Identification of Pheromone Components of Plagionotus detritus (Coleoptera: Cerambycidae), and Attraction of Conspecifics, Competitors, and Natural Enemies to the Pheromone Blend

(1) Background: The principal aim of our work was to identify pheromone components for Plagionotus detritus (L.) (Coleoptera: Cerambycidae), which could be exploited for developing a pheromone-based monitoring system for the complementary purposes of plant protection in areas where it might become a pest, and natural conservation in areas where it is rare or endangered. (2) Methods: Collection and analysis of headspace volatiles were carried out with field-collected beetles. Bioactive volatile compounds identified [(R)-3-hydroxyhexan-2-one and (S)-2-hydroxyoctan-3-one] from extracts of