Leaf-cutting ants’ critical and voluntary thermal limits show complex responses to size, heating rates, hydration level, and humidity

AbstractThermal variation has complex effects on organisms and they respond to these effects through combined behavioral and physiological mechanisms. However, it is less clear how these traits combine in response to changes in body condition (e.g., size, hydration) and environmental factors that surround the heating process (e.g., relative humidity, start temperatures, heating rates). We tested whether these body conditions and environmental factors influence sequentially measured Voluntary Thermal Maxima (VTmax) and Critical Thermal Maxima, (CTmax) in leaf-cutting ants (Atta sexdens rubropilosa, Forel, 1908). VTmax and CTmax reacted differently to changes in body size and relative humidity, but exhibited similar responses to hydration level, start temperature, and heating rate. Strikingly, the VTmax of average-sized workers was closer to their CTmax than the VTmax of their smaller and bigger sisters, suggesting foragers maintain normal behavior at higher temperatures than sister ants that usually perform tasks within the colony. Previous experiments based on hot plate designs might overestimate ants’ CTmax. VTmax and CTmax may respond concomitantly or not to temperature rises, depending on body condition and environmental factors.

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Integrative Responses of Leaf-Cutting Ants to Temperature Rises

10.1101/2020.08.04.236844 ◽

2020 ◽

Author(s):

Cleverson de Sousa Lima ◽

André Frazão Helene ◽

Agustín Camacho

Keyword(s):

Body Size ◽

Relative Humidity ◽

Thermal Tolerance ◽

Heating Rates ◽

Atta Sexdens ◽

Physiological Tolerance ◽

Labor Division ◽

Leaf Cutting ◽

Summary Statement ◽

Start Temperature

AbstractThermal variation has complex effects on organisms and they deal with it by combining behavioral and physiological thermal tolerance. However, we still do not understand well how these two types of traits relate to body condition (e.g. size, hydration) and environmental variables (e.g. relative humidity), some of which are typical aspects of thermal tolerance experiments (warming rates, start temperature). We explored these interactions using a set of experiments that sequentially measure behavioral (Voluntary Thermal Maxima) and physiological thermal tolerance (Critical Thermal Maxima) for individuals of Atta sexdens rubropilosa (Forel, 1908). We found non-linear effects of body size on behavioral thermal tolerance and refuted the traditional hypothesis that body size increases ant’s physiological thermal tolerance. Hydration state and humidity had complex effects on behavioral and physiological tolerance. However, both tolerance measures increased with heating rates and start temperature. Our work helps understanding how an ectotherm integrates stimuli affecting its thermal tolerance to decide which temperatures to avoid. We discuss implications for the ecology of ants, their labor division, and for their susceptibility to climate warming and drought.Summary StatementHere we show how internal (body size, hydration level) and external factors (heating rate, relative humidity) affect leaf-cutting ants behavioral and physiological responses to temperature rises.

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Queen influence on workers behavior of the leaf-cutting ant Atta sexdens rubropilosa (Forel, 1908)

Brazilian Journal of Biology ◽

10.1590/s1519-69842006000300016 ◽

2006 ◽

Vol 66 (2a) ◽

pp. 503-508 ◽

Cited By ~ 4

Author(s):

L. Sousa-Souto ◽

D. J. Souza

Keyword(s):

Environmental Factors ◽

Ant Colony ◽

Foraging Efficiency ◽

Atta Sexdens ◽

Initial Development ◽

Atta Sexdens Rubropilosa ◽

Cuticular Compounds ◽

Leaf Cutting

In an ant colony, the queen is the single reproducer and can interact with her workers via pheromones and cuticular compounds. However, in most species queen importance is not restricted to reproduction: in the initial development of the colony, her presence might play a more important role. In this work, we studied the effects of queen absence on workers behavior displayed in the foraging arena. Ant’s mortality and refuse accumulation was also measured daily. The results showed that queen absence did not alter either workers behavior or foraging efficiency. However, we observed increased ant mortality accompanied by a decrease in refuse dumping outside the nest. These results corroborate the hypothesis that environmental factors are more important than intrinsical factors in the allocation of external tasks. Probably, the queen could only influence internal activities of the colony.

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Antibiotic-producing bacteria associated with the nests of the leaf-cutting ant Atta sexdens rubropilosa

Planta Medica ◽

10.1055/s-0035-1556204 ◽

2015 ◽

Vol 81 (11) ◽

Author(s):

EA Silva-Junior ◽

CR Paludo ◽

FS Nascimento ◽

CR Currie ◽

J Clardy ◽

...

Keyword(s):

Atta Sexdens ◽

Atta Sexdens Rubropilosa ◽

Leaf Cutting

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Exposure Assessment of Airborne Bacteria Emitted from Swine Manure Composting Plant

Processes ◽

10.3390/pr9081283 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1283

Author(s):

Ki-Youn Kim

Keyword(s):

Relative Humidity ◽

Environmental Factors ◽

Swine Manure ◽

Airborne Bacteria ◽

Particulate Matters ◽

Distribution Characteristics ◽

E Coli ◽

Enterococcus Spp ◽

Staphylococcus Spp ◽

Rotary Type

This study was performed to investigate the distribution characteristics of airborne bacteria emitted from swine manure composting plants. The types of swine manure composting plants selected for the survey in this study were as follows: screw type, rotary type, and natural dry type. Mean levels of airborne bacteria in swine manure composting plants were 7428 (±1024) CFU m−3 for the screw type, 3246 (±1407) CFU m−3 for the rotary type, and 5232 (±1217) CFU m−3 for the natural dry type, respectively. Based on the results obtained from this study, the swine manure composting plant operated by screw type showed the highest concentration of airborne bacteria, followed by the natural dry type and rotary type. The monthly concentration of airborne bacteria was the highest in August and the lowest in November, regardless of the type of swine manure composting plant. The respirable size of airborne bacteria accounted for about 50% of the total. The ratio of respirable to the total quantity of airborne bacteria was 50%. The correlation relationships between airborne bacteria and environmental factors (temperature, relative humidity, particulate matters, and odor) were not found to be significant in the swine manure composting plants. The predominant genera of airborne bacteria identified were Micrococcus spp., Staphylococcus spp., Escherichia(E-coli) spp., Enterococcus spp., and Enterobacteriaceae spp.

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Sympodiomyces attinorum sp. nov., a yeast species associated with nests of the leaf-cutting ant Atta sexdens

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijs.0.63200-0 ◽

2004 ◽

Vol 54 (5) ◽

pp. 1891-1894 ◽

Cited By ~ 27

Author(s):

Solange C. Carreiro ◽

Fernando C. Pagnocca ◽

Maurício Bacci ◽

Marc-André Lachance ◽

Odair C. Bueno ◽

...

Keyword(s):

Yeast Species ◽

Novel Species ◽

Large Subunit ◽

Growth Characteristics ◽

Rrna Gene ◽

The Novel ◽

Atta Sexdens ◽

Leaf Cutting ◽

Large Subunit Rrna ◽

Waste Deposit

Four strains of a novel yeast species were isolated from laboratory nests of the leaf-cutting ant Atta sexdens in Brazil. Three strains were found in older sponges and one was in a waste deposit in the ant nests. Sequencing of the D1/D2 region of the large-subunit rRNA gene showed that the novel species, named Sympodiomyces attinorum sp. nov., is phylogenetically related to Sympodiomyces parvus. Unlike Sympodiomyces parvus, Sympodiomyces attinorum can ferment glucose, assimilate methyl α-d-glucoside, salicin and citrate, and grow at 37 °C, thus enabling these two species to be distinguished. Differentiation from other related species is possible on the basis of other growth characteristics. The type strain of Sympodiomyces attinorum is UNESP-S156T (=CBS 9734T=NRRL Y-27639T).

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EFFECTS OF ENVIRONMENT ON GROWING HYDROPONICS MAIZE FODDER USING LOW-COST GREENHOUSE CULTIVATING UNIT FOR LIVESTOCK PRODUCTION.

10.36106/ijsr/0431788 ◽

2021 ◽

pp. 71-72

Author(s):

Adamu, B. ◽

Abdullahi, S. ◽

Saidu, S. G ◽

Yustus Sunday Francis

Keyword(s):

Relative Humidity ◽

Environmental Factors ◽

Production System ◽

Low Cost ◽

Factors Affecting ◽

Production Water ◽

Fodder Production ◽

Food Requirement ◽

Greenhouse Cultivation ◽

Near Future

The term 'Hydroponics' was derived from Greek words 'hydro' means water and 'ponics' means labor. Hydroponic is a modern agricultural technique that uses nutrient solution rather than soil solution for fodder production. As population increases the food demand also increased, the existing system of agriculture will not be able to meet the food requirement in the near future due to environmental challenges in the industry. The major environmental factors affecting the hydroponics production system are; Temperature, relative humidity, and light. The objectives of this studies are to examine the hydroponics greenhouse technologies, impact of environmental factors on hydroponics greenhouse cultivation and challenges of growing on hydroponics greenhouse system. This study revealed that hydroponics greenhouse cultivation is a better option for improved fodder production, water utilization, palatability and digestibility.

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Droplet and Aerosol Suspension Times in Ambient Air in Confined Spaces and Transmission of COVID-19: Influence of Environmental Factors

Journal of Scientific Research ◽

10.3329/jsr.v13i2.50273 ◽

2021 ◽

Vol 13 (2) ◽

pp. 495-506

Author(s):

M. R. Islam ◽

S. H. Naqib

Keyword(s):

Relative Humidity ◽

Environmental Factors ◽

Ambient Air ◽

Confined Space ◽

Natural Processes ◽

Confined Spaces ◽

Potential Source ◽

Aerosol Droplet ◽

Exhaled Air ◽

Mode Of Transmission

The COVID‑19 pandemic, alternatively known as the coronavirus pandemic, is an unfolding pandemic of coronavirus disease 2019 (COVID‑19) across the entire globe in an unprecedented proportion. COVID-19 is caused by severe acute respiratory syndrome coronavirus 2. The mode of transmission of COVID-19 is a subject of intense research. The airborne transmission is one prime possibility. Breathing and talking are natural processes which generate exhaled particles. The exhaled air is an aerosol/droplet composed of naturally produced particulates of varying size. The duration over which the aerosols/droplets are suspended in the air is an important factor. Long suspended aerosols/droplets are potential source of transmission, particularly in confined spaces. We have calculated times of suspension by considering various environmental factors, namely, the ambient temperature and relative humidity in a confined space, in this work. Both temperature and relative humidity affect the suspension time of the exhaled aerosols/droplets with varying degree. The effects of environmental factors are significant for aerosols, particularly for those with small radii. We have discussed the possible implications of our findings in this paper.

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Distribution of Atta (Hymenoptera - Formicidae) in "terra-firme" rain forest of Central Amazonia: density, species composition and preliminary results on effects of forest fragmentation

Acta Amazonica ◽

10.1590/1809-43921988183315 ◽

1988 ◽

Vol 18 (3-4) ◽

pp. 309-315 ◽

Cited By ~ 14

Author(s):

Heraldo Luís de Vasconcelos

Keyword(s):

Species Composition ◽

Rain Forest ◽

Abundant Species ◽

Forest Fragments ◽

Forest Fragment ◽

Terra Firme ◽

Atta Sexdens ◽

Conservation Areas ◽

Continuous Forest ◽

Leaf Cutting

One hundred and fourteen hectares of a "terra-fiirme" rain forest 70 km north of Manaus, Amazonas, Brazil, were surveyed for leaf-cutting ant colonies (Atta spp). One half of this area was in isolated forest fragments (surrounded by pastures or second growth) of two sizes: 1 and 10 ha. The other half was in non-isolated fragments (connected to a large parch of forest) of the same sizes. Only two species occured in this forest: Atta sexdens sexdens L. and A. cepfhalotes L. The first was the most abundant species with a mean density of 0.35 colonies per ha. The mean density of A. cephalotes colonies was 0.03 per ha. The density of colonies was not significantly different between the isolated fragments and the continuous forest. Furthermore, the species composition did not change with isolation. However, pre-isolation data and long term monitoring are necessary to conclude that the isolation of a forest fragment has no effect upon Atta colonies. The non-uniform spatial distribution of Atta colonics within the "terra-firme" forest must be taken into account when selecting conservation areas in the Amazon, in order to preserve this important group of ants together with their native habitat.

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BIOLOGICAL CONTROL IN LEAF-CUTTING ANTS, Atta sexdens (HYMENOPTERA: FORMICIDAE), USING PATHOGENIC FUNGI

Revista Árvore ◽

10.1590/1806-908820210000016 ◽

2021 ◽

Vol 45 ◽

Author(s):

Tarcísio Marcos Macedo Mota Filho ◽

Luis Eduardo Pontes Stefanelli ◽

Roberto da Silva Camargo ◽

Carlos Alberto Oliveira de Matos ◽

Luiz Carlos Forti

Keyword(s):

Biological Control ◽

Chemical Control ◽

Pathogenic Fungi ◽

Behavioral Changes ◽

The Other ◽

Fungus Garden ◽

Atta Sexdens ◽

Main Method ◽

New Methods ◽

Leaf Cutting

ABSTRACT Chemical control using toxic baits containing the active ingredient sulfluramid at 0.3% (w/w) is the main method for controlling leaf-cutting ants of the genera Atta and Acromyrmex. However, since 2009, when sulfluramid was included in Annex B of the Stockholm Convention on Persistent Organic Pollutants, there has been an intense search for new methods that are efficient in controlling these insects. Among said new methods, biological control using pathogenic fungi has shown promising results in laboratory conditions. The objective of this study, given the context presented, was to assess the potential of the fungi Beauveria bassiana and Trichoderma harzianum in controlling Atta sexdens. Colonies of A. sexdens were exposed to the fungi by means of formulated baits provided in a foraging chamber, or of suspensions sprayed on the fungus garden, and had their behavioral changes recorded for 21 days. For both formulations, concentrations of 10 and 20% (w/w) of the fungi being studied were used. The results allowed concluding that baits containing 10 and 20% (w/w) of the fungi B. bassiana and T. harzianum were not efficient in controlling colonies of A sexdens. On the other hand, spraying suspensions of 20% (w/w) of B. bassiana and 10% and 20% (w/w) of T. harzianum was efficient and resulted in 100% mortality of the colonies 11, 9 and 7 days after application, respectively. These findings indicate that the fungi B. bassiana and T. harzianum are promising as agents for the control of A. sexdens colonies, when sprayed on the fungus garden, although there are still some challenges as to their use related to the development of technologies for the application of the pathogen.

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Environmental Factors Affecting the Diversity and Photosynthetic Pigments of Trentepohlia Species in Northern Thailand’s Chiang Dao Wildlife Sanctuary

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.8912 ◽

2020 ◽

Vol 89 (1) ◽

Author(s):

Santi Saraphol ◽

Srunya Vajrodaya ◽

Ekaphan Kraichak ◽

Anchalee Sirikhachornkit ◽

Nuttha Sanevas

Keyword(s):

Relative Humidity ◽

Environmental Factors ◽

Photosynthetic Pigments ◽

Dominant Species ◽

Winter Season ◽

Morphological Identification ◽

Wildlife Sanctuary ◽

Total Carotenoids ◽

Carotene Content ◽

Factors Affecting

This study addressed the environmental factors that affect Trentepohlia spp. in the Chiang Dao Wildlife Sanctuary at altitudes of 399 to 1,503 meters above sea level (m a.s.l.) during the rainy, winter, and summer seasons. Species were identified using characteristic morphological identification. The influence of environmental factors on the algae was analyzed using a statistical program, and seasonal changes in the quantity of photosynthetic pigments in the dominant species were evaluated. The average relative humidity was 69.34 ± 12.90%, the average temperature was 26.23 ± 3.79 °C, and the average light intensity was 139.78 ± 42.21 µmol photon m−2 s−1. Thirteen species were found: Trentepohlia chapmanii, Trentepohlia sp. 1, Trentepohlia sp. 2, Trentepohlia sundarbanensis, Trentepohlia sp. 3, Trentepohlia rigidula, Trentepohlia sp. 4, Trentepohlia effusa, Trentepohlia monilia, Trentepohlia abietina, Trentepohlia sp. 5, Trentepohlia aurea, and Trentepohlia umbrina. The largest number of species (seven to nine) were found at lower altitudes, from 473 to 517 m a.s.l. Species diversity was greatest in the winter season (13 species). Species found at low attitude were grouped together (Group 1) and had the greatest diversity, and the remaining species were divided into Groups 2, 3, and 4. Environmental factors had both positive and negative influences on the species, especially T. chapmanii, which was found below 1,003 m a.s.l., and T. monilia, which was found in areas with a high relative humidity of 74.50% to 83.93%. The ratio of the total carotenoids to chlorophyll of T. rigidula, the dominant species, was relatively high at 4.96:1, and the β-carotene content (46.89 %w/w) was highest during winter.

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