@article{UhlerRedlichZhangetal.2021, author = {Uhler, Johannes and Redlich, Sarah and Zhang, Jie and Hothorn, Torsten and Tobisch, Cynthia and Ewald, J{\"o}rg and Thorn, Simon and Seibold, Sebastian and Mitesser, Oliver and Morin{\`e}re, J{\´e}r{\^o}me and Bozicevic, Vedran and Benjamin, Caryl S. and Englmeier, Jana and Fricke, Ute and Ganuza, Cristina and Haensel, Maria and Riebl, Rebekka and Rojas-Botero, Sandra and Rummler, Thomas and Uphus, Lars and Schmidt, Stefan and Steffan-Dewenter, Ingolf and M{\"u}ller, J{\"o}rg}, title = {Relationships of insect biomass and richness with land use along a climate gradient}, series = {Nature Communications}, volume = {12}, journal = {Nature Communications}, number = {1}, doi = {10.1038/s41467-021-26181-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265058}, year = {2021}, abstract = {Recently reported insect declines have raised both political and social concern. Although the declines have been attributed to land use and climate change, supporting evidence suffers from low taxonomic resolution, short time series, a focus on local scales, and the collinearity of the identified drivers. In this study, we conducted a systematic assessment of insect populations in southern Germany, which showed that differences in insect biomass and richness are highly context dependent. We found the largest difference in biomass between semi-natural and urban environments (-42\%), whereas differences in total richness (-29\%) and the richness of threatened species (-56\%) were largest from semi-natural to agricultural environments. These results point to urbanization and agriculture as major drivers of decline. We also found that richness and biomass increase monotonously with increasing temperature, independent of habitat. The contrasting patterns of insect biomass and richness question the use of these indicators as mutual surrogates. Our study provides support for the implementation of more comprehensive measures aimed at habitat restoration in order to halt insect declines.}, language = {en} } @article{StormsJakharMitesseretal.2022, author = {Storms, Mona and Jakhar, Aryan and Mitesser, Oliver and Jechow, Andreas and H{\"o}lker, Franz and Degen, Tobias and Hovestadt, Thomas and Degen, Jacqueline}, title = {The rising moon promotes mate finding in moths}, series = {Communications Biology}, volume = {5}, journal = {Communications Biology}, doi = {10.1038/s42003-022-03331-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301365}, year = {2022}, abstract = {To counteract insect decline, it is essential to understand the underlying causes, especially for key pollinators such as nocturnal moths whose ability to orientate can easily be influenced by ambient light conditions. These comprise natural light sources as well as artificial light, but their specific relevance for moth orientation is still unknown. We investigated the influence of moonlight on the reproductive behavior of privet hawkmoths (Sphinx ligustri) at a relatively dark site where the Milky Way was visible while the horizon was illuminated by distant light sources and skyglow. We show that male moths use the moon for orientation and reach females significantly faster with increasing moon elevation. Furthermore, the choice of flight direction depended on the cardinal position of the moon but not on the illumination of the horizon caused by artificial light, indicating that the moon plays a key role in the orientation of male moths.}, language = {en} } @article{SchenkMitesserHovestadtetal.2018, author = {Schenk, Mariela and Mitesser, Oliver and Hovestadt, Thomas and Holzschuh, Andrea}, title = {Overwintering temperature and body condition shift emergence dates of spring-emerging solitary bees}, series = {PeerJ}, volume = {6}, journal = {PeerJ}, doi = {10.7717/peerj.4721}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228544}, pages = {e4721, 1-17}, year = {2018}, abstract = {Solitary bees in seasonal environments must align their life-cycles with favorable environmental conditions and resources; the timing of their emergence is highly fitness relevant. In several bee species, overwintering temperature influences both emergence date and body weight at emergence. High variability in emergence dates among specimens overwintering at the same temperatures suggests that the timing of emergence also depends on individual body conditions. However, possible causes for this variability, such as individual differences in body size or weight, have been rarely studied. In a climate chamber experiment using two spring-emerging mason bees (Osmia cornuta and O. bicornis), we investigated the relationship between temperature, emergence date, body weight, and body size, the last of which is not affected by overwintering temperature. Our study showed that body weight declined