Posted Mon, Nov, 28,2016
Insects constitute the largest and most diversified group in the animal kingdom, making up about 80% of the animal species. They have a fundamental role in the terrestrial ecosystems functioning (i.e. trophic network and pollination) and can be of economic importance. Some are pests and some vectors of human, plant and animal diseases while others are beneficial (i.e. biological control agents.)
To act in their environments, insects need to feed and to reproduce, two fascinating innate behaviours for their species survival. Although "food" finding is a crucial activity for their development, all activities linked to their dispersal, mating/partner finding, as well as progeny deposition, called reproductive traits, constitute the main driven-factors in species survival. But to be successful, a species has to learn how to avoid competition or loss of resources, and to be faster for first occupation than other species. The mechanism of avoidance can be species specific may be linked to their phylogeny or evolutionary history. To address the question "Can we link insect's reproductive traits with their phylogeny?," closely related insect species were studied, because species which are phylogenetically distant, for example, mosquitoes and butterflies, are not occupying the same resources and environment. Thus, eight noctuid species, which have similar behavioural traits, were used. I.e. the larvae bore and live inside the stems of monocotyledons; female moths lay their eggs between the leaf sheath and stem of the plants; the adults are active only during the night and prefer to live in a humid environment. It was shown that some of the reproductive traits seemed to be constrained by environmental adaptation and thus not linked to the insect's phylogeny. In contrast, the traits under conservative selection have more chance to be linked with the insect's phylogeny.
Integrating reproductive traits with the phylogeny is not a trivial task. Elucidating the complex and dynamic interactions between them is still largely uncharted territory. In this sense, improving the multivariate phylogenetic comparative methods with more powerful tests represent a promising approach towards a more comprehensive understanding of the nature and dynamics of the reproductive traits in insect's evolutionary history as well as their implications on insect's diversification and speciation.
Dr. Paul-André Calatayud is author of the recently published paper Relationships of Reproductive Traits With the Phylogeny of the African Noctuid Stem Borers, available for download now in International Journal of Insect Science.
Posted in: Public Science Insights