HYMENOPTERA. — TENTHREDINIDE. 109 
The perfect insects are of moderate size ; some, however (Cimbex, 
&c.), are amongst the largest species of Hymenoptera inhabiting this 
country ; they do not, however, much exceed an inch in length. They 
are ordinarily of dark colours, varied more or less with pale markings of 
white, red, or yellow. Their flight is, in general, heavy, and attended 
with a humming noise in the larger species. Those of the genus 
Lyda, however, are exceedingly agile in the hot sunshine. The 
males, in some species, are very fierce; and I have observed two male 
-Trichiosome lucorum fighting and biting each other violently. The 
species seem, for the most part, inhabitants of moderate climes, very 
few species being received from the tropics. There is considerable 
difference in the appearance of the sexes of some of the species ; and 
in some the males are met with abundantly (as in Abia), whilst in 
others the females are far more abundant (Zara). Mr. Curtis has 
figured a singular gynandromorphous individual of Tenthredo (Stron- 
gylogaster) cingulata Fabr., in which the opposite sides are not sym- 
metrical, the right half being feminine, and the left masculine. 
The number of parasites which subsist upon these insects is very 
great, many species attacking the same species of saw-fly: thus, 
Hartig gives a list of twenty parasites of Lophyrus Pini, fifteen of 
which are Ichneumonide. 
They are chiefly vernal; they frequent nectariferous and _pollini- 
ferous plants in the greatest abundance, especially those of the Um- 
belliferae, obtaining their chief supply of food from the pollen or nectar- 
like syrup of the flowers. Various species, however (T. viridis, sca- 
laris, &c.), attack and devour living insects which frequent the same 
plants, as observed by St. Fargeau (Ann. Soc. Ent. de France, 1834, 
p- 11.), and Dahlbom (Prod. Hym. Scand. yp. 38.). 
Amongst the various insects collected by Mr. Raddon from raw 
turpentine, were many specimens of two large new species of Lyde, 
which had evidently lost their lives from having been attracted to the 

ations, and { shall use every endeavour to breed the male this season. There is 
but one brood in the year; and it is somewhat singular that the earliest portion of 
their lives is passed in our winter, when we are subject to heavy rains. When rest- 
ing in the day, the larvez, like most other 'Terebrantizw, carry their heads erect ; on 
their mouths is a drop of yellow gummy fluid, and, if touched, they throw their heads 
back, and vomit this in some quantity [thus materially differing from the larve of 
the Cimbices]. It is very thick, and seems to be given them as a protection against 
Ichneumonide, one of which tribe preys upon them; and I have seen it dead, with 
the wings and legs covered and glued together by the gummy matter.” 
