Pulci

Pulci, or fleas, are small wingless insects that parasitize mammals and birds. They belong to the order Siphonaptera and are adapted for life on hosts, with laterally compressed bodies, short antennae, and powerful hind legs for jumping. Adults typically range from about 1 to 4 millimeters in length and feed exclusively on blood. Many species have specialized head and body structures, such as comb-like rows of spines (ctenidia), that help distinguish groups.

Fleas undergo complete metamorphosis: egg, larva, pupa, and adult. Eggs are laid on the host or in the host’s environment, such as nests, bedding, or soil. Larvae feed on organic material, including organic debris and flea feces. Pupae develop in cocoons and can remain dormant for extended periods until conditions indicate a nearby host, such as increased carbon dioxide, warmth, or movement.

Ecology and impact: Fleas infest a wide range of hosts, especially domestic dogs and cats, rodents, and humans. They are notable vectors of diseases, most famously the plague bacterium Yersinia pestis, transmitted mainly by Xenopsylla cheopis, and various rickettsial diseases such as murine typhus. Flea bites can cause itching and allergic dermatitis in animals and people, and heavy infestations can lead to anemia in young or immunocompromised hosts.

Distribution and control: Fleas have a global distribution but are more common in warm, humid environments with abundant hosts. Control relies on integrated pest management: treating animals with veterinarian-approved products, cleaning bedding and living areas, vacuuming, and reducing wildlife access. Regular preventive measures on pets help minimize infestations and disease risk.