1. Vibrational noise disrupts Nezara viridula communication, irrespective of spectral overlapRok Janža, Nataša Stritih Peljhan, Aleš Škorjanc, Jernej Polajnar, Meta Virant-Doberlet, 2024, izvirni znanstveni članek Povzetek: Insects rely on substrate vibrations in numerous intra- and interspecific interactions. Yet, our knowledge of noise impact in this modality lags behind that in audition, limiting our understanding of how anthropogenic noise affects insect communities. Auditory research has linked impaired signal perception in noise (i.e., masking) to spectral overlap. We investigated the impact of noise with different spectral compositions on the vibrational communication of the stink bug Nezara viridula, examining courtship behaviour and signal representation by sensory neurons. We found negative effects of vibrational noise regardless of spectral overlap, challenging common expectations. Noise impaired the ability of males to recognize the female signal and localise its source: overlapping noise decreased sensitivity of receptor neurons to the signal and disrupted signal frequency encoding by phase-locking units, while non-overlapping noise only affected frequency encoding. Modelling neuronal spike triggering in sensory neurons linked disrupted frequency encoding to interference-induced alterations of the signal waveform. These alterations also affected time delays between signal arrivals to different legs, crucial for localisation. Our study thus unveils a new masking mechanism, potentially unique to insect vibrosensory systems. The findings highlight the higher vulnerability of vibration-mediated behaviour to noise, with implications for insect interactions in natural and anthropogenically altered environments.
Ključne besede: biotremology, vibrations, noise, communication, neurons, masking, entomology, neurobiology
Objavljeno v DiRROS: 21.11.2024; Ogledov: 133; Prenosov: 2474
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2. Čmrlji in čebele samotarke - prezrti opraševalciDanilo Bevk, 2015, druge monografije in druga zaključena dela 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: 350; Prenosov: 246
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3. Monitoring populacij izbranih ciljnih vrst hroščev v letih 2016 in 2017 : prvo delno poročiloAl Vrezec, Špela Ambrožič Ergaver, Andrej Kapla, elaborat, predštudija, študija Povzetek: V končnem poročilu so predstavljeni rezultati terenskih raziskav štirih varstveno pomembnih vrst hroščev v Sloveniji v letu 2016. Za močvirskega krešiča (Carabus variolosus), rogača (Lucanus cervus), alpskega kozlička (Rosalia alpina) in bukovega kozlička (Morimus funereus) je v Sloveniji že vzpostavljena shema populacijskega in distribucijskega monitoringa. V tem poročilu so podani rezultati popisov populacijskega in distribucijskega monitoringa v letu 2016. V tem letu smo izvedli vzorčenja za populacijski monitoring za močvirskega krešiča (deseto snemanje), rogača (deseto snemanje), alpskega (deveto snemanje) in bukovega kozlička (osmo snemanje) ter vzorčenja za distribucijski monitoring za močvirskega krešiča in rogača (četrto leto v tretjem petletnem ciklusu). Dodatno so glede na najnovejše raziskave podani predlogi izboljšanja sheme monitoringa za rogača in alpskega kozlička. V poročilu so predstavljeni rezultati popisa v letih 2016 in 2017 za dopolnitev strokovnih podlag za puščavnika (Osmoderma eremita) in škrlatnega kukuja (Cucujus cinnaberinus). Za obe vrsti sta podani tudi predlogi sheme monitoringa. V okviru naloge smo opravili pregled vodnega telesa v Spodnjem Krapju in pet vodnih teles ob reki Muri za namene ugotavljanja prisotnosti ovratniškega plavača (Graphoderus bilineatus). Vrsto smo v letu 2017 zopet potrdili ob reki Muri in sicer v Murski šumi, kar je nova lokacija za vrsto v Sloveniji, ne pa tudi v mrtvici pri Spodnjem Krapju, ki je bila do nedavna edina recentna lokaliteta za vrsto pri nas, kjer je bil ovratniški plavač potrjen v letu 2011.
