Fleas (Ctenocephalides)

• an adult female flea lays eggs following a blood meal from the host – laid in bunches ~20– One adult can lay ~40 eggs

every day• eggs represent ~50% of

the fleas in an average home– eggs take anywhere from

2-14 days to develop– warm and humid = best

conditions

Fleas(Ctenocephalides)

• Emerging Larvae– blind – avoid being light– eat pre-digested blood (flea dirt) that adult fleas pass– up to ¼-inch long – white (almost see-through) – Legless– make up ~ 35% of fleas in the average household– spin cocoons in ~5-20 days of hatching from their eggs

Fleas(Ctenocephalides)

• Pupae – ~10 percent of the flea population in a home– cocoon protects the pupae for several days or weeks before the

adult flea emerges– if environmental conditions are not right for emergence, the

cocoon can protect the developing flea for months or years.

• cocoons – sticky outer coating that allows them to hide deep in the

carpeting– light vacuuming or sweeping will not remove them– serves to protect the developing adults from chemicals

Flea Pupae

Fleas(Ctenocephalides)

• Adult– must begin to begin feed from a host within a few

hours of emerging from cocoon– after the first meal, breeding and laying eggs occur

within a few days– female fleas are not able to lay eggs until they obtain

a blood meal– account for less than 5% of the entire flea population

in a home– live on the host for a couple of weeks to several

months

Adult Flea

Fleas - Tapeworm(Diphylidium)

• Flea tapeworm capsule is shed into the environment in the feces of an infected host– each egg capsule has 5-30

eggs• Larval flea ingests egg

capsule– Consumes eggs in capsule– Eggs hatch, releasing

embryos (hexacanths) that invade larval flea’s body

Fleas - Tapeworm (Diphylidium)

• When larval flea cocoons, the tapeworm embryos grow into a cysticercoid

• Adult flea emerges and feeds on host– host consumes flea– cysticercoids develop into

adult tapeworms in the small intestine

– competes with host for nutrients

Fleas - Tapeworm(Diphylidium)

• 2-3 weeks after ingestion by host, the adult tapeworm matures and sheds segments of its body (proglottids) into the host’s feces– proglottids full of egg

capsules

• Cycle repeats

Horse Bots

• Eggs – Can deposit 150 - 1000

eggs on a horse's body– typically occurs during

the early summer months

– ~0.05 inches long– pale to grayish yellow – eggs are essentially

stalk-less and are attached near the tip of the hair

Horse Bot Eggs

Horse bot fly, Gasterophilus intestinalis (DeGeer), egg case (hatched) attached to a horse hair.

Horse Bots

• Larvae– Develop within five days of being deposited– eggs hatch into a maggot 7 - 10 days of being laid– larvae are stimulated to emerge by the horse

licking or biting the attached, fully developed eggs• larvae either crawl to the mouth or are ingested • bury themselves in the tongue, gums, or lining of the

mouth for ~28 days ; molting occurs• attach to the lining of the stomach

– remain immobile for 9 - 12 months

Hot Bot Larvae

Dorsal view (head on left) of the third instar larva of the common horse bot fly, Gasterophilus intestinalis

Horse Bot Infestation in Horse Stomach

Horse Bots

• Pupae– larvae have matured– detach from the gastrointestinal tract and pass

from the horse's body in the feces– larvae burrow into the soil or dried manure where

they pupate and remain for 1-2 months– occurs between late winter and early spring

Horse Bot Pupae

Pupa of the common horse bot fly, Gasterophilus intestinalis

Horse Bots

• Adult – adult horse bot fly

emerges after 3-10 weeks period during the summer or fall

– After emerging from the pupa season it mates (manure pile)