582 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



Besides tliese, two adults were observed in the fields, in tlie act of pairing, on the 

 1:2th of November. 



Ou account of absence from home no examination was made until tlie loth of 

 A])ril of the present year, wlu^n larva; were again found in the fields, in less num- 

 bers but in af)()ut the same stage of development as during the previous December. 

 No pupte were observed, but two adults were found, which died soon after, without 

 liaving- in tlie mean time deposited any eggs. 



On May 25 both larvae and pupa? were found, the former in still less numbers 

 than they were during April, but now they were, for the most part, nearly or quite 

 full giown. An adult, taken also on this date, died on tlie .30th inststant without ovi- 

 positing. June 14 several adults were observed, and from this time forward they 

 appeared in increasing numbers until August, when they seemed to reach the 

 upward limit. 



The deposition of eggs may commence in July, but we obtained none until Au- 

 gust 7, and then only after keeping adults contined in the breeding-cage for four 

 days; nor could we at this date observe any larvte in plants in the fields, although 

 very small ones were common enough in and about the tender lateral shoots early 

 in September, but in no case were they buiTowing in the main stem exce]:)t in the 

 tenderer portions, under the base of leaf-stalks, as previously indicated. 



In summing up the life-history of the species, they may be said to emerge as 

 adults as late as July, and deposit their eggs from the last of that month until cold 

 weather begins. The larvae, hatching within two days after the eggs are deposited, 

 feed upon the tender portion of the clover stems, probably burrowing into them 

 sometimes, especially when they are from one-fourth to one-half grown, and, barely 

 jjossibly, subsisting in part upon the roots when older. They pass tlie winter, for 

 the most part, in tliis stage, but occasionally as adults. The larvte pupate in spring, 

 and after remaining about twenty days in this state emerge as adults. 



The adults seem to wander about considerably early in the season, and we have 

 observed them traveling about on fences, upon the heads of gi'ain, and crawling 

 up the trunks of trees, and also found them hidmg away under nibbish. 



THE CLOVER-STEM MAaOOT. 



(Oscinis sp.) 



Sufficient opportunity has not been offered to study more than a portion of the 

 probable cycle of this insect, yet the very deceptive resemblance between the work 

 of the larvai and those of Sitones renders some account of it almost a necessity in 

 order to prevent confusion. 



The adult insect is a small, rather robust, black fly. The individual larva is 4™™ 

 long, with a breadth across the thoracic segments of .0"^"", footless, slightly dunin- 

 ishing posteriorly, with the division of the segments after the first three A'ery ob- 

 scure. Color yellowish- white, with a tinge of green, becoming nearly white at ex- 

 tremities; oral parts quite large and jot black. Near the posterior extremity is an 

 abrupt ventral restriction, and on the rounded anal segment are two short, robust, 

 brown processes, each terminating in a corolla of small circular i^ustules. 



The puparium is 2.4""" long and .8""" broad, elongate, oval, slighth^ tapering 

 posteriori}^, and rather less obtusely pointed than at anterior extremity. The two 

 posterior processes are here reproduced, and two others, shorter and more widely 

 separated, are placed on the anterior extremity. Color at first yellowish- white, with 

 tinge of green, but later turning to brown, and from this to' nearly jet black. 



The insect w\as first observed by us on August 6 of the present year in the pupal 

 stage, and within a stem of white clover, which had evid(nitly been destroyed by it 

 while in the larval stage. During the four succeeding days other impjiria wer6 

 found, but only two larvaj. From the puparia one adult emerged on August 12, 

 others following a few days later, thereby indicating that the brood of which they 

 were a part was rapidly approaching maturity. 



The exact time and place of oviposition it was, of course, impossible to determine, 

 but the maggots are found singly in the stem, sometimes just under the epidermis 

 and sometimes in the center, but' in either case excavating parallel channels, work- 

 ing from the point where the stem originated. Hence we are led to infer that the 

 eggs are deposited near the main roots, and the larva, as its pushes forward, is pro- 

 vided with a continual sujiply of fresh-grown food, the terminal or growing jiortion 

 of the stem being in part sustained by lateral roots thrown out at equal intervals. 

 It is also possible that tlie eggs are sometimes placed on the young lateral stems, 

 through wliich the maggots burrow their way to the main stem. 



As yet we have no trace of more than the one brood mentioned, although it is not 

 at all improbable that there may be several in a season. 



