Interommatidial sensilla of the praying mantis: Their central neural projections and role in head‐cleaning behavior

Abstract

The compound eye of the praying mantis is covered with approximately 600 bristles and campaniform sensilla. Their afferents project to the brain, and to the suboesophageal and prothoracic ganglia. Cutting the eye branch of the dorsal tegumentary nerve (DTN), the peripheral nerve innervating the corneal sensilla, makes it impossible to initiate head grooming by tactile stimulation of the eye. This stimulus is a strong releaser of grooming behavior in normal animals. Head grooming can be initiated, after cutting the eye branch of the DTN, by stimulation of the frons (the operation leaves the sensory innervation of this part of the cuticle intact). Frame-by-frame analysis of films of head grooming after cutting the nerve reveals a reduction of the speed at which the forelimb is brushed across the surface of the head and eye. The significance of this finding is discussed in terms of a putative feedback loop from the corneal sensilla to the motor neurons controlling the grooming movements.

Morphological and anatomical observations on the hairy eyes of males and females of the marine amphipoddulichia porrecta(crustacea, amphipoda, podoceridae)

“…While in some species a cleaning function has been suggested for such hairs (Honegger, 1977;Zack & Bacon, 1981), in others, for example troglophilic species (Meyer-Rochow & Waldvogel, 1979), a mechanoreceptive purpose seems more likely. It would be fair to say, however, that in most cases where interommatidial hairs occur, their precise role is still unknown (Hinton, 1970).…”

Cuticular microstructures of abdominal tergites and sternites of <i>Cloeon</i> sp. (Ephemeroptera; Baetidae) during post-embryonic development

“…Nevertheless, extrapolations from SEM and TEMbased studies on insect sensilla generally enable us to suggest some of their possible functions. Sensilla trichoidea type 1, with their slender, pliable setae, and sockets that allow movement in all directions, are likely to be mechano-or contact chemosensilla (Frazier 1985, Crouau & Crouau-Roy 1991 and may also be used for cleaning detrital and other debris from the abdominal surface as well (Honegger 1977, Zack & Bacon 1981. Sensilla trichoidea type 2, in the absence of sockets, may only serve simple tactile functions (Schmidt & Smith 1987).…”

Compound eyes of insects and crustaceans: Some examples that show there is still a lot of work left to be done

“…That suggests a role in detecting air currents and flight control (Tyrer et al ., ) and a similarity to other body hair in insects, especially those of the head region has been noticed (Insausti & Lazzari, ). In the mantis, the eye is covered with approximately 600 bristles and campaniform sensilla and cutting the eye branch of the dorsal tegumentary nerve, the peripheral nerve innervating the corneal sensilla, eliminates head grooming by tactile stimulation of the eye (Zack & Bacon, ). This stimulus is a strong releaser of grooming behavior in normal animals as Honegger et al .…”

“…The afferent axons of the hairs reach deep into the interommatidial spaces and beyond and according to Honegger (1977) in Gryllus, Mobbs (1985) in the honeybee, and Zack and Bacon (1981) in the praying mantis appear to enter the brain through lateral-dorsal and medial-dorsal tegumentary nerves that arborize in the suboesaphgeal and prothoracic ganglia. That suggests a role in detecting air currents and flight control (Tyrer et al, 1979) and a similarity to other body hair in insects, especially those of the head region has been noticed (Insausti & Lazzari, 2000).…”

“…This stimulus is a strong releaser of grooming behavior in normal animals as Honegger et al (1979) had earlier shown, when they concluded that stimulation of the hairs elicited eye-cleaning behaviors. Head grooming continues to occur in the operated insects when bristles on the frons are stimulated, because the operation leaves their innervation intact (Zack & Bacon, 1981).…”