during hibernation more strongly in warm than in cold overwintering temperatures. Although bees emerged earlier in warm than in cold overwintering temperatures, at the time of emergence, bees in warm overwintering temperatures had lower body weights than bees in cold overwintering temperatures (exception of male O. cornuta). Among specimens that experienced the same overwintering temperatures, small and light bees emerged later than their larger and heavier conspecifics. Using a simple mechanistic model we demonstrated that spring-emerging solitary bees use a strategic approach and emerge at a date that is most promising for their individual fitness expectations. Our results suggest that warmer overwintering temperatures reduce bee fitness by causing a decrease in body weight at emergence. We showed furthermore that in order to adjust their emergence dates, bees use not only temperature but also their individual body condition as triggers. This may explain differing responses to climate warming within and among bee populations and may have consequences for bee-plant interactions as well as for the persistence of bee populations under climate change.}, language = {en} } @article{RandlkoferJordanMitesseretal.2009, author = {Randlkofer, Barbara and Jordan, Florian and Mitesser, Oliver and Meiners, Torsten and Obermaier, Elisabeth}, title = {Effect of vegetation density, height, and connectivity on the oviposition pattern of the leaf beetle Galeruca tanaceti}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49665}, year = {2009}, abstract = {Vegetation structure can profoundly influence patterns of abundance, distribution, and reproduction of herbivorous insects and their susceptibility to natural enemies. The three main structural traits of herbaceous vegetation are density, height, and connectivity. This study determined the herbivore response to each of these three parameters by analysing oviposition patterns in the field and studying the underlying mechanisms in laboratory bioassays. The generalist leaf beetle, Galeruca tanaceti L. (Coleoptera: Chrysomelidae), preferentially deposits its egg clutches on non-host plants such as grasses. Earlier studies revealed that oviposition within structurally complex vegetation reduces the risk of egg parasitism. Consequently, leaf beetle females should prefer patches with dense, tall, or connected vegetation for oviposition in order to increase their reproductive success. In the present study, we tested the following three hypotheses on the effect of stem density, height, and connectivity on oviposition: (1) Within habitats, the number of egg clutches in areas with high stem densities is disproportionately higher than in low-density areas. The number of egg clutches on (2) tall stems or (3) in vegetation with high connectivity is higher than expected for a random distribution. In the field, stem density and height were positively correlated with egg clutch presence. Moreover, a disproportionately high presence of egg clutches was determined in patches with high stem densities. Stem height had a positive influence on oviposition, also in a laboratory two-choice bioassay, whereas stem density and connectivity did not affect oviposition preferences in the laboratory. Therefore, stem height and, potentially, density, but not connectivity, seem to trigger oviposition site selection of the herbivore. This study made evident that certain, but not all traits of the vegetation structure can impose a strong influence on oviposition patterns of herbivorous insects. The results were finally compared with data on the movement patterns of the specialised egg parasitoid of the herbivore in comparable types of vegetation structure.}, subject = {Blattk{\"a}fer}, language = {en} } @article{PoethkeHovestadtMitesser2003, author = {Poethke, Hans-Joachim and Hovestadt, Thomas and Mitesser, Oliver}, title = {Local extinction and the evolution of dispersal rates: Causes and correlations}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47718}, year = {2003}, abstract = {We present the results of individual-based simulation experiments on the evolution of dispersal rates of organisms living in metapopulations. We find conflicting results regarding the relationship between local extinction rate and evolutionarily stable (ES) dispersal rate depending on which principal mechanism causes extinction: if extinction is caused by environmental catastrophes eradicating local populations, we observe a positive correlation between extinction and ES dispersal rate; if extinction is a consequence of stochastic local dynamics and environmental fluctuations, the correlation becomes ambiguous; and in cases where extinction is caused by dispersal mortality, a negative correlation between local extinction rate and ES dispersal rate emerges. We conclude that extinction rate, which both affects and is affected by dispersal rates, is not an ideal predictor for optimal dispersal rates.