Measuring the silk footprint of embiids (Embioptera): Does one size fit all?

Embiids spin silk, produced in glands in their foretarsi, to protect themselves and their offspring from biotic and abiotic threats, such as natural enemies and heavy rain respectively. They spin by pressing their spinnerets against the substratum, then pulling back as silk issues forth. They live across a variety of habitats, from tropical to Mediterranean. Despite the variation in habitats, adult females show little morphological diversity across taxonomic families and environments. The purpose of this study was to determine if differences in silk-spinning behavior have arisen in response to varying ecological pressures. If specific behaviors are symptomatic of the insects’ ecological pressures, than embiids living in exposed conditions (as is characteristic of arboreal lifestyles) should invest more in silk production than those residing in concealed microhabitats, such as leaf litter or subterranean burrows. Behavioral diversity was quantified by filming individuals as they spun and scoring their propensity to spin silk, spinning choreography, and attributes of the silk product. Multivariate statistical techniques were used to identify possible behavioral syndromes and to determine if ecological factors correlate with characteristics that emerge within species-specific spinning patterns. Preliminary results support the hypothesis that exposure and habitat select for particular spinning behavioral syndromes. In addition, phylogeny explains some of the variability in the choreography of spinning.