Contrasting Plasticity in Ovariole Number Induced by A Dietary Effect of the Host Plants between Cactophilic Drosophila Species

Abstract

Under the preference-performance hypothesis, natural selection will favor females that choose oviposition sites that optimize the fitness of their offspring. Such a preference-performance relationship may entail important consequences mainly on fitness-related traits. We used the well-characterized cactus-Drosophila system to investigate the reproductive capacity in the pair of sibling species D. buzzatii and D. koepferae reared in two alternative host plants. According to our hypothesis, ovariole number (as a proxy of reproductive capacity) depends on host plant selection. Our results indicate that the capacity of D. buzzatii showed to be mild, only increasing the number of ovarioles by as much as 10% when reared in its preferred host. In contrast, D. koepferae exhibited a similar reproductive capacity across host cacti, even though it showed a preference for its primary host cactus. Our study also revealed that D. buzzatii has a larger genetic variation for phenotypic plasticity than its sibling, although ovariole number did not show clear-cut differences between species. We will discuss the weak preference-performance pattern observed in these cactophilic species in the light of nutritional and toxicological differences found between the natural host plants.

Reproductive Capacity Evolves in Response to Ecology through Common Changes in Cell Number in Hawaiian Drosophila

“…For example, in African drosophilids and tephritid Dacus flies, generalist species that oviposit on a variety of egg-laying substrates have higher fecundity than specialists [9,13,29]. Moreover, specialist species of African and Central American Drosophila species are more fit in the presence of host-specific compounds [14,[56][57][58], some of which are toxic to other species of Drosophila. For example, D. sechellia is best reared on lab media supplemented with Morinda fruit [14], while D. pachea cannot be reared in laboratory conditions without supplementing media with sterols from its host cactus [59].…”

Reproductive capacity evolves in response to ecology through common developmental mechanisms in Hawai’ianDrosophila

“…In African drosophilids and tephritid Dacus flies, generalist species that oviposit on a variety of egg-laying substrates have higher fecundity than specialists (1, 22, 37). Moreover, specialist species of African and Central American Drosophila species are more fit in the presence of host-specific compounds (40, 56-58), some of which are toxic to other species of Drosophila . For example, D. sechellia is best reared on lab media supplemented with Morinda fruit (40), while D. pachea cannot be reared in laboratory conditions without supplementing media with sterols from its host cactus (59).…”