Morphology and Diversity of Exocrine Glands in Lepidopteran Larvae

Abstract

The morphology of 21 exocrine glands and 13 supposedly exocrine structures recorded for lepidopteran larvae is reviewed. The epitracheal glands, for which a double role (exocrine and endocrine) has been demonstrated, are examined as well. Function is well known for at least 8 glands but completely unknown for 6 glands, for 10 putative glandular structures, and for the exocrine component of the epitracheal glands. Functional studies on the remaining structures are insufficient; in some cases (mandibular gland and adenosma) homologous glands may play a different role depending on the species, and only a few taxa have been examined. The secretions of 13 glandular types have been analyzed chemically. The histology of 11 glands is known at the ultrastructural level, whereas that of 6 glands and 7 putative glandular structures is completely unknown. Comparative anatomical studies of the osmeterium, adenosma, and Verson's glands may yield useful information for phylogenetic reconstructions.

The Multiple Strategies of an Insect Herbivore to Overcome Plant Cyanogenic Glucoside Defence

“…This keeps CNglcs from L. corniculatus intact during feeding and digestion by Z. filipendulae . The mandible morphology of other less specialised species belonging to Zygaenoidea ( Aglaope infausta or Heterogynis penella which feed on cyanogenic and non-cyanogenic plant species) differs as their mandibles are more toothed and compact [32], [33], [34], [35]. In general, leaf-snipping lepidopterans have simple, round-shaped and non-toothed mandibles, which enable them to ingest plant fragments of a similar size [30], [31] as observed in Z. filipendulae .…”

Apocrine Secretion in Drosophila Salivary Glands: Subcellular Origin, Dynamics, and Identification of Secretory Proteins

“…In textbooks and reviews, apocrine secretion is frequently described either in association with the lactation activity of mammary glands, the Harderian gland, and some exocrine glands [25]–[27] or notably as a differential diagnostic marker for some benign metaplasias and in many dermatogenic and some breast cancers [28]–[37].…”

Trail Marking by Larvae of the Cactus Moth,Cactoblastis cactorum

“…The anterior end of each gland narrows to a duct approximately 0.4 mm long, which terminates in the apodeme of the adductor muscle of the mandible (Figure 3). Studies of the mandibular glands of other pyralids indicate that the contents of the mandibular gland are secreted into the lumen of the apodeme and exit to the outside through an opening in the apodeme that occurs mesally at the base of the mandible (Vegliante and Hasenfuss 2012). The mean wet mass of caterpillars from which glands were extracted in the present study was 99 ± 5 (SE) mg.…”