Effect of temperature on the defensive and predatory behavior of the scorpion Hadrurus obscurus (Scorpiones: Hadruridae)

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  Effect of temperature on the defensive and predatory behavior of the scorpion Hadrurus obscurus (Scorpiones: Hadruridae) Abstract Scorpions employ their stinging mechanism both for defense and predation, and being ectothermic, temperature influences their physiology and behavior. As such, we hypothesized that temperature both affects defensive stinging and prey-capture behavior in scorpions. We tested the effects of body temperature on these behaviors in the desert hairy scorpion, Hadrurus obscurus Williams, 1970. In the first experiment, scorpions were placed in temperature-controlled chambers with either high (26-28°C) or low (21- 22°C) temperatures and probed to elicit a defensive sting. We recorded the reaction time and the number of probes needed to elicit a sting. In the second experiment, we observed and recorded prey capture behavior at three different temperatures (21, 29, and 33°C). Scorpions with higher body temperatures had faster defensive reaction times and require...

Chalcochares hirsutifemur (Banks) (Hymenoptera: Pompilidae: Pompilinae), a probable obligate parasitoid of Aptostichus Simon (Araneae: Mygalomorphae: Euctenizidae) in California

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Chalcochares hirsutifemur (Banks) (Hymenoptera: Pompilidae: Pompilinae), a probable obligate parasitoid of Aptostichus Simon (Araneae: Mygalomorphae: Euctenizidae) in California


Abstract


Size equivalence, seasonal synchronicity, geospatial sympatry, habitat specificity, and host-search­ing behavior implicate the spider wasp Chalcochares hirsutifemur (Banks) (Hymenoptera: Pompilidae: Pompilinae) as an obligate parasitoid on species of the wafer-lid spider genus Aptostichus Simon (Araneae: Mygalomorphae: Euctenizidae) on coastal sandy back dunes in San Luis Obispo and Santa Barbara coun­ties, CA. This is substantiated by 2010–2022 macrophotographs, videos, and field observations. Such host evidence supports recent unpublished phylogenomic studies that place Chalcochares as a sister genus of the spider wasp tribe Aporini, in which all species are known obligate parasitoids on trapdoor spiders and related Mygalomorphae. Chalcochares hirsutifemur and C. engleharti (Banks) are separated based on morphological, geographic, and probable host spider differences. Resource partitioning on the coastal sand dunes between C. hirsutifemur and three species of smaller Aporus Spinola is proposed.


Kurczewski FE, Abela AJ, Shimizu A. 2023. Chalcochares hirsutifemur (Banks) (Hymenoptera: Pompilidae: Pompilinae), a probable obligate parasitoid of Aptostichus Simon (Araneae: Mygalomorphae: Euctenizidae) in California. Insecta Mundi 1004: 1–13.