Photoperiodic Diapause and the Establishment ofAedes albopictus(Diptera: Culicidae) in North America

Abstract

The invasion and range expansion of Aedes albopictus (Skuse) in North America represents an outstanding opportunity to study processes of invasion, range expansion, and climatic adaptation. Furthermore, knowledge obtained from such research is relevant to developing novel strategies to control this important vector species. Substantial evidence indicates that the photoperiodic diapause response is an important adaptation to climatic variation across the range of Ae. albopictus in North America. Photoperiodic diapause is a key determinant of abundance in both space and time, and the timing of entry into and exit out of diapause strongly affects seasonal population dynamics and thus the potential for arbovirus transmission. Emerging genomic technologies are making it possible to develop high-resolution, genome-wide genetic markers that can be used for genetic mapping of traits relevant to disease transmission and phylogeographic studies to elucidate invasion history. Recent work using next-generation sequencing technologies (e.g., RNA-seq), combined with physiological experiments, has provided extensive insight into the transcriptional basis of the diapause response in Ae. albopictus. Applying this knowledge to identify novel targets for vector control represents an important future challenge. Finally, recent studies have begun to identify traits other than diapause that are affected by photoperiodism. Extending this work to identify additional traits influenced by photoperiod should produce important insights into the seasonal biology of Ae. albopictus.

Population genomics of the Asian tiger mosquito, Aedes albopictus: insights into the recent worldwide invasion

“…First, its affinity to human‐made containers and environments allowed this species to quickly expand its range within and among continents due to regional and global trade among distant geographic regions (Medley, Jenkins, & Hoffman, ; Tatem, Hay, & Rogers, ) as has been observed in other Aedes species as well (Damal, Murrell, Juliano, Conn, & Loew, ; Egizi, Kiser, Abadam, & Fonseca, ). Second, the capacity for facultative photoperiodic diapause (Hawley, ; Mori, Oda, & Wada, ; Urbanski, Benoit, Michaud, Denlinger, & Armbruster, ) is largely responsible for the capacity of this mosquito to adapt to a temperate climate, enabling its range expansion into regions at higher latitudes in North America and North Europe (Armbruster, ; Becker et al., ; Flacio, Engeler, Tonolla, & Müller, ; Urbanski et al., ). Diapause is a preprogrammed, hormonally controlled dormancy that enables many insects to survive the unfavorable conditions of temperate winters (Denlinger & Armbruster, ).…”

Predicting the success of an invader: Niche shift versus niche conservatism

“…However, niche differences observed between US populations and their sources (Figure ), or the native Asian range (Medley, ), are probably due to niche unfilling (Cunze et al, ). Despite niche conservatism characterizes the European and North American invasions, the rapid evolution of traits (Europe: present study; Kreß et al, , United States: Urbanski et al, ; Armbruster, ; Medley, Westby, & Jenkins, ) suggests genetic shift from standing variation in response to new selective pressures encountered in the invaded area. Adaptive shifts could relate to niche differences induced by niche conservatism.…”

“…Cold and drought are crucial factors influencing the survival of overwintering insects (Block, 1996). Aedes albopictus winter survivorship in cold environments is determined by the photoperiodic induced diapause of eggs (Hanson & Craig, 1994;Hawley, 1988), which has a complex molecular basis (Armbruster, 2016). In Europe, Ae.…”

Cold adaptation in the Asian tiger mosquito's native range precedes its invasion success in temperate regions

“…In support of this hypothesis, a rapid evolution of the diapause response has been documented during the American invasive range expansion of A. albopictus (Urbanski et al. ; Armbruster ; Kreß et al. ; Kreß et al.…”

“…Because ddRADseq is a random sampling of whole genome, none of the thousands of SNPs analyzed were located within 20 kb of any of the diapause genes or signaling pathways involved in diapause regulation (e.g., biological clocks, hormones, and signaling cascades) previously described in A. albopictus and other insects (Bradshaw and Holzapfel ; Meuti and Denlinger ; Sim and Delinger ; Huang et al. ; Armbruster ; Denlinger and Armbruster 2016; Koštál et al. ).…”