484 
Observations on the various Insects 
the wings glitter with red and green, and extend a little beyond 
the body : the legs are greyish at the base, black at tlie extre- 
mities.* 
"I am still ignorant whether the eggs are deposited in the stalks 
of the rye ; but the larvae, which were yet small on the 23rd of 
April, had acquired their full size on the 25th of May. I do not see 
any holes upon the sides of the stems, for which reason it would 
appear that the eggs or the worms are deposited upon the leaves. 
When we find any holes there, they are made by ' the Whiteworms 
of the ear,' or other insects. When the fly has issued from the 
pupa, it climbs up the stalk and flies away. 
" The quantity of dwarf i-ye, which began to grow yellow and 
decay on the 14th of June, amounted to from Sto 12and 14in every 
4 square feet. We see by this how much mischief the insect could 
do to the growth of rye ; it is therefore necessary to pull up and 
burn the attacked plants, whilst the worms and the pupae are 
inside. I have sometimes pulled up as many as 350 affected 
stalks in a few hours, and one or more persons could collect 
some thousands in a day, which would be of great importance, 
because then the numbers would be less considerable the succeed- 
ing years." 
Gmelinf gives the following description, in Latin, of 3Iusca 
pumilionis, which he considers the essential characters of Bier- 
kander's insect : — " Black ; underside, head, and two lines on the 
thorax yellow ; halteres white ; legs cinereous ; apex black." And 
adds, " The larva, which has an acute head and black apex, 
inhabits the stems of rye to an extent hurtful to their increase, as 
they scarcely reach 1, 2, or 3 inches in height." 
Unfortunately there is no description of the species which we 
shall next notice, and the figures in the plate are not sufficiently 
accurate to determine if it be Bierkander's insect ; but I am 
inclined to think not.Jl This excellent paper, being " Some 
Account of the Musca jmmilionis of Gmelin's Edition of the Syst. 
Naturae, by William Markwick, Esq., F.L.S.," was read before the 
Linnean Society on the 1st of November, 1791.§ He says, "Early 
in the course of the last spring some fields of wheat in the neigh- 
bourhood of Battle appearing to be much blighted, a friend of 
mine discovered it to be caused by a small insect of the grub or 
cateii)illar kind, lodged in the centre or very heart of the stem, 
just above the root. About the latter end of March I procured 
* Evidently related to our fig. 20, pi. L. 
•i- Gmelin's Systema Naturae, vol. v. p. 2849, No. 217. 
% They are represented of a larger size than I conceive Bierkander's to 
be, and with ]>ale, in all probability yellow, Icja ; there are also indications 
of lour black stripes on the thorax in the smaller figures. 
(J Vol. ii. p. 70, of their Transactions, 
