The American red flat bark beetle, Cucujus clavipes, is a wide distributed saproxylic species divided into two subspecies: ssp. clavipes restricted to eastern regions of North America and ssp. puniceus occurring only in western regions of this continent. Unique morphological features, including body shape and body coloration, make this species easy to recognize even for amateurs. Surprisingly, except some studies focused on physiological adaptations of the species, the ecology of C. clavipes was almost unstudied. Based on over 500 records collected by citizen scientists and deposited in the iNaturalist data base, we studied phenological activity of adult beetles, habitat preferences and impact of future climate change for both subspecies separately. The results clearly show that spp. clavipes and ssp. puniceus can be characterized by differences in phenology and macrohabitat preferences, and their ranges do not overlap at any point. Spp. clavipes is found as more opportunistic taxon occurring in different forests as well as in urban and agricultural areas with tree vegetation always in elevations below 500 m, while elevational distribution of ssp. puniceus covers areas up to 2300 m, and the beetle was observed mainly in forested areas. Moreover, we expect that climate warming will have negative influence on both subspecies with the possible loss of proper niches at level even up to 47-70% of their actual ranges during next few decades. As the species is actually recognized as unthreatened and always co-occurs with many other species, we suggest, because of its expected future habitat loss, to pay more attention to conservationists for possible negative changes in saproxylic insects and/or forest fauna in North America. In addition, as our results clearly show that both subspecies of C. clavipes differ ecologically, which strongly supports earlier significant morphological and physiological differences noted between them, we suggest that their taxonomical status should be verified by molecular data, because very probably they represent separate species.

• Klíčová slova
• Canada, Coleoptera, Cucujidae, North America, USA, citizen scientific data, habitat loss, iNaturalist, macrohabitat preferences, phenological activity,
• Publikační typ
• časopisecké články MeSH

Conservation of threatened animals is frequently limited by lack of knowledge about their ecological preferences, and often artificial feeding is one of the few chances to save endangered species. We investigated the possibility to artificially feed two endangered flat bark beetles dependent on dead wood for their diet-namely, Cucujus cinnaberinus (Scopoli, 1763) and Cucujus haematodes Erichson, 1845-by examining their dietary preferences, life cycle duration, and survival in laboratory conditions. Individuals of the two species were caught in the wild and larvae and adults were fed in laboratory conditions by live or dead prey. Three species of saproxylic beetles: two cerambycids (Acanthocinus griseus Fabricius, 1793 and Rhagium inquisitor Linnaeus, 1758), one scolytid (Ips sexdentatus Börner, 1776) one tenebrionid (Tenebrio molitor (Linnaeus, 1758)) one dipteran (Lucilia sericata (Meigen, 1826)) and one ant (Lasius sp. Fabricius, 1804) were used as prey, with minced meat as a control. Our results indicated high survival and no difference in prey choice between the two flat beetle species. Larvae and adults preferred dead prey, but no significant preference was detected among dead prey taxa, supporting the hypothesis that the two species are opportunistic scavengers. Comparing data with previous results, both species and their developmental stages should be classified as obligate saproxylic organisms with preference to the dead and decaying organic material. Successful artificial feeding and rearing of these endangered species, followed by the release in the wild through rescue or reintroduction programs, therefore appear relevant for their protection and future conservation.

