Nutritional dynamics during the development of xylophagous beetles related to changes in the stoichiometry of 11 elements

The present study examines the adaptive strategy used by wood-boring beetles to compensate for the lack of nutrients in dead wood. The contents of nutritional elements in growing wood-boring beetles (Stictoleptura rubra L. and Chalcophora mariana Dejean) are compared with the elemental composition of decaying dead wood (pine stumps), showing changes during the beetles' ontogenetic (i.e. larval) development. The stoichiometric ratios of C and other nutritional elements (N, P, K, Na, Ca, Mg, Fe, Zn, Mn and Cu) are investigated to identify the most important nutrients for larval development. The degree of nutritional mismatch that is encountered by the beetle larvae changes dramatically over 3-4 years of simultaneous larval growth and wood decay. Excluding C, the relative contents of nutritional elements increase substantially in decaying wood, whereas the opposite tendency is found in larvae, most likely because of carbon deposition in fat. The elements limiting larval development because of their scarcity in dead wood are N, P, K, Na, Mg, Zn and Cu. Fungal activity (i.e. the transport of nutrients from the surrounding environment to decaying stumps) can explain the observed mitigation of the original mismatch, although prolongation of the larval development time is still necessary to compensate for the scarcity of some of the required elements in food

How to make a beetle out of wood : multi-elemental stoichiometry of wood decay, xylophagy and fungivory

The majority of terrestrial biomass is wood, but the elemental composition of its potential consumers, xylophages, differs hugely from that of wood. This causes a severe nutritional imbalance. We studied the stoichiometric relationships of 11 elements (C, N, P, K, Ca, Mg, Fe, Zn, Mn, Cu, Na) in three species of pine-xylem-feeding insects, Stictoleptura rubra, Arhopalus rusticus (Coleoptera, Cerambycidae) and Chalcophora mariana (Coleoptera, Buprestidae), to elucidate their mechanisms of tissue growth and to match their life histories to their dietary constraints. These beetles do not differ from other Coleoptera in their absolute elemental compositions, which are approximately 1000 (N), 100 (P, Cu) and 50 (K, Na) times higher than in dead but undecayed pine wood. This discrepancy diminishes along the wood decay gradient, but the elemental concentrations remain higher by an order of magnitude in beetles than in highly decayed wood. Numerical simulation of the life history of S. rubra shows that feeding on nutrient-poor undecayed wood would extend its development time to implausible values, whereas feeding on highly decomposed wood (heavily infected with fungi) would barely balance its nutritional budget during the long development period of this species. The changes in stoichiometry indicate that the relative change in the nutrient levels in decaying wood cannot be attributed solely to carbon loss resulting from decomposer respiration: the action of fungi substantially enriches the decaying wood with nutritional elements imported from the outside of the system, making it a suitable food for wood-eating invertebrates

Interakcje roślin z owadami mogą być kształtowane przez stechiometrię ekologiczną

International audienceThe energy budget of organisms is a primary factor used to generate hypotheses in ecosystem ecology and evolutionary theory. Therefore, previous studies have focused on the energy costs and benefits of adaptations, the efficiency of energy acquisition and investment, and energy budget limitations. The maintenance of stoichiometric balance is equally important because inconsistency between the chemical composition of the consumer's tissues and that of its food sources strongly affects the major life-history traits of the consumer and may influence the consumer's fitness and shape plant–herbivore interactions. In this short review, the framework of ecological stoichiometry is introduced, focusing on plant–insect interactions in terrestrial ecosystems. The use of the trophic stoichiometric ratio (TSR) index is presented as a useful tool for indicating the chemical elements that are scarce in food and have the potential to limit the growth and development of herbivores, thereby influencing plant – herbivorous insect interactions. As an example , the elemental composition and stoichiometry of a pollen consumer (mason bee Osmia bicornis) and its preferred pollen are compared. The growth and development of O. bicornis may be colimited by the scarcity of K, Na, and N in pollen, whereas the development of the cocoon might be colimited by the scarcity of P, Mg, K, Na, Zn, Ca, and N. A literature review of the elemental composition of pollen shows high taxonomical variability in the concentrations of bee-limiting elements. The optimized collection of pollen species based on the elemental composition may represent a strategy used by bees to overcome stoichiometric mismatches, influencing their interactions with plants. It is concluded that the dependence of life-history traits on food stoichiometry should be considered when discussing life history evolution and plant–herbivore interactions. The TSR index may serve as a convenient and powerful tool in studies investigating plant-insect interactions.Głównym czynnikiem, którego wpływ na organizmy uwzględnia się w ekologii ekosystemów i ekologii ewolucyjnej, jest bilans energetyczny. Wskutek tego badacze skupiają się na energetycznych korzyściach i kosztach adaptacji, wydajności przyswajania i inwestycji energii oraz ograniczeniach budżetu energetycznego. Jednak równie ważny jest problem bilansu stechiometrycznego i rozbieżności pomiędzy składem budulca tworzącego tkanki konsumenta oraz jego pokarmu. Ta rozbieżność kształtuje cechy historii życiowych organizmów (np. tempo wzrostu, wielkość ciała czy strategię reprodukcji) oraz wpływa na interakcje roślin z roślinożercami. W związku z tym stechiometria (proporcje pierwiastków) tkanek konsumenta i jego pokarmu może służyć jako narzędzie badawcze podczas studiowania mechanizmów kształtujących interakcje roślin z owadami roślinożernymi. W części przeglądowej niniejszej pracy przedstawione są ramy programu badawczego stechiometrii ekologicznej, w kontekście oddziaływań roślina-owad w ekosystemach lądowych. Zaproponowany jest wskaźnik trophic stoichiometric ratio (TSR) – narzędzie użyteczne do wykrywania pierwiastków stężonych w pożywieniu w zbyt małych ilościach względem potrzeb konsumenta, potencjalnie limitujących wzrost i rozwój roślinożercy, tym samym kształtując zależności między roślinami, a roślinożercami. Rozwijając idee przedstawione w części przeglądowej, zaprezentowano, na przykładzie murarki ogrodowej (Osmia bicornis – pszczoła samotna, pyłkożerca), jak zastosowanie programu stechiometrii ekologicznej do badania interakcji roślina-owad, może owocować interesującymi hipotezami i ważkimi wyjaśnieniami. Wzrost i rozwój murarki może być kolimitowany przez niedór K, Na oraz N w pożywieniu (pyłku roślinnym), natomiast produkcja kokonu może być kolimitowana przez niedobór P, Mg, K, Na, Zn Ca oraz N. Skład pierwiastkowy pyłku odznacza się wysoka zmiennością taksonomiczną. Konieczność stechiometrycznego zbilansowania diety może kształtować strategie zdobywania pokarmu i reprodukcji oraz wpływać na śmiertelność i dostosowanie pyłkożercy, kształtując interakcje owada z roślinami. Zależność cech historii życiowych od stechiometrii pożywienia powinna być brana pod uwagę podczas badania ewolucji historii życiowych oraz interakcji roślin z owadami. Wskaźnik TSR może służyć jako poręczne, a zarazem skuteczne narzędzie podczas takich badań

