113 



whether the red Lirvie of the rhlceothrii>s are hirv.e of Cecidomyia. 

 The Thrips is ahnost constantly to be found in clover heads and it is 

 l>erhaps not strange that persons unused to separating different kinds 

 of insects, in looking- for minute si)ecies in Clover heads, should be de- 

 ceived by these little creatures, conspicuous from their numbers if not 

 from their size. 



The JassidtB, occurring upon grasses, have been present in their usual 

 abundance, and have been watched during the season especially to de- 

 termine important steps in their life-history. The first point which it 

 was our effort to deterndne was as to the method of hibernation. 

 Adults of Deltocephalus inimicus and dchilis and Agallia sanf/uineolenta 

 had been taken in sheltered locations last seajson up to the time that 

 winter actually set in, and with the opening of spring search was at 

 once begun for them in such places as they were most certain to ap- 

 pear. The only species found, however, was Agallia sanguiaeolenta^ and 

 no specimens whatever < »f Deltocephalus were found. Search for adults 

 began March 8 and continued till larviT3 appeared all over grass land, 

 and had adults been present they could scarcely have escaped notice. 

 This seemed to show pretty fully that eggs must be deposited in fall 

 and that the adults i)erished during Avinter if not in late autumn. To 

 determine more certainly the j)lace of deposition of eggs and whether 

 adults could possibly survive the winter to oviposit, a pen was made 

 about G by 10 feet in size, inclosed by boards placed close together and 

 set down into the ground, 2 feet in height, and with all cracks or open- 

 ings closely stopped, but open above to sun and rain. This was carefully 

 examined to make certain of the absence of the adults and repeatedly 

 searched to make sure of any introduction of Jassids. Larvse from 

 without could not x>ossibly enter, as they can jumj) but a few inches 

 from the ground at best and very little when lirst hatched, while the 

 possibility of adults getting into this inclosnre, even if any had been 

 found in any place, were very slight indeed, and any such would have 

 been found in the frequent examinations of the pen. As soon, how- 

 ever, as hirvi^ appeared over grass lands in general, and they appeared 

 in millions within a few days of the time that the very lirst were found, 

 this inclosnre also contained larvie in numbers. The proof therefore 

 seems conclusive that larvie hatch from eggs that have been deposited 

 in the grass in the autumn or early winter preceding. 



The first larvte were seen April 23 in grass on the south side of one 

 of the college buildings, but had not appeared elsewhere, nor did they 

 appear in great numbers till ]\Iay 12, evidently being-retarded by cold and 

 wet weather. The larvje taken April 23 were nearly black in color and 

 developed into I), inimicus, one adult being secured June 20. Larvte 

 of the same species of later broods are usually much lighter colored, 

 almost whitisli, with occasional individuals of darker color, and after 

 first or second moult all present a characteristic marking, consisting of 

 a. black lateral margin to thorax and abdomen. Larv;e of Z>. inimicus 



