PACHYGASTRIA TRIFOLII. 27 



ing cannot be separated from the remainder ot cocoon as in that of 

 L. quercus. Edelsten notes : " The cocoon is oblong in shape, yellow 

 in colour, attached by white silken threads, that of L. quercHs being 

 larger, more elongated, dark-brown, very firm and coriaceous in texture, 

 and smooth inside. ;; Bacot notes : " Cocoon of the usual ' eggar ' 

 shape, oval, golden-brown in colour, slightly swollen centrally." On 

 the emergence of the moth, the cocoon is usually opened at one end 

 by an irregular fracture which is sometimes longitudinal, small pieces 

 of the brittle structure of the cocoon being broken off on either side. 

 Sometimes the loosened piece is circular and turned back lid-like, 

 reminding one of the pseudo-lid of the cocoon of Lachneis lanestris. 

 In other? a circular opening is made, rather to one side and not at the 

 end, and the disturbed material appears then to be pushed back all 

 round the opening. There is sometimes an abundant staining at the 

 emergence-end, suggesting the use of a fluid at the time of escape of 

 the moth-. 



Abnormal cocoons. — Newnham records (lint. Rec, i., p. 236) 

 the occurrence of two pupae of this species in one cocoon. Clark 

 notes (Pntom., xxi., p. in) a single cocoon with two exits, the exit 

 end of the cocoon thinner than the rest of the cocoon. 



Comparison of cocoons of Pachygastria trifolii and Lasio- 

 campa var. viburni. — These cocoons are superficially very similar, 

 but that of P. trifolii is much thinner and the two coats are not distinct, 

 the inner being a mere varnish as though coated with white of egg 

 (Bacot). 



Pupa. — Three pupae gave the following measurements : $ greatest 

 length JL| i n#j greatest width * § in. j $ length ^L } n ^ w idth * f in. ; 

 $ length J in., width * -^ in. — $ . The female pupa is short, stout, and 

 dumpy, widest at the 4th abdominal segment (end of w T ing-cases), tapers 

 rapidly from here to the blunt rounded anus and more gradually to 

 shoulders, from here it curves bluntly round to head ; the face-parts 

 project ventrally but the venter otherwise almost flat from head to anus ; 

 much curved dorsally; distinctly constricted at metathorax and first 

 abdominal ; leg- eye- and antenna-cases prominent ; these and wings 

 dark umber-brown, lighter on thorax, the abdomen whitish-yellow with 

 a broad dark mediodorsal line or band, darker at anus ; spiracles 

 large and prominent, blackish-brown; proleg scars on sixth and seventh 

 abdominal segments; anus rounded, blunt, shows scars of anal claspers, 

 thickly covered with short, scattered bristles : abdominal incisions very 

 marked. 3 ■ The male pupa more slender and much paler than that 

 of 2 ; the wings, antennae, legs, head and thorax light reddish-brown, 

 rather paler on thorax ; the abdomen pale yellow ; spiracles black ; 

 the wing-cases very transparent, the covered abdominal segments 

 visible through them ; rather concave in outline dorsally at 4th and 

 5th abdominal segments ; the cremaster as in $ pupa but the bristles 

 more numerous (Bacot). 



Food - plants. — Grass, elm, hornbeam, bramble (Reaumur), 

 Artemisia (Staudinger), Spartium, Genista, and other Leguminosae 

 (Rambur), Ononis spinosa, Cytisus laburnum, some few species of 

 grasses (Rossler), Calluna vulgaris (Sepp), Retama monosperma (Walker), 



* The width of the pupa is almost the same as that of the cocoon, the pupa 

 filling up (in this direction) almost the whole of the available space in the cocoon. 

 The pupa is usually somewhat shorter, however, than the length of the cocoon (Bacot). 



