Cediopsylla simplex

Geographic Range

Cediopsylla simplex requires rabbits for various aspects of its life. Therefore, it is distributed in the same manner as its host. The widely known cottontail rabbit ( Sylvilagus floridanus ) and its relatives are preferred hosts (Rothschild and Ford 1972). These rabbits are most heavily concentrated in the eastern United States.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Cediopsylla simplex lives on rabbits. Therefore, it can be concluded that these fleas are found in habitats that are suitable for rabbit populations. These fleas can live on rabbits or in the rabbits' nests, though they require host contact for food and reproduction. Specifically, Cediopsylla simplex prefers to inhabit the ears of rabbits, possibly because of favorable temperatures at the ears (Rothschild 1965). The larvae inhabit newborn rabbits and the nest, where fecal deposits serve as a food source.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• forest forest
• scrub forest scrub forest

• Other Habitat Features
• suburban suburban
• agricultural agricultural

Physical Description

Fleas are small, just visible to the naked eye. To see the features of the flea body, low power light microscopy is suitable. However, for fine details, electron microscopy is necessary (Amrine and Lewis 1978).

All fleas lack wings. There are six legs, and the back pair is specialized to facilitate an incredible jumping ability. The mouthparts are specialized for a piercing-sucking feeding behavior. The mouthparts consist of paired laciniae which surround the epipharynx, forming the food channel. Labial palps protect the mouthparts, while maxillary palps aid in sensory aspects of feeding (Amrine and Lewis 1978). Cediopsylla simplex also has a genal ctenidium. This is a comb-like structure on the side of the head that prevents the insect from being moved through the hair of its host. The vertical orientation of the genal ctenidium helps distinguish this species from other species of fleas, including cat fleas, Ctenocephalides felis , and dog fleas, Ctenocephalides canis .

Flea larvae resemble tiny white maggots. They are eyeless and legless, covered in short bristles, and possess mandibles for chewing. Flea pupae spin silken coccoons that are often studded with debris picked up from the nearby area.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

Development

The flea life cycle consists of three distinct stages, characteristic of complete metamorphosis: larva, pupa, and adult. Larvae develop within the eggs for anywhere from two days to over a month, depending on temperature and humidity. There are three larval stages, or instars; overall, the larval period lasts anywhere from 9 to 200 days, also depending on temperature and humidity. The pupal stage can last up to a year in unfavorable conditions. Maturation of adult Cediopsylla simplex is closely tied to hormone fluctuations of host rabbits; cortisol and corticosterone released by pregnant female rabbits stimulate adult fleas to develop sexually.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

Mating takes place on newborn rabbits. Not much else is known about the mating systems of this species.

The reproductive behavior of Cediopsylla simplex has earned it much attention from the research community. These fleas have evolved a reproductive schedule that precisely coincides with that of its rabbit host (Rothschild and Ford 1972). This coordination is achieved through hormonal control. Pregnant rabbits present an increase in hormones such as cortisol and corticosterone to the blood stream, from which the fleas feed (Roberts and Janovy 1996). The fleas have evolved the ability to detect these hormones, and the fleas only reach sexual maturity when they are detected. Therefore during the rabbit pregnancy the fleas reach sexual maturity, and by the time the baby rabbits are born the female fleas have ripe eggs (Rothschild 1965). When newborn rabbits come in close contact with the head of their mother, the fleas are able to relocate from the mother onto the young rabbits. While on the young rabbits, the fleas feed heavily and they detect the hormone somatropin from the baby rabbits, which stimulates the fleas to mate and lay their eggs (Roberts and Janovy 1996). Like all flea eggs, the eggs of C. simplex are not sticky and thus fall into the nest of the host. While on the young rabbits the adult fleas also defecate at a highly increased rate, creating a food source for the larvae that will soon emerge from the eggs (Rothschild 1965). The fleas then return to the adult rabbit.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • internal internal
• oviparous oviparous

Female fleas provide nutrients to their eggs before laying them; after that, there is no further involvement on the part of the parents.

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • female

Lifespan/Longevity

Although no specific information is available on the lifespan of C. simplex , other flea species have been known to live two to three years given a steady food supply and favorable climate.

