EFFECTS OF TEMPERATURE. 327 



At intervals of a few days several of the caterpillars of 

 the dift'erent ages were removed from the refrigerator and 

 placed on suitable food in a warm room ; and in this way the 

 length of time the caterpillars could exist without food, was 

 determined. None of the caterpillars between the third and 

 fourth molt were alive when removed from the box April 6. 

 Of those between the second and third molt, a single cater- 

 pillar remained alive April 24, and this one, when supplied 

 with lettuce leaves, revived, fed and molted at the end of 

 nine days. April 12, a number of caterpillars between the 

 first and second molt were removed, and when supplied with 

 food revived and began feeding. Several of the newly 

 hatched caterpillars were found to be alive April 24, and 

 when supplied with food a number of them were able to feed, 

 and so reached maturity, after having been deprived of food 

 for a period of three weeks. 



A nearly full-grown caterpillar, confined in a box July 

 30, 1894, without food, lived until August 9, but died the 

 night of that day. Lodi states that a caterpillar of this moth 

 in Europe went without food for twenty-seven days without 

 injury ("Opuscol. scelt.," vol. XII, page 183, 1789). 



E_ffect of Extremes of Temperature on Cater2nllars of the 



Gypsy Moth. 

 Effect of Heat. — Fifty caterpillars, in lots of ten, taken 

 from the different molts, from those just hatched up to and 

 including the fourth molt, were exposed for fifteen minutes 

 to a temperature of 110*^ F., and were then placed in jars 

 and supplied with food. Of those just hatched, only one 

 died ; of those of the first molt, three ; of the second molt, 

 three ; of the third molt, three ; and of the fourth molt, 

 three. The rest of the caterpillars survived and molted. 

 Fifty caterpillars, selected in the same manner as those of 

 the preceding experiment, were exposed to a temperature 

 of 120*^ for a period of fifteen minutes. Of those just 

 hatched, ten died ; of the first molt, ten ; of the second 

 molt, ten ; of the third molt, nine ; and of the fourth molt, 

 only one. April 4, fifty caterpillars were exposed to a tem- 

 perature of 130*^ for a period of fifteen minutes. The cater- 

 pillars used in this experiment comprised those just hatched 



