26 



THE REP ORT OF THE 



No.19 



The following table, which I have made up from the last five completed volumes of the 

 Canadian Eatonioloyisl, will give an idea of the usual length of the egg stage of insects : — 



Colias interior, 6 or 7 days, Lyman, Vol. XXIX., No. 11. 



EpirrmUhns obfirmaria, 13 days, Fyles, Vol. XXIX., No. 11. 



Brephos infans, 8, 9, or 10 days, Brainerd, Vol. XXIX , No. 11. 



Trigoiiophora periculosa, 10 days, Fyles, Vol. XXXI., No. 2. 



Euprepia caja, 9,days, Gibson, Vol. XXXII., No. 11. 



Arctia phahrata, 7 or 8 days, Gibson, Vol. XXXII., No. 12. 



Xylina Bethunei, about 14 days, Lyman, Vol XXXIII., No. 1. 



Fhlyctienia fe.rrugalis, 14 days, Fletcher & Gibson, Vol. XXXIII. , No. 5. 



Arctia lurgmicula, 7 or 8 days, Gibson, Vol. XXXIII., No. 12. 

 The most remarkable egg period that has come under my notice is that of Pamphila Mani- 

 toba. Thi egg stage of ^this insect lasts for eight months. In the year 1894, on the 8th day of 

 August, I witnessed the laying of a batch of the eggs. On the 20th day of April, in the follow- 

 ing year, I saw the tiny larvae bite their way to freedom from the shells in which they had 

 lived so long. The other stages of the insect's life were completed within four months — in less 



than half the period of the egg stage. m, i i ■ ■, ■, • • i-m 



Ihe larval period also varies in diner- 



ent species. It is the insect's feeding 



time. In the case of a Bombyx, it is the 



time when sufficient nutriment must eb 



assimilated, to sustain the insect through 



all its after e.xistence. Some larvae are 



quickly " full fed," and go directly after 



into chrysalis. Others spend the Winter 



in a state of torpidity, and complete their 



growth in the Spring. Such, for instance, 



are the larva? of Melifn^a Harrisii Scudder. 



These are oT'^^garioni in the Fall, and may 



Fi<f. 10. Caterpillar anJ Chrysalis of a Cossus. 



be seen'^apparently tangled) up in dirty- 

 looking webs upon the heads of the 

 White Aster. When disturbed they 

 strike an attitude, and seem to be all 

 legs. In the Spring they scatter, and 

 feed up on the young shoots of the 

 plant. The butterflies from them ap- 

 pear in June. Their life is completed 

 within a twelvemonth. 



But with the Cossidte the larval 

 stige is greatly prolonged. Packard 

 has given illustrations of Cuasas Gen- 

 terensis, Lintiier, in which the appear- 

 ance of the larva is shewn after a 

 growth of four months, of a year and 

 four months, of two years and four 

 months, and of three years, when the 

 caterpillar was ready to pupate. ( H'ig. 

 10.) 



But the most extraordinary prolongation of insect life is that of Cicada septendecim, 

 Linneus (Fig. 11). This creature, as its name implies, is seventeen ytrars in attaining perfec- 

 ti<m. In lenijth of life it stands alone amongst insects. 



Cicada seiitoiidt 

 form ; il. 



a, laiva ; b, pupa case 

 dfposiled in a twif;'. 



, perfect 



