Oviposition and performance in natural hosts in cactophilic Drosophila

Abstract

The cactus-yeast-Drosophila model system provides an excellent opportunity to investigate the significance of ecological factors in evolution. D. buzzatii and D. koepferae are sister species, with partially overlapping distribution ranges and a certain degree of habitat overlap. The main breeding and feeding resources of D. buzzatii are the decaying cladodes of prickly pears (genus Opuntia), whereas D. koepferae utilizes mainly columnar cacti of the genera Cereus and Echinopsis. These host plants differ in their chemical composition, the microflora associated to the decaying process and patterns of spatial and temporal predictability. The aim of the present work is to investigate host plant selection and utilization of two different cactus hosts. We report the results of field and laboratory studies examining behavioral traits related to egg-laying (oviposition preference and host acceptance) and several measures of performance (viability, developmental time, wing morphology and starvation resistance) in flies reared in the two main host cacti that D. buzzatii and D. koepferae exploit in the studied area: O. sulphurea and E. terschekii. The main conclusion of our study is the clear connection between the distribution of the cactophilic species, D. buzzatii and D. koepferae, and the abundance of the two main natural hosts, which is line with the remarkable influence that cactus hosts impose on larval and adult life history traits and behavioral traits. Overall, the results of field and laboratory work point to the important role of host plant shifts in the evolutionary history of these species.

Pupal emergence pattern in cactophilic Drosophila and the effect of host plants

“…Drosophila buzzatii uses necrotic cladodes of prickly pears of the genus Opuntia as primary hosts, whereas D. koepferae exploits mainly columnar cacti of the genera Cereus and Trichocereus . Nonetheless, in the vast areas where both species occur in sympatry, a certain degree of overlap in host exploitation occurs, with the 2 species emerging from both resources despite maintaining a preference for their respective primary host (Hasson et al ., ; Soto et al ., ). Previous studies showed that traits associated to fitness were maximized when flies were reared in their primary hosts (Soto et al ., ,b, , ; Hurtado et al ., ).…”

Biodiversity of cactophilic microorganisms in western Argentina: community structure and species composition in the necroses of two sympatric cactus hosts

“…A total of 17 samples of decaying tissues of O. sulphurea and 15 of T. terscheckii were collected by aseptically cutting one sample of necrotic tissue per plant and placing it in individual sterile vials that were subsequently transported and stored under refrigerated conditions. Previous work in the area of study has shown that these two cactus species are the only ones to develop active necroses (Soto et al, 2012). All samples were collected within the natural reserve in a transect approximately 200 m wide and 2 km long in which both species were evenly interspersed.…”

“…D. buzzatii uses necrotic cladodes of Opuntia spp. as primary hosts, whereas D. koepferae mainly exploits columnar cacti of the genera Cereus and Trichocereus (Fanara et al, 1999;Hasson et al, 2009;Soto et al, 2012). Nonetheless, a certain degree of overlap in host exploitation occurs in the vast areas where both species live in sympatry, with the two species emerging from both resources, despite maintaining their preference for their respective primary host (Hasson et al, 1992(Hasson et al, , 2009).…”

“…Nonetheless, a certain degree of overlap in host exploitation occurs in the vast areas where both species live in sympatry, with the two species emerging from both resources, despite maintaining their preference for their respective primary host (Hasson et al, 1992(Hasson et al, , 2009). In some of these regions of sympatry, two dominant species, the prickly pear Opuntia sulphurea and the columnar cactus Trichocereus terscheckii (card on) are used as feeding and breeding substrata by both fly species (Soto et al, 2012). Although this oligophagous habit is not uncommon in the D. repleta group (Oliveira et al, 2012), most Drosophila species only exploit a single host at a given locality, as occurs for example in the cactus-yeast-Drosophila system of the Sonoran desert (Fogleman and Abril, 1990;Fogleman and Danielson, 2001).…”

Pheromone races of Cydia splendana (Lepidoptera, Tortricidae) overlap in host plant association and geographic distribution

“…Plant volatile compounds play a key role in host choice and the colonization of new host plants in insect herbivores (Bengtsson et al, 2006;Bruce and Pickett, 2011;Cha et al, 2012) and host plant shifts have been associated with speciation events (Dres and Mallet, 2002;Servedio et al, 2011;Soto et al, 2012;Safran et al, 2013). Pheromone races in moths are sometimes associated with different host plants, for example in the European corn borer Ostrinia nubilalis (Leppik and Frerot, 2012;Unbehend et al, 2014).…”