·
Kingdom – Animalia (Animals)
·
Phylum – Arthropoda
Body have jointed appendages, divisible into head,
thorax and abdomen, head bears antenna and eye may be compound or simple
(ocelli), the joints are covered by arthroidal membrane.
·
Subpphylum – Hexapoda
Walking appendages are reduced to six with three body segments
·
Class – Insecta
Body segmented into head thorax and abdomen, head composed
of six segments, Thorax is composed of 3 segments (pronotum, mesonotum, metanotum),
abdomen upto 11 segments or more.
·
Order - Siphonaptera
Ø The
Siphonaptera is a monophyletic[1] group of some 2000 species.
Ø All
adults of which are highly modified, apterous[2] and laterally compressed ectoparasites[3] of birds and mammals.
Ø The
mouth parts are modified for piercing and sucking, without mandibles. The gut
has a salivary pump[4]
and a pharyngeal pump[5] and a cibarial pump[6].
Ø Compound
eyes are absent and ocelli[7] may
be absent to well developed.
Ø The
body has many backwardly directed spines, some may be grouped into combs and are
called ctenidia, which may be present on gena[8]
and thorax (especially the prothorax).
Ø The
metathorax is large and houses hind leg muscles, which power the prodigious[9]
leaps made by these insects. The legs are long and strong, terminating in
strong claws for grasping host hairs.
Ø Large
eggs are held in the host’s nest, where free-living worm-like larvae develop on
material such as skin debris shed from the host.
Ø The larvae
are pale legless worm-like, body is covered with sparse bristles; head reduced,
eyeless, with chewing mouthparts.
Ø High
temperature and moisture are required for development of most of the fleas.
Including those on domestic cats (Ctenocephalides felis), dogs (C.
Canis) and humans (Pulex irritans).
Ø The
pupa is exarate[10]
and adecticous in a loose cocoon.
Ø Adults
of both sexes are hematophagous (take blood from host).
Ø Some
species are monoxenous[11].
Ø The
plague flea (Xenopsylla cheopis) is polyxeny[12] and
facilitates transfer of plague from rat to human host.
Ø Fleas
transmit some other diseases of minor significance from other mammals to
humans, including murine typhus, tularaemia, but apart from plague, the most
common human health threat is from allergic reaction to frequent bites from the
fleas of our pets C. felis and C.
Canis.
·
The laterally flattened body allows easy movement
among the host’s fur, feathers or hairs.
·
Backwardly pointed bristles prevent fleas from falling
of or being easily captured by the host.
·
Some fleas can jump 200 times their body length
·
Fleas only infest animals that have a regular nest
site, which is why most rodents have fleas.
[1]
It is a group of organisms
descended from a common evolutionary ancestor or ancestral group, especially
one not shared with any other group.
[2] An insect having no wings
[3] A parasite, such as a flea, that
lives on the outside of its host.
[4] To inject saliva into the wound.
[5] For sucking up the blood.
[6] In hematophagous insects, the
cibarial pump is a structure associated with a complex of muscles located in
the head. It controls the ingestion of blood from the host and transfers it to
the gut.
[7] Simple eye
[8] Part of head
[10] Grooved or furrowed pupa having the
appendages not cemented to the body, see figure 2
[12] Parasitizes more than one host
[i] Gullian PJ, Cranston PS, The insects:
an outline of entomology, fifth edition, Wiley Blackwell, Chennai, India.
[iii] 1999, Addison Wesley Longman, Inc.
[iv] https://www.phrygane.tk/natural-enemies/imaginal-or-adult-phase.html
[v] American Insects: A Handbook of the
Insects of America North of Mexico, Ross H. Arnett. 2000. CRC Press.
