124 THE CANADIAN ENTOMOLOGIST 



Stage V. — Structurally similar, but colour much darker, fre- 

 quently a deep purple brown with the stripes showing very con- 

 trastingly. On joint ten IVa is well developed, though not bear- 

 ing seta, as does IV. 



Stage VI .^ — Colour fades to dull pink, the pale yellow lines 

 wide and conspicuous. Tubercles I and II become more prominent, 

 especially on joint eleven; and on twelve their mergence into a 

 single plate preceding the anal shield, is even of greater definition. 



Maturity. — The full-grown larva is normal for the group, 

 though rather robust as compared with the resultant moth. The 

 lines become vague and the general tone a yellowish translucence, 

 with the brown plates at the tubercles conspicuous when they are 

 larger than the black spiracle. The single seta they bear is scarcely 

 discernible except with a lens. The head assumes a darker hue, 

 and the anal plate becomes heavier and nearly black. Tubercle 

 IVa on joint ten seems never to bear setae. Larval lengths for the 

 stages: 27, 33, 40 and 47 mm. respectively. 



The pupa shows no departure from normal. It is polished 

 brown, the shell of rather thin texture so that the white stigmata 

 of the primaries may be discerned a week prior to emergence. 

 Fungus claimed a large percentage whether left in the earthen cell 

 or removed and giv^en antiseptic treatment. Thus the assumption 

 arises that infection occurs while the larva is yet feeding. The 

 pupal period is about four weeks; emergence dates for the series 

 bred, Sept. 3 to 23. 



One of the first plants to attract attention while examining the 

 flora of the Chicago Plain in 1915, was Eryngium aqiiaticum L., 

 one of those anomalous denizens of this area which subsist equally 

 well through great extremes of moisture, or of dryness. We were 

 under the able guidance of local entomologists, Messrs. A. Kwiat 

 and E. Beer at the time, and remarked this one seemed favourable 

 for tenanting a Papaipema, its Yucca-like foliage suggesting some- 

 thing quite difi^erent from the usual line of food plants. Should 

 such an one be selected, the associate might be expected to show 

 some departure from the customary type, and our enquiry if this 

 plant had been followed up previously elicited the reply that 

 numerous observations of it the preceding year were negative in 

 result. At a momentary pause, Mr. Beer devoted himself to several 



