by Chuck » Wed Oct 05, 2022 11:45 am
Impact of environment- temperature, daylight, etc discussed in this paper. Below is an excerpt.
The role of latitudinal, genetic and temperature variation
in the induction of diapause of Papilio glaucus (Lepidoptera:
Sean F. Ryan1,2, Patti Valella3,4, Gabrielle Thivierge1, Matthew L. Aardema3,5 and J. Mark Scriber3,6
1Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA; 2USDA-ARS Center for Medical, Agricultural,
and Veterinary Entomology, 1600/1700 Southwest 23rd Drive, Gainesville, Florida, USA; 3Department of Entomology, Michigan State
University, East Lansing, Michigan, USA; 4Life Science Department, Long Beach City College, Long Beach, California, USA; 5Sackler
Institute for Comparative Genomics, American Museum of Natural History, New York, New York, USA and 6McGuire Center for Lepidoptera
and Diversity, University of Florida, Gainesville, Florida, USA
Abstract A key adaptation in insects for dealing with variable environmental conditions is
the ability to diapause. The tiger swallowtail butterflies, Papilio glaucus and P. canadensis
are ideal species to explore the genetic causes and population genetic consequences of
diapause because divergence in this trait is believed to be a salient factor in maintaining
a hybrid zone between these species. Yet little is known about the factors that influence
diapause induction in this system. Here we explored how spatial (latitudinal), environmental
(temperature) and genetic (hybridization) factors affect diapause induction in this system.
Specifically, a series of growth chamber experiments using wild caught individuals from
across the eastern United States were performed to: (1) evaluate how critical photoperiod
varies with latitude, (2) isolate the stage in which induction occurs, (3) test whether changes
in temperature affected rates of diapause induction, and (4) explore how the incidence of
diapause is affected in hybrid offspring. We find that induction occurs in the larval stage, is
not sensitive to a relatively broad range of temperatures, appears to have a complex genetic
basis (i.e., is not simply a dominant trait following a Mendelian inheritance pattern) and
that the critical photoperiod increases by 0.4 h with each increasing degree in latitude.
This work deepens our understanding of how spatial, environmental and genetic variation
influences a key seasonal adaptation (diapause induction) in a well-developed ecological
model system and will make possible future studies that explore how climatic variation
affects the population dynamics and genetics of this system.
Key words adaptation; critical photoperiod; development; diapauses; facultative;