580 



Mr. C. L. Withycombe's Notes o)i 



forms a complete white band across the middle, and two white 

 spots may extend forward from this. 



The abdomen is about one and a half times the length of the thorax, 

 and tapers to the posterior extremity. It is white laterally, brown 

 in the middle, becoming paler and more yellow in the terminal 

 segments. The first, and two of the middle segments of the abdo- 

 men, are usually white entirely, thus making gaps in the brown 

 colour. Underside of body wholly white or greyish, darker in the 

 middle line, due to gut contents being visible. The legs are long, 

 hairy and whitish. 



The marldngs liere given are for a typical larva. There 

 is much variation, however, and a series of sketches shows 

 all stages in the encroaching of the white fat body on the 

 middle darker area. 



When about to spin up, the larva, if of the first brood, 

 selects a site on the flat surface of a leaf, or on the bark of 

 the tree. If of the second brood, spinning takes place 

 always on the tree bark, preferably in a crevice, but often 

 on a flat surface. The larva moves the anal spinneret to 

 and fro over its back, thus forming a circular outer envelope 

 of white silk. Inside this, a smaller flat envelope is spun, 

 this time above and below the body of the larva. The 

 outer envelope is from 5-8 mm. diameter; the inner, 

 about 3 mm. Within this double cocoon the change 

 to pupa takes place, and the adult escapes by a semi- 

 circular slit in both envelopes. 



^ |Hatched.|^Av^.Ll^<>,,. j J-^,_ | Cococn. 



Tmp. hp^^^d- 



Emerged 



Av. 

 Temp. 



14/5/21 j 27/5/21 | 65° F. 30/5/21 ! 6/6/21 16/6/21 I 63° F. | 20/6/21 



30/6/21 1 66° F. 



28/7/20 10/8/20 | 65° F. 13/8/20 , 19/8/20 30/8/20 i 62° F. 4/4/21 



27/4/21 51° F. 



Above are typical life-histories. In the case of the 

 second brood, the cocoon is spun in August or Septem- 

 ber, sometimes as early as July. The larva does not 

 pupate, but remains in the cocoon throughout the whole 

 winter. When warmer weather arrives the change to 

 pupa takes place, followed by the appearance of the imago 

 in about ten days to three weeks. 



The principal food of C. psocijormis on oak is Phylloxera 

 punctata Licht., Chioyuispis salicis L., and various mites, 

 of which may be mentioned Tetranychus quermius Berl. 



