SOME INSECTS INJURIOUS TO TRUCK CROPS. 



The larva (fig 

 white in color. 



Fig. 2.--Agromyza simplex: a, larva, lateral 

 view; 6, thoracic spiracles; c, anal spiracles; 

 d, puparium from side; e, same from above; 

 /, section of asparagus stalk, showing injury 

 and location of puparia on detached sec- 

 tion; o-f, much enlarged; /, slightly reduced 

 (original). 



2, a) is about one-fifth of an inch long and milk- 

 Like other maggots, it is footless, large at the 

 posterior extremity, and tapering 

 toward the head. 



The puparium (fig. 2, <^, e) is not 

 unlike the "flaxseed" of the perni- 

 cious Hessian fl3^ with Avhich it has 

 been aptly compared. At a little dis- 

 tance, also, it suggests a Lecanium 

 scale. This stage is remarkable be- 

 cause of its peculiar flattened and 

 curved position, as seen from the 

 side. It is red in color, and meas- 

 ures about 3.5 mm. in length and 

 about 1 mm. in width. 



The egg has not been observed. 

 This species belongs to the dipter- 

 ous family Agromyzidas, and was described by Loew in 1869," the 

 locality being given as "Middle States." 



DISTRIBUTION. 



In its injurious occurrences this species appears to be limited to the 

 eastern United States, from New England to Tennessee. From avail- 

 able data it is quite obvious, however, that it may be destructive over a 

 considerable territory, including a large portion of Massachusetts and 

 Connecticut, Long Island, the District of Columbia, Pennsylvania, 

 and Tennessee. As it is recorded from New Jersey, it is probably 

 injurious there, although no reports of injury in that State have 

 reached this ofiice. In time it will doubtless attract attention in inter- 

 mediate points and in States farther north and west. It has also 

 appeared in asparagus beds in California. 



HISTORICAL AND BIOLOGICAL NOTES. 



In May, 1897, and afterwards this fly was observed in abundance by 

 the writer on terminal shoots of asparagus, particularly at Cabin 

 John, Md. Two weeks later no more flies were seen, but June 26 

 they reappeared and were then usually seen i?i copula. It was sur- 

 mised at the time that this second appearance indicated the first new 

 generation of the year and its abundance on asparagus seemed to show 

 that it lived in some manner at the expense of that plant. Examination 

 of asparagus plants at that time, however, failed to show attack. The 

 facts which have just been narrated were published in 1898.* 



«Diptera Americse septentrionalis indigena, Centuria octava 84, p. 46. 

 6 Bui. 10, n. s., Div. Ent, U. S. Dept. Agric, p. 62, 1898. 



