200 



THE CANADIAN ENTOMOLOGIST 



Leng as Pelenomus sidcicollis Fahrs. (Curculionidae), and as nothing has ever 

 been published on the biology of this genus I think these few notes may be of 

 interest. 



The beetles were very abundant during August and early September, 

 oftentimes five or six beetles being present on a single leaf. They feed largely 

 on the leaf tissue, skeletonizing it; though this year, on account of the almost 

 complete destruction of the leaves by the larvae, the beetles were forced to feed 

 on the stems and mid-ribs of the leaves. These they cut into with their mandi- 

 bles, and then eat the softer parts within. During the latter part of September 

 the beetles became fewer and fewer in numbers, and there is no doubt that they 

 hibernate somewhere amongst the fallen leaves and rubbish. 



After some search I found where the eggs are laid. Just beneath the 

 lower epidermis of the leaves near the veins I found a few empty egg-shells. 

 (Plate XVIII, Fig. 3). The eggs are laid singly and, as a result of the oviposition. 

 the area in which the egg is laid dies and becomes brown. This dead area 

 shows only on the lower surface, evidently the parenchyma not being suffi- 

 ciently damaged. 



The larvae feed on the lower surface of the leaves almost entirely. They 

 destroy the lower epidermis and parenchyma, leaving the upper epidermis 

 intact. This soon dies, and large open spaces are left, giving the appearance 

 shown in Plate XVII T, Figs. 1 and 2. As the larvae do not possess legs they 

 evidently move by the action of the large flat surfaces on the ventral side of each 

 segment. These can evidently be moved slightly by muscular action, though 

 I have never seen the lar\ ae actuallv crawl. 



m^-:'\-  -i ;.*y.;---.i.v..\-: ■.■:■. f i- ;; !?& 



Fig 23. — Pelenomus sulcicoUis Fahrs.; mature larva, pupa and adult. 



When mature the larv8e""spin small silken cocoons on the under surface or 

 axil of the leaf, and in the destroyed ends of the stem. These pupal cases are 

 rather beautiful' especially when a number of them are formed close together. 

 (Plate XVIII, Fig. 5.) In these silken cells the larvae transform to pupae within 

 a few days, and the adults emerge in about two weeks. After emergence the 

 beetles feed quite extensively before going into hibernation. So far as my 

 observations go there is undoubtedly only a single generation a season. 



