Synchronisation of pre‐imaginal development and reproductive success in the winter moth, Operophtera brumata L.

Abstract

The phenology of a winter moth population originating from tributaries of the river Rhine (50°30′ N) was investigated. The eggs spend winter in the canopy of the trees without chilling to be necessary for larval eclosion. Larval development was temperature dependent with a theoretical development null point at 1.5 and 1.8 °C., calculated according to time of development as well as larval growth rate (R.G.R.). Photoperiod had no effect. Influence of the host plant (Salix spp.) was obvious (p < 0.01) in only 1 of 21 examples. In the field, pupal aestivation was a mean of 171 d. Aestivation period differed between sexes, with aestivation 7 d shorter in males (p < 0.001). Photoperiod had a minor effect with 4 d shorter at short‐day (LD 8/16) comparing to long‐day (LD 16/8) (p < 0.05). An influence of temperature was evident during the initial phase of aestivation resulting in a time of pupation which deviated by a maximum of 10 d (p < 0.05). When temperatures differed during the terminal phase of aestivation, the effect on time of pupation was more pronounced. The shortest aestivation period was found at 10°C (= 169 d). At lower temperatures (5 °C) and higher temperatures (20 °C) time of adult emergence was retarded to > 200 d. Host plants, in the main did not influence pupation period. Within the population two different reaction patterns were found which may synchronize the development of individuals: 1. When larval development was accelerated by high temperatures resulting in an early date of pupation, the subsequent aestivation period was prolonged. 2. When larvae fed on young leaves later in the season rather than on leaves growing earlier, time of larval development was shortened. Fecundity of females was temperature dependent with an optimum value at 10 °C. At lower and higher temperatures the mean number of eggs/ ♀ decreased. Photoperiod did not influence fecundity and the host plants the larvae fed on, mostly had no effect. Zusammenfassung Einfluß von Temperatur, Photoperiode und Wirtspflanze auf die Entwicklung und Fekundität des Kleinen Frostspanners (Operophtera hrumata L.) Die Phänologie des Kleinen Frostspanners wurde am Beispiel einer Population aus dem Ahrtal (50°30′N) untersucht. Die Eier überwintern und entwickeln sich an Zweigen verschiedener Laubbäume, ohne daß der Einfluß niedriger Temperaturen zur Beendigung der Embryonalentwicklung erforderlich war. Die Larvenentwicklung ist temperaturabhängig, mit einem theoretischen Entwicklungsnullpunkt bei 1–2 °C. Dieser Wert ergab sich einerseits nach der Entwicklungsgeschwindigkeit, andererseits nach der Wachstumsrate (R.G.R.). Larvalentwicklung und Aestivationsperiode der Puppe wurden kaum durch die Photoperiode oder durch die Wirtspflanzen (Salix spp.) beeinflußt. Allerdings wurden zwei verschiedene Reaktionsmuster festgestellt, die als Synchronisationsmechanismen der Individualentwicklungen innerhalb von Populationen gedeutet wurden. 1. Fand die Larvalentwicklung bei hohen Temperaturen (20 °C) statt und erfolgte dadurch der Zeitpunkt der Verpu...

Warmer springs lead to mistimed reproduction in great tits (Parus major)

“…E. Visser, unpublished data). The caterpillar peak is well predicted by the mean daily temperature from 21 February to 10 May (F 1,26 52.3, p50.0001; ¢gure 1; see also van Balen 1973). The regression model allows us to predict the date of peak caterpillar biomass each year over the period 1973^1995 using temperature data supplied by the KNMI (Royal Dutch Meteorological Institute) in De Bilt.…”

“…(c) Annual peak dates of caterpillar biomass Annual peak dates of caterpillar biomass are calculated from a regression model based on caterpillar peaks determined from frass-fall samples on the Hoge Veluwe (1985^1997), Vlieland (1988^1995) and Oosterhout (1958^1968) (van Balen 1973;Verboven et al 1998;M. E. Visser, unpublished data).…”

“…Selection di¡erentials estimate the amount of directional selection on a trait (Falconer 1981;Endler 1986;Schluter & Smith 1986;van Noordwijk et al 1995). We calculated the selection di¡erential for laying date as the di¡erence between the mean date of laying of ¢rst clutches, weighted for the number of recruits produced per female over the entire season, and the unweighted mean laying date of ¢rst clutches.…”

Phase-dependent outbreak dynamics of geometrid moth linked to host plant phenology

“…Jepsen et al 4125 season (Karlsson et al 2003;Shutova et al 2006;Pudas et al 2008), while the same temperature increase translates to a 7-10 days earlier onset of the growing season in oceanic northwest Norway . Assuming that larval hatching depends more directly on temperature than does budburst (Topp & Kirsten 1991;Van Asch & Visser 2007), there is a large potential for local and regional differences in the degree of match between larval hatching and birch budburst in individual years. Thus for the observed massive large-scale outbreak to develop, meteorological conditions providing a good phenological match must have occurred simultaneously at a large scale.…”

Phenotypic plasticity and development of cold-season insects (Coleoptera: Leiodidae) and their response to climatic change

“…This strategy not only enables the winter moth to live in the temperate zone but also to survive in the sub arctic conditions north of the polar circle. For example, in western Europe where harsh winter temperatures usually only exist for a short period, individual hatching occurs early in the season and the pupal aestivation has to be long to allow a developmental synchronisation with the season (Topp & Kirsten, 1991). In contrast, in northern Europe where harsh winter temperatures last longer, indi vidual hatching occurs late in the season and a short pupal aestivation serves to optimise the date of reproduction in autumn (Peterson & Nilssen, 1998).…”