scholarly journals Defensive Glands of the Darkling BeetleMesomorphus villigerBlanchard (Coleoptera: Tenebrionidae)

2013 ◽  
Vol 2013 ◽  
pp. 1-3 ◽  
Author(s):  
C. M. Seena ◽  
Sabu K. Thomas

Massive home invasion by the darkling beetleMesomorphus villigerBlanchard 1853 (Coleoptera: Tenebrionidae) during monsoon season make it a nuisance pest in many regions of south India. Morphology of defensive glands and mode of release and dispersal of the defensive secretion were analysed. Defensive glands were separated from the abdominal sternites by cutting along the posterior margin of the seventh sternite. Glands are evaginations of intersegmental membrane between the seventh and eighth sternites consisting of two long sac-like reservoirs, and glandular secretion is released by exudation and spread through epipleural gutter of elytra. Gradual release of the secretion is a strategy to repel the predators for a longer duration.

Zootaxa ◽  
2017 ◽  
Vol 4338 (1) ◽  
pp. 163 ◽  
Author(s):  
MAXIM NABOZHENKO ◽  
SABER SADEGHI

The troglobitic darkling beetle Foranotum perforatum gen. et sp. nov. from a cave in Southern Zagros Mountains (Iran) is described. This new taxon belongs to the family Tenebrionidae based on the following combination of characters: tarsal formula 5-5-4, antennal insertions concealed from above, antennae 11-segmented, mesocoxal cavities laterally closed by meso- and metaventrite. It is close to Kuhitangia kryzhanovskii Medvedev, 1962 by sharing a similar structure of procoxa (open cavities), labrum (reduced tormal arms) and prothorax (perforating holes on lateral sides of disc). Based on a comprehensive character analysis the subfamily Kuhitangiinae (type genus Kuhitangia Medvedev, 1962) is reestablished. Kuhitangiinae belongs to the pimelioid branch of the family Tenebrionidae based on open mouthparts (mentum small, exposing most of maxillae), mesocoxae externally closed by meso- and metaventrite, metacoxae externally narrowly closed by metaventrite and first abdominal ventrite, tentyrioid structure of abdominal ventrites (absence of membranes between abdominal ventrites 3–5) and absence of defensive glands. The subfamily Kuhitangiinae is divided into following two tribes: Kuhitangiini with a single species Kuhitangia kryzhanovskii Medvedev, 1962 and Foranotini trib. n. with Foranotum perforatum sp. nov. The new tribe differs from Kuhitangiini by the presence of trochanters and epipleura, structure of pronotum, abdominal ventrites and sculpture of meso- and metaventrites. 


1991 ◽  
Vol 69 (8) ◽  
pp. 2100-2108 ◽  
Author(s):  
Douglas W. Whitman ◽  
Johan P. J. Billen ◽  
David Alsop ◽  
Murray S. Blum

In the lubber grasshopper Romalea guttata, the respiratory system produces, stores, and delivers a phenolic defensive secretion. The exudate is secreted by a glandular epithelium surrounding the metathoracic spiracular tracheal trunks. Embedded in the glandular tissue are multiple secretory units, each comprised of a basal secretory cell and an apical duct cell. Secretory cells have numerous mitochondria, a tubular, smooth endoplasmic reticulum, well-developed Golgi bodies, and a microvillilined vesicle thought to transfer secretion to the intracellular cuticular duct of a duct cell. Ducts empty into the metathoracic tracheal lumina where the exudate is stored behind the closed metathoracic spiracle. Tactile stimulation elicits secretion discharge, which begins when all spiracles except the metathoracic pair are closed and the abdomen is compressed. Increased hemostatic and pneumatic pressures drive air and secretion out of the spiracle with an audible hiss. Both metathoracic spiracles discharge simultaneously. The secretion erupts first as a dispersant spray, then as an adherent froth, and finally assumes the form of a slowly evaporating repellent droplet. Discharge force and number vary with eliciting stimuli, volume of stored secretion, and age, disturbance state, and temperature of the insect. Molting grasshoppers are unable to discharge because the stored exudate is lost with the shed cuticle. The advantages and limitations of a tracheal defensive system are discussed.


Zootaxa ◽  
2020 ◽  
Vol 4780 (2) ◽  
pp. 201-258
Author(s):  
LUNA GREY ◽  
AARON D. SMITH

The darkling beetle genus Hypogena Dejean, 1834 (Tenebrionidae: Tenebrioninae) is revised. Hypogena is entirely composed of dorsoventrally flattened species that live subcortically in dead trees. This genus is generally identified by male specific characters, particularly the presence of cephalic horns. Hypogena is currently placed within the tribe Triboliini Gistel, 1848. However, several previously overlooked morphological characters call into question its placement within the tribe. A morphological matrix of 94 external adult characters was assembled to examine species relationships and boundaries. The resulting phylogeny is presented. Thirteen Hypogena species were previously recognized as valid, including Hypogena marginalis Doyen & Poinar from Dominican amber. Four previously unidentified species are described in this study: Hypogena akuma sp. nov. (Brazil), Hypogena cryptica sp. nov. (Mexico), Hypogena hirsuta sp. nov. (Ecuador), and Hypogena reburra sp. nov. (Colombia). Lectotypes are designated for Hypogena depressa (Champion, 1886), Hypogena dejeani (Champion, 1886), Hypogena canaliculata (Champion, 1886), and Hypogena vacca (Fabricius, 1801). A neotype is designated for Tenebrio biimpressus (Latreille, 1833) (type species of Hypogena, synonymized under Hypogena brasilica (Perty)) in order to maintain stability within the genus.  


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