Sticky secretion from two pairs of defensive glands of rove beetleDeleaster dichrous (Grav.) (Coleoptera: Staphylinidae)

1985 ◽  
Vol 11 (7) ◽  
pp. 859-883 ◽  
Author(s):  
Konrad Dettner ◽  
Gerhard Schwinger ◽  
Paul Wunderle
Keyword(s):  
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.


2020 ◽  
Vol 287 (1934) ◽  
pp. 20201311
Author(s):  
Paulina Kowalski ◽  
Michael Baum ◽  
Marcel Körten ◽  
Alexander Donath ◽  
Susanne Dobler

Phytophagous insects can tolerate and detoxify toxic compounds present in their host plants and have evolved intricate adaptations to this end. Some insects even sequester the toxins for their defence. This necessitates specific mechanisms, especially carrier proteins that regulate uptake and transport to specific storage sites or protect sensitive tissues from noxious compounds. We identified three ATP-binding cassette subfamily B (ABCB) transporters from the transcriptome of the cardenolide-sequestering leaf beetle Chrysochus auratus and analysed their functional role in the sequestration process. These were heterologously expressed and tested for their ability to interact with various potential substrates: verapamil (standard ABCB substrate), the cardenolides digoxin (commonly used), cymarin (present in the species's host plant) and calotropin (present in the ancestral host plants). Verapamil stimulated all three ABCBs and each was activated by at least one cardenolide, however, they differed as to which they were activated by. While the expression of the most versatile transporter fits with a protective role in the blood–brain barrier, the one specific for cymarin shows an extreme abundance in the elytra, coinciding with the location of the defensive glands. Our data thus suggest a key role of ABCBs in the transport network needed for cardenolide sequestration.


A pharmacologically active choline ester closely resembling β, β -dimethylacrylylcholine is present in very high concentrations in the cervical (prothoracic) defensive glands of the garden tiger moth, Arctia caja (L.). It is suggested that the active substance is acrylylcholine itself, β, β -dimethylacrylylcholine, or a closely related derivative. Another substance, non-dialyzable and heat-labile, is present in the abdominal tissues of A. caja . This substance markedly increases capillary permeability on intradermal injection and causes death on intravenous injection into guinea-pigs. Its lethal action appears to be due to constriction of bronchial smooth muscle. The tissues of A. caja contain neither histamine nor 5-hydroxytryptamine. Very high concentrations of histamine are present, however, in the abdominal tissues of some other moths.


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. 


1975 ◽  
Vol 16 (28) ◽  
pp. 2367-2370 ◽  
Author(s):  
J. Meinwald ◽  
J. Smolanoff ◽  
A.T. McPhail ◽  
R.W. Miller ◽  
T. Eisner ◽  
...  

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