Task specialization in two social spiders, Stegodyphus sarasinorum
 (Eresidae) and Anelosimus eximius
 (Theridiidae)

Abstract Predators living in social groups often show consistent interindividual differences in prey capture behavior that may be linked to personality. Though personality predisposes individuals for certain behaviors, responses can also be influenced by context. Studies examining personality-dependent participation in prey capture have largely employed only one prey species, offering the predator no choice. In nature, predators encounter a range of prey species, therefore participation in or leading a prey capture event must also depend on prey attributes (e.g., size and risk). In the social spider Stegodyphus sarasinorum, collective prey capture is mediated by personality types as a consequence of which some individuals are consistently more likely to attack. Here, we examined if an individual’s consistency to attack persisted within and between the 2 prey species (honeybees and grasshoppers) and if the same individuals attacked first with both prey species. Our results showed that interindividual differences in attacking persisted within and between the 2 prey species. Spiders showed greater participation in attacking grasshoppers relative to bees. Identities of the first attackers were not the same for bees and grasshoppers. Spiders showed greater consistency over time in attacking bees relative to grasshoppers. Bees attracted fewer attackers than size-matched grasshoppers. These results suggest that greater task specialization may be necessary to successfully subdue bees. Spiders handled bees more cautiously, which is likely to explain the observed plasticity in attacking the 2 prey species. Thus, participation in prey capture in social spiders is influenced by the attributes of prey species.

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Polymorphism and division of labour in a socially complex ant: neuromodulation of aggression in the Australian weaver ant, Oecophylla smaragdina

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.0704 ◽

2015 ◽

Vol 282 (1811) ◽

pp. 20150704 ◽

Cited By ~ 27

Author(s):

J. Frances Kamhi ◽

Kelley Nunn ◽

Simon K. A. Robson ◽

James F. A. Traniello

Keyword(s):

Social Systems ◽

Division Of Labour ◽

Oecophylla Smaragdina ◽

Minor Worker ◽

Task Specialization ◽

Territorial Defence ◽

Weaver Ant ◽

Eusocial Insects ◽

Worker Size ◽

Pharmacological Manipulations

Complex social structure in eusocial insects can involve worker morphological and behavioural differentiation. Neuroanatomical variation may underscore worker division of labour, but the regulatory mechanisms of size-based task specialization in polymorphic species are unknown. The Australian weaver ant, Oecophylla smaragdina , exhibits worker polyphenism: larger major workers aggressively defend arboreal territories, whereas smaller minors nurse brood. Here, we demonstrate that octopamine (OA) modulates worker size-related aggression in O. smaragdina . We found that the brains of majors had significantly higher titres of OA than those of minors and that OA was positively and specifically correlated with the frequency of aggressive responses to non-nestmates, a key component of territorial defence. Pharmacological manipulations that effectively switched OA action in major and minor worker brains reversed levels of aggression characteristic of each worker size class. Results suggest that altering OA action is sufficient to produce differences in aggression characteristic of size-related social roles. Neuromodulators therefore may generate variation in responsiveness to task-related stimuli associated with worker size differentiation and collateral behavioural specializations, a significant component of division of labour in complex social systems.

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The Life-History of Badumna-Candida (Araneae, Amaurobioidea)

Australian Journal of Zoology ◽

10.1071/zo9930441 ◽

1993 ◽

Vol 41 (5) ◽

pp. 441 ◽

Cited By ~ 8

Author(s):

MF Downes

Keyword(s):

Sex Ratio ◽

Egg Production ◽

Production Cycle ◽

Social Spider ◽

Social Spiders ◽

Primary Sex Ratio ◽

The Social ◽

The Status ◽

History Of ◽

Changes Over Time

A two-year study of the social spider Badumna candida at Townsville, Queensland, provided information on colony size and changes over time, maturation synchrony, temperature effects on development, sex ratio, dispersal, colony foundation, fecundity and oviposition. Key findings were that B. candida outbred, had an iteroparous egg-production cycle between March and October, had an even primary sex ratio and achieved maturation synchrony by retarding the development of males, which matured faster than females at constant temperature. There was no overlap of generations, the cohort of young from a nest founded by a solitary female in summer dispersing the following summer as subadults (females) or subadults and adults (males). These findings confirm the status of B. candida as a periodic-social spider (an annual outbreeder), in contrast to the few known permanent-social spider species whose generations overlap. Cannibalism, normally rare in social spiders, rose to 48% when spiders were reared at a high temperature. This may be evidence that volatile recognition pheromones suppress predatory instincts in social spiders.

