Spider lures exploit insect preferences for floral colour and symmetry

Abstract

Sensory systems can capture only a fraction of available information, which creates opportunities for deceptive signalling. The sensory traps and sensory bias models have proven valuable for explaining how visual systems and environments shape the design of sexual signals, but their application to deceptive signals is largely untapped. Here we use the 'jewelled' orb-web spider Gasteracantha fornicata to experimentally test two longstanding hypotheses for the function of deceptive visual lures. Namely, that they: (1) exploit generalised preferences for conspicuous colouration (sensory bias), or (2) co-opt the otherwise-adaptive foraging response of prey toward flowers (sensory traps). In a field-based study we manipulated the conspicuous dorsal signal of female spiders along two axes --colour pattern and symmetry -to generate a gradient of floral resemblance, and monitored the per-individual consequences for prey interception. As predicted by the traps model, the most attractive phenotypes were those with flower-like radial symmetry and solid colour patterns, and their attractiveness equaled that of wild-type models. These results demonstrate that deceptive orb-web spider lures function, in part, as inter-kingdom sensory traps via floral mimicry, and support the broader extension of sensory-based models to deceptive signalling contexts.

Geometry-based navigation in the dark: layout symmetry facilitates spatial learning in the house cricket, Acheta domesticus, in the absence of visual cues

“…Nevertheless, one has to remain aware of the possible variance of mechanisms among the species (Vallortigara 2018 ). Our hypotheses were further substantiated by previous findings that insects exhibit sensitivity to object symmetry (Giurfa et al 1996 ; Møller and Sorci 1998 ; Rodríguez et al 2004 ; White and Kemp 2020 ), and they can tactilely recognize previously seen objects while in the dark (Solvi et al 2020 ). Furthermore, insects exhibit good navigational performance in tasks where the spatial layout is geometrically regular (Wystrach and Beugnon 2009 ; Sovrano et al 2012 ; Lee and Vallortigara 2015 ).…”

“…Research on insect navigation utilizing environmental geometry is scarce, and mainly concerns navigation in rectangular arenas (Wystrach and Beugnon 2009 ; Sovrano et al 2012 ; Lee and Vallortigara 2015 ). However, aside from the studies directly concerning layout geometry, there are other reports suggesting that miniature nervous systems are able to process the geometric properties of objects, such as symmetry (Giurfa et al 1996 ; Møller and Sorci 1998 ; Rodríguez et al 2004 ; White and Kemp 2020 ).…”

Geometry-based navigation in the dark: Layout symmetry facilitates spatial learning in the house cricket,Acheta domesticus, in the absence of visual cues

“…Nevertheless, one has to remain aware of the possible variance of mechanisms among the species (Vallortigara 2018). Our hypotheses were further substantiated by previous findings that insects exhibit sensitivity to object symmetry (Giurfa et al 1996; Møller and Sorci 1998; Rodríguez et al 2004; White and Kemp 2020), and they can tactilely recognize previously seen objects while in the dark (Solvi et al 2020). Furthermore, insects exhibit good navigational performance in tasks where the spatial layout is geometrically regular (Wystrach and Beugnon 2009; Sovrano et al 2012; Lee and Vallortigara 2015).…”

“…Research on insect navigation utilizing environmental geometry is scarce and mainly concerns navigation in rectangular arenas (Wystrach and Beugnon 2009; Sovrano et al 2012; Lee and Vallortigara 2015). However, aside from the studies directly concerning layout geometry, there are other reports suggesting that miniature nervous systems are able to process geometric properties of objects, such as symmetry (Giurfa et al 1996; Møller and Sorci 1998; Rodríguez et al 2004; White and Kemp 2020).…”

Deceptive pollinator lures benefit from physical and perceptual proximity to flowers

“…Co-locating with flowers near doubled the capture success of spiders irrespective of their visual resemblance, while the benefit of colour-matching flowers was only apparent for those spiders already in close proximity to flowers (Figures 2 and 3). That predators exploit resources desired by prey is well known (Heiling & Herberstein, 2004;White et al, 2022), though is noteworthy here in that it entails the aggressive mimicry of the resource itself (or at least the exploitation of shared cues; White & Kemp, 2020). A comparable effect has been shown only once previously in the flower-mimicking orchid mantis (which, to human viewers, represents a more convincing mimic; O 'Hanlon, Herberstein, & Holwell, 2014), and thus stands as a conceptual replication of the long-hypothesised 'magnet' effect among deceptive predators (Annandale, 1900).…”