Iskanje po repozitoriju

A+ | A- | | SLO | ENG

Povzetek: In Ensifera, the lack of well-supported phylogeny and the focus on acoustic communication of the terminal taxa hinders understanding of the evolutionary history of their signalling behaviour and the related sensory structures. For Rhaphidophoridae, the most relic of ensiferans following morphology-based phylogenies, the signalling modes are still unknown. Together with a detailed description of their mating process, we provide evidence on vibratory signalling for the sympatric European species Troglophilus neglectus and T. cavicola. Despite their temporal shift in reproduction, the species’ behaviours differ significantly. Signalling by abdominal vibration constitutes an obligatory part of courtship in T. neglectus, while it is absent in T. cavicola. Whole-body vibration is expressed after copulation in both species. While courtship signalling appears to stimulate females for mating, the function of post-copulation signals remains unclear. Mating and signalling of both species were found to take place in most cases on bark, and less frequently on other available substrates, like moss and rock. The signals’ frequency spectra were substrate dependent, but with the dominant peak always expressed below 120 Hz. On rock, the intensity of T. neglectus courtship signals was below the species’ physiological detection range, presumably constraining the evolution of such signalling in caves. The species’ behavioural divergence appears to reflect their divergent mating habitats, in and outside caves. We propose that short-range tremulation signalling in courtship, such as is expressed by T. neglectus, represents the primitive mode and context of mechanical signalling in Ensifera. The absence of high-frequency components in the signals may be related to the absence of the crista acoustica homologue (CAH) in the vibratory tibial organ of Rhaphidophoridae. This indirectly supports the hypothesis proposing that the CAH, as an evolutionary precursor of the ear, evolved in Ensifera along the (more) complex vibratory communication, also associated with signals of higher carrier frequency.
Ključne besede: insects, communication (biology), animal behaviour
Objavljeno v DiRROS: 12.03.2025; Ogledov: 544; Prenosov: 371
Celotno besedilo (492,80 KB)
Gradivo ima več datotek! Več...

Povzetek: Field crickets (Gryllidae) produce sounds by tegminal stridulation, well-studied for its role in female attraction and choice. However, understanding female preferences for their courtship song remains elusive, despite considering additional chemical, visual, and thermal signals. Beyond stridulation, crickets also display vibrational courtship behaviours that remain largely unexplored. Using Acheta domesticus as a model, we conduct the first comprehensive analysis of the entirety of vibroacoustic courtship signals in crickets, including their interaction. Employing audio recording, laser vibrometry, and videorecording, we unveil a complex signal involving simultaneous wing stridulation, body tremulation, and leg drumming against the substrate in a prolonged display, unique among insects. We identify robust correlations, coupling, and coordination between these signal components. We show the tightest coupling between the two types of stridulation pulses, and between tremulation and drumming signals, while drumming-stridulation coupling is less consistent, revealing a constraint on drumming performance. This constraint in the expression of one signal component, without a trade-off, represents a specific case within complex dynamic signalling. In addition, we find no correlation between drumming rate and its accuracy relative to stridulation, challenging common expectations. Our findings indicate that the information conveyed by the complex courtship display in A. domesticus is not simply proportional to that in the song, shedding light on previous ambiguities surrounding its function. Spectral-intensity analysis indicates the closest perceptual connection between stridulation and drumming signals, likely commonly influencing female choice, while proposing another function for tremulation. Further research should delve deeper into the function of this intricate signal.
Ključne besede: male quality, substrate vibration, sound, complex signal, dynamic signal, insects, zoology, biology
Objavljeno v DiRROS: 04.12.2024; Ogledov: 720; Prenosov: 1270
Celotno besedilo (5,61 MB)
Gradivo ima več datotek! Več...

