The Prey Attack Behavior of Achaearanea Tesselata (Araneae, Theridiidae)

Abstract

The attack behavior of the cobweb spider Achaearanea tesselata (Keyserling 1884) is roughly separated into three sequential steps: descend from the suspended retreat, pass through the sheet threads, and wrap the prey from underneath the sheet. The position and speed as the spider descended varied apparently according to prey type. In the fastest descent, A. tesselata fell free upside down, with all legs free and stretched upward. Two other relatively slow types of descent occurred when spiders approached the sheet head down or climbing down on a mesh thread. The behavior used to pass between the sheet lines showed little variation. It occurred at high speed with the legs folded dorsally; when the legs were in this position the spider offered a very small area of impact, apparently permitting the femora to penetrate or open a space between the lines of the sheet. The spider then opened the femora of the legs to create enough space for the cephalothorax, and seizing the sheet from underneath with legs I, II, and III, the spider pulled the abdomen and hind legs through the sheet. Then the spider rushed to the prey, flung viscid lines at the prey, and wrapped it. Attacks occurred in as little as 0.11 s after the spider began its descent. The design of the webs of A. tesselata transmits information regarding the location of the prey trapped on the sheet to reach the resting spider inside the retreat. The first response of the spider in her retreat was to turn to face the prey; the spider then climbed down along mesh threads following a nearly straight line to the prey.

Incidence of Parasitoids and Predators on Eggs of Seven Species of Therididae (Araneae)

“…Araneidae and Theridiidae) (Austin 1985;Cobb & Cobb 2004). In this study, the theridiids parasitized by Baeus also varied in habitat use and web design (Eberhard 1972;Barrantes & Weng 2006Eberhard, Agnarsson & Levi 2008;Madrigal-Brenes & Barrantes 2009). P. tepidariorum and N.…”

“…are synanthropic species that construct isolated, three-dimensional, meshed webs outside and inside buildings; webs of these species are seldom found on structures other than buildings. T. sisyphoides build their domed-sheet webs on isolated treelets and bushes with rigid leaves for web building, primarily in open areas (Madrigal-Brenes & Barrantes 2009), and P. tesselata construct their sheet webs on similar plants, also in open areas, and often in colonies (Eberhard 1972;Barrantes & Weng 2006). T. evexum construct their webs on undergrowth herbs and bushes of secondary and mature forests, and the webs consist of a retreat built by a folded leaf from which the spider lays straight sticky threads that it attaches mostly to leaves and twigs below the retreat (Barrantes & Weng 2007).…”

Construction and function of the web of Tidarren sisyphoides (Araneae: Theridiidae)

“…Both species often returned to the retreat during filling-in behavior, presumably using lines previously laid in the near vicinity of the retreat. This behavior results in only a few lines converging at the mouth of the retreat, and explains the ability of the spider to orient inside the retreat toward the prey in the web before launching an attack (Barrantes & Weng 2006a;Jö rger & Eberhard 2006). Having few threads converging at the retreat is also a feature of newly constructed webs of several Latrodectus (Szlep 1965;Eberhard et al 2008b).…”

“…Web designs in Theridiidae are strikingly variable (Szlep 1965(Szlep , 1966Lamoral 1968;Eberhard 1972Eberhard , 1981Eberhard , 1991Agnarsson 2004Agnarsson , 2005Agnarsson , 2006Eberhard et al 2008a), and similar designs have evolved independently in different genera, and in different species within a genus (Darchen & Ledoux 1978;Eberhard 1991;Japyassú & Jotta 2005;Barrantes & Weng 2006aJörger & Eberhard 2006;Eberhard et al 2008a). The broad disparity in theridiid webs is possibly the result of their great flexibility in microhabitat use, their ability to adjust web design to different physical spaces, prey types, and prey availability (Turnbull 1964;Eberhard 1990a;Agnarsson & Coddington 2007;Jörger & Eberhard 2006;Eberhard et al 2008b), and their response to parasitism and predation pressures (Blackledge et al 2003;Agnarsson 2004; Barrantes et al 2008).…”

Characteristics of the Capture Threads ofSynotaxussp. (ProbablyS. turbinatus) Webs (Araneae, Synotaxidae)

“…of Styrofoam and under a dissecting microscope the glass slide was gently brought up to the threads from below; the threads were cut at the edges of the slide as they contacted the slide. Other sticky thread samples were collected on glass slides framed with strips of double-sided adhesive tape as described in Barrantes & Weng (2006). Both methods permit photographing viscid droplets without their being distorted by contact with the slide surface.…”