- Ecology, Evolution, Behavior
- Life history theory
- Phenotypic plasticity
- Mating system evolution
- Climate change, phenology shifts and the interaction with:
- Photoperiodism (day length measurements)
- Diurnal rhythms
- Circadian clocks
I currently work at Gent University, Project
Bet-hedging strategies of multivoltine species
Temperate species need to time diapause or egg production with the onset of winter. The onset of winter is, however, not perfectly predictable, so phenotypic plasticity (which relies on predictive cues) is not a sufficient strategy. It may be a better strategy to spread one's risk among their offspring, either by letting some offspring disperse to other habitats, or by varying the timing of diapause. I plan to model the joint evolution of dispersal and diapause in multivoltine species, and later validate the models with an empirical study.
Previous project in the Zoo3, Würzburg:
PhD study in Würzburg, SFB 1047 : "Insect timing: Mechanisms, plasticity and interactions"
Common responses to climate change are shifts in the phenology (seasonal timing) and northward range expansion. Both scenarios cause organisms to experience novel day length : temperature correlations. I studied how animals cope with the novel time budget.
I first studied day length constraints in the pea aphid Acyrthosiphon pisum, which generally produces eggs to overwinter and thus does normally not experience short day conditions. Some lines have, however, lost the seasonal response, and I used such a permanently asexual (anholocyclic) line to study fitness constraints of short days without inducing phenotypic change. I showed that short days constrain fitness in the pea aphid.
I hypothesized that constraints under shorter days are caused by the diurnal niche, i.e. , a day - active animal has less time available under short days. I showed that Chrysoperla carnea is, similar to A. pisum, constrained by shorter days, whereas the night-active aphid predator Episyrphus balteatus is constrained by longer day lengths.
I then studied the diurnal rhythm of aphids on artificial diets, independently of a host plant, and showed that aphids are day-active. The pea aphid's diurnal niche may thus indeed explain the short day constraints.
Ultimately I wanted to study the circadian clock of Acyrthosiphon pisum, which is a molecular mechanism that tracks time. A. pisum is not only a model for phenotypic plasticity, but aphids are also classical models for the link of circadian clocks and phenology. However, getting a suitable readout of activity is not trivial, because aphids do not move much. By improving the artificial diet and adding a food colourant I was able to monitor honeydew excretion. In addition, we monitored locomotor activity and showed that the aphid circadian clock has the properties of a damped circadian oscillator
2018 Research fellowship, DFG, Gent (Belgium). ESTIMAS - Escaping in Time and Space
2017 Research fellowship, Graduate School of Life Sciences, Würzburg (Germany)
2013 - 2017 PhD, SFB 1047 "Insect Timing", Würzburg, Germany. Is the phenology of pea aphids (Acyrthosiphon pisum) constrained by diurnal rhythms?
2010 - 2012 Msc Biology, University of Konstanz, Germany. Do selfers differ from outcrossers in growth and resistance to caterpillars?
2009 - 2010 Chinese courses at 同济大学 (Tongji University), Shanghai, China.
2006 - 2009 Bsc Biology, University of Konstanz, Germany. Allelochemical Interactions among Myriophyllum spicatum and bacteria
Insect Conservation and Diversity
Grants and awards
Jul 2017: Biocenter Science Award (Prize for outstanding thesis)
Apr 2017: Graduate School of Life Sciences Würzburg (GSLS) Career development fellowship
Nov 2015: GSLS travel fellowship, 500€
Dec 2015: GSLS travel fellowship, 500€
Sep 2016: GSLS travel fellowship, 500€
Joschinski J, Krauss, J. (2017). The relationship of phenology shifts, diurnal time budgets and the circadian clock in an aphid-predator system. BES, GFÖ, NECOV and EEF joint annual meeting: Ecology across borders. Gent, Belgium (talk)
Joschinski J, Krauss, J. (2016). Coloured artificial diets: Their use in circadian clock research and beyond. Royal Entomological Society Annual National Science Meeting (Ento '16), Newport (Shropshire), United Kingdom. (talk)
Joschinski J, Krauss, J. (2015). Climate change and phenology shifts: does a changing time budget constrain aphids? British Ecological Society annual meeting 2015, Edinburgh, United Kingdom. (talk)
Joschinski J, Krauss, J. (2015). Day length constraints and diurnal activity of the pea aphid. Joint meeting of the French Aphid Research Network and the Aphid Special Interest Group of the Royal Entomological Society, Paris, France. (talk)
Joschinski J, Hovestadt T, Krauss, J. (2015). Do phenology shifts cause day length constraints in aphids? Ecological Society of Germany, Austria and Switzerland. 45th Annual Meeting, Göttingen, Germany (talk)
Beer K1, Joschinski J1, Arrazola Sastre A, Krauss J & Helfrich-Förster C (2017) A damping circadian clock drives weak oscillations in metabolism and locomotor activity of aphids (Acyrthosiphon pisum). Scientific Reports 7: 14906. DOI: dx.doi.org/10.1038/s41598-017-15014-3
Joschinski J, Kiess T, Krauss J. Day length constrains the time budget of aphid predators. Insect Science. Early view. DOI: dx.doi.org/10.1111/1744-7917.12507
Joschinski J, Krauss J. (2017) An improved artificial aphid diet: Food colouring as new possibility to study aphid feeding. Entomologia Experimentalis et applicata, 164: 141-149. DOI: dx.doi.org/10.1111/eea.12598
Joschinski J, Beer K, Helfrich-Förster C, Krauss J. (2016) Pea aphids (Hemiptera: Aphididae) have diurnal rhythms when raised independently of a host plant. Journal of Insect Science, 16 (31): 1-5. DOI: dx.doi.org/10.1093/jisesa/iew013
Joschinski J, Hovestadt T, Krauss J. (2015) Coping with shorter days: do phenology shifts constrain aphid fitness? PeerJ 3:e1103. DOI: dx.doi.org/10.7717/peerj.1103
Joschinski J, van Kleunen M, Stift M. (2015) Costs associated with the evolution of selfing in North American populations of Arabidopsis lyrata? Evolutionary Ecology 29: 749-764. DOI: https://dx.doi.org/10.1007/s10682-015-9786-3
Joschinski J. (2016) Benefits and costs of aphid phenological bet-hedging strategies. Research Ideas and Outcomes, 2: e9580. DOI: https://dx.doi.org/10.3897/rio.2.e9580. [PostDoc Project Plan, not peer-reviewed]