}, subject = {Ausbreitung}, language = {en} } @article{MuellerMitesserSchaeferetal.2023, author = {M{\"u}ller, J{\"o}rg and Mitesser, Oliver and Schaefer, H. Martin and Seibold, Sebastian and Busse, Annika and Kriegel, Peter and Rabl, Dominik and Gelis, Rudy and Arteaga, Alejandro and Freile, Juan and Leite, Gabriel Augusto and de Melo, Tomaz Nascimento and LeBien, Jack and Campos-Cerqueira, Marconi and Bl{\"u}thgen, Nico and Tremlett, Constance J. and B{\"o}ttger, Dennis and Feldhaar, Heike and Grella, Nina and Falcon{\´i}-L{\´o}pez, Ana and Donoso, David A. and Moriniere, Jerome and Buřivalov{\´a}, Zuzana}, title = {Soundscapes and deep learning enable tracking biodiversity recovery in tropical forests}, series = {Nature Communications}, volume = {14}, journal = {Nature Communications}, doi = {10.1038/s41467-023-41693-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-358130}, year = {2023}, abstract = {Tropical forest recovery is fundamental to addressing the intertwined climate and biodiversity loss crises. While regenerating trees sequester carbon relatively quickly, the pace of biodiversity recovery remains contentious. Here, we use bioacoustics and metabarcoding to measure forest recovery post-agriculture in a global biodiversity hotspot in Ecuador. We show that the community composition, and not species richness, of vocalizing vertebrates identified by experts reflects the restoration gradient. Two automated measures - an acoustic index model and a bird community composition derived from an independently developed Convolutional Neural Network - correlated well with restoration (adj-R² = 0.62 and 0.69, respectively). Importantly, both measures reflected composition of non-vocalizing nocturnal insects identified via metabarcoding. We show that such automated monitoring tools, based on new technologies, can effectively monitor the success of forest recovery, using robust and reproducible data.}, language = {en} } @article{MitesserWeisselStrohmetal.2007, author = {Mitesser, Oliver and Weissel, Norbert and Strohm, Erhard and Poethke, Hans-Joachim}, title = {Adaptive dynamic resource allocation in annual eusocial insects: Environmental variation will not necessarily promote graded control}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45412}, year = {2007}, abstract = {Background: According to the classical model of Macevicz and Oster, annual eusocial insects should show a clear dichotomous "bang-bang" strategy of resource allocation; colony fitness is maximised when a period of pure colony growth (exclusive production of workers) is followed by a single reproductive period characterised by the exclusive production of sexuals. However, in several species graded investment strategies with a simultaneous production of workers and sexuals have been observed. Such deviations from the "bang-bang" strategy are usually interpreted as an adaptive (bet-hedging) response to environmental fluctuations such as variation in season length or food availability. To generate predictions about the optimal investment pattern of insect colonies in fluctuating environments, we slightly modified Macevicz and Oster's classical model of annual colony dynamics and used a dynamic programming approach nested into a recurrence procedure for the solution of the stochastic optimal control problem. Results: 1) The optimal switching time between pure colony growth and the exclusive production of sexuals decreases with increasing environmental variance. 2) Yet, for reasonable levels of environmental fluctuations no deviation from the typical bang-bang strategy is predicted. 3) Model calculations for the halictid bee Lasioglossum malachurum reveal that bet-hedging is not likely to be the reason for the graded allocation into sexuals versus workers observed in this species. 4) When environmental variance reaches a critical level our model predicts an abrupt change from dichotomous behaviour to graded allocation strategies, but the transition between colony growth and production of sexuals is not necessarily monotonic. Both, the critical level of environmental variance as well as the characteristic pattern of resource allocation strongly depend on the type of function used to describe environmental fluctuations. Conclusion: Up to now bet-hedging as an evolutionary response to variation in season length has been the main argument to explain field observations of graded resource allocation in annual eusocial insect species. However, our model shows that the effect of moderate fluctuations of environmental conditions does not select for deviation from the classical bang-bang strategy and that the evolution of graded allocation strategies can be triggered only by extreme fluctuations. Detailed quantitative observations on resource allocation in eusocial insects are needed to analyse the relevance of alternative explanations, e.g. logistic colony growth or reproductive conflict between queen and workers, for the evolution of graded allocation strategies.