TRICHIURA CRATAEGI. 487 



to Finmark (Aurivillius), Tromso (Schneider), Stockholm, Jamtland, Lapland 

 (Lampa), Dovre (Schoyen), S. Varanger (Collett), Lyeksele (Zetterstedt). Switzer- 

 land : Upper Engadine, 5000ft.-8000ft. (Pfaffenzeller), Gadmenthal, Simplon 

 (Ratzer). 



It is evident that the large mountain form, which has a habit of 

 spending its first winter as an egg or young larva, and its second as 

 pupa, has a different facies in different districts, and presents, as does 

 the smaller lowland type, males with white, and males with grey 

 ground-colour, for Freyer describes the large ariae that he bred from 

 the Tyrol as being " bright white-grey " in tint. This form we have 

 named ab. freyeri in the succeeding paragraph. Staudinger diagnoses 

 var. ariae as "major obscurior." Aurivillius observes that the type 

 form occurs in the south of Scandinavia, the var. ariae, on the other 

 hand, as far north as Finmark. Schneider says that he possesses two 

 examples from Sydvaranger and bred one at Tromso all of the var. 

 ariae, and further remarks on the different life-history of the insect 

 from the far north, observing that the larva hybernates* quite small, 

 is full-fed in July or August, that the pupa then hybernates, the imago 

 appearing the following June, thus taking two years to reach maturity. 

 Teich observes that a Lapland pupa which he expected to emerge in 

 the autumn of 1879 (as does the type in Livonia), did not do so until 

 the spring of 1880. Wocke notes the var. ariae as flying on the crest 

 of the Kiesen in May and June, the larva feeding on Sorbus and 

 Vaccinium myrtillus. Hoffmann says that in the moorland districts of 

 the Upper Hartz the larvae are exceedingly variable, are found 

 throughout June till mid- July, principally on Vaccinium uliginosum and 

 V. myrtillus ; the greater part of the imagines appear in August and 

 the beginning of September!, the remainder of the pupae yield the 

 moths in the early spring of next year; almost all the imagines belong 

 to the dark var. ariae, a few specimens only forming transitions 

 between this mountain form and the lighter form of the lowlands ; the 

 imagines emerge from the pupa towards evening, and the male flies 

 about swiftly as soon as the wings are dry. This experience is 

 identical with that of Home, who notes the species as "common in the 

 larval stage on heather, on all the moors near Aberdeen, from these, 

 imagines appear in August and September, and 25 per cent, generally 

 pass the winter in the pupal state and emerge the following summer. 

 All the imagines from this district are darker than the English speci- 

 mens." Reid confirms this, and notes that on the Scotch moors the 

 larvae are common, that they hybernate the first winter, pupate the 

 next summer, and emerge the following autumn. Guthrie notes larvae 



* Barrett observes (Brit. Lcp., iii., pp. 7-8) that " a statement has been made 

 that in the north-east of Scotland, the larva does not feed up within the year, but 

 hybernates as a larva, producing the moth in the following season, but this seems 

 so improbable that one is led to suspect a confusion with the larva of one of the 

 larger Bombyces." We suspect Mr. Barrett was not aware that Schneider, Milliere, 

 Reid, and others, had noticed the larval hybernating habit. The Scotch entomolo- 

 gists could not well " confuse it with the larva of one the larger Bombyces," for, with 

 the exception of half-fed L. var. callunae, full-fed M. rubi, imdC.potatoria, none of 

 the larger Bombyces found in Scotland hybernate in the larval state. 



t Hoffmann suggests that it is a question whether they do so in a state of nature. 

 He thinks it may only be a reversion of the mountain-form to the habit of the low- 

 land form, due to breeding them indoors. He adds that in a state of nature the 

 moth has never been found in the autumn. Bischoff, however, observes that in the 

 Engadine the larvee of var. ariae are full-grown in July and the imagines appear in 

 October. 



