CODLING MOTH IN COLORADO. 109 



distance of about three-fourths inch. In many of the burrows no 

 larvae were found, they evidently having decided to leave after they 

 had consumed most of the softer tissue of the new growth. The 

 larvae found were in either the third or fourth instars. An attempt 

 was made to rear some of these larvae in pear twigs, but this was un- 

 successful. Two of the larvae obtained from the pear twigs, how- 

 ever, were transferred to apples on the date collected, June 24, and 

 from these two moths were reared, one moth issuing on July 19 and 

 the other on July 20. 



EXPERIMENTS WITH BLACK AND WHITE BANDS. 



In fruit districts where the codling moth is abundant, spraying is 

 frequently supplemented with banding. With the banding method 

 a strip of cloth is placed around the trunk of the tree and the cod- 

 ling-moth larvae that form cocoons beneath the cloth are destroyed at 

 intervals of about 10 days throughout the season. The question has 

 frequently been asked whether dark-colored bands are more attrac- 

 tive as a place of concealment than bands of a light color. To deter- 

 mine this, an experiment was made in 1916 in which were used bands 

 of cloth folded to three thicknesses, each alternate quarter of which 

 was black and white. (See PL VII.) The trunks of 10 trees were 

 first thoroughly scraped and were then encircled with bands of this 

 description on July 5. The segments of the bands were arranged so 

 that the white and black quarters alternated with the four quarters 

 of the trunk. Thus on 5 trees there was a black segment on the 

 northeast side of the tree, while on the 5 remaining trees there was 

 a white segment covering this quarter. The bands were first exam- 

 ined for larvae on July 8 and every 3 days thereafter to August 19, 

 inclusive. The results of this study are given in Table LXXIX, in 

 which it will be seen that the codling-moth larva is strongly inclined, 

 when the opportunity is present, to spin its cocoon beneath dark- 

 colored cloth. Out of a total of 2,362 larvae collected, 2,083, or 

 "88.19 per cent, spun their cocoons beneath the black segments of the 

 bands. A summa^ of this table is given in Table LXXX, which 

 shows the number of larvae collected under each segment. Accord- 

 ing to these figures, the codling-moth larvae, with one exception, pre- 

 ferred the northern exposure of the tree trunk. 



