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Psyche 4:327-328, 1883.

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ENTOMOLOGICAL ITEMS.
THE PROCESS OF SKIX-CASTIXG IN A LEP~-
DOPTEIIOUS LARVA.--T~~ following account of a larva casting its skin may be of interest, and may also tlirow some light on the curious phenomenon of "moulting," for in many
works on entomology we are only told thnt 'the skin breaks at the back near the head. and thnt the larva walks out of its skin after a due amount of twitching and wriggling." Whilst examining a looper caterpillar, about 4 inch [i cm.] long and very transparent, under the microscope, I was very much
struck with a peculiar internal movementy 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 liead, 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 stiilionary an if held by the other segments, whilst the particular one in mo- tion freed itself within. After remaining motionless tor a &hurt interval, the skin near the htxd sweiied and burst open at the back; then I became aware of the fact that the curious procet-s of "moulting" wan going on before my eves. Presentij out comes the head of the new caterpillar. pui-hing forward the old one; looking wonderfiilly clean with its ten shining black eyes on n cream colatired pound. After ii hl-iort struggie the new, true legs, transparent flesli~ limbti, ve1-1 111~~11 ~ e - sembling those of a newly-batclieil spider, appear, pushing off and treading undei foot the old ones. '1'112 outer skin must have snd- denly contracted, and althougli I did not see the actual process of contracting, I cowlude 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. 1 have no doubt that such is the process with all larvae, a1- though the interna! movements of most,
especially those having thick and opaque skins, cannot be so easily watched as the young and more transparent ones.-Edward
Howgate (The naturalist, Nov. 1885, no. 134. P. 366)-
PROGNOSTICATIONS OF WKATHER BY IS-
SECTS.-T~~ current number (No. 17) of me natw contains an article by Hen- Einmerig, of Lauingen, on German bees as storm
wnrners. 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 hvgrometer foretold a storm, the bees remaining quiet, and no storm occurred; or the 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 stiil, one need not fear a storm. With regard to rain, . merely, the bnrometer and hygromet~r are safer guides than bees; not so, however, in the case of a thunderstorin. Finally, the writer trusts that his remarks on this subject may lead to further observation.-1Vniu-i-e, 23 April 1885, v. 31, p. 587.




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In regard to the prognostications of
weather by insects, the following passages from Kirby & Spence's "Introduction to en- tomology" may be added :-
, "Huber says that he has ascertained by a great number of observations that electricity is singularly favourable to the secretion of the substance of which honey is formed by flow- ers ; the bees never collect it in greater abun- dance, nor is the formation of wax ever more active, than when the wind is in the south. the air humid and warm, and a storm gather- ing."-~. 4, p. 141.
+But besides receiving notices from the
atmosphere, of sounds, and of the approach or proximity of other insects, &c., the anten- nae are probably the organs by which insects can discover alterations in its state, and fore- tel by certain prognostics when a change of weather is approaching. Bees possess thib faculty to an admirable degree. When en- gaged in their daily labours. if a. shower is approaching, though we can discern no
signs of it, they foresee it, and return sudden- ly to their hives. If they wander far from home, and do not return till late in the even- ing, it is n prognostic to be depended upon, that the following day will be fine: but if they remain near their habitations, mid are seen frequently going nncl returning, al- though no other indication of wet should be discoverable, clouds will soon arise and rain come on. Ants ;ilso are observed to be
excellently gifted in this respect : though they daily bring out their larvae to sun them, they are never overtaken by sudden show- ers.* Previously to rain, as you well know, numberless insects seek the house; then the Stomossys caicifrans. leaving more ignoble prey, attacks us in our apartment&, nnd inter- rupts our studies and meditations. t The --
* Lelimann, M. C. G. De untcnnis insectnrnii). Dis~ertutio posterior.. . , I%O, p. 6*>-. fK.&S.,v.i,p.+S,no.
1 See, for further nrguinents, hhinnnn, ubi supf., cnp. 9.
insects of prey also foresee the approach of wet weather, and the access of flies, &c., to places of shelter. Then the spiders issue from their lurking-place*. and the ground- beetles in the evening run nbout our houses. Passive antenna:, which are usually fur- nished with a terminal or lateral bristle, and plumose and pectinated ones, seem calculiited for the action of the electric and other fluids dispersed in the atmosphere, which in certain states and proportions may certainly indicate the approach of a tempest, or of showers, or a rainy season, and may 60 affect these
organs as to enable the insect to make a sure pr~gnostic of any approaching change : and we know of no other organ that is so likely to have this power. I sny electric fluid, because when the atmosphere is in a highly electrified state, and a tempest is approacli- ing, is the time when insects are usuall~ most abundant in the air, e!-liedally toward;! the evening; and mnny species may then
be taken, which nre not at other times to be met with : but before the storin conies on, all disappear, and you will i.carce1.y see a single individual upon the wing. This seems to
indicate that insects are particularly excited by electricit!.-But uptm this head I wish to milhe no positive ti-herlion, I only suggest the pi'fibabilit! of the opinion.+"-v. 43 P. 253-2 54.
Dr. 11. A. llagen, in his Bibliotheca ento- ~nologicil [Rec,. 33061. dtffi the following papers on this subject :-
WORZEICI~EX der wiititning an cinigen
insecten. (Nettes Wittenb. wochenblatt.
1810. p. ?~<i-238.)
STUUBEL, PelIegrino.
Saggio (11 oi- serva-
zivni (enologifhe rplative ai ctinici deil'agro p:ive.w e stiidii -u !;I flora de eks-i prediletta. (Atti Soc. ititl. xi. "at . 1861, v. 3, p. 181.) [not ~een.1
-
Nw, ~i crc i-ut-d 35 X<w. IS%.
Nus. ioj.tq were issued 22Jii11. IS:.




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