Feeding and the salivary gland response in free-ranging yellow-winged grasshoppers (Gastrimargus musicus)

Abstract

Yellow-winged grasshoppers (Gastrimargus musicus) were captured in the field to examine the morphology and amine immunohistochemistry of their salivary glands. Fifty-eight grasshoppers were collected, with only five being males. Eight of 53 female grasshoppers had food in their crop, and the salivary glands of those insects were significantly heavier than those of grasshoppers without food in their crops. The salivary gland of the yellow-winged grasshopper was an acinar-type gland, similar to gland descriptions for other Orthoptera. The primary secretory part of acini of each gland is composed of zymogen and parietal cells. Staining patterns indicated that serotonin and dopamine could act as neurotransmitters and/or neurohormones to stimulate the glands. The pattern of staining of serotonin in the salivary gland suggested that serotonin stimulates both zymogen and parietal cells. Only the parietal cells were positively stained with dopamine. Comparing staining of glands of grasshoppers with food in their crop with the glands of grasshoppers with empty crops suggested a reduction in staining for serotonin in the latter. The differential staining pattern suggests that these amines have different roles in the salivary gland of G. musicus. The lack of difference in structure but increased mass with feeding suggests that all glands were active, but that secretion was actively occurring only in animals with the heavier glands.

A Novel Head Capsule Labial Gland Lobe in the Black Field Cricket (Orthoptera: Gryllidae)

“…The control of the cephalic labial gland lobes appears to be through a similar pathway as has been reported in other alveolar glands, as the presence of serotonin was consistent with that observed for cockroaches ( Baumann et al 2002 ), locusts ( Ali 1997 ), and yellow-winged grasshoppers ( Wahida and Cooper 2014 ). However, we cannot be certain that serotonin does stimulate fluid secretion within the cephalic lobes, as we have not performed that experiment.…”

Feeding and Amines Stimulate the Growth of the Salivary Gland following Short-Term Starvation in the Black Field Cricket, Teleogryllus commodus

“…We reported that the salivary glands of yellow-winged grasshoppers ( Gastrimargus musicus ) were reduced in size in insects that did not have food in the crop, but we could not distinguish whether this resulted from either not feeding or as a result of flight when the grasshoppers were caught [ 27 ]. The aim of this study is (1) to determine how starvation–feeding cycles might affect the morphology of the thoracic salivary gland of the cricket, Teleogryllus commodus , and (2) whether the amines serotonin or dopamine play a role in any gland changes by observing the effect of incubating semi-isolated glands of 72 h starved insects with amines, as well as measuring the concentration of these amines in starved and fed crickets.…”