Behavior

Cediopsylla simplex spends more time in association with its host than many fleas do. It attaches itself to the ears of rabbits and hangs on for long intervals, leaving only to breed. Many flea species must leave their hosts when not feeding because mammalian body temperatures are too high; perhaps C. simplex can hang on longer because the temperature of the rabbit's ears is more tolerable than the rabbit's core body temperature.

Like all fleas, Cediopsylla simplex is specialized for jumping. It has a highly elastic protein called resilin at the joints of its legs that allows it to launch itself high into the air while expending very little energy. This adaptation allows fleas to quickly hitch rides on passing hosts.

Fleas are not known to associate with one another, except during breeding.

• Key Behaviors
• saltatorial saltatorial
• parasite parasite
• motile motile
• sedentary sedentary
• solitary solitary

Communication and Perception

Fleas have a sensory organ called a pygidium near the rear of their bodies that allows them to detect vibrations and air currents. No information is available on how fleas communicate with one another.

• Perception Channels
• tactile tactile
• vibrations vibrations

Food Habits

Cediopsylla simplex feeds on the blood of its host. It has piercing-sucking mouthparts consisting of a fascicle made up of three stylets. The lacinia cut the skin while the epipharynx draws blood out of a host blood vessel (Roberts and Janovy 1996). These fleas prefer to feed on the ears of their rabbit host, and once there they tend to remain with their mouthparts embedded for long periods of time (Rothschild 1965). Electron microscopy reveals three rows of teeth on the lacinia, demonstrating that they are in fact making incisions into the skin (Amrine and Lewis 1978). The larvae of Cediopsylla simplex feed on the feces of their parents, which is abundant in rabbits' nests, and on the newborn rabbits.

Though Cediopsylla simplex pierces the skin of its host and feeds on its blood, there seems to be minimal mechanical damage to the host. Little or no hemorrhage is observed when a feeding flea removes its stylets from the host (Roberts and Janovy 1996).

• Primary Diet
• carnivore carnivore
  • sanguivore sanguivore

• Animal Foods
• blood

• Other Foods
• detritus detritus

Ecosystem Roles

Cediopsylla simplex is commonly known as the rabbit flea. It is a nidicolous ectoparasite of rabbits (Roberts and Janovy 1996). Various literature sources cite the cottontail rabbit ( Sylvilagus floridanus ) as a host (Rothschild and Ford 1972). These fleas require the rabbit hosts for many aspects of their survival. They feed on the blood of the rabbits, they live on them or in their nests, and most interestingly, they have adapted a sychronization of their reproductive cycle to that of their hosts.

• Ecosystem Impact
• parasite parasite

Economic Importance for Humans: Positive

Cediopsylla simplex is a vector for the virus that causes myxomatosis. The virus is fatal to rabbits, and therefore can be theoretically used to control wild rabbit populations.

• Positive Impacts
• controls pest population

Economic Importance for Humans: Negative

Rabbit fleas do not frequently bite people. However, because they carry myxomatosis, they are potentially damaging to the domestic rabbit industry.

• Negative Impacts
• causes or carries domestic animal disease causes or carries domestic animal disease

Additional Links

Encyclopedia of Life

Contributors

Allison Poor (editor), University of Michigan-Ann Arbor.

Eric Knapp (author), University of Michigan-Ann Arbor, Solomon David (editor), University of Michigan-Ann Arbor.

References

Amrine, J., R. Lewis. 1978. The Topography of the Exoskeleton of Cediopsylla simplex (Baker 1895) (Siphonaptera: Pulicidae). Journal of Parasitology , 64(2): 343-58.

Roberts, L., J. Janovy. 1996. Foundations of Parasitology 6th edition . United States: McGraw-Hill.

Rothschild, M., B. Ford. 1972. Breeding Cycle of the Flea Cediopsylla simplex is Controlled by Breeding Cycle of Host. Science , 178(61): 625-6.

Rothschild, M. 1965. FLEAS. Scientific American , 213(44): 44-53.

Strohlein, D., B. Christensen. 1983. Metazoan Parasites of the Eastern Cottontail Rabbit in Western Kentucky. Journal of Wildlife Diseases , 19(1): 20-3.