The role of ecological availability and host plant characteristics in determining host use by the bogus yucca moth Prodoxus decipiens

Abstract

1. Specialisation in host plant use is strongly correlated with speciation in many plant-feeding insects. Specialised taxa, however, could be restricted in host range due to limits in ecological availability of host plant species rather than trade-offs in using alternate host species.2. Moths in the genus Prodoxus are extreme specialists on Yucca and speciation is closely tied to host plant shifts. However, many Yucca ranges are allopatric. This study examined whether the bogus yucca moth Prodoxus decipiens is limited in host range because of biogeographic factors or due to differences in the characteristics of host plant species.3. In a common garden, local P. decipiens moths that use Yucca filamentosa were exposed to individuals of five Yucca species, two that are known hosts of P. decipiens in other parts of its range and three that are used by its sister species, Prodoxus quinquepunctellus.4. Local moths were attracted to flowers of all Yucca species and females attempted oviposition in the flowering stalks of all species. However, larvae successfully completed development to diapause in only one of the five host plant species. Larval development on non-natal Yucca species was significantly reduced compared with the local host.5. The results suggest that differences in host plant characteristics among Yucca species would result in strong natural selection during a host shift. Thus, specialisation in host plant use is probably due to trade-offs involved with using novel host plant species as well as ecological availability.

Specialization in the yucca–yucca moth obligate pollination mutualism: A role for antagonism?

“…Across much of its range, P. decipiens uses Y. filamentosa (Groman and Pellmyr, 2000; Althoff et al, 2001; Althoff and Pellmyr, 2002). Althoff et al (2014a) demonstrated that females of P. decipiens recognize Y. pallida and successfully deposit eggs into the inflorescence stalks, but no fully developed larvae were produced because of early larval mortality. In addition, P. decipiens was also unable to complete development on two other species within the Rupicolae, Y. rupicola , the sister to Y. pallida , and Y. reverchoni .…”

The roles of geography and founder effects in promoting host‐associated differentiation in the generalist bogus yucca moth Prodoxus decipiens

“…Our results build on past findings to suggest that P. decipiens is likely a widespread species comprised of host forms across different species of Yucca (Groman & Pellmyr, ; Althoff et al ., ). The process of HAD, however, is also dependent on other demographic and geographic factors.…”

“…due to phenological differences) or intense selection on moth populations stills needs investigation. Recent work by Althoff et al (2014) has demonstrated that moths from Y. filamentosa are unable to develop in other closely related capsularfruited Yucca species used by P. decipiens in different parts of its range. It is likely that a combination of both host-related selection and changes in population demography is contributing to the genetic differentiation of moths on Y. aloifolia.…”

Should I stay or should I go? Pollinator shifts rather than cospeciation dominate the evolutionary history of South African Rediviva bees and their Diascia host plants

“…Phylogenetic congruence, a hallmark of cospeciation, may result not only from co‐evolution but also from the same vicariance events experienced by interacting species (Janz, ; Morand et al, ). Moreover, phylogenetic congruence may also arise via phylogenetic tracking, where one species tracks the speciation events of its interaction partner, rather than a process in which both simultaneously speciate in response to each other (Althoff, Fox, & Frieden, ; Suchan & Alvarez, ).…”

“…Moreover, phylogenetic congruence may also arise via phylogenetic tracking, where one species tracks the speciation events of its interaction partner, rather than a process in which both simultaneously speciate in response to each other (Althoff, Fox, & Frieden, 2014;Suchan & Alvarez, 2015).…”