Photoreceptor physiology of two species of crab spiders (Araneae: Thomisidae)

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  Photoreceptor physiology of two species of crab spiders (Araneae: Thomisidae) Abstract Spiders are a diverse order of predatory arachnids with more than 53.000 described species, most of which have eight eyes. Many webless hunting spiders, most noticeably the jumping spiders (Salticidae) have been shown to have excellent eyes with high spatial resolution and colour vision. The family of crab spiders (Thomisidae) is also hypothesized to be visual hunters, employing a “sit and wait” or ambush hunting technique; however, little is currently known about their visual capacity. Here we use extracellular electrophysiology to examine the photoreceptor physiology of two crab spiders living in two different ecological niches.  Ozyptila praticola  (C.L. Koch, 1837) hunts on the ground in dim habitats whereas  Xysticus cristatus  (Clerck, 1757) hunts in the typical bright open grasslands. We test the hypotheses that (1) each species has special-purpose eyes, (2) that male...

Fatal Attraction: Argiope Spiders Lure Male Hemileuca Moth Prey with the Promise of Sex

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Fatal Attraction: Argiope Spiders Lure Male Hemileuca Moth Prey with the Promise of Sex

Abstract

Predator–prey coevolution, particularly chemo-ecological arms races, is challenging to study as it requires the integration of behavioral, chemical ecology, and phylogenetic studies in an amenable system. Moths of the genus Hemileuca (Saturniidae) are colorful, diurnal, and fast and often fly well above the vegetation canopy layer. However, several Hemileuca species have been reported as being captured in spider webs, specifically Argiope species (Araneidae). Female Hemileuca are known to produce mating pheromones and spiders of the Araneidae family are known to use pheromone lures to attract lepidopteran prey. We presented primarily female Argiope aurantia, which are attractive to male Anisota pellucida (Saturniidae), to different populations of Hemileuca species across the southern and western United States to categorize the homing response strength of different species of male Hemileuca. When we mapped these Argiope lure attraction strength categories onto the most recently published Hemileuca phylogeny, the behavioral patterns suggested a potential co-evolutionary arms race between predators and prey. Males of Hemileuca maia, H. grotei, and H. nevadensis (all in the same clade) appeared to have no attraction to A. aurantia, while H. magnifica and H. hera (within a different, separate clade) appeared to be strongly attracted to A. aurantia, but H. nuttalli (also within the H. hera and H. magnifica clade) displayed no attraction. Furthermore, Hemileuca eglanterina (yet a different clade) displayed strong, weak, and no attraction to A. aurantia, depending on the population. These apparent clade partitioning patterns of Argiope lure effectiveness and within-species variation in Hemileuca lure responses suggest a predator–prey coevolutionary history of measures and countermeasures.

Warren, Andrew D., and Paul M. Severns. 2024. "Fatal Attraction: Argiope Spiders Lure Male Hemileuca Moth Prey with the Promise of Sex" Insects 15, no. 1: 53. https://doi.org/10.3390/insects15010053