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THE ESSEX NATURALIST
the envelope before releasing the body from the trap. Then I roll up the
envelope, place it in a tin with some chloroform (any other liquid
anaesthetic or killing agent can be used), reset the trap and continue
on to the rest of the traps. By the time home is reached all the parasites
are dead. Each animal is examined, one at a time, the envelope is torn
open and all folds searched, and the fleas are tubed. Some collectors
use polythene bags or cloth bags but these must be searched with
extremely great care so as to avoid contamination of later gatherings
by overlooked specimens. The destruction of the envelopes effectively
prevents this happening. The tube must contain a date label stating,
inter alia, that the collection was made from a body.
Bodies of large animals must be searched as the facilities available
to the collector dictate but if hung over a large pan of water the fleas
can eventually be collected from the water.
As bat populations are rarely large great care must be taken not to
kill these animals, and as they will withstand very little in the way
of anaesthesia without dying I advise collecting from the untreated
animal whenever possible.
During collecting many other ectoparasites will be seen, e.g. parasitic
flies (Hippoboscidae and Nycteribiidae), mites, bettles and lice. These
should be collected and forwarded to the appropriate experts who wel-
come such material.
Most collectors desire to know the identity and something of the
biology of their specimens and thus two very excellent papers by Smit
(1957 a and b) are essential tools of the British siphonapterist. The first
gives an immense amount of distribution data, host lists and a very full
bibliography, the second is, in effect, a text book on collecting, mount-
ing and identifying the British flea fauna, on the host and habitat
relationships of our fleas, and also contains a useful glossary. In my
1958 paper I have brought together further details of distribution and
literature but even this paper is now considerably out of date.
PULICIDAE
Pulex irritans L., 1758. The Human Flea. This flea must be fairly
frequent throughout the whole county but there are very few records:
Colchester district (Harwood, 1903); 1♂ from Arvicola agrestis, Rayleigh,
F. W. Frohawk (Hopkins and Rothschild, 1953) ; about a dozen.
Loughton (Bacot, 1914).
*Archaeopsylla c. erinacei (Bouche), 1835. The Hedgehog Flea. This
flea will be found on almost every hedgehog, sometimes in great num-
bers, but the only records I have are from R. Knowles: ♂ ♂ ♀ ♀ from
Hedgehog. Oak Woods, South Ockendon. —.vii.57, and young Hedge-
hog. Aveley, —.viii, 57.
Ctenocephalides canis (Curtis), 1826. The Dog Flea. Another common
flea for which there are but two records: Loughton (Bacot, 1914); 1♂,
in a house, Billericay, —.viii. 58, R. Knowles.
*Species so marked are additional to the Essex List given in Smit (1957a).