Responses to Moving Small-Field Stimuli by the Praying Mantis, <i>Sphodromantis lineola </i>(Burmeister)

Abstract

Adult, female praying mantises, Sphodromantis lineola (Burmeister), were presented with mechanically driven or computer generated stimuli in a series of seven experiments in order to test several hypotheses regarding visual prey recognition. When presented with a series of square black and white computer generated stimuli against a white background, mantises performed the highest rates of predatory behavior in response to those stimuli with a greater proportion of black versus white pixels (i.e., those that produced larger luminance decrements). Higher response rates to computer generated stimuli that produced larger luminance decrements were also seen when the stimuli were irregularly shaped or consisted of two small synchronized stimuli. Mantises responded characteristically to mechanically driven stimuli that were camouflaged to match the background against which they moved, preferring small (vs. large) squares and rectangles that were elongated parallel (vs. perpendicular) to their direction of movement. Finally, response rate to a small, preferred, mechanically presented or computer generated stimulus was suppressed by a concurrent large-field stimulus in inverse proportion to the distance between the two stimuli. This phenomenon is characteristic of systems that include phasic lateral inhibitory circuits. All of these results are consistent with the existence of a movement detector visual sub-system, as found in other orthopteromorph insects such as acridid grasshoppers and cockroaches.

Response Properties of Visual Interneurons to Motion Stimuli in the Praying Mantis, Tenodera aridifolia

“…In behavioral experiments, the mantis frequently strikes a small moving block (Iwasaki, 1990;Prete, 1990) or a small moving square generated on a computer display (Prete and Mahaffey, 1993;Prete and McLean, 1996). This behavioral size-preference coincides with the spatial tuning of the SF neurons.…”

Responses of Movement-Sensitive Visual Interneurons to Prey-Like Stimuli in the Praying Mantis Sphodromantis lineola (Burmeister)

“…All visual stimuli and associated protocols were the same as those used in previous psychophysical analyses and have been described thoroughly elsewhere Prete and Mahaffey, 1993a;Prete and McLean, 1996;Prete, 1999].…”

“…for overviews, see Prete, 1999 (mantids); Ewert, 1987Ewert, , 1989 ;Roth, 1987 (salamanders)]. For mantids, as well as toads, a stimulus is defined as 'prey' (versus 'not prey') if it falls within a perceptual envelope defined by five fundamental stimulus parameters: (1) overall size, (2) length of the leading edge, (3) contrast to the background, (4) location in the visual field, and (5) apparent speed [Prete, , 1999Prete and Mahaffey, 1993a;Prete and McLean, 1996]. From the second perspective, it is interesting that mantids have evolved a prey-recognition subsystem that seems to be unique among the orthopteroidea [i.e.…”

Visual stimulus characteristics that elicit tracking and striking in the Praying Mantises, Parasphendale affinis (Giglio-Tos), Popa spurca (Stål), and Sphodromantis lineola (Burmeister)

“…For instance, P. affinis responded to the mottled grey stimulus used here but P. spurca and S. lineola did not. However, in previous studies S. lineola has both tracked and struck at synchronously moving arrays of subthreshold black dots or rectangles moving against similarly patterned black and white backgrounds Prete and McLean, 1996) (Fig. 6, column III).…”