• Klíčová slova
• Cucujus cinnaberinus, Cucujus haematodes, conservation, diet preference, life cycle,
• MeSH
• brouci růst a vývoj   MeSH
• dieta MeSH
• nutriční podpora * MeSH
• ohrožené druhy * MeSH
• stadia vývoje MeSH
• stravovací zvyklosti MeSH
• zachování přírodních zdrojů * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: The codling moth (Cydia pomonella) is a major insect pest of apples worldwide. Fully grown last instar larvae overwinter in diapause state. Their overwintering strategies and physiological principles of cold tolerance have been insufficiently studied. No elaborate analysis of overwintering physiology is available for European populations. PRINCIPAL FINDINGS: We observed that codling moth larvae of a Central European population prefer to overwinter in the microhabitat of litter layer near the base of trees. Reliance on extensive supercooling, or freeze-avoidance, appears as their major strategy for survival of the winter cold. The supercooling point decreases from approximately -15.3 °C during summer to -26.3 °C during winter. Seasonal extension of supercooling capacity is assisted by partial dehydration, increasing osmolality of body fluids, and the accumulation of a complex mixture of winter specific metabolites. Glycogen and glutamine reserves are depleted, while fructose, alanine and some other sugars, polyols and free amino acids are accumulated during winter. The concentrations of trehalose and proline remain high and relatively constant throughout the season, and may contribute to the stabilization of proteins and membranes at subzero temperatures. In addition to supercooling, overwintering larvae acquire considerable capacity to survive at subzero temperatures, down to -15 °C, even in partially frozen state. CONCLUSION: Our detailed laboratory analysis of cold tolerance, and whole-winter survival assays in semi-natural conditions, suggest that the average winter cold does not represent a major threat for codling moth populations. More than 83% of larvae survived over winter in the field and pupated in spring irrespective of the overwintering microhabitat (cold-exposed tree trunk or temperature-buffered litter layer).

• MeSH
• aminokyseliny metabolismus   MeSH
• analýza přežití MeSH
• energetický metabolismus MeSH
• fyziologická adaptace * MeSH
• glutamin metabolismus   MeSH
• glykogen metabolismus   MeSH
• hemolymfa metabolismus   MeSH
• larva metabolismus   MeSH
• metabolismus lipidů MeSH
• metabolismus sacharidů MeSH
• metabolom MeSH
• můry fyziologie   MeSH
• nízká teplota * MeSH
• osmolární koncentrace MeSH
• polymery metabolismus   MeSH
• roční období * MeSH
• tělesná hmotnost MeSH
• voda MeSH
• zmrazování MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aminokyseliny MeSH
• glutamin MeSH
• glykogen MeSH
• polymery MeSH
• polyol MeSH Prohlížeč
• voda MeSH

Among vertebrates, only a few species of amphibians and reptiles tolerate the formation of ice crystals in their body fluids. Freeze tolerance is much more widespread in invertebrates, especially in overwintering insects. Evolutionary adaptations for freeze tolerance are considered to be highly complex. Here we show that surprisingly simple laboratory manipulations can change the chill susceptible insect to the freeze tolerant one. Larvae of Drosophila melanogaster, a fruit fly of tropical origin with a weak innate capacity to tolerate mild chilling, can survive when approximately 50% of their body water freezes. To achieve this goal, synergy of two fundamental prerequisites is required: (i) shutdown of larval development by exposing larvae to low temperatures (dormancy) and (ii) incorporating the free amino acid proline in tissues by feeding larvae a proline-augmented diet (cryopreservation).

• MeSH
• biologická proměna MeSH
• dieta MeSH
• Drosophila melanogaster účinky léků   růst a vývoj   fyziologie   MeSH
• fyziologická adaptace MeSH
• kryoprotektivní látky farmakologie   MeSH
• krystalizace MeSH
• larva MeSH
• led MeSH
• prolin farmakologie   MeSH
• tělesná voda MeSH
• zmrazování * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kryoprotektivní látky MeSH
• led MeSH
• prolin MeSH

