MACROTHYLACIA RUBI. 141 



darker in colour than those obtained from Folkestone (hi litt.). 



Comparison of larvae of Macrothylacia rubi and Lasio- 

 campa quercus. — In the larva of L. querais the five transverse 

 ridges of urticating hairs that make up the dorsal fur on each 

 abdominal segment show more distinctly than in the larva of 

 M. rubi, and a perhaps adventitious resemblance between the 

 larvae of the two species is heightened by a similar series of 

 subdorsal black slashes, produced by the widening of the bare 

 inter-subsegmental areas in the larva of M. rubi at the 3rd sub- 

 segment, but in that of L. quercus at the first. On some segments, the 

 larva of M. rubi shows a tendency to develop the dark streak or slash 

 at the 1 st as well as at the 3rd division of the subsegment, but 

 the larvae of L. quercus examined show no corresponding tendency 

 to develop a widening at the 3rd. (Bacot, in litt., May 9th, 1900). 



Pupation. — The cocoon is generally placed more or less 

 vertically among its foodplant, and forms a long tube securely 

 attached thereto. Day found, April 18th, 1897, near the top of 

 Penmaenmawr, a great number of cocoons of M. rubi, many just 

 formed, some containing larvae not yet pupated, others with newly 

 formed pupae ; these cocoons were spun in the coarse moss which 

 grows to a depth of six or more inches among the bilberry and 

 heather ; the top of each cocoon, slightly projecting above the moss, 

 made it quite easy to distinguish where a cocoon was placed, the little 

 dark brown end appearing just above the level of the moss. Lambil- 

 lion observes also that the long cocoon stretches straight up from the 

 roots of grass or heath in the Namur district, and Bostock that they 

 are spun up among the heather on Cannock Chase, whilst they were 

 found to be exceedingly abundant in 1887 on a large tract of heathy 

 ground at the Lizard. McArthur notes that the cocoons are 

 frequently to be met with in the Isle of Lewis among the short 

 heath or moss, and Barnes that in the Reading district they are woven 

 among the heather and rubbish at the roots of nut and birch 

 bushes. Robson asserts that the pupae move freely up and down 

 in the cocoon in order to take advantage of the sun. Pupation takes 

 place usually in March and April all over the British Islands. 



Cocoon. — The cocoon often measures 2 — 3 inches in length, 

 and forms a sort of loose tube, generally fixed more or less vertically 

 among the larval foodplants. The cocoon has a loose outside part, a 

 closer and compact inner structure ; still the cocoon is thin and not 

 tough as is that of L. quercus, &c. ; the inside is smooth ; the 

 pupa, if touched, shows considerable activity whilst in the cocoon. 

 If the fullfed larvae are placed in rather small chip boxes for pupa- 

 tion, a certain percentage nearly always makes round cocoons, and the 

 pupae in these are usually malformed ; it is best to use a fairly large 

 loose paper box in which each fullfed larva may spin when reared in 

 confinement (Robson). The cocoon is enormously disproportionate 

 to the size of the moths, being sometimes as much as 3 inches 

 in length, composed of a sort of thin felt, in the manufacture of 

 which the hairs of the larva are largely employed ; it is of a dark 

 brown colour, semi-transparent, the enclosed pupa readily seen, 

 occupying about a third of the interior (Newman). Day describes the 

 cocoon as being of the colour of dark brown paper, very long — 

 about two inches — ruggedly finished off at the bottom, but with 