Ključne besede: hrošči, monitoring, ekologija
Objavljeno v DiRROS: 03.09.2024; Ogledov: 265; Prenosov: 714
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4. Stink bug communication and signal detection in a plant environmentAndrej Čokl, Alenka Žunič Kosi, Nataša Stritih Peljhan, Maria Carolina Blassioli Moraes, Raúl Alberto Laumann, Miguel Borges, 2021, pregledni znanstveni članek 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: 327; Prenosov: 280
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5. The subgenual organ complex in the cave cricket Troglophilus neglectus (Orthoptera: Rhaphidophoridae) : comparative innervation and sensory evolutionJohannes Strauß, Nataša Stritih Peljhan, Reinhard Lakes-Harlan, 2014, izvirni znanstveni članek Povzetek: Comparative studies of the organization of nervous systems and sensory organs can reveal their evolution and specific adaptations. In the forelegs of some Ensifera (including crickets and tettigoniids), tympanal hearing organs are located in close proximity to the mechanosensitive subgenual organ (SGO). In the present study, the SGO complex in the non-hearing cave cricket Troglophilus neglectus (Rhaphidophoridae) is investigated for the neuronal innervation pattern and for organs homologous to the hearing organs in related taxa. We analyse the innervation pattern of the sensory organs (SGO and intermediate organ (IO)) and its variability between individuals. In T. neglectus, the IO consists of two major groups of closely associated sensilla with different positions. While the distal-most sensilla superficially resemble tettigoniid auditory sensilla in location and orientation, the sensory innervation does not show these two groups to be distinct organs. Though variability in the number of sensory nerve branches occurs, usually either organ is supplied by a single nerve branch. Hence, no sensory elements clearly homologous to the auditory organ are evident. In contrast to other non-hearing Ensifera, the cave cricket sensory structures are relatively simple, consistent with a plesiomorphic organization resembling sensory innervation in grasshoppers and stick insects.
Ključne besede: neuroanatomy, chordotonal organ, mechanoreceptor, sensory innervation, neural phylogeny
Objavljeno v DiRROS: 02.08.2024; Ogledov: 290; Prenosov: 268
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6. Olfactory signaling of aggressive intent in male-male contests of cave crickets (Troglophilus neglectus; Orthoptera: Rhaphidophoridae)Nataša Stritih Peljhan, Alenka Žunič Kosi, 2017, izvirni znanstveni članek 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: 308; Prenosov: 201
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7. Novel, male-produced aggregation pheromone of the cerambycid beetle Rosalia alpina, a priority species of European conservation concernAlenka Žunič Kosi, Yunfan Zou, Michal Hoskovec, Al Vrezec, Nataša Stritih Peljhan, Jocelyn G. Millar, 2017, izvirni znanstveni članek Povzetek: Several recent studies have demonstrated the great potential for exploiting semiochemicals in ecology and conservation studies. The cerambycid beetle Rosalia alpina represents one of the flagship species of saproxylic insect biodiversity in Europe. In recent years its populations appear to have declined substantially, and its range has shrunk considerably as a result of forest management and urbanization. Here, we collected volatile chemicals released by males and females of R. alpina. Analyses of the resulting extracts revealed the presence of a single male-specific compound, identified as a novel alkylated pyrone structure. In field bioassays in Slovenia, traps baited with the synthesized pyrone captured both sexes of R. alpina, indicating that the pyrone functions as an aggregation pheromone. Our results represent the first example of a new structural class of pheromones within the Cerambycidae, and demonstrate that pheromone-baited traps can provide a useful tool for sampling R. alpina. This tool could be particularly useful in the ongoing development of conservation strategies for the iconic but endangered Alpine longicorn.
Ključne besede: pheromones, beetles, plants, endangered species, conservation science
Objavljeno v DiRROS: 25.07.2024; Ogledov: 338; Prenosov: 391
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8. A male-produced aggregation-sex pheromone of the beetle Arhopalus rusticus (Coleoptera: Cerambycidae, Spondylinae) may be useful in managing this invasive speciesAlenka Žunič Kosi, Nataša Stritih Peljhan, Yunfan Zou, J. Steven McElfresh, Jocelyn G. Millar, 2019, izvirni znanstveni članek Povzetek: The longhorned beetle Arhopalus rusticus (Coleoptera: Cerambycidae, Spondylinae) is a common species in conifer forests of the Northern Hemisphere, but with global trade, it has invaded and become established in New Zealand, Australia, and South America. Arhopalus rusticus is a suspected vector of the phytopathogenic nematode, Bursaphelenchus xylophilus, the causative agent of pine wilt disease, which is a major threat to pine forests worldwide. Here, we report the identification of a volatile, male-produced aggregation-sex pheromone for this species. Headspace odours from males contained a major male-specific compound, identified as (2 S, 5E)-6,10-dimethyl-5,9-undecadien-2-ol (common name (S)-fuscumol), and a minor component (E)-6,10-dimethyl-5,9-undecadien-2-one (geranylacetone). Both compounds are known pheromone components for species in the same subfamily. In field trials in its native range in Slovenia, (S)-fuscumol was significantly more attractive to beetles of both sexes, than racemic fuscumol and a blend of host plant volatiles commonly used as an attractant for this species. Fuscumol-baited traps also caught significant numbers of another spondylidine species, Spondylis buprestoides (L.), and a rare click beetle, Stenagostus rufus (De Geer). The pheromone can be exploited as a cost-effective and environmentally safe tool for detection and monitoring of this invasive species at ports of entry, and for monitoring the beetle’s distribution and population trends in both endemic and invasive populations.
Ključne besede: pheromones, invasive organisms
Objavljeno v DiRROS: 24.07.2024; Ogledov: 303; Prenosov: 153
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