TY - JOUR

T1 - Convergent photoperiodic plasticity in developmental rate in two species of insects with widely different thermal phenotypes

AU - Kutcherov , Dmitry

AU - Lopatina, Elena

AU - Balashov, Sergei

PY - 2018

Y1 - 2018

N2 - Growth and development rates in many insects are affected by photoperiod, which enables insects to synchronize their life histories with seasonal events, but this aspect of insect photoperiodism remains understudied. Here we use several experimental combinations of constant day length and temperature to determine whether there are quantitative developmental responses to photoperiod in the bug Scantius aegyptius and leaf beetle Timarcha tenebricosa. The thermal ecology of these two species is strikingly different: the former is thermophilic and active throughout summer and the latter is spring-active and avoids the hottest time of the year. In accordance with their contrasting natural thermal environments, S. aegyptius survives better and achieves a larger final body mass at the high experimental temperatures, while T. tenebricosa survives better and is heavier at the low experimental temperatures. Despite this polarity, long-day conditions accelerate larval development relative to a shortday photoperiod in both species, and this developmental response is stronger at low temperatures. Our re-visitation of previous literature in light of the new findings indicates that this similarity in photoperiodic response is superficial and that relatively faster development in midsummer is likely to have a different ecological role in summer- and spring-active species. In the former, it may allow completion of an additional generation during the favourable season, whereas in the latter, this acceleration likely ensures that the larval stage, which is vulnerable to heat, is completed before the onset of hot weather.

AB - Growth and development rates in many insects are affected by photoperiod, which enables insects to synchronize their life histories with seasonal events, but this aspect of insect photoperiodism remains understudied. Here we use several experimental combinations of constant day length and temperature to determine whether there are quantitative developmental responses to photoperiod in the bug Scantius aegyptius and leaf beetle Timarcha tenebricosa. The thermal ecology of these two species is strikingly different: the former is thermophilic and active throughout summer and the latter is spring-active and avoids the hottest time of the year. In accordance with their contrasting natural thermal environments, S. aegyptius survives better and achieves a larger final body mass at the high experimental temperatures, while T. tenebricosa survives better and is heavier at the low experimental temperatures. Despite this polarity, long-day conditions accelerate larval development relative to a shortday photoperiod in both species, and this developmental response is stronger at low temperatures. Our re-visitation of previous literature in light of the new findings indicates that this similarity in photoperiodic response is superficial and that relatively faster development in midsummer is likely to have a different ecological role in summer- and spring-active species. In the former, it may allow completion of an additional generation during the favourable season, whereas in the latter, this acceleration likely ensures that the larval stage, which is vulnerable to heat, is completed before the onset of hot weather.

KW - Body size

KW - Chrysomelidae

KW - Coleoptera

KW - Development

KW - Hemiptera

KW - Photoperiod

KW - Pyrrhocoridae

KW - Reaction norm

KW - Scantius aegyptius

KW - Seasonality

KW - Temperature

KW - Timarcha tenebricosa

UR - http://www.scopus.com/inward/record.url?scp=85057865210&partnerID=8YFLogxK

U2 - doi: 10.14411/eje.2018.060

DO - doi: 10.14411/eje.2018.060

M3 - Article

VL - 115

SP - 624

EP - 631

JO - European Journal of Entomology

JF - European Journal of Entomology

SN - 1210-5759

ER -