THE ENTOMOLOGIST. 201 



Life-history of Plerophorim litJiodactylus, — The larva 

 feeds in May and June on the leaves of Conyza squarrosa, 

 sometimes quite defoliating and thus destroying the plant; it 

 is somewhat onisciform, of a light whitish green colour and 

 hairy ; when full-fed it is about six or seven lines in length, 

 with a broad pinkish dorsal stripe ; the head is obtuse and 

 the anal segment narrow. Pupa hairy, the head and wing- 

 cases green, the abdomen lighter green with a pinkish tinge, 

 suspended by the tail : the pupa state lasts about fifteen 

 days, when the perfect insect appears. Antennae rather long 

 and very slender; head dark; thorax ashy; fore wings ashy, 

 clouded with brownish purple or pinkish, with a dark patch 

 on the costa ; above the base of the first cleft is a light mark ; 

 then another dark costal mark, and frequently two or three 

 dark marks on the first feather ; below the first costal mark 

 is a somewhat cuneiform mark, edged at its broad or outer 

 end with whitish ; hind wings ashy ; abdomen with a double 

 mark on each segment ; legs long, rather strong ; wings in 

 repose folded, held horizontally. This is another species 

 which is useful to man, living as it does on a noxious weed 

 which so abounds in some lime-stone sheep fells in North 

 Lancashire and in Westmoreland, that anything which has a 

 tendency to check or destroy it must be esteemed useful ; 

 for although the husbandman may work ever so hard in ex- 

 tirpating the low-growing plants, he is powerless on the rock- 

 faces and narrow ledges from whence the seeds are being 

 regularly scattered ; but here we have one of Nature's agents, 

 an insect which so consumes the leaves that the plant dies, 

 and useful herbage springs up where once a wide-spreading 

 and useless plant encumbered the ground. I may remark 

 incidentally that 1 have selected instances of useful insects 

 from those whose life-history is either unknown or imperfectly 

 known : I do not know a single species of the genus Pte- 

 rophorus that feeds upon a useful plant, although, in Eng- 

 land, Pterophorus rhododactylus feeds on, but does not 

 destroy, that most ornamental garden plant, the rose. — C S. 

 Gregson. 



Life-history of Pterophorus osteodactylus. — Larva delicate 

 pale brown, with five darker longitudinal stripes ; rather 

 stout in the middle, but attenuated at both ends : it feeds 

 upon the flowers and seeds of Solidago Virgaurea (golden 