}, subject = {Insekten}, language = {en} } @article{MitesserWeisselStrohmetal.2006, author = {Mitesser, Oliver and Weissel, Norbert and Strohm, Erhard and Poethke, Hans J.}, title = {The evolution of activity breaks in the nest cycle of annual eusocial bees: A simple model of delayed exponential growth}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-48196}, year = {2006}, abstract = {Abstract: Background Social insects show considerable variability not only in social organisation but also in the temporal pattern of nest cycles. In annual eusocial sweat bees, nest cycles typically consist of a sequence of distinct phases of activity (queen or workers collect food, construct, and provision brood cells) and inactivity (nest is closed). Since the flight season is limited to the time of the year with sufficiently high temperatures and resource availability, every break reduces the potential for foraging and, thus, the productivity of a colony. This apparent waste of time has not gained much attention. Results We present a model that explains the evolution of activity breaks by assuming differential mortality during active and inactive phases and a limited rate of development of larvae, both reasonable assumptions. The model predicts a systematic temporal structure of breaks at certain times in the season which increase the fitness of a colony. The predicted pattern of these breaks is in excellent accordance with field data on the nest cycle of the halictid Lasioglossum malachurum. Conclusion Activity breaks are a counter-intuitive outcome of varying mortality rates that maximise the reproductive output of primitively eusocial nests.}, language = {en} } @phdthesis{Mitesser2006, author = {Mitesser, Oliver}, title = {The evolution of insect life history strategies in a social context}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-22576}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2006}, abstract = {This thesis extends the classical theoretical work of Macevicz and Oster (1976, expanded by Oster and Wilson, 1978) on adaptive life history strategies in social insects. It focuses on the evolution of dynamic behavioural patterns (reproduction and activity) as a consequence of optimal allocation of energy and time resources. Mathematical modelling is based on detailed empirical observations in the model species Lasioglossum malachurum (Halictidae; Hymenoptera). The main topics are field observations, optimisation models for eusocial life histories, temporal variation in life history decisions, and annual colony cycles of eusocial insects.}, subject = {Schmalbienen}, language = {en} } @article{HovestadtThomasMitesseretal.2019, author = {Hovestadt, Thomas and Thomas, Jeremy A. and Mitesser, Oliver and Sch{\"o}nrogge, Karsten}, title = {Multiple host use and the dynamics of host-switching in host-parasite systems}, series = {Insect Conservation and Diversity}, volume = {12}, journal = {Insect Conservation and Diversity}, number = {6}, doi = {10.1111/icad.12374}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204747}, pages = {511-522}, year = {2019}, abstract = {The link between multi-host use and host switching in host-parasite interactions is a continuing area of debate. Lycaenid butterflies in the genus Maculinea, for example, exploit societies of different Myrmica ant species across their ranges, but there is only rare evidence that they simultaneously utilise multiple hosts at a local site, even where alternative hosts are present. We present a simple population-genetic model accounting for the proportion of two alternative hosts and the fitness of parasite genotypes on each host. In agreement with standard models, we conclude that simultaneous host use is possible whenever fitness of heterozygotes on alternative hosts is not too low. We specifically focus on host-shifting dynamics when the frequency of hosts changes. We find that (i) host shifting may proceed so rapidly that multiple host use is unlikely to be observed, (ii) back and forth transition in host use can exhibit a hysteresis loop, (iii) the parasites' host use may not be proportional to local host frequencies and be restricted to the rarer host under some conditions, and (iv) that a substantial decline in parasite abundance may typically precede a shift in host use. We conclude that focusing not just on possible equilibrium conditions but also considering the dynamics of host shifting in non-equilibrium situations may provide added insights into host-parasite systems.}, language = {en} }