Prey Availability Increases Less Quickly Than Nest Size in the Social Spider Stegodyphus Mimosarum

Aspects of the biology of the social spider Phryganoponrs candidus (=Badumna candida) (L. Koch) in relation to its life history are described, based on data from a field and laboratory study conducted over several years at Townsville, Queensland. Host plant records and preferences are given, and an analysis made of the effects of nest height and ecotone proximity on nest occurrence. Founded between October and February as a chambered silk funnel by a solitary subadult female, the nest was enlarged by the female and her progeny into a complex retreat area and an outlying prey-trapping area. The architecture of the retreat was not an aggregation of repeated subunits. Closely adjacent nests sometimes united their prey-capture webbing to form compound nests. From a tagged sample of new-founded nests, 31% reached a stage at which thriving spiderlings were present. Numbers of spiders in nests ranged from 9 to 224 and correlated with nest size, which ranged from 70 to more than 20 000 cm(2). At the peak of nest growth in October, the stage at which subadult spiders began to disperse, about 90 spiders inhabited each nest; only 12% of new-founded nests reached this stage. Summer dispersal left nests empty; they degenerated under rain and became moribund by March. The main host plants were Zizyphus mauritiana (the chinee apple) and Dolichondrone heterophylla. Most nests occurred between 0.5 and 2.5 m from the ground but height did not influence nest success. Nests were prevalent at ecotones, although they did not thrive better there. Because so much of the social biology of spiders is integrated with the structure and function of their nests, these findings are relevant to an understanding of the evolution of sociality in spiders.

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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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DNA Methylation Patterns in the Social Spider, Stegodyphus dumicola

Genes ◽

10.3390/genes10020137 ◽

2019 ◽

Vol 10 (2) ◽

pp. 137 ◽

Cited By ~ 16

Author(s):

Shenglin Liu ◽

Anne Aagaard ◽

Jesper Bechsgaard ◽

Trine Bilde

Keyword(s):

Gene Expression ◽

Dna Methylation ◽

Sequence Data ◽

Social Spider ◽

The Social ◽

Genome Bisulfite Sequencing ◽

Differential Gene ◽

Methylation Patterns ◽

Comparative Phylogenetic Analysis

Variation in DNA methylation patterns among genes, individuals, and populations appears to be highly variable among taxa, but our understanding of the functional significance of this variation is still incomplete. We here present the first whole genome bisulfite sequencing of a chelicerate species, the social spider Stegodyphus dumicola. We show that DNA methylation occurs mainly in CpG context and is concentrated in genes. This is a pattern also documented in other invertebrates. We present RNA sequence data to investigate the role of DNA methylation in gene regulation and show that, within individuals, methylated genes are more expressed than genes that are not methylated and that methylated genes are more stably expressed across individuals than unmethylated genes. Although no causal association is shown, this lends support for the implication of DNA CpG methylation in regulating gene expression in invertebrates. Differential DNA methylation between populations showed a small but significant correlation with differential gene expression. This is consistent with a possible role of DNA methylation in local adaptation. Based on indirect inference of the presence and pattern of DNA methylation in chelicerate species whose genomes have been sequenced, we performed a comparative phylogenetic analysis. We found strong evidence for exon DNA methylation in the horseshoe crab Limulus polyphemus and in all spider and scorpion species, while most Parasitiformes and Acariformes species seem to have lost DNA methylation.

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