparium was 

 found inside. These puparia were taken to the laboratory, 

 placed in vials, and on the 26th of May adult flies began to 

 emerge. These were identified by Dr. O. A. Johannsen as 

 Agromyza later ella. 



In going over the literature on this species, I find that 

 Thompson! reports having bred A. laterella (equals magni- 

 cornis Loew) from galls on blue flag. His paper is accompanied 

 with an illustration of an \xis, leaf showing the gall. A short 

 description of the gall is given. He suggests that the larval 

 life seems to be completed the previous fall, but has not investi- 

 gated this assumption. 



With the adults emerging the latter part of May, the ques- 

 tion naturally arose as to where the eggs would be placed, 

 or in what stage the summer and fall would be spent, assuming 

 that the winter was passed in the pupal stage. With this 

 object in view a number of the adults were placed in cages 

 with iris plants, in an effort to induce the flies to mate and 

 oviposit; they failed, however, to reward the observer with 

 either of these performances in captivity. It was found, 

 though, that the adults were very common around iris plants, 

 especially during the middle part of the day. At such times 

 the females were carefully observed. They appear very 

 nervous, darting here and there, and are easily disturbed. 

 It was noticed that the females were stopping often to exert 

 their ovipositors and work them on the tissue of the leaf. 

 Such a leaf, later, showed a speckled appearance as shown in 

 Plate II, Fig. 11. A number of these leaves were taken into 

 the laboratory and an effort made to locate the eggs, but 

 although these punctures or abrasions were very apparent, 

 the eggs were not found. 



It was while observing this "oviposition, " that Dr. Needham 

 suggested the possibility of having a case here, where the first 

 generation of flies took on the leaf-mining habit, while the 

 later, or second generation would be the ones producing the 

 galls. Should this alternation of habits occur in the same 

 species of insect, it would help to substantiate the theory that 

 leaf-mining and gall-making are very closely related, the main 



tMillet B. Thompson, Psyche Vol. XIV, 71-74, 1913. "Three galls made by 

 Cyclorrhaphous Flies." 



