Mating success depends on rearing substrate in cactophilic Drosophila

JUAN HURTADO; EDUARDO M. SOTO; LILIANA ORELLANA; ESTEBAN HASSON

EVOLUTIONARY ECOLOGY

SPRINGER

Lugar: Geelong, VIC, Australia; Año: 2012 vol. 26 p. 733 - 743

0269-7653

Drosophila buzzatii and D. koepferae coexist in the arid lands of southern South America and exploit different types of cactus as breeding hosts. The former prefers to lay eggs on the rotting pads of prickly pears (genus Opuntia) whereas D. koepferae exhibits greater acceptance for columnar cacti (e.g., Echinopsis terschekii). Here, we demonstrate that the rearing cacti affect male mating success which is higher in flies reared in each species?s preferred host. Opuntia sulphurea medium endows D. buzzatii males with greater mating ability while D. koepferae males perform better when flies develop in Echinopsis terschekii. These effects are not mediated through body size, even in D. buzzatii whose body size happens to be affected by the rearing cacti. This scenario, which is consistent with the evolution of host specialization and speciation through sensory drive, emphasizes the importance of habitat isolation in the coexistence of these cactophilic Drosophila.