The structure and defensive eicacy of glandular secretion of the larval osmeterium in Graphium agamemnon agamemnon Linnaeus, 1758 (Lepidoptera: Papilionidae)

Abstract

Histomorphological study of the larval (inal instar) osmeterium gland in Graphium agamemnon agamemnon Linnaeus shows that each fully protruded Y-shaped osmeterium is composed of 2 elongated hollow tubular arms, which arise from a basal peduncle. he surface of the osmeterium has irregular folds, and papillae arise from some cells. here is an oval opening (gland pore, structurally less complicated than in other evolved species) in the proximal second seventh of the segment on each tubular arm on its posterior face. Histologically, 2 main types of secretory cells can be observed (excluding the muscle iber cells and supporting cells): i) ellipsoid gland cells within the gland pore region and ii) tubular arm cells extending from the upper part of the ovoid gland pore region to the distal part of the tubular arms. he defensive eicacy of the osmeterial secretion in larvae was also examined, both in the laboratory and ield, and was observed to be very complicated