141 



trees. The relatively large number of caterpillars present suggests 

 that in this woods they were attended by a large number of parasitic 

 flies and parasitic Hymenoptera in addition to predaceous insects. 

 The twig-pruners, Blaphidion, are referred to here because they be- 

 long to the crown commuity for at least a part of their lives. For 

 a summary of our knowledge of these beetles reference should be 

 made to Chittenden ('98 and '10,) and to Forbes ('11, pp. 50-53), 

 who gives a summary of their injury to oaks and hickories in Illi- 

 nois. The oak primer, BlapMdion villosum Fabr. (PI. XXIII, figs. 

 3 and 4) was taken by me at Bloomington July 3. It is injurious to 

 hickory, maple, and other trees. The normal duration of the life 

 cycle appears to be one year, but in dry wood this period may be pro- 

 longed to four or more years (Hamilton, '87; Chittenden, '10, p. 

 5) — another example of the prolongation of life in dry wood. Mr. 

 W. P. Flint informs me that Oncidcrcs cingulatiis Say is a common 

 Illinois beetle, which girdles hickory branches, and that in the dead 

 fallen branch its larva develops. It is reported from hickory and 

 basswood by Hopkins ('93b: 198.) 



Additional defoliators of trees taken at Bloomington include 

 Macrobasis unicolor Kby. (PI. XXIV, fig. 2), taken June 2j on the 

 Kentucky coffee-tree, Gymnocladus. Other specimens were taken 

 June 4 and 12. Hamilton (Can. Ent, Vol. 21, p. 103) also records 

 this as defoliating locust. The larvae of the curculionid Conotrache- 

 lus clcgans Say, taken September 5, is recorded as feeding on the 

 leaves of hickory. The imbricated snout-beetle, Epiccvrus imbrica- 

 tus Say (PI. XXIII, fig. 1), was taken June 4, and, copulating, 

 June 27, at Bloomington. It has been recorded feeding upon the 

 leaves of wild cherry, plum, gooseberry, etc. 



The nut-weevils may be properly considered as members of the 

 crown population. Of these Balaninus nasicus Say was taken August 

 1 (on papaw) at Bloomington, and during September at Chicago. 

 This is recorded as from acorns, hazelnuts, and hickory-nuts. Bal- 

 aninus uniformis Lee. was taken August 20, 21, and September 21 

 at Bloomington. This, too, is recorded as from acorns, as also is 

 B. caryce Horn, taken August 27. Miss Murtfeldt ('94) has ob- 

 served B. reniformis ovipositing in acorns and has described the 

 process. This weevil is associated and in competition with the acorn 

 codling-caterpillar, Mclissopus latifcrrcana Walsm. These two in- 

 sects pave the way for a small caterpillar of the genus Gclcclu'a, and 

 for a second caterpillar, the larva of the acorn moth, Blastobasis 

 glandulclla Riley, which feeds on the refuse within the acorn, and is 

 thus a scavenger. The debris of the predecessors is an essential for 

 the one that follows. Hamilton ('90) has given a good account of 



