A HISTORY OF DURHAM 



fascia sometimes spreads and makes the entire underside dark. It does not appear to affect the 

 upper side at all. 



The Purple Hair Streak, Thecia quercus, occurs only in the north-west of the county, 

 about Gibside and the Derwent Valley. It is far from common, and is the only Hair Streak 

 occurring in the county. The Copper, Polyommatus phlaas, is plentiful. Varieties approaching 

 Schmidtii have been met with near Hartlepool and elsewhere. The Brown Argus, Lycana 

 agestis, occurs on the coast, extending up the Denes almost as far as they run. The local 

 form, which is generally without the orange marginal spots, was considered distinct, and was 

 named salmach by Stephens. Artaxerxes, the Scotch White Spot, occurs occasionally, and 

 sometimes has, as well as the type, the marginal row of orange spots. I have twice taken a 

 variety in which the spots on the underside are without the white line around them. The 

 insect is slowly disappearing from the banks at Black Halls. It has already left Marsden, but 

 it is still plentiful between Black Halls and Seaham Harbour. The Common Blue, Lycana 

 alexh, is very common everywhere. The Little Blue, L. alsus, was well distributed over the 

 county, and still occurs at a few places. The Holly Blue, L. argiolus, was also well dis- 

 tributed, occurring apparently everywhere. There has been no record of its capture for over 

 fifty years. 



The Dingy Skipper, Thanaos tages, is tolerably well distributed, and there are few places 

 where it may not be taken. The Common Skipper, Hesperia syhinius, has been taken at 

 Darlington, Castle Eden Dene, and other places. The last I know of were taken in Castle 

 Eden Dene in i86o, and in Hcsleden Dene in 1861. 



HETEROCERA 



Moths 



NOCTURNI 



The Eyed Hawk Moth, Smerinthm ocellatus, has occurred occasionally, but it is not a 

 resident species, though the larvae have been met with more than once. The Poplar Hawk 

 Moth, S. populi, is abundant everywhere. The Death's Head, Acherontia aU-opos, occurs all 

 over, not regularly, but almost every year. I have had the imago brought mc that had come 

 on board fishing boats at sea. The larvs is also occasionally found. The Convolvulus Hawk, 

 Sphinx convolvuli^ is rarer than the last, and generally occurs singly. The larva has never 

 been met with, but in the adjoining county more than fifty were found on a hedge overgrown 

 with Convolvulus septum. The Privet Hawk, S. ligustrl, was once found, unexpanded, in a 

 street in Hartlepool. It ought to occur in the Denes, where privet abounds, but we have 

 never found it. The Bedstraw Hawk, Deleiphila gtiUi, has been taken on the coast whenever 

 the insect has appeared in Britain. The larv.ne has also been found on the Bedstraw more than 

 once. D. lincata has been recorded three times — near Sunderland, by the late William Back- 

 house, on the moor at Hartlepool in 1888, and again there in 1896. Charocampa celcrio has 

 been met with a few times in the same way. The Small Elephant, C. porcclliis, was formerly 

 common along the coast, and may probably occur yet, between Black Halls and Seaham 

 Harbour, but there are no records for several years. A single specimen of C. ner'ii was taken 

 by Mr. Gardner at Hartlepool on 23 July, 1885. The Humming Bird Hawk, Macroglosso 

 stellatarum, is generally common on the coast, but much rarer inland. M. Iwmhyliformis 

 appears to occur near Duriiam city. It w.ns taken at Siuill over fifty years ago by the late 

 William Backhouse ; Mr. Wood also took it near Durham (E. W. I., i. 150). Mr. Hcdworth 

 saw it in May, 1869, near Winlaton Mill. I know of no more recent records. Saia formictv- 

 formis, the Red-tipped Clearwing, has been taken once, by Mr. Thom.as Pigg, who took three 

 on an umbelliferous plant at Gibside. It also occurs in the Chester-le-Street district. i\ tipuli- 

 formiiy the Currant Clearwing, is commoner, and no doubt occurs in old gardens in many 

 parts ot the county. It has been taken at Darlington, Wolsingham, and Durham city. 

 S. hcmhi-dfoniiis occurs commonl)' in most jjarts of the county. S. apiformis was taken once 

 near High Force, Upper Tecsdalc, by the late William Backhouse, over fifty years ago. The 

 Goat Moth, C'ossiis ligtii/nrrl/i, is sparingly distributed about tlu- county. All the genus Hcpialus 

 occur trc'-ly. The Gulden Swift, //. Imtits, in woods and ilenes, flying at sunset for a few 

 minutes only. The Common Swift, //. lupulini/s, is nidst abundant everywhere. The 

 Beautiful Swift, //. sylvhiiis, is perhaps the least |)li niilul ; it occurs in open gromul in August. 

 The Northern Swift, //. vcllidn, in woods and open ground. The Ghost, //. humuli^ is the 

 most abundant of all, the male flying everywhere in its endeavour to attract the female. The 



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