MOLTING. 



Caterpillars grow in a peculiar way which is termed molting. When a few 

 days old, they lie dormant for awhile, then the skin splits on the back of the 

 thorax and is cast off, and they appear in a new and larger skin. This process 

 is repeated four or five times during their lives. Eliot and Soule, in "Caterpillars 

 and Their Moths," say: "Most caterpillars molt four times, a few less often, and 

 some oftener. Ten molts are the largest number so far observed in any species." 

 During the molting period larvae should not be disturbed. Under the best condi- 

 tions it is a critical period in larval life and under the best of care many will some- 

 times perish. Just after they have molted their skins are extremely delicate and 

 tender and fatal results will follow if they receive slight injury. 



TIN BOXES AS CAGES. 



Eliot and Soule urge the use of tin boxes. They say: "When the cater- 

 pillars hatch they may be put into boxes a little larger than the egg-boxes — still 

 round ones, with scrim on top, young and tender leaves inside, and the cover 

 shut tight over the scrim. The leaf or leaves should be sprinkled, for the little 

 crawlers like water. It is a good plan not to move them from the egg-box until 

 it is certain that they do not mean to eat any more shell. They never nibble the 

 egg-shells after eating leaf-pulp. We soon learned that leaves did not keep fresh 

 half a day in open or pasteboard boxes; we found that bottles of water in cages 

 or boxes were a source of danger to the caterpillars and a trouble to us; so rea- 

 soning that plants would keep fresh a long time in closed tin boxes> and that cater- 

 pillars needed very little air, we tried the experiment of putting our sprays of 

 leaves into water for an hour or two (as we should put flowers we meant to send 

 away in boxes), and then putting them into our larva-tins for the caterpillars to 

 eat, or into our big tin boxes to be kept till needed. We watched our first tins 

 of caterpillars very closely, and soon satisfied ourselves that the crawlers certainly 

 grew as fast and as large as when in the open air, while the leaves kept far 

 fresher than in bottles of water in open boxes or cages. Moreover, no parasitic 

 flies can sting them in these tins, unless they are put in with the leaves, and this 

 chance is very small. We believe we have had one instance of it, and only one. 

 The tin boxes protected the caterpillars from mice also, while in more than one 

 case our 'best specimen' had fallen a victim to mice when we used cages or netted 

 boxes. The piece of scrim over the top of the box should be large enough to 

 hang down on all sides for half an inch or more. We found that we occasionally 

 beheaded a caterpillar in putting on the box-cover before we used scrim, but we 

 have had no trouble since. With several very lively crawlers in a large box it 

 is difficult to be sure that all are safely out of harm's way, especially since some 

 species are much excited by light and crawl toward it very fast. The scrim keeps 

 them away from the edge and saves some lives. Leaves should not be left in the 

 tins after they begin to lose their freshness, or after the caterpillars have eaten a 

 part and abandoned them. Fresh food and plenty of it, a few drops of water, 

 clean tins, and no crowding are the essentials." 



GLASS JARS WITH TIN COVERS. 



Excellent success may be obtained by rearing most all kinds of larvae with 

 fruit jars, candy jars, tobacco jars, Horlick's Malted Milk jars, and others which 

 have screw tin-tops. They can be removed and replaced without loss of time, 

 and so long as only a few larvae are in each jar they seem to have an abundance 

 of air. Possibly, as some scientists have suggested, the larvae having been accus- 



42 



