The peregrine falcon's rapid dive: on the adaptedness of the arm skeleton and shoulder girdle.

During a dive, peregrine falcons (Falco peregrinus) can reach a velocity of up to 320 km h. Our computational fluid dynamics simulations show that the forces that pull on the wings of a diving peregrine can reach up to three times the falcon's body mass at a stoop velocity of 80 m s (288 km h). Since the bones of the wings and the shoulder girdle of a diving peregrine falcon experience large mechanical forces, we investigated these bones.

The impact of infrared radiation in flight control in the Australian "firebeetle" Merimna atrata.

Infrared (IR) receptors are rare in insects and have only been found in the small group of so-called pyrophilous insects, which approach forest fires. In previous work the morphology of the IR receptors and the physiology of the inherent sensory cells have been investigated. It was shown that receptors are located on the thorax and the abdomen respectively and show an astounding diversity with respect to structure and the presumed transduction mechanism.

Age-dependent male mating tactics in a spider mite-A life-history perspective.

Males often fight with rival males for access to females. However, some males display nonfighting tactics such as sneaking, satellite behavior, or female mimicking. When these mating tactics comprise a conditional strategy, they are often thought to be explained by resource holding potential (RHP), that is, nonfighting tactics are displayed by less competitive males who are more likely to lose a fight.

Form-function relationships in dragonfly mandibles under an evolutionary perspective.

Functional requirements may constrain phenotypic diversification or foster it. For insect mouthparts, the quantification of the relationship between shape and function in an evolutionary framework remained largely unexplored. Here, the question of a functional influence on phenotypic diversification for dragonfly mandibles is assessed with a large-scale biomechanical analysis covering nearly all anisopteran families, using finite element analysis in combination with geometric morphometrics.

Concept of an Active Amplification Mechanism in the Infrared Organ of Pyrophilous Melanophila Beetles.

Jewel beetles of the genus Melanophila possess a pair of metathoracic infrared (IR) organs. These organs are used for forest fire detection because Melanophila larvae can only develop in fire killed trees. Several reports in the literature and a modeling of a historic oil tank fire suggest that beetles may be able to detect large fires by means of their IR organs from distances of more than 100 km.

Morphological properties of the last primaries, the tail feathers, and the alulae of Accipiter nisus, Columba livia, Falco peregrinus, and Falco tinnunculus.

We investigated the mechanical properties (Young's modulus, bending stiffness, barb separation forces) of the tenth primary of the wings, of the alulae and of the middle tail feathers of Falco peregrinus. For comparison, we also investigated the corresponding feathers in pigeons (Columba livia), kestrels (Falco tinnunculus), and sparrowhawks (Accipiter nisus). In all four species, the Young's moduli of the feathers ranged from 5.

A model for μ-biomimetic thermal infrared sensors based on the infrared receptors of Melanophila acuminata.

Beetles of the genus Melanophila acuminata detect forest fires from distances as far as 130 km with infrared-sensing organs. Inspired by this extremely sensitive biological device, we are developing an IR sensor that operates at ambient temperature using MEMS technology. The sensor consists of two liquid-filled chambers that are connected by a micro-fluidic system.

Thermomechanical properties of the stimulus transducing cuticle in the infrared organ of Merimna atrata (Coleoptera, Buprestidae).

The pyrophilous Australian "fire-beetle" Merimna atrata strongly depends on the occurrence and localization of forest fires for its reproduction. As a special adaptation to its unusual biology, elaborate infrared (IR) organs have evolved in this species. The IR-organs consist of a specialized cuticular portion, the absorbing area, innervated by a sensory complex.

Bimodal innervation of the infrared organ of Merimna atrata (Coleoptera, Buprestidae) by thermo- and mechanosensory units.

The pyrophilous Australian "fire-beetle"Merimna atrata approaches forest fires and possesses abdominal infrared (IR) organs. Each round IR organ is centrally innervated by a sensory complex showing two different units: one thermoreceptive multipolar neuron and one mechanosensitive chordotonal organ (CO) consisting of two scolopidia. We investigated the CO and found that the scolopidia are mononematic (the scolopale cap remains below the cuticle) and monodynal (one sensory cell per scolopidium).

Material properties of photomechanical infrared receptors in pyrophilous Melanophila beetles and Aradus bugs.

Jewel beetles of the genus Melanophila and some pyrophilous species of the flat bugs genus Aradus show a pyrophilous behaviour and have developed so-called photomechanical infrared (IR) receptors. In a spherical photomechanical IR sensillum incoming IR radiation is converted into micromechanical action, finally stimulating the dendritic tip of a mechanosensitive sensory cell. The tip is located inside a tiny cuticular sphere with a diameter of about 12 μm.

Modelling a historic oil-tank fire allows an estimation of the sensitivity of the infrared receptors in pyrophilous Melanophila beetles.

