Distinguishing between anticipatory and responsive plasticity in a seasonally polyphenic butterfly

Abstract

Seasonal generations of short-lived organisms often differ in their morphological, behavioural and life history traits, including body size. These differences may be either due to immediate effects of seasonally variable environment on organisms (responsive plasticity) or rely on presumably adaptive responses of organisms to cues signalizing forthcoming seasonal changes (anticipatory plasticity). When directly developing individuals of insects are larger than their overwintering conspecifics, the betweengeneration differences are typically ascribed to responsive plasticity in larval growth. We tested this hypothesis using the papilionid butterly Iphiclides podalirius as a model species. In laboratory experiments, we demonstrated that seasonal differences in food quality could not explain the observed size difference. Similarly, the size differences are not likely to be explained by the immediate effects of ambient temperature and photoperiod on larval growth. The qualitative pattern of natural size differences between the directly developing and diapausing butterflies could be reproduced in the laboratory as a response to photoperiod, indicating anticipatory character of the response. Directly developing and diapausing individuals followed an identical growth trajectory until the end of the last larval instar, with size differences appearing just a few days before pupation. Taken together, various lines of evidence suggest that between-generation size differences in I. podalirius are not caused by immediate effects of environmental factors on larval growth. Instead, these differences rather represent anticipatory plasticity and are thus likely to have an adaptive explanation. It remains currently unclear, whether the seasonal differences in adult size per se are adaptive, or if they constitute co-product of processes related to the diapause. Our study shows that it may be feasible to distinguish between different types of plasticity on the basis of empirical data even if fitness cannot be directly measured, and contributes to the emerging view about the predominantly adaptive nature of seasonal polyphenisms in insects.

The Temperature–Size Rule in Lecane inermis (Rotifera) is adaptive and driven by nuclei size adjustment to temperature and oxygen combinations

“…Such a response could be explained in terms of anticipatory vs. responsive plasticity (Whitman andAgrawal, 2009, after Esperk et al, 2013). In this distinction, responsive plasticity results from immediate effects of an environmental factor, for example, temperature (as in the case of TSR) or food, whereas anticipatory plasticity evolves as a response to environmental cues that indicate future conditions, for example, photoperiod (Esperk et al, 2013). Responsive plasticity does not need to be adaptive; on the contrary, anticipatory plasticity is generally assumed to be adaptive (Esperk et al, 2013 and citations therein).…”

Aedes aegypti pharate 1st instar quiescence: A case for anticipatory reproductive plasticity

“…In the case of anticipatory plasticity, phenotypic changes are induced in response to cues which signal future environmental conditions prior to the actual onset of these conditions (Esperk et al, 2012). In tropical and subtropical regions mosquitoes are often exposed to a favorable rainy season with abundant breeding sites and vegetation, and a stressful drier winter (Vinogradova, 2007; Denlinger, 1986; Mori et al, 1981) during which resources may be less plentiful (Gary and Foster, 2001; Foster, 1995; Yaro, et al, 2012).…”

Aedes aegypti Pharate First Instar Aseasonal Quiescence Cues Anticipatory Plasticity with Implications for Urban Vector Ecology and Control

“…Moreover, as seasonal polyphenisms usually are multitrait responses, it may well be the case that some traits show anticipatory plasticity while differences in others may be a result of responsive plasticity to environmental conditions. Nevertheless, attempts to explicitly confront these different explanations are limited (Esperk, et al, 2012). Some seasonal polyphenisms are tightly coupled with diapause.…”

“…The generation experiencing lower temperatures during the larval life could thus attain a larger adult size also in response to temperature. (Esperk, et al, 2012). In addition, body size difference are not the only parameter to consider since nutritional reserves are not necessarily proportional to body size as demonstrated in chapter five.…”

“…In the case of anticipatory plasticity, phenotypic changes are induced in response to cues which signal future environmental conditions prior to the actual onset of these conditions (Esperk et al, 2012). In tropical and subtropical regions mosquitoes are often exposed to a favorable rainy season with abundant breeding sites and vegetation, and a stressful drier winter Denlinger, 1986;Mori et al, 1981) during which resources may be less plentiful (Gary and Foster, 2001;Foster, 1995;Yaro, et al, 2012).…”