June, '04] 



ENTOMOLOGICAL NEWS. 



189 



Attelabus bipustulatus Fab. 



(COLEOPTERA.) 



Theory of Oviposition and Construction of Nidus; Miscellaneous Notes. 

 BY A. ARSENE GIRAULT, Blacksburg, Va. 



May 18. Many egg-cases found on different species of Oak (Q. rubra, 

 nigrum, alba}. Most of them have been hanging for some time, being 

 browned and brittle ; a few under construction. Eggs present. 



/. General method of construction of nidus, with observations 

 showing method followed for different oak types. 



9 simply makes a crescentic, smooth-edged 

 incision along margin of the leaf ; this inci- 

 sion extends from a point on the margin on 

 each side of one of the principal veins from 

 the midrib, to this vein, the latter thus con- 

 tinuing through the section cut out, forming 

 a petiole for the nidus after construction 

 (vide figure). It is now obvious that the 

 nidus is formed from the portion of the leaf 

 separated out by this crescentic incision ; 

 the separated section is simply rolled up. 



/. First method of construction and oviposi- 

 tion. O. rubra. 



May 22 rubra. 



(a) Construction of nidus. 



After cutting out section of leaf, as shown in foregoing, the female 

 crawls slowly up and down the midrib of the section on the under side 

 and creases the leaf, using its legs as levers, biting afterwards with its 

 jaws to keep the crease in place. It repeatedly folds the section face to 

 face in this manner, i. e., by sprawling the legs on each side, apart and 

 over the midrib, and then bringing them together, generally using the 

 legs on one side of the body as a force, the corresponding opposite ones 

 as a base against which the force is applied. (Analogous to the thumb and 

 fingers. Imagine a leaf held, face out, petiole down, between the thumb 

 and fingers, so that the midrib is equidistant between the base (thumb) 

 and the force (fingers) ; now if the leaf is folded so that the two upper 

 faces are approximate, the midrib forming the line of creasage, or the 

 hinge, it exactly illustrates the relative position of the dextral and sinistral 

 series of legs.) 



It continues the creasing, going up and down the midrib of the section 

 until the two upper faces are approximate. Then it makes diagonal 

 creases from the midrib, crawling slowly with the beak applied to the 



EXPLANATION OF PLATK. Leaf of <?. rubrum, showing at ub incision made by 

 beetle; the shriveled section isolated, and the natural outlines (the dotted lines) of the 

 section from which the nidus is made ; the vein d forms the petiole of the nidus. ORIG. 