Povzetek: Kako privabiti divje opraševalce? Število divjih opraševalcev najlažje povečamo tako, da jim zagotovimo dovolj hrane in varnih mest za gnezdenje. Hrano zagotovimo s sajenjem rastlin, na katerih nabirajo cvetni prah in medičino in z redkejšo košnjo dela travnikov. Pomembno je, da je hrana na razpolago tudi v času, ko kmetijske rastline, ki bi jih želeli opraševati, ne cvetijo. Gnezdilna mesta najlažje zagotovimo z nastavljanjem posebnih gnezdilnic. Pomembno je tudi, da opustimo ali vsaj zmanjšamo uporabo pesticidov. V ustreznem okolju se bodo opraševalci naselili sami in ne bodo zahtevali posebne skrbi.
Ključne besede: čmrlji, čebele samotarke, opraševanje
Objavljeno v DiRROS: 04.09.2024; Ogledov: 966; Prenosov: 775
Celotno besedilo (3,33 MB)
Gradivo ima več datotek! Več...

Povzetek: Plants influenced the evolution of plant-dwelling stink bugs’ systems underlying communication with chemical and substrate-borne vibratory signals. Plant volatiles provides cues that increase attractiveness or interfere with the probability of finding a mate in the field. Mechanical properties of herbaceous hosts and associated plants alter the frequency, amplitude, and temporal characteristics of stink bug species and sex-specific vibratory signals. The specificity of pheromone odor tuning has evolved through highly specific odorant receptors located within the receptor membrane. The narrow-band low-frequency characteristics of the signals produced by abdomen vibration and the frequency tuning of the highly sensitive subgenual organ vibration receptors match with filtering properties of the plants enabling optimized communication. A range of less sensitive mechanoreceptors, tuned to lower vibration frequencies, detect signals produced by other mechanisms used at less species-specific levels of communication in a plant environment. Whereas the encoding of frequency-intensity and temporal parameters of stink bug vibratory signals is relatively well investigated at low levels of processing in the ventral nerve cord, processing of this information and its integration with other modalities at higher neuronal levels still needs research attention.
Objavljeno v DiRROS: 05.08.2024; Ogledov: 921; Prenosov: 952
Celotno besedilo (3,07 MB)
Gradivo ima več datotek! Več...

Povzetek: In animal contests, communicating aggressive motivation is most often mediated by visual or acoustic signals, while chemical signals are not expected to serve such a function since they are less able to be modulated by the sender during the changing behavioral context. We describe a rare example of ephemeral olfactory signals in terrestrial animals, signals that are emitted via protrusive scent glands in male cave crickets Troglophilus neglectus (Orthoptera, Rhaphidophoridae) to reflect the state of the signaler’s aggression. We correlate the intensity of behaviorally expressed aggression of the individuals in dyadic contests with the frequency and extent of their gland tissue protrusion, the latter serving as an indication of the amount of released odor. We detected large amounts of odor release during brief gland protrusions, and the absence of its release during gland retraction. Males protruded the glands during and after encountering a rival, with the degree of protrusion increasing with the intensity of the signalers’ aggression. During the encounters, the degree of gland protrusion increased most strongly with the occurrence of the elevated body posture, directly preceding the attack. This degree was significantly higher in encounter winners than in losers displaying such posture, suggesting the highly important role of the released odor for contest resolution. After the encounters, glands were protruded almost exclusively by winners, apparently announcing victory. We tested for the function of the olfactory signals also directly, by preventing gland tissue protrusion in symmetric and asymmetric treatments of the contestants. Treating only the dominant individuals decreased the percentage of encounters they won by over 60%, while treating both contestants elicited a significant increase in the frequency and duration of fights. During contests, the olfactory signals of T. neglectus apparently function as a highly effective threat, which prevents maximal contest escalation and decreases the conflict-related costs.
Ključne besede: animal behaviour, bioacoustics, aggression
Objavljeno v DiRROS: 25.07.2024; Ogledov: 1388; Prenosov: 542
Celotno besedilo (13,82 MB)
Gradivo ima več datotek! Več...