Fungal transformation of tree stumps into a suitable resource for Xylophagous Beetles via changes in elemental ratios

The elements present in dead pine stumps inhabited by larvae of wood-boring beetles (Stictoleptura rubra, Arhopalus rusticus and Chalcophora mariana) were analyzed over the initial (first 5 years; a chronosequence) stages of wood decay. The quantities of N, P, K, Ca, Mg, Fe, Zn, Mn, Cu and Na (but not S) increased with increases in the content of ergosterol (used as a proxy for the amount of fungal tissue). In fact, the amounts of P, N, K, Fe and Cu presented marked increases. These findings show that fungi stoichiometrically rearrange dead wood by importing externally occurring nutrients to decaying stumps. During the first years of wood decay, the ratios of C to other elements decrease substantially, but differently, for various elements, whereas the N:Fe, N:Cu, N:P and N:K ratios remain relatively stable. Therefore, the stoichiometric mismatch between xylophages and their food is greatly reduced. By changing the nutritional stoichiometry of dead wood, fungi create a nutritional niche for wood-eaters, and these changes enable the development of xylophages

Sexual dimorphism in the multielemental stoichiometric phenotypes and stoichiometric niches of spiders

Nutritional limitations may shape populations and communities of organisms. This phenomenon is often studied by treating populations and communities as pools of homogenous individuals with average nutritional optima and experiencing average constraints and trade-offs that influence their fitness in a standardized way. However, populations and communities consist of individuals belonging to different sexes, each with specific nutritional demands and limitations. Taking this into account, we used the ecological stoichiometry framework to study sexual differences in the stoichiometric phenotypes, reflecting stoichiometric niches, of four spider taxa differing in the hunting mode. The species and sexes differed fundamentally in their elemental phenotypes, including elements beyond those most commonly studied (C, N and P). Both species and sexes were distinguished by the C:N ratio and concentrations of Cu, K and Zn. Species additionally differed in concentrations of Na, Mg and Mn. Phosphorous was not involved in this differentiation. Sexual dimorphism in spiders’ elemental phenotypes, related to differences in their stoichiometric niches, suggests different nutritional optima and differences in nutritional limitation experienced by different sexes and species. This may influence the structure and functioning of spider populations and communities

The influence of COMT gene functional polymorphism on formation of chronic pain

Introduction and purpose The prevalence of chronic pain is estimated at around 30% of the world's population. The risk of developing chronic pain depends, among others, on from genetic factors. Considering that chronic pain is a serious diagnostic and therapeutic problem, and if treated inadequately constitutes a serious threat to public health, focus should be on identifying the risk factors for its occurrence in order to establish an effective treatment. The aim of the work is to summarize the latest knowledge about the influence of functional polymorphism of the COMT gene on the formation of chronic pain. Material and methods The material for this literature review were publications on the subject of research from the last 5 years. Relevant articles have been identified by two authors using PubMed, Google Scholar and Researchgate publishing bases using key words: "gene COMT", "headache", "chronic pain", "chronic back pain", "fibromyalgia", "temporomandibular disorder", "postoperative pain" according to Medical Subject Headings. The review of articles consisted of 3 stages. Finally, 19 works were qualified for the review. Results Functional polymorphism of the COMT gene is one of the factors affecting the modulation of pain. Its single genetic variants will positively correlate with the occurrence of temporomandibular disorders and chronic lower back pain. Differences in genetic variants of the COMT gene will also affect the susceptibility to fibromyalgia and increase the severity of clinical symptoms. The COMT gene polymorphism does not seem to correlate with chronic headaches. Conclusions Research to determine the effect of COMT gene polymorphism can significantly affect the diagnosis and treatment of chronic pain