Oviposition Acceptance and Fecundity Schedule in the Cactophilic Sibling Species Drosophila Buzzatii and D. Koepferae on Their Natural Hosts

Abstract

Abstract. We tested for the occurrence of oviposition acceptance for different media prepared with cactus tissues of three alternative cactus hosts: Opuntia sulphurea, O. quimilo and Trichocereus terschekii for 4 consecutive days in lines of two Drosophila buzzatii populations and one population of D. koepferae. Our results showed that the former laid significantly more eggs on both Opuntia cacti than on T. terschekii, whereas D. koepferae preferred T. terschekii. In addition, fecundity schedules differed between species: D. buzzatii laid similar numbers of eggs along the fourday sampling period, whereas D. koepferae showed an oviposition peak on the second day of egg collection on T. terschekii. We suggest that the between-species disparities observed in oviposition acceptance and fecundity schedule may be related to the temporal and spatial predictability of Opuntia versus T. terschekii (cardó n) as part of the different adaptive strategies that have evolved after the split of D. koepferae and D. buzzatii from their recent common ancestor. Therefore, the willingness to accept hosts would be an important factor in the habitat selection and in the maintenance of species diversity.

Mating success depends on rearing substrate in cactophilic Drosophila

“…Previous studies in D. buzzatii and D. koepferae revealed the paramount importance of the host plant on wing and genital morphology, viability and developmental time (Fanara et al 1999;Soto et al 2007Soto et al , 2008a. Also, there is evidence that these species differ in their preferences for egg laying sites (Fanara and Hasson 2001). These evidences are consistent with the evolution of host specialization (Hasson et al 2009).…”

Oviposition and performance in natural hosts in cactophilic Drosophila

“…The insect-host association persists into the adult stage in many groups. So, acquisition of a novel host may drive adaptive divergence in traits related to the location of, mating, oviposition and performance in a new host (Mitter and Futuyma 1983;Etges 1990;Jaenike 1990;Fanara and Hasson 2001;Matzkin et al 2006;Jaureguy and Etges 2007;McBride 2007;Tilmon 2008). In addition, adaptation to new hosts may cause the evolution of extrinsic and/or intrinsic habitat isolation, highlighting the evolutionary role of host plant shifts (e.g.…”

“…Host plant selection is the search for, movement to and settling on a potential breeding site and is followed by the acceptance or rejection of the site for oviposition. Female insects use a wide variety of cues to evaluate potential sites for oviposition, either abiotic like environmental light (Wogaman and Seiger 1983), temperature (Fogleman 1979), chemical composition (Amlou et al 1998;Fanara and Hasson 2001), resource texture and/or biotic, such as the presence of predators, conspecifics and heterospecific larvae in the resource (Chess and Ringo 1985). However, to understand the role of host shifts in speciation we need to evaluate how host-related recognition and performance traits change through time (Bush 1975;Coyne and Orr 2004).…”

Filogenia do Complexo Drosophila Buzzatii (Grupo Repleta): Inferências de Análises Multilocus Mitocondriais e Nucleares.

“…Embora não sejam diferentemente atraídas por Opuntia (O. sulphurea) ou cactos hospedeiros colunares (T. terschekii) (Fanara et al 1999), a composição da comunidade de moscas que emerge de substratos naturais em ambos os tipos de cactos difere significativamente (Fanara et al 1999). Na natureza ou em laboratório, D. buzzatii ovoposita preferencialmente em cactos do gênero Opuntia, enquanto D. kopferae tem como sítio de ovoposição preferencial a espécie T. terschekii (Fanara & Hasson 2001). …”

“…Como D. buzzatii e D. kopfreae apresentaram a mesma viabilidade, tempo de desenvolvimento e tamanho de corpo em cultura média preparada com material hospedeiro de O. sulphurea ou T. terschekii (Fanara et al 1999), há duas alternativas para explicar a diferença entre a capacidade e os padrões encontrados na natureza: preferência por sítios de ovoposição distintos e/ou competição interespecífica (Fanara et al 1999, Fanara & Hasson, 2001). …”