|uly— Scpteiiilier 1SS5. 



PSYCHE. 



3-_'7 



ENTOMOLOGICAL ITEMS, 



The process of skin-casting in a lepi- 

 DOPTEROUS LARVA. — The following account 

 of a larva casting its skin may be of interest, 

 and maj also throw some light on the curious 

 phenomenon of "moulting," for in many 

 works on entomology we are only told that 

 "the skin breaks at the back near the head, 

 and that the larva walks out of its skin after 

 a due amount of twitching and wriggling." 

 Whilst examining a looper caterpillar, about 

 3 inch [i cm.] long and very transparent, 

 under the microscope. I was very much 

 struck with a peculiar internal movement — 

 each separate segment, commencing at the 

 head, elongated within the outer skin whilst 

 the next ones remained in their former state. 

 Each segment in its turn behaved in this 

 curious manner until the last was reached, 

 when the motion was reversed and proceeded* 

 toward the head, when it was again reversed. 

 I only saw this process of elongation accom- 

 plished three times, although it may have 

 been going on for some time before I cap- 

 tured the caterpillar, which I found in a 

 quiescent state. The whole proceeding ap- 

 peared as if the larva was gliding within 

 itself, segment after segment, the outer skin 

 remaining stationary as if held by the other 

 segments, whilst the particular one in mo- 

 tion freed itself within. .\fter remaining 

 motionless for a short interval, tlie skin neai' 

 the head swelled and burst open at the back : 

 then I became aware of the t'act that tlie 

 ciirioLis process of •■moulting" was going on 

 before my eyes. Presently out comes the head 

 of the new caterpillar, pushing forward the 

 old one; looking wonderfully clean with its 

 ten shining black eyes on a cream coloured 

 ground. After a short struggle the new, true 

 legs, transparent fleshy limbs, very much re- 

 sembling those of a newly-hatched spider, 

 appear, pushing oft' and treading under foot 

 the old ones. Thi outer skin must have sud- 

 denly contracted, and allhougb I did not see 

 tlie actual process of contracting. I conclude 



such was the case, for on examining the 

 latter segments, there I found the skin and 

 the old true legs shrivelled up. The larva 

 then, by a series of wild wriggles, endeavored 

 to extricate its new prolegs (false legs), 

 which in a short time it accomplished. Then 

 all is clear, and the larva, which is quite ex- 

 hausted, coils itself up and literally pants for 

 breath. When it has "got its wind," it 

 wanders off probably in search of the food 

 which it has well earned. I have no doubt 

 that such is the process with all larvae, al- 

 though the internal movements of most, 

 especially those having thick and opaque 

 skins, cannot be so easily watched as the 

 young and more transparent ones. — Edward 

 Howgate (^Thc iiatutalisi, Nov. 1885, no. 124, 

 p. 366). 



Prognostications of weather by in- 

 sects. — The current number (No. 17) o{ Die 

 natur contains an article by Herr Emnierig, 

 of Lauingen, on German bees as storm 

 Warners. From numerous observations, the 

 writer advances tentatively the theory that 

 on the approach of thunderstorms, bees, 

 otherwise gentle and harmless, become ex- 

 cited and exceedingly irritable, and will at 

 once attack any one, even their usual atten- 

 dant, approaching their hives. A succession 

 of instances are given in which the barometer 

 and hygrometer foretold a storm, the bees 

 remaining quiet, and no storm occurred; or 

 tlie instruments gave no intimation of a 

 storm, but the bees for hours before were 

 irritable, and the storm came. He concludes, 

 therefore, that the conduct of bees is a relia- 

 ble indication whether a storm is impending 

 over a certain district or not, and that, what- 

 ever the appearances, if bees are still, one 

 need not fear a storm. With regard to rain, 

 merely, the barometer and hygrometer are 

 safer guides than bees; not so, however, in 

 the case of a thunderstorm. Finally, the 

 writer trusts that his remarks on this subject 

 may lead to further observation. — Nature. 

 23 .^pril 188.V V. 31. p. 587. 



