Parthenogenesis : Self Reproduction

For connoisseurs, the term “parthenogenesis” often evokes a reproduction without fertilization the female gamete by a male gamete (without genetic material). That is a mode of reproduction single parent (or asexual). In plants, this mode of reproduction is fairly common as well as in the animal Kingdom. Some reptiles, nematodes and arthropods have the capacity. So, lovers of insects will be surprised to learn that the aphids, ants, stick insects, and bees are known for this specific feature. However, there are several types of parthenogenesis Depending on the species concerned.

For the bees and ants, when the whole of posterity is made up only of malesWe talk about parthenogenesis Arrhenotoque. Indeed, you will notice that with the approach of summer, the appearance of the males is produced by the Queen but not fertilized eggs.

By contrast, in stick insects and aphids which the offspring consists only of females, We talk about parthenogenesis Thelytoque. It is also that we are talking about for some species of Mantis. However, this phenomenon is rare in nature due to the presence of males who cannot resign itself to contribute!

Finally, for your information, the third case is between it two: the production of individuals males and females named parthenogenesis Deuterotoque.

Some species have this extraordinary capability in the world of the Mantis: it’s the case of the females Sphodromantis viridis or even Miomantis paykullii (70 species in the genus), which can produce the egg cases which the eggs will only give females. However, this mechanism is not performing at all and very few individuals are born and still less arrive at adulthood)Imago). In captivity, we saw that the offspring was often much more weak and vulnerable in comparison to nymphs from a sexual coupling. In addition, in this species, this feature is optional in the absence of fertilization and laying of an ootheca by parthenogenesis is not always observed.

However, other species such as Bruneria borealis reproduce only by this mechanism (5 species in the genus present in North America: Arizona, Texas and Canada).

But what is the purpose of this mechanism? Generally, in any population of insects, the production of males compared to females represents a significant energy loss. Let me explain, in the animal world, we know that the females provide most of the energy required for sexual reproduction. For the colonizers of circles, this energy is being used for the purpose of produce a maximum number of individuals in a minimum of time. So, it makes sense for some species, to generate that females who unlike the males, will be able to produce new individuals without the need for mating.

Thus, parthenogenesis can be an asset of importance for species in the race for the conquest of a habitat. But in the long term, the parthenogenese may have a negative effects. Multiplication without fertilization reduced genetic diversity and therefore the power
adaptation of the species to its environment.