BACKGROUND: Drosophila melanogaster is a chill-susceptible insect. Previous studies on this fly focused on acute direct chilling injury during cold shock and showed that lower lethal temperature (LLT, approximately -5°C) exhibits relatively low plasticity and that acclimations, both rapid cold hardening (RCH) and long-term cold acclimation, shift the LLT by only a few degrees at the maximum. PRINCIPAL FINDINGS: We found that long-term cold acclimation considerably improved cold tolerance in fully grown third-instar larvae of D. melanogaster. A comparison of the larvae acclimated at constant 25°C with those acclimated at constant 15°C followed by constant 6°C for 2 d (15°C→6°C) showed that long-term cold acclimation extended the lethal time for 50% of the population (Lt(50)) during exposure to constant 0°C as much as 630-fold (from 0.137 h to 86.658 h). Such marked physiological plasticity in Lt(50) (in contrast to LLT) suggested that chronic indirect chilling injury at 0°C differs from that caused by cold shock. Long-term cold acclimation modified the metabolomic profiles of the larvae. Accumulations of proline (up to 17.7 mM) and trehalose (up to 36.5 mM) were the two most prominent responses. In addition, restructuring of the glycerophospholipid composition of biological membranes was observed. The relative proportion of glycerophosphoethanolamines (especially those with linoleic acid at the sn-2 position) increased at the expense of glycerophosphocholines. CONCLUSION: Third-instar larvae of D. melanogaster improved their cold tolerance in response to long-term cold acclimation and showed metabolic potential for the accumulation of proline and trehalose and for membrane restructuring.

• MeSH
• aklimatizace * MeSH
• aminokyseliny metabolismus   MeSH
• analýza přežití MeSH
• časové faktory MeSH
• Drosophila melanogaster metabolismus   fyziologie   MeSH
• larva metabolismus   fyziologie   MeSH
• mastné kyseliny metabolismus   MeSH
• metabolismus sacharidů MeSH
• metabolom * MeSH
• nízká teplota * škodlivé účinky   MeSH
• polymery metabolismus   MeSH
• zmrazování škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aminokyseliny MeSH
• mastné kyseliny MeSH
• polymery MeSH
• polyol MeSH Prohlížeč

The larva of the drosophilid fly, Chymomyza costata, is probably the most complex metazoan organism that can survive submergence in liquid nitrogen (-196 °C) in a fully hydrated state. We examined the associations between the physiological and biochemical parameters of differently acclimated larvae and their freeze tolerance. Entering diapause is an essential and sufficient prerequisite for attaining high levels of survival in liquid nitrogen (23% survival to adult stage), although cold acclimation further improves this capacity (62% survival). Profiling of 61 different metabolites identified proline as a prominent compound whose concentration increased from 20 to 147 mM during diapause transition and subsequent cold acclimation. This study provides direct evidence for the essential role of proline in high freeze tolerance. We increased the levels of proline in the larval tissues by feeding larvae proline-augmented diets and found that this simple treatment dramatically improved their freeze tolerance. Cell and tissue survival following exposure to liquid nitrogen was evident in proline-fed nondiapause larvae, and survival to adult stage increased from 0% to 36% in proline-fed diapause-destined larvae. A significant statistical correlation was found between the whole-body concentration of proline, either natural or artificial, and survival to the adult stage in liquid nitrogen for diapause larvae. Differential scanning calorimetry analysis suggested that high proline levels, in combination with a relatively low content of osmotically active water and freeze dehydration, increased the propensity of the remaining unfrozen water to undergo a glass-like transition (vitrification) and thus facilitated the prevention of cryoinjury.

• MeSH
• 1-pyrrolin-5-karboxylátdehydrogenasa nedostatek   MeSH
• aklimatizace účinky léků   MeSH
• analýza hlavních komponent MeSH
• analýza přežití MeSH
• dieta MeSH
• diferenciální skenovací kalorimetrie MeSH
• Drosophilidae účinky léků   fyziologie   MeSH
• dusík farmakologie   MeSH
• fyziologická adaptace účinky léků   MeSH
• kryoprezervace * MeSH
• larva účinky léků   fyziologie   MeSH
• osmóza účinky léků   MeSH
• prolin metabolismus   MeSH
• prolinoxidasa nedostatek   MeSH
• sklo MeSH
• stravovací zvyklosti účinky léků   MeSH
• tělesná voda účinky léků   MeSH
• vrozené poruchy metabolismu aminokyselin patofyziologie   veterinární   MeSH
• zmrazování MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1-pyrrolin-5-karboxylátdehydrogenasa MeSH
• dusík MeSH
• prolin MeSH
• prolinoxidasa MeSH