Pyrophilous jewel beetles of the genus Melanophila approach forest fires and there is considerable evidence that these beetles can detect fires from great distances of more than 60 km. Because Melanophila beetles are equipped with infrared receptors and are also attracted by hot surfaces it can be concluded that these infrared receptors are used for fire detection.The sensitivity of the IR receptors is still unknown.

Infrared receptors in pyrophilous ("fire loving") insects as model for new un-cooled infrared sensors.

Beetles of the genus Melanophila and certain flat bugs of the genus Aradus actually approach forest fires. For the detection of fires and of hot surfaces the pyrophilous species of both genera have developed infrared (IR) receptors, which have developed from common hair mechanoreceptors. Thus, this type of insect IR receptor has been termed photomechanic and shows the following two special features: (i) The formation of a complex cuticular sphere consisting of an outer exocuticular shell as well as of a cavernous microfluidic core and (ii) the enclosure of the dendritic tip of the mechanosensitive neuron inside the core in a liquid-filled chamber.

Water as a major modulator of the mechanical properties of insect cuticle.

The mechanical properties of the sternal cuticle of the locust were investigated by nanoindentation. Modulus and hardness of the exo-, meso-, and endocuticular layers were locally measured under dry and fully wetted conditions in the normal (i.e.

Distribution and functional morphology of photomechanic infrared sensilla in flat bugs of the genus Aradus (Heteroptera, Aradidae).

Globally the flat bug genus Aradus comprises about 200 species. About half a dozen Aradus species can be primarily found on burnt areas and, therefore, have been called pyrophilous. Bugs and their offspring feed on fungi growing on burnt wood.

Micromechanical properties of consecutive layers in specialized insect cuticle: the gula of Pachnoda marginata (Coleoptera, Scarabaeidae) and the infrared sensilla of Melanophila acuminata (Coleoptera, Buprestidae).

Insect cuticle is a highly adaptive material that fulfils a wide spectrum of different functions. Cuticle does not only build the exoskeleton with diverse moveable parts but is also an important component of a stunning variety of mechanosensory receptors. Therefore, the mechanical properties of these specialized cuticular systems are of crucial importance.

Microfluidic photomechanic infrared receptors in a pyrophilous flat bug.

Infrared (IR) receptors are so far known only in boid and crotalid snakes and in three genera of pyrophilous beetles that seek out forest fires. Pyrophilous insects can also be found in other orders, however, so it can be hypothesised that IR receptors also occur in some of these species. We investigated the pyrophilous Australian flat bug Aradus albicornis and found a small number of dome-shaped sensilla (diameter 13 microm) on the prothorax, which have previously not been described.

The analysis of the mechanosensory origin of the infrared sensilla in Melanophila acuminata (Coeloptera; Buprestidae) adduces new insight into the transduction mechanism.

The thoracic infrared (IR) sensilla of the pyrophilous jewel beetle Melanophila acuminata most likely have evolved from hair mechanoreceptors (sensilla trichodea). To further elucidate the sensory transduction mechanism, the morphology of IR sensilla and of neighbouring hair mechanoreceptors was investigated by using conventional electron microscopical techniques (SEM, TEM) in combination with focused ion beam milling (FIB). It was assumed that any deviation from the bauplan of a sensillum trichodeum is of particular concern for the transduction of IR radiation into a mechanical stimulus.

Variation in number and differentiation of the abdominal infrared receptors in the Australian 'fire-beetle' Merimna atrata (Coleoptera, Buprestidae).

Most individuals of the Australian 'fire-beetle' Merimna atrata have two pairs of IR receptors which are located ventrolaterally on the second and third abdominal sternite. An IR receptor consists of a specialized IR absorbing area, which is innervated by a neural complex. This complex contains one thermoreceptive multipolar neuron with a unique terminal dendritic mass (TDM) and two scolopidia and was termed 'sensory complex'.

Electrophysiological characterisation of the infrared organ of the Australian "Little Ash Beetle" Acanthocnemus nigricans (Coleoptera, Acanthocnemidae).

This study characterises the response properties of the sensilla located on the prothoracic disc organ of the beetle Acanthocnemus nigricans, such as intensity response functions and temporal coding properties. Warming the sensilla by a red laser accelerated their ongoing spiking activity, cessation of the stimulus suppressed their firing as revealed by extracellular recordings. Convective heat sources also increased sensillum activity, but stimuli of other modalities failed to elicit responses.

A new type of insect infrared organ of low thermal mass.

The Australian beetle Acanthocnemus nigricans is attracted by forest fires and has a pair of complex infrared (IR) receptor organs on the first thoracic segment. Each organ consists of a tiny sensory disc (diameter 120-130 microm) which serves as an absorbing structure for IR radiation. The disc is arranged above an air-filled cavity which is located just anteriorly to the coxae of the prothoracic legs.