SAWFLY CATERPILLARS. 87 
all, had specimens of before as injurious on this large scale to Oak- 
leafage. The hanging down of the “looper’”’ caterpillars (as those of 
the Winter and Mottled Umber Moths) by their threads is a charac- 
teristic habit, and one which in the course of last year was noticed as 
the cause of a deal of annoyance. Mr. A. D. Christie, on May 26th, 
wrote requesting information on specimens sent :— 
‘©No. 1 we have more or less every year in the Oak woods, and at 
present time are very bad, and most disagreeable for one to walk under 
the trees, as they hang down with gossamer threads, sticking over 
one’s face and clothes. No. 2 has never been noticed until this year. 
While some are in the woods, they are most abundant on individual 
specimen trees in the park, and have no threads or webs, but drop 
down all over; at the bottom of the stems we can lift them in 
shovelfuls. The stems themselves are covered with them trying to 
getup. . . . Weare destroying all we can with paraffin, gas-lime, 
salt, &c., and are more or less successful.” 
No. 2 proved to be specimens of Sawfly caterpillars, of which the 
kinds which infest the Oak in this country are considered to be about 
twelve in number, as noted by Mr. P. Cameron in his ‘ Monograph ’ 
referred to below * (see his list, vol. i. p. 89). There is considerable 
difficulty in identifying some of the Sawfly larve merely from descrip- 
tion; but by working on Mr. Cameron’s lines, and putting aside, firstly, 
those which are leaf-miners; secondly, a kind which lives within the 
swollen end of an Oak-shoot; and, thirdly, those of which the cater- 
pillars appear so customarily in August that they would in no way 
coincide with the May infestations, and also putting aside two spiny 
kinds, the specimens now under consideration appear to be almost 
certainly caterpillars of the Oak-feeding species, Hmphytus tibialis or 
EF. serotinus, and in either case they may be known from moth cater- 
pillars by their greater number of legs, having in all twenty-two,—that 
is, three pairs of claw-feet, seven pairs of sucker-feet beneath the body, 
and another pair at the end of the tail. 
The Emphytus serotinus larvee are common on the Oaks in June, 
and also to be found in May, newly hatched on the young leaves. 
The caterpillars are from four- to five-eighths of an inch long, bare, 
cylindrical, and having a light green ground, covered all over, as well 
as the head, by a light green powder; but at the last moult the 
powder is lost, and the caterpillar becomes yellowish green and shining, 
the head yellow. ‘These caterpillars were found by Mr. Cameron to 
change to chrysalis in the ground without spinning a cocoon, and the 
Sawflies from them appeared in September and October. Therefore 
* ‘Monograph of British Phytophagous Hymenoptera,’ by Peter Cameron. 
London: printed for the Ray Society. 
