02299nas a2200217   4500008004100000020001400041245015800055210006900213260001100282300001400293490000700307520151000314653002001824100001501844700001601859700001701875700001801892700002201910700001401932856013501946       2011                        eng d  a0022-191000aPhysiological and biochemical analysis of overwintering and cold tolerance in two Central European populations of the spruce bark beetle, Ips typographus0 aPhysiological and biochemical analysis of overwintering and cold  cAugust  a1136-11460 v573 aOverwintering success is one of the key aspects affecting the development and outbreaks of the spruce bark beetle, Ips typographus (L.) populations. This paper brings detailed analysis of cold tolerance, and its influence on overwintering success, in two Central European populations of I. typographus during two cold seasons. Evidence for a supercooling strategy in overwintering adults is provided. The lower lethal temperature corresponds well to the supercooling point that ranges between -20 and -22 [degree]C during winter months. The supercooled state is stabilized by the absence of internal ice nucleators and by seasonal accumulation of a mixture of sugars and polyols up to the sum concentration of 900 mM. The cryoprotective function of accumulated metabolites is probably based on increasing the osmolality and viscosity of supercooled body fluids and decreasing the relative proportion of water molecules available for lethal formation of ice nuclei. No activity of thermal hysteresis factors (stabilizers of supercooled state) was detected in hemolymph. Lethal times for 50% mortality (Lts50) in the supercooled state at -5, -10 or -15 [degree]C are weeks (autumn, spring) or even months (winter), suggesting relatively little mortality caused by chill injury. Lts50 at -15 [degree]C are significantly shorter in moist (6.9 days) than in dry (>42 days) microenvironment because there is higher probability of external ice nucleation and occurrence of lethal freezing in the moist situation.10aIps typographus1 aKostal, V.1 aDolezal, P.1 aRozsypal, J.1 aMoravcova, M.1 aZahradnickova, H.1 aSimek, P.  uhttps://weevil.myspecies.info/physiological-and-biochemical-analysis-overwintering-and-cold-tolerance-two-central-european-populat00951nas a2200169   4500008004100000020001400041245007000055210006800125260001000193300001200203490000800215520042300223653002000646100001600666700001500682856008400697       2007                        eng d  a0931-204800aA simple method for the detection of imaginal diapause in beetles0 asimple method for the detection of imaginal diapause in beetles  cApril  a221-2230 v1313 aInvestigations on Ips typographus and Leptinotarsa decemlineata revealed that the activity of mitochondrial enzymes in the flight muscles provides a reliable criterion for the discrimination of diapausing and non-diapausing adults. Enzyme activity is conveniently detected in situ with commercially available tetrazolium salts. Staining intensity is correlated with the flight ability and often also with reproduction.10aIps typographus1 aDolezal, P.1 aSehnal, F.  uhttps://weevil.myspecies.info/simple-method-detection-imaginal-diapause-beetles02443nas a2200169   4500008004100000020001400041245011000055210006900165260001000234300001200244490000800256520183500264653002002099100001602119700001502135856012302150       2007                        eng d  a0931-204800aEffects of photoperiod and temperature on the development and diapause of the bark beetle Ips typographus0 aEffects of photoperiod and temperature on the development and di  cApril  a165-1730 v1313 aDiapause was induced in a Central European population of Ips typographus grown at 20 [degree]C when the day length decreased below 16 h (50% diapause incidence occurred in the 14.7:9.3 h L:D (light: dark) regime). The nondiapausing adults fed on days 2-6 and 10-14 after the ecdysis and swarmed after the second feeding bout with chorionated eggs in the ovaries and sperm in the spermiducts. Neither gonads nor the flight muscles matured and no swarming occurred in the diapausing adults. The development from egg to adult took about 34 days in both 18:6 h (no diapause) and 12:12 h L: D (diapause) regimes, but it was extended by up to 30% without diapause induction when only larvae or pupae were exposed to L: D 12:12 h. Diapause was induced in insects reared at L: D 12:12 h through the last larval and the pupal instars and/or in the adult stage. Temperature 23 [degree]C prevented diapause induction at L:D 12:12 h but diapause occurred at L: D 14:10 h associated with 26:6 [degree]C thermoperiod. The effect of thermoperiods on the developmental rate requires further research. Exposure of the non-diapausing adults to 5 [degree]C for several days blocked feeding and evoked a diapause- like state, whereas diapausing adults fed and their gonads slowly developed at this temperature. Diapausing adults exposed in forest to low night temperatures and transferred in October to 20 [degree]C readily reproduced at 18:6, but not 12:12 h L: D photoperiods. After 2-months at 5 [degree]C and darkness, they became insensitive to the photoperiod, matured and most of them also swarmed at 20 [degree]C in the 12:12 h L:D regime. In a Scandinavian population, diapause occurred at 18:6 h L:D and was terminated either by exposure to 5 [degree]C or by very long photoperiod (L: D 20:4 h) combined with high temperature (23 [degree]C)10aIps typographus1 aDolezal, P.1 aSehnal, F.  uhttps://weevil.myspecies.info/effects-photoperiod-and-temperature-development-and-diapause-bark-beetle-ips-typographus