scholarly journals Thermal tolerance varies with dim‐light foraging and elevation in large carpenter bees (Hymenoptera: Apidae: Xylocopini)

2020 ◽  
Vol 45 (3) ◽  
pp. 688-696 ◽  
Author(s):  
Victor H. Gonzalez ◽  
John M. Hranitz ◽  
Catherine R. Percival ◽  
Kristen L. Pulley ◽  
Stephen T. Tapsak ◽  
...  
Keyword(s):  
Thermal Tolerance ◽  
Carpenter Bees ◽  
Dim Light ◽  
Light Foraging

scholarly journals Species and sex differences in eye morphometry and visual responsivity of two crepuscular sweat bee species (Megalopta spp., Hymenoptera: Halictidae)

2020 ◽  
Vol 130 (3) ◽  
pp. 533-544
Author(s):  
Beryl M Jones ◽  
Brett M Seymoure ◽  
Troy J Comi ◽  
Ellis R Loew
Keyword(s):  
Sympatric Species ◽  
Visual Sensitivity ◽  
Ecological Niches ◽  
Physiological Mechanisms ◽  
Light Levels ◽  
Morphological Adaptations ◽  
Dim Light ◽  
Future Work ◽  
Facet Size ◽  
Light Foraging

Abstract Visually dependent dim-light foraging has evolved repeatedly, broadening the ecological niches of some species. Many dim-light foraging lineages evolved from diurnal ancestors, requiring immense visual sensitivity increases to compensate for light levels a billion times dimmer than daylight. Some taxa, such as bees, are anatomically constrained by apposition compound eyes, which function well in daylight but not in starlight. Even with this constraint, the bee genus Megalopta has incredibly sensitive eyes, foraging in light levels up to nine orders of magnitude dimmer than diurnal relatives. Despite many behavioural studies, variation in visual sensitivity and eye morphometry has not been investigated within and across Megalopta species. Here we quantify external eye morphology (corneal area and facet size) for sympatric species of Megalopta, M. genalis and M. amoena, which forage during twilight. We use electroretinograms to show that males, despite being smaller than females, have equivalent visual sensitivity and increased retinal responsivity. Although males have relatively larger eyes compared with females, corneal area and facet size were not correlated with retinal responsivity, suggesting that males have additional non-morphological adaptations to increase retinal responsiveness. These findings provide the foundation for future work into the neural and physiological mechanisms that interface with morphology to influence visual sensitivity, with implications for understanding niche exploitation.

scholarly journals Body size limits dim-light foraging activity in stingless bees (Apidae: Meliponini)

2016 ◽  
Vol 202 (9-10) ◽  
pp. 643-655 ◽  
Author(s):  
Martin Streinzer ◽  
Werner Huber ◽  
Johannes Spaethe
Keyword(s):  
Body Size ◽  
Stingless Bees ◽  
Foraging Activity ◽  
Dim Light ◽  
Size Limits ◽  
Light Foraging

scholarly journals Photic niche invasions: phylogenetic history of the dim-light foraging augochlorine bees (Halictidae)

2011 ◽  
Vol 279 (1729) ◽  
pp. 794-803 ◽  
Author(s):  
Simon M. Tierney ◽  
Oris Sanjur ◽  
Grethel G. Grajales ◽  
Leandro M. Santos ◽  
Eldredge Bermingham ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Binding Pocket ◽  
Stabilizing Selection ◽  
Ancestral State ◽  
Geological Time ◽  
Visual Transduction ◽  
Morphological Specialization ◽  
History Of ◽  
Dim Light ◽  
Light Foraging

Most bees rely on flowering plants and hence are diurnal foragers. From this ancestral state, dim-light foraging in bees requires significant adaptations to a new photic environment. We used DNA sequences to evaluate the phylogenetic history of the most diverse clade of Apoidea that is adapted to dim-light environments (Augochlorini: Megalopta , Megaloptidia and Megommation ). The most speciose lineage, Megalopta , is distal to the remaining dim-light genera, and its closest diurnal relative ( Xenochlora ) is recovered as a lineage that has secondarily reverted to diurnal foraging. Tests for adaptive protein evolution indicate that long-wavelength opsin shows strong evidence of stabilizing selection, with no more than five codons (2%) under positive selection, depending on analytical procedure. In the branch leading to Megalopta , the amino acid of the single positively selected codon is conserved among ancestral Halictidae examined, and is homologous to codons known to influence molecular structure at the chromophore-binding pocket. Theoretically, such mutations can shift photopigment λ max sensitivity and enable visual transduction in alternate photic environments. Results are discussed in light of the available evidence on photopigment structure, morphological specialization and biogeographic distributions over geological time.

Replacement names for two small carpenter bees from India (Hymenoptera: Apidae, Ceratina)

2018 ◽  
Vol 154 (4) ◽  
pp. 296-298
Author(s):  
Michael S. Engel
Keyword(s):  
Carpenter Bee ◽  
Carpenter Bees ◽  
Small Carpenter Bee

Nomenclatorial corrections are provided for two cases of secondary homonymy within the small carpenter bee genus Ceratina Latreille (Apidae: Xylocopinae: Ceratinini). Images of female and male paratypes are included for Ceratina (Pithitis) apatela nom. nov. (formerly P. vechti Baker).

Disturbing Gtp-Binding Protein Function Through Microinjection Into The Visual Cell Of Limulus

1992 ◽  
Vol 47 (11-12) ◽  
pp. 915-921 ◽  
Author(s):  
Henmg Stieve ◽  
Barbara Niemeyer ◽  
Klaus Aktories ◽  
Heidi E. Hamm
Keyword(s):  
Monoclonal Antibody ◽  
G Protein ◽  
Protein Function ◽  
Clostridium Botulinum ◽  
Functional Role ◽  
Electrical Response ◽  
Visual Cell ◽  
Gtp Binding ◽  
Dim Light ◽  
Ventral Nerve Photoreceptor

We have tested the action of three agents microinjected into the ventral nerve photoreceptor of Limulus on the electrical response to dim light. 1. A monoclonal antibody (mAb 4 A) against the Gɑ subunit of frog transducin reduces the size of the receptor current to 60%, suggesting an interaction with Gɑ in the Limulus photoreceptor. 2. Injection of Clostridium botulinum ADPribosyltransferase C 3 reduces the size to 46%; latency is not affected. The results imply that small GTP-binding proteins play a functional role in photoreception of invertebrates. 3. Injection of GD P-β-S reduces dose-dependently the size of the receptor current to 15% and prolongs the latency to 200%, presumably by reducing number and rate of G-protein activations

scholarly journals Thermal Inactivation of Susceptible and Multiantimicrobial-Resistant Salmonella Strains Grown in the Absence or Presence of Glucose

2003 ◽  
Vol 69 (7) ◽  
pp. 4123-4128 ◽  
Author(s):  
R. T. Bacon ◽  
J. R. Ransom ◽  
J. N. Sofos ◽  
P. A. Kendall ◽  
K. E. Belk ◽  
...  
Keyword(s):  
Heat Stress ◽  
Protective Effect ◽  
Thermal Tolerance ◽  
Thermal Inactivation ◽  
Survival Curves ◽  
Acid Adaptation ◽  
Circulating Water ◽  
Glucose Levels ◽  
Study Results ◽  
Peptone Water

ABSTRACT The heat resistance of susceptible and multiantimicrobial-resistant Salmonella strains grown to stationary phase in glucose-free tryptic soy broth supplemented with 0.6% yeast extract (TSBYE−G; nonadapted), in regular (0.25% glucose) TSBYE, or in TSBYE−G with 1.00% added glucose (TSBYE+G; acid adapted) was determined at 55, 57, 59, and 61°C. Cultures were heated in sterile 0.1% buffered peptone water (50 μl) in heat-sealed capillary tubes immersed in a thermostatically controlled circulating-water bath. Decimal reduction times (D values) were calculated from survival curves having r 2 values of >0.90 as a means of comparing thermal tolerance among variables. D 59°C values increased (P < 0.05) from 0.50 to 0.58 to 0.66 min for TSBYE−G, TSBYE, and TSBYE+G cultures, respectively. D 61°C values of antimicrobial-susceptible Salmonella strains increased (P < 0.05) from 0.14 to 0.19 as the glucose concentration increased from 0.00 to 1.00%, respectively, while D 61°C values of multiantimicrobial-resistant Salmonella strains did not differ (P > 0.05) between TSBYE−G and TSBYE+G cultures. When averaged across glucose levels and temperatures, there were no differences (P > 0.05) between the D values of susceptible and multiantimicrobial-resistant inocula. Collectively, D values ranged from 4.23 to 5.39, 1.47 to 1.81, 0.50 to 0.66, and 0.16 to 0.20 min for Salmonella strains inactivated at 55, 57, 59, and 61°C, respectively. zD values were 1.20, 1.48, and 1.49°C for Salmonella strains grown in TSBYE+G, TSBYE, and TSBYE−G, respectively, while the corresponding activation energies of inactivation were 497, 493, and 494 kJ/mol. Study results suggested a cross-protective effect of acid adaptation on thermal inactivation but no association between antimicrobial susceptibility and the ability of salmonellae to survive heat stress.

Sign in / Sign up

Export Citation Format

Share Document