02162nas a2200241 4500008004100000245012300041210006900164300001400233490000800247520145500255653001401710653001501724653001201739653002101751653001201772653001501784653001101799100001501810700001501825700001401840700001701854856004901871 2017 eng d00aFlexible responses to visual and olfactory stimuli by foraging Manduca sexta: larval nutrition affects adult behaviour0 aFlexible responses to visual and olfactory stimuli by foraging M a2739-27450 v2763 a

"Here, we show that the consequences of deficient micronutrient (β-carotene) intake during larval stages of Manduca sexta are carried across metamorphosis, affecting adult behaviour. Our manipulation of larval diet allowed us to examine how developmental plasticity impacts the interplay between visual and olfactory inputs on adult foraging behaviour. Larvae of M. sexta were reared on natural (Nicotiana tabacum) and artificial laboratory diets containing different concentrations of β-carotene (standard diet, low β-carotene, high β-carotene and cornmeal). This vitamin-A precursor has been shown to be crucial for photoreception sensitivity in the retina of M. sexta. After completing development, post-metamorphosis, starved adults were presented with artificial feeders that could be either scented or unscented. Regardless of their larval diet, adult moths fed with relatively high probabilities on scented feeders. When feeders were unscented, moths reared on tobacco were more responsive than moths reared on β-carotene-deficient artificial diets. Strikingly, moths reared on artificial diets supplemented with increasing amounts of β-carotene (low β and high β) showed increasing probabilities of response to scentless feeders. We discuss these results in relationship to the use of complex, multi-modal sensory information by foraging animals."

10aBEHAVIOUR10aCAROTENOID10aECOLOGY10aLARVAL NUTRITION10aMANDUCA10aSPHINGIDAE10aVISION1 aGoyret, J.1 aKelber, A.1 aPfaff, M.1 aRaguso, R.A. uhttps://sphingidae.myspecies.info/node/2289802528nas a2200349 4500008004100000245007900041210006900120300001300189490000800202520164900210653001101859653001401870653001001884653000901894653001301903653001501916653001201931653001301943653001001956653001201966653001501978653001501993653001402008653001502022100001602037700001802053700001602071700001602087700001602103700001702119856004202136 2023 eng d00aHaemolymph viscosity in hawkmoths and its implications for hovering flight0 aHaemolymph viscosity in hawkmoths and its implications for hover a202221850 v2903 a

"Viscosity determines the resistance of haemolymph flow through the insect body. For flying insects, viscosity is a major physiological parameter limiting flight performance by controlling the flow rate of fuel to the flight muscles, circulating nutrients and rapidly removing metabolic waste products. The more viscous the haemolymph, the greater the metabolic energy needed to pump it through confined spaces. By employing magnetic rotational spectroscopy with nickel nanorods, we showed that viscosity of haemolymph in resting hawkmoths (Sphingidae) depends on wing size non-monotonically. Viscosity increases for small hawkmoths with high wingbeat frequencies, reaches a maximum for middle-sized hawkmoths with moderate wingbeat frequencies, and decreases in large hawkmoths with slower wingbeat frequencies but greater lift. Accordingly, hawkmoths with small and large wings have viscosities approaching that of water, whereas hawkmoths with mid-sized wings have more than twofold greater viscosity. The metabolic demands of flight correlate with significant changes in circulatory strategies via modulation of haemolymph viscosity. Thus, the evolution of hovering flight would require fine-tuned viscosity adjustments to balance the need for the haemolymph to carry more fuel to the flight muscles while decreasing the viscous dissipation associated with its circulation."

10aAGRIUS10aCERATOMIA10aDOLBA10aENYO10aEUMORPHA10aHAEMOLYMPH10aHEMARIS10aHOVERING10aHYLES10aMANDUCA10aPHYSIOLOGY10aSPHINGIDAE10aVISCOSITY10aXYLOPHANES1 aBrasovs, A.1 aPalaoro, A.V.1 aAprelev, P.1 aBeard, C.E.1 aAdler, P.H.1 aKornev, K.G. uhttps://doi.org/10.1098/rspb.2022.21802238nas a2200265 4500008004100000245010400041210006900145260001200214300001300226490000800239520148400247653001501731653001201746653001701758653001201775653002101787653001501808653001501823653001101838653002201849100001801871700002001889700001801909856004501927 2017 eng d00aHigher-order neural processing tunes motion neurons to visual ecology in three species of hawkmoths0 aHigherorder neural processing tunes motion neurons to visual eco c06/2017 a201708800 v2843 a

"To sample information optimally, sensory systems must adapt to the ecological demands of each animal species. These adaptations can occur peripherally, in the anatomical structures of sensory organs and their receptors; and centrally, as higher-order neural processing in the brain. While a rich body of investigations has focused on peripheral adaptations, our understanding is sparse when it comes to central mechanisms. We quantified how peripheral adaptations in the eyes, and central adaptations in the wide-field motion vision system, set the trade-off between resolution and sensitivity in three species of hawkmoths active at very different light levels: nocturnal Deilephila elpenor, crepuscular Manduca sexta, and diurnal Macroglossum stellatarum. Using optical measurements and physiological recordings from the photoreceptors and wide-field motion neurons in the lobula complex, we demonstrate that all three species use spatial and temporal summation to improve visual performance in dim light. The diurnal Macroglossum relies least on summation, but can only see at brighter intensities. Manduca, with large sensitive eyes, relies less on neural summation than the smaller eyed Deilephila, but both species attain similar visual performance at nocturnal light levels. Our results reveal howthe visual systems of these three hawkmoth species are intimately matched to their visual ecologies."

10aDEILEPHILA10aECOLOGY10aMACROGLOSSUM10aMANDUCA10aNEURAL SUMMATION10aPHYSIOLOGY10aSPHINGIDAE10aVISION10aVISUAL PROCESSING1 aStöckl, A.L.1 aO'Carroll, D.C.1 aWarrant, E.J. uhttp://dx.doi.org/10.1098/rspb.2017.088002238nas a2200265 4500008004100000245005200041210005100093300001200144490000800156520154900164653001501713653001501728653001301743653001201756653001701768653001501785653001501800653001101815653001801826653002201844100001901866700001801885700002001903856004901923 2010 eng d00aWide-field motion tuning in nocturnal hawkmoths0 aWidefield motion tuning in nocturnal hawkmoths a853-8600 v2773 a

"Nocturnal hawkmoths are known for impressive visually guided behaviours in dim light, such as hovering while feeding from nectar-bearing flowers. This  requires tight visual feedback to estimate and counter relative motion. Discrimination of low velocities, as required for stable hovering flight, is fundamentally limited by spatial resolution, yet in the evolution of eyes for nocturnal vision, maintenance of high spatial acuity compromises absolute sensitivity. To investigate these trade-offs, we compared responses of wide-field motion-sensitive neurons in three species of hawkmoth: Manduca sexta (a crepuscular hoverer), Deilephila elpenor (a fully nocturnal hoverer) and Acherontia atropos (a fully nocturnal hawkmoth that does not hover as it feeds uniquely from honey in bees’  nests). We show that despite smaller eyes, the motion pathway of D. elpenor is tuned to higher spatial frequencies and lower temporal frequencies than A. atropos, consistent with D. elpenor’s need to detect low velocities for hovering. Acherontia atropos, however, presumably evolved low-light sensitivity without sacrificing temporal acuity. Manduca sexta, active at higher light levels, is tuned to the highest spatial frequencies of the three and temporal frequencies comparable with A. atropos. This yields similar tuning to low velocities as in D. elpenor, but with the advantage of shorter neural delays in processing motion."

10aACHERONTIA10aDEILEPHILA10aHOVERING10aMANDUCA10aNIGHT VISION10aPHYSIOLOGY10aSPHINGIDAE10aVISION10aVISUAL ACUITY10aVISUAL PROCESSING1 aTheobald, J.C.1 aWarrant, E.J.1 aO'Carroll, D.C. uhttps://sphingidae.myspecies.info/node/21483