Reproduction
Like many insects, Aedes aegypti mosquito has several
different stages of their indirect life cycle. The life cycle of the
mosquito, from egg to the mature adult, lasts eight to ten days. The four stages include two terrestrial
phases at the beginning and the end of their life cycle, the egg and
the adult, and the two aquatic phases, in the middle of their life
cycle, the larva and pupa (Center of Disease, 2012). Throughout each
egg laying period, the female feed primarily on
human blood and less
frequently on sugars. To learn more about the interaction
between humans and Aedes aegypti, visit the
Interactions page. It is also known that sugars are not
needed to reproduce, as exhibited by wild females (Harrington et al,
2001). The females
lay their eggs on wet surfaces until larvae hatch. The eggs are durable enough that if there is no
flood of water, which allows them to hatch into larvae, the eggs can
stay alive for several months. Larvae
consume microorganisms and organic particulates. To reach pupa stage, they have to shed their
exoskeletons to reach the fourth instar, which occurs after molting
three times (Center of Disease, 2012). An instar happens when an
arthropod molts successively (Merriam-Webster, 2013).
When
enough energy has been stored up in the fourth instar, metamorphosis
begins and the larva is transformed into a pupa. The pupa stage does not need to consume food
. The body changes until it molts a final
time and becomes the adult mosquito stage of life. The adult mosquito then lives the rest of its life
out of the water after the pupa phase (Centers for Disease, 2012).
Mating of the Aedes aegypti occurs in swarms, consisting of mostly
males with the females entering separately. Different frequencies
attract the males and female to each other. Once the male and
female find the compatible partner, the mating couple forms a union, called a copula; the
mating process occurs in only a few seconds while the mosquitoes are
in flight. Females are able to reject
males by removing the male from her body with her legs. She can also
use her legs to hold the male away and fend him off. But in the instance of acceptance, the male
positions himself so his abdomen is against the females’, allowing
the two mosquitoes to start the reproduction process. The number of gametes has shown to have a
positive correlation with the body size of the mosquito, but has no
affect on mating success. The body size
of females is also positively correlated with their ability to
produce offspring. (Cator & Harrington, 2011)
The lowest frequency, fundamental, and specific frequencies,
harmonic, (comPADRE, 2013) are combined to make the flight tone of a
mosquito. Females give off a lower
fundamental frequency, which assist males in locating the females in
a swarm. When a male and female are near
each other, usually within a few body lengths, they modify their
frequency to connect at harmonic frequencies. It is said that these tones help male mosquitoes offer
important information to females during the process of attempting to
win the female over, or courtship. These
signals contain information that the males could pass on to their
offspring, such as fitness and genetic characteristics. Males offer females direct or indirect fitness
benefits. Direct benefits include providing nutritional supply or
nesting territories, which increases reproductive rate and decreases
the mortality rate among the offspring.
Indirect benefits are genetic benefits (Cator & Harrington, 2011).
When these genetic benefits are communicated between male and female
before copulating, females take them into account before choosing
her mate because these benefits increase the fitness of the
offspring.