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Influence of prey availability on web-building in the social spider Stegodyphus sarasinorum (Araneae: Eresidae)

Journal of Arachnology ◽

10.1636/joa-s-19-080 ◽

2021 ◽

Vol 49 (1) ◽

Author(s):

Saroja Ellendula ◽

Carol Tresa ◽

Divya Uma

Keyword(s):

Prey Availability ◽

Social Spider ◽

The Social ◽

Web Building ◽

Stegodyphus Sarasinorum

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Collecting large datasets of rotational electron diffraction with ParallEM and SerialEM

10.1101/2020.06.01.128793 ◽

2020 ◽

Author(s):

Kiyofumi Takaba ◽

Saori Maki-Yonekura ◽

Koji Yonekura

Keyword(s):

Electron Diffraction ◽

Data Collection ◽

Large Scale ◽

General Purpose ◽

Task Specialization ◽

Camera Control ◽

Combined Use ◽

Electron Microscopes ◽

Diffraction Patterns ◽

Automated Protocol

AbstractA semi-automated protocol has been developed for rotational data collection of electron diffraction patterns by combined use of SerialEM and ParallEM, where SerialEM is used for positioning of sample crystals and ParallEM for rotational data collection. ParallEM calls standard camera control software through an AutoIt script, which adapts to software operational changes and to new GUI programs guiding other cameras. Development included periodic flashing and pausing of data collection during overnight or day-long recording with a cold field-emission beam. The protocol proved to be efficient and accurate in data collection of large-scale rotational series from two JEOL electron microscopes, a general-purpose JEM-2100 and a high-end CRYO ARM 300. Efficiency resulted from simpler steps and task specialization. It is possible to collect 12–20 rotational series from ∼ −68º to ∼ 68º at a rotation speed of 1º /s in one hour without human supervision.

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ENHANCED SPIDER ALGORITHM FOR MINIMIZATION OF REAL POWER LOSS

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v6.i4.2018.1665 ◽

2018 ◽

Vol 6 (4) ◽

pp. 301-311

Author(s):

K. Lenin

Keyword(s):

Power Loss ◽

Reactive Power ◽

High Quality ◽

Quality Performance ◽

Real Power ◽

Social Spiders ◽

The Real ◽

Spider Web ◽

Simulation Results ◽

Power Problem

In this paper Enhanced Spider (ES) algorithm is proposed to solve reactive power Problem. Enthused by the spiders, a new Enhanced Spider (ES) algorithm is utilized to solve reactive power problem. The composition is primarily based on the foraging approach of social spiders, which make use of of the vibrations spread over the spider web to choose the position of prey. The simulation results demonstrate high-quality performance of Enhanced Spider (ES) algorithm in solving reactive power problem. The projected Enhanced Spider (ES) algorithm has been tested in standard IEEE 57,118 bus systems and compared to other reported standard algorithms. Results show that Enhanced Spider (ES) algorithm is more efficient than other algorithms in reducing the real power loss.

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Social spiders and hybrid webs at Studio Tomás Saraceno

Cultural Geographies ◽

10.1177/1474474016647371 ◽

2016 ◽

Vol 24 (1) ◽

pp. 161-169 ◽

Cited By ~ 5

Author(s):

Sasha Engelmann

Keyword(s):

Specific Production ◽

Social Spiders ◽

Visual Material ◽

Social Encounter ◽

Species Specific

A spider’s web is the species-specific production of spacetime; it is an aesthetic as well as an evolutionary, metabolic and climatic achievement. As part of a long-term engagement with spiders and their webs, the artist Tomás Saraceno has collaborated with populations of spiders and other creatures to produce hybrid webs. The processual and patterned production of hybrid webs at Studio Tomás Saraceno inspires thought on the axes of more-than-human sympoeisis, on collaboration between and across multitudes of creatures, and on a spectrum of social and semi-social encounter between different species. Through interviews, storytelling, visual material and critical description, this paper develops a notion of hybrid webs as philosophical-aesthetic propositions for multispecies sociality.

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