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  • Thumbnail for CONSPICUOUSNESS OF BAND-WINGED GRASSHOPPERS TO PREDATORS AND CONSPECIFICS (ORTHOPTERA: ACRIDIDAE: OEDIPODINAE)
    CONSPICUOUSNESS OF BAND-WINGED GRASSHOPPERS TO PREDATORS AND CONSPECIFICS (ORTHOPTERA: ACRIDIDAE: OEDIPODINAE) by Salazar, Brae Anne

    In band-winged grasshoppers (subfamily Oedipodinae), the variety of hindwing colors—ranging from blue to red—is both striking and unexplained. Hindwing color can vary both within and between species. However, the functional significance, if any, of this variation is unknown. Notably, the colorful hindwings are revealed only in flight, and remain hidden in stationary individuals. Although experimental evidence is lacking, this flash of color has been proposed to 1) startle potential predators, 2) to signal the quality of a potential mate, and 3) to enhance species recognition. To elucidate their potential function(s), here I measure the spectral and spatial characteristics of the hindwing patterns in 6 different band-winged species. I then model how an avian predator or potential mate might view grasshopper wings at behaviorally relevant distances. These data suggest that there is a rapid change in conspicuousness as a grasshopper moves from rest to flight regardless of the color vision of the receiver. However, there is little within species variation in coloration or wing patterning. My results indicate that while hindwings 1) may function as a protean defense against avian predators, 2) it is unlikely that they serve as a signal of mate quality, although, they 3) may deliver enough information for species recognition. This research helps to elucidate evolutionary relationships leading to the diversification of behavior, visual systems, and coloration within band-winged grasshoppers.

  • Thumbnail for Spatial vision in band-winged grasshoppers (Orthoptera: Acrididae: Oedipodinae)
    Spatial vision in band-winged grasshoppers (Orthoptera: Acrididae: Oedipodinae) by Duncan, Alexander Brett

    Visual acuity, the ability to resolve fine spatial details, can vary dramatically between and within insect species. Body-size, sex, behavior, and ecological niche are all factors that may influence an insect’s acuity. Band-winged grasshoppers (Oedipodinae) are a subfamily of grasshoppers characterized by their colorfully patterned hindwings. Although researchers have anecdotally suggested that this color pattern may attract mates, few studies have examined the visual acuity of these animals, and none have examined its implications on intraspecific signaling. Here, we compare the visual acuity of three bandwing species: Dissosteira carolina, Arphia pseudonietana, and Spharagemon equale. To measure acuity in these species we used a modified radius of curvature estimation (RCE) technique. Visual acuity was significantly coarser 1) in males compared to females, 2) parallel to the horizon compared to the perpendicular, and 3) in S. equale compared to other bandwings. Unlike many insect families, body size within a species did not correlate with visual acuity. To examine the functional implications of these results, we modeled the appearance of different bandwing patterns to conspecifics. These results suggest that hind- wing patterning could only be used as a signal to conspecifics at short distances (<50cm). This study furthers the exploration of behavior and the evolution of visual systems in bandwings.

  • Thumbnail for Spatial vision in band-winged grasshoppers (Orthoptera: Acrididae: Oedipodinae)
    Spatial vision in band-winged grasshoppers (Orthoptera: Acrididae: Oedipodinae) by Duncan, Alexander

    Visual acuity, the ability to resolve fine spatial details, can vary dramatically between and within insect species. Body-size, sex, behavior, and ecological niche are all factors that may influence an insect’s acuity. Band-winged grasshoppers (Oedipodinae) are a subfamily of grasshoppers characterized by their colorfully patterned hindwings. Although researchers have anecdotally suggested that this color pattern may attract mates, few studies have examined the visual acuity of these animals, and none have examined its implications on intraspecific signaling. Here, we compare the visual acuity of three bandwing species: Dissosteira carolina, Arphia pseudonietana, and Spharagemon equale. To measure acuity in these species we used a modified radius of curvature estimation (RCE) technique. Visual acuity was significantly coarser 1) in males compared to females, 2) parallel to the horizon compared to the perpendicular, and 3) in S. equale compared to other bandwings. Unlike many insect families, body size within a species did not correlate with visual acuity. To examine the functional implications of these results, we modeled the appearance of different bandwing patterns to conspecifics. These results suggest that hind- wing patterning could only be used as a signal to conspecifics at short distances (<50cm). This study furthers the exploration of behavior and the evolution of visual systems in bandwings.