Lice vs Fleas
Insects could be considered the best-adapted group of animals on the present day Earth, considering their numbers. One of the main underlying causes for that is their versatility in adapting to different kinds of niches. They show close resemblances with each other, but the occupied niches are different and their adaptations are slightly different from each other. Lice and fleas have been two of those closely resembling insects with different niches and adaptations.
Lice
Lice are the insects that have been classified in the Order: Phthiraptera of the Superorder: Exopterygota. More than 3,000 lice species have been identified as of present. Being disease agents, these wingless creatures can cause many problems for humans and other mammals. However, they have not been a problem for the monotremes, but all other mammalian and avian species could be their hosts. In other words, lice have been defined as obligate ectoparasites of every mammal and bird.
Lice have a small head equipped with piercing and sucking mouthparts. Their thorax contains three pairs of legs in such a way that each leg has a claw with an opposing-thumb-like claw. Those claws are helpful for them to climb and move on hairy or feathery skins of mammals and birds. Females lay eggs after breeding, and the secreted saliva will keep the eggs attached to the hairs or feathers of the host. The lice eggs are commonly known as nits, and the nymphs are hatched from them. After going through three moults, nymphs become adults. Adult lice may be of different colours depending on the species and the amount of blood sucked. Their colours naturally range from pale beige to dark grey.
Some microbial diseases and helminthic infections can be transmitted into hosts from lice through their bites. In addition, heavy infestations can cause reductions in thermoregulation effects of plumage in birds. Furthermore, lice infestations could cause reduced life expectancy and sometimes to be defeated in sexual competitions.
Fleas
Fleas are the insects of the Order: Siphonaptera of the Superorder: Endopterygota. There are more than 2,000 of described flea species in the world. Fleas do not fly, as they do not have wings, but their mouthparts are well adapted to pierce the skin and suck the blood of hosts; that means they are ectoparasites feeding on avian and mammalian blood. In addition, it would be important to know that their sharp mouthparts are developed like a tube, to carry the sucked blood of the hosts.
These wingless and dark-coloured creatures have three pairs of long legs, but the hind-most pair is the longest of all, and it is as twice as the other two pairs in length. In addition, those two legs are equipped with good muscle supply. All these mean that the hind legs can be used to jump a considerable range, which is about seven inches above the ground against the gravity. Therefore, fleas do not have to wait for their hosts to touch the ground to find a food source, but they can attach to one as soon as the host gets nearby.
Fleas can cause problems to host in many ways including itching from bites or skin rashes. However, their infestations can be very dangerous since they are vectors of many bacterial (murine typhus), viral (myxomatosis), helminthic (tapeworms), and protozoan (Trypanosomes) diseases.
What is the difference between Lice and Fleas?
• Lice and fleas belong to different taxonomic orders as well as to different superorders.
• Fleas are more developed for moving through the external body of the hosts than lice are.
• Usually most of the lice species are ovular in shape while fleas could have flattened shapes, as well.
• Taxonomic diversification is higher in lice than in fleas.
• Fleas can cause more diseases than lice could cause, for their hosts.