Cat fleas don’t reproduce asexually. They aren’t parthenogenetic. Offspring are only produced after flea eggs are fertilized through successful mating.
Virgin Females & Non-Viable Eggs
Virgins Lay Infertile Eggs
Virgin female fleas can lay eggs 24 hours after their first blood meal. The eggs appear normal, but they’ll never hatch. Eggs from virgins aren’t viable. An unmated female produces around 1.6 eggs a day, which can continue for up to 58 days.
The fact that virgin females can lay any eggs at all suggests that fleas may be moving towards parthenogenetic (asexual) reproduction. Sexual reproduction is considered primitive in insects.
The Purpose of Non-Viable Eggs
Flea larvae feed on conspecific eggs. They’ll fail to develop into adults without the eggs in their diet. Thus, it’s believed fleas evolved to produce non-viable eggs in order to provide larvae with a nutritional supplement. Cannibalization of fertile eggs is reduced when the larvae are able to feed on non-viable eggs.
Mated Females & Viable Eggs
After female fleas mate with males, they’re able to deposit viable eggs and their output quadruples. To reach full fertility, females need to successively mate with numerous male partners. Females that mate with multiple partners lay over nine times as many fertile eggs as once-mated females.