188 
Observations on the various Insects 
of Entomology, especially that branch of it which embraces the 
natural history of insects, will not be neglected by the agricul- 
turist, who has the best means in his power for furnishing men of 
science with the materials wanted, to dispel erroneous notions 
and clear up doubts, as well as placing them in a better position 
to assist the farmer in saving his crops, when they are threatened 
by those powerful armies, often composed of atoms, it is true, but 
whose combined force is sometimes irresistible.* 
Callimome Dauci, the Carrot Gall-fly. 
When the carrots are in full flower, the umbels often appear 
distorted, and on examination one finds a number of small vege- 
table galls that are produced, it may be presumed, by the punc- 
tures of some Cynips or Cecidomyia when the eggs are laid. It 
is a very singular fact, but there are a few groups of flies which 
have the power of causing a derangement in the sap-vessels and an 
extravasation of the fluids, giving rise to excrescences assuming 
the most remarkable figures. Tiie greatest number are formed 
upon the oak, one of them being the Gall of Commerce ; others 
are the oak-apples, and the bedeguar, or moss-like balls upon the 
stems of dog-roses, which must be known to everybody. These 
are all the creations of different species of Cynipcs,\ but a beau- 
tiful little fly of the same genus as the carrot gall fly is also pro- 
duced from them, which is no doubt a parasite. The female 
Callimome is furnished with a slender oviduct as long or longer 
than the body ; this she insinuates through the cuticle of the plant, 
to deposit her eggs in the maggots of tlie Cynips, which reside in 
the centre of the galls, where they undergo their transformation 
to pupae, and subsequently the flies are hatched and emerge from 
a hole in the gall, excepting those which are inoculated by the 
Callimome; and it is very singular, but from the galls of the 
carrot I never bred any other species, and consequently the 
Cynips or Cecidomyia \ which by analogy ought to produce the 
galls, is unknown to me at present. I first observed the carrot- 
galls in the Isle of Wight, about the middle of August, upon the 
umbels of the wild carrot. On opening the galls, they contained 
little maggots of a bright orange colour, from which I bred a 
great number of both sexes of C. Dauci the following September. 
* Dr. Barton, as quoted by Dr. Asa Fitch, in his recent admirable ' Essay 
on the Hessian Fly,' says that this little pest has been more destructive 
" than would be an army of 20,000 Hessians," who were believed to have 
introduced t])is dreadful scourge into the United States, with the straw 
they canied over with them. 
t Curtis's 'Biit. Ent.,' fol. and pi. G88. ' Guide,' Genus 5C4. 
".j; The same Genus as the "Wheat-Midge. — 'Royal Agr. Journal,' vol. vi. 
p. Vd'J. 
