278 



TRANSACTIONS OF THE NORTHERN 



them. ■S\nien they are alarmed by anj- disturbance, they curve the body forward and in a possum- 

 like manner allow themselves to fall to the ground,— a habit quite common among many kinds of 

 insects. 



"Sept. 11, 1864.— I placed one of the larva in a vial, after having captured it in the field in the very 

 act of devouring chincli bugs ; I then threw a number of chinch bugs of all sizes into the vial, but 

 they had hardly reached the bottom before it seized one of the larger ones, piei-ced it with its 

 long mandibles, held it almost motionless for about a minute while it was sucking the juices 

 from the body of its victim ; it then threw down the lifeless shell. In this way I saw it 

 destroy in quick succession about a dozen bugs ; towards the last, as its appetite was becoming 

 satiated, it spent Ave or more minutes in sucking the juices from the body of one bug. After this 

 bountiful repast it remained motionless for an Imur or more as if asleep. Never for a single moment 

 during the feast did it pause in the work ; when not in possession of a bug, it was on the search for 

 or in the pursuit of others. It manifested much eagerness in the pursuit of its prey, yet not with a 

 lion-like boldness, for on seyeral occasions I observed a manifest timorousuess— a luilting in the 

 attack as if conscious of danger in its Imuting expeditions, allhougli here there was none from the 

 cliincli bugs. Sometimes when two or more bugs were approacliing rapidly, it would shrink baek 

 trom the attack and turning aside go in pursuit of others. At length, awakening, it would renew 

 the assault as before. On one occasion wlieu it was on the side of the vial, two inches up, with a 

 large bug in its mouth, I jarred the vial so that it fell to the bottom and rolled over and over across 

 the bottom, but holding on to its prey it regained its footing and mounted np to its former position. 

 Occasionally the chinch bugs would luisten to escape when pursued, as if in some degree conscious 

 of danger, ' ' 



It is strange that chinch bugs, like plant lice, are so stupid when threatened by danger of any 

 kind ; the winged insect even will not take wing and tly away from the most tlireatening danger. 

 The chrysopia larvw are naturally timorous, for in their avidity they often destroy each other, the 

 successful comliataut sucking the body of his vanquished brother. I never found it safe to put two 

 individuals into the same breeding box, for like the larva of the "cutworm lion" (Calosoma 

 Calidum), they are sure to destroy each other. Even when attenuating to carry two of the latter 

 home in a box, only one usually is found alive. 



Sept. 12.— 5Iy specimen in the vial which was feeding so voraciously yesterday that I feared it 

 would burst, is less greedy to-day. "Evening. — I observed it in an angle formed by some paper at 

 the bottom of the vial spinning a very attenuated web. It had just commenced the work, having 

 thrown out some of tlie outer stays as a support for the intended cocoon ; its body is curved in the 

 form of a semicircle, its head drawn inwards towards its breast ; fixed in this position it is spinning 

 with its very pliant tail (a very interesting feature, and new to me then, regarding this insect, for ver\' 

 few insects proper spin with the tail), tlirusting it out in all directions, l)ending It as freely and 

 gracefully as the trunk of an elephant, but with great rapidity. As I silently thus watched it for a 

 long time by the liglit of my lamp, I reflected that tliisis certainly a very beautiful sight to beliold, so 

 frail a creature constructing with such unerring and mathematical precision its temporary coffin, 

 with a lid prepared that it may lift ofl' when it sees fit to escape, and come forth from this temporary 

 resurrection in a new dress. In a different form of life, in which it exchanges the meanness of the 

 worm for the beauty of the lace-wing fly ; and the thought very naturally suggests itself: has it au 

 idea of its future ressurrection in newness of life, and does this foreknowledge induce it to prepare 

 Its work accordingly ? When accidentally jarring the vial it reuuiins motionless fo;i' the si>ace of ton 

 minutes or more, now, if possible, more cautious than ever before, still true to its former nature, 

 depending upon playing the 'possum" for safety. At length after all has remained s^ill and quiet 

 for a long time, it commences very slowly and cautiously to continue spinning its web. and now 

 apparently feeling safe from danger, it works rapidly as before, occasionally shifting half way around 

 in the direction of itsiliead by a (juick jerk : in this way its very flexible tail has access to every part 

 of its cocoon. During my entire oliservatiou of several hours, it holds its l)ody in the same plane— 

 tlie plane in wliich it was curved when I saw it commencing its work, and doulttless remained in 

 this position within the cocoon. Thus it worked, and on the following morning I found tliat the 

 outer visil)Ie worli was comi)leted. In the centre of tlie tliinly scattered outer fibres it has formed 

 a closely woven subspherical cocoon, very smootli exteriorly, of a light gray color, about the size 

 of a No. 1 shot, slightly prolate-spheroidal, 0.16 by 0.125 inches. Afterabout one month the perfect 

 insect lifted off a lid, which it had previously prepared, and came forth, at first quite tender but 

 soon, by exposure to tlie air, hardened and developed into the perfect insect. 



During the entire autumn I saw an unusual number of this and other species of the lace-wing flj- 

 011 the wing, even as late as December 1st. May not the perfect insect live over tlie winter to deposit 

 its eggs in the spring? The pupa, however, appears in a better condition to weather the storms of 

 the frozen season. In the early part of September I beheld many of these lace-wing flies in the corn 

 where I was conducting my observation, for 1 had au acre of thickly sown com near at hand for a 

 breeding c;ige, and I found it a much better one than I ever had in the studio. As I mowed this corn 

 for fodder from time to time, every stroke of the scythe would cause three or four dozen of them to 



