Department of Entomology

Siphonaptera (Fleas)

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Siphonaptera - Brigham Young/VPI & SU PCD0330067

I. Background information

A. Origin of name

1. Latin - siphon, pipe; aptera, wingless
2. Relates to sucking mouthparts and wingless condition.

B. Classification

1. Suborders - none
2. America north of Mexico - 5 families, ? genera, 258 species
3. World - ? families, ? genera, 2,200+ species
4. Estimate of undescribed species - 8% in N. America.

C. Common names - Fleas

D. Type of metamorphosis - Holometabolous

E. Phylogenetic relationships

1. Considered decencded from a winged mecopteran-like ancestor.
2. Also hypothesized that fleas arose from primitive Diptera since legless larvae with well-developed head capsules and adults without mandibles are shared by both taxa.

II. Morphological characteristics

A. Small, wingless, generally less than 5mm

B. Body laterally flattened, bristly, heavily sclerotized

C. Sucking type mouthparts with well-developed palps.

D. Antennae 3-segmented fitting into grooves on head

E. Legs relatively long with large coxae.

F. Usually jumping insects.

III. Biological summary for the order

A. Life history

1. Eggs
a. Laid on host or in nest of host.
b. If laid on the host then the eggs fall off and larvae develop off the host.
c. Number varies by species (3 for cat flea, 6 for rat fleas, 18 for squirrel fleas)
d. Tungidae interesting because the adults burrow under the skin of their hosts, feed, and then females lay eggs to the outside of the host.
2. Larvae - three instars with a prepupal stages where the contents of the alimentary canal are expelled and the larva spins a silken cocoon to which grains of sand or dust adhere.
3. Pupae - pupation occurs in the cocoon
4. Adults
5. Generation time can be 3-4 weeks.

B. Habitat

1. 74% of the species parasitize rodents and 6% parasitize birds.
2. Some species have lost the ability to jump and are restricted to animal nests. Leave the host when it becomes active.
3. Other species stay with host and are good jumpers.
4. Clinging to host is however, the only means of significant dispersal.

C. Habits (mode of existence)

1. Adults feed on blood.
2. Larvae are scavengers

D. Collecting and preserving

1. Directly from the body of a host.
2. Direct examination of host nest over long period of time being sure to keep the nesting material moist.
3. 75% alcohol suitable for both adults and larvae.
4. Slide mounts.

E. Behavior

1. Common species (on cats or dogs) jump when disturbed.
2. Leave host for long periods (vacation) and reinfest upon return.

F. Significance

Very important from the standpoint of discomfort caused by feeding adults. Also important as disease vectors of bubonic plague¾ )transfered from rats), endemic typhus (also from rats), and tapeworm (dogs).



Prepared by: F. W. Ravlin, VPI & SU
Last modified: 9/3/96