Укр Eng


< Leonid I. Frantsevich >

Leonid Frantsevich

Indirect closing of elytra by the prothorax in beetles (Coleoptera): general observations and exceptions

Journal of Zoology (2012) 115: 12-21.

Voluntary movements of the prothorax and the elytra in tethered flying beetles and manually induced movements of these parts in fresh dead beetles were recorded in 30 species representing 14 families. Participation of prothoracic elevation in the closing of the elytra was demonstrated in three ways. (i) The elevation was always simultaneous with elytral closing, in contrast to depression and elytral opening; a rare exception occurred in Lucanus cervus, whose elytra sometimes started to close before the cessation of wing strokes and the elevation of the prothorax. (ii) The manipulated elevation always induced closing of the spread elytra; the mechanical interaction between the hind edge of the pronotum and the roots of the elytra is a universal mechanism of closing the elytra in beetles. (iii) The prevention of pronoto-elytral contact in live beetles by the excision of the hind edge of the pronotum in front of the root prevented elytral closing after normal flight. Exceptions to this rule included some beetles that were able to close their elytra after such an excision: tiger beetles and diving beetles (seldomly) and rose chafers (always). This ability in Adephaga may be explained by attachments of the muscle actuating the 4th axillary plate, which differ from the attachments in Polyphaga. Cetoniinae open their elytra only by a small amount. It is proposed that their small direct adductors in combination with the elasticity of the sclerites are enough to achieve elytral closing without additional help from the prothorax.

Coordination between the prothorax and the elytra in a tiger beetle

Coordination between the elevation α of the prothorax (see direction of a rod glued to the pronotum) and elevation ε of the elytron (see direction of the costal edge) in Cicindela hybrida. Six short flight bouts traced in two films.

Manipulated closing by the elevation of the prothorax in a dead leaf beetle Chrysomela sanguinolenta

Manipulated closing by the elevation of the prothorax in a dead rose chafer
Potosia aeruginosa

Prevention of closing after excision in the hind edge of the pronotum in front of the right elytron

Excision in the hind edge of the pronotum in front of the right elytron in a potatoe beetle Leptinotarsa 10-lineata

A potatoe beetle Leptinotarsa 10-lineata is unable to close the right elytron after the excision of a piece of the pronotum in front of the right elytron

Excision on the posterior edge of the pronotum in front of the right elytron hinders closing in Leptinotarsa decemlineata. (А) stages of a flight episode in one specimen: (1) before opening, (2) flight, (3) finish of closing. (B-E) finish of closing in other four specimens. Selected frames from video films.

Tiger beetles Cicindela hybrida suffer difficulties with the closing after the excision of a piece in front of the right root

Rose chafers do not suffer after such excision

Mesothoracical wing muscles in Adephaga (Cybister)
and Polyphaga (Prionus, Cetonia).

Flat projections onto the frontal plane. Sclerites are spaced, real proportions of some muscles may be distorted. Axillary plates are painted red.

Direct closer M43 in Adephaga inserts onto the coxa, its analog M35 in Polyphaga - onto the articulatory membrane above the spiracle. Muscles subserving both legs and wings M39 and M47 in Adephaga originate from the tergite, their analogs M42 and M50 in Polyphaga insert onto the first axillary plate.



Collection of films:

Courtship dances in a fly, Lispe spp.

Stick friction in a lantern fly, Lycorma delicatula

Arolium of a hornet, Vespa crabro

Indirect closing of elytra in a cockchafer, Melolontha

Righting kinematics in beetles (Insecta: Coleoptera)

Leg coordination during turning on an extremely narrow substrate in a bug, Mesocerus marginatus (Heteroptera, Coreidae)

Swimming in the Diving Wasp Prestwichia aquatica (Hymenoptera: Trichogrammatidae)

Kinematics of elytra in beetles

Indirect closing of elytra in various beetles

Double rotation of the opening (closing) elytra in beetles (Coleoptera)

Actuation and performance of the elytron-to-body articulation in a diving beetle


I. I. Schmalhausen Institute of Zoology, 2004-2009