The male reproductive accessory glands of the blister beetle Meloe proscarabaeus Linnaeus, 1758 (Coleoptera: Meloidae): Anatomy and ultrastructure of the cantharidin-storing organs

Unraveling the role of male reproductive tract and haemolymph in cantharidin-exuding Lydus trimaculatus and Mylabris variabilis (Coleoptera: Meloidae): a comparative transcriptomics approach

“…Overall, the transcriptome of MRT of both species encompassed a large set of protein domains whose enrichment was expected based on the fundamental role that these organs play in insect reproduction. Dynein, kinesin, microtubule-associated domains were the most abundant protein families, plausibly involved in mobilization of sperms, but also of secretory vesicles (and of their associated lipid and protein-based content) that were observed to replenish MAG [ 47 ]. Many other domains were associated to germ-cell proliferation or, more in general, to those developmental processes ongoing in reproductive organs of male insects, usually mediated by phosphorylation, nucleic acid regulation, ubiquitination and induction of many signalling cascades (as in T. castaneum ) [ 48 ].…”

“…Then, other self-protective strategies are more likely than direct detoxification, such as sequestration of toxic compounds in intracellular compartments (Phase III), an additional mechanism which several insects evolved to tolerate xenobiotics [ 63 – 65 ]. Indeed, the observation of numerous replenished vesicles inside the cells of the glandular epithelia of MAG and vasa deferentia of M. proscarabeus [ 47 ] could support a compartmentalization strategy of CA.…”

Discovery of a complex sclerotized sperm pump in Monotomidae (Coleoptera): Functional morphology and phylogenetic value

“…The male reproductive organs were studied in detail in the archostematan beetle Tetraphalerus bruchi Heller, and no specialized section of dej was found (Hünefeld et al, 2011); and such structures are also unknown in Adephaga (e.g., Sasakawa, 2007; Schubert et al, 2017). Within Polyphaga, a plesiomorphic dej is known among Scarabaeoidea (Scarabaeoidae: Jacob, 1989); and Tenebrionoidea (Meloidae: Muzzi et al, 2020; Tenebrionidae: Hopkins et al, 1993). Plesiomorphic dej was also found in certain groups of the polyphagan Chrysomelidae (Chrysomeloidea), as in Criocerinae (Matsumura & Suzuki, 2008), but in Donaciinae a distinct swelling of dej is present (Matsumura & Suzuki, 2008).…”

“…Considering the remarkable size of the pump (Figure 1 organs were studied in detail in the archostematan beetle Tetraphalerus bruchi Heller, and no specialized section of dej was found (Hünefeld et al, 2011); and such structures are also unknown in Adephaga (e.g., Sasakawa, 2007;Schubert et al, 2017). Within Polyphaga, a plesiomorphic dej is known among Scarabaeoidea (Scarabaeoidae: Jacob, 1989); and Tenebrionoidea (Meloidae: Muzzi et al, 2020;Tenebrionidae: Hopkins et al, 1993).…”

Proctodeal extrusion as a defensive behavioral response in blister beetles (Coleoptera: Meloidae)

“…Although a wide array of taxa (including vertebrates) (Humphreys and Ruxton 2018) display thanatosis, the autohemorrhage behavior is mostly limited to species whose hemolymph contain toxic or noxious compounds (Evans and Schmidt 1990), as in the case of species of Meloidae. Blister beetles are able to synthesize cantharidin, a potent systemic toxin that can degrade tissues (Bertaux et al 1988;Muzzi et al 2020), and serves as a powerful deterrent to invertebrate and vertebrate predators (Carrel and Eisner 1974).…”