The clypeal gland: A new exocrine gland in termite imagoes (Isoptera: Serritermitidae, Rhinotermitidae, Termitidae)

The labral gland in termite soldiers

“…It was only recently, and following Šobotník et al's (2010b) study on the defensive glands in Glossotermes oculatus, and Costa-Leonardo & Haifig's ( 2014) study on the labral gland in Cornitermes cumulans, that additional data on the labral gland appeared. In addition to the presence of the labral gland in termite soldiers, it was also recently observed in some imagoes (Křížková et al, 2014) and certain workers (Palma-Onetto V and Šobotník J, our unpublished data). These random observations suggest that the labral gland might be present in all termite castes, pointing to its importance during termite evolution.…”

“…The function of these lineage-/caste-specific glands is not fully understood, apart from the defensive function of the crystal glands in Neocapritermes taracua workers (Šobotník et al, 2012Bourguignon et al, 2016). The labral gland is one of these poorly known exocrine glands, known only from the soldier caste of three termite species (Deligne, Quennedey & Blum, 1981;Quennedey, 1984;Šobotník et al, 2010b;Costa-Leonardo & Haifig, 2014), and from some imagoes (Křížková et al, 2014).…”

Termiticidal lectins from Myracrodruon urundeuva (Anacardiaceae) cause midgut damage when ingested by Nasutitermes corniger (Isoptera: Termitidae) workers

“…Enteroendocrine cells were not visualised in the midguts of termites treated with M. urundeuva lectins. These cells synthesise and secrete peptides, monoamines and other substances that exert paracrine effects in stem and digestive cells, influencing the production of enzymes, pheromones and defensive compounds . Thus, the termiticidal activity of M. urundeuva lectins may result from damage to enteroendocrine cells and the consequent impairment of digestive and endocrine processes of the insects.…”

Exocrine glands in the legs of the social wasp Vespula vulgaris

“…This is a typical feature for class-3 glands in wasps, that is not found in other social insect groups (Van der Vecht's gland: Delfino et al, 1979, Marino Piccioli et al, 1986venom gland: Delfino et al, 1983, Petrocelli et al, 2014Richards' gland: da Silva et al, 2014). The precise three-dimensional organization of the end apparatus is often complex, and may be interpreted as a coiled appearance (Křížková et al, 2014), although the branched nature in wasps is supported by electron microscopy observations. Most glands are found in the three leg pairs of queens, workers and males.…”