184 



The Naturalist. 



fair to state that in the same year numerous captures of the perfect 

 insect were reported from various parts of the kingdom. 



A case of a similar character, but still more remarkable, is thus 

 recorded in the Zoologist for 1857, by the late Edward Newman. It 

 is headed " Capture of Mallota vittata on the banks of the Thames : — 

 1 have been so fortunate as to find, in countless profusion, a dipterous 

 insect, the very name of which has only crept into Britain as it were 

 by stealth, and British examples of which appear almost unknown." 

 He further states : "It is figured at plate 429 of Curtis' s British 

 Entomology as EelopJiilas Ruddii, from a specimen taken near Yar- 

 mouth, in Norfolk." Now, from that time to the present twenty-four 

 years have passed away, and no notice of its occurrence in Britain 

 again has been published. I therefore consider myself fortunate in 

 possessing two of the specimens captured by Mr. Newman, and have 

 brought one of them to exhibit. You see it is an insect measuring 

 about half-an-inch in length, and three-quarters of an inch in expanse, 

 and therefore not likely to be overlooked by a dipterist, and it is not 

 likely either, to be mistaken for any other British species. 



There is another point which deserves our attention ; it is the fact 

 of insects becoming scarce in, or apparently deserting altogether, 

 localities where formerly they existed in plenty. Such cases may in 

 some instances be readily accounted for ; the drainage of fens and 

 marshes, the clearing of woods and forests, the breaking up of waste 

 lands, the increase of building along our coasts, and the various ways 

 in which rural haunts are intruded upon, no doubt contribute much to 

 this effect ; but there are many cases which are mysterious. I shall 

 give a few examples from the butterflies, because they are taken notice 

 of by all entomologists, and when they leave a locality for a few years, 

 their absence is, one may almost say, felt like the absence of a friend. 

 In Newman's " British Butterflies," published in 1871, there is ample 

 testimony to the fact of disappearance. Of Vanessa C-albiim the 

 report from Dorsetshire is — " Formerly in plenty at Glanvilles 

 Wootton, but none have been met with for fifty-four years. — J. C. 

 Dale." Of Lycana Acis Mr. Dale's report is, " Glanvilles Wootton, 

 formerly in plenty, but none have been taken since 1841." In three 

 other localities where this butterfly was formerly common, the report 

 is that it has not been taken since 1861. It is evident also that 

 LyccEna Arion and Aporia cratcegi have deserted localities where they 

 used to be plentiful. Of Polyommattis HippotJwe it is recorded, " not 

 taken in Cambridgeshire since 1845," and not seen in Huntingdon- 

 shire since 1848. Lancashire and Cheshire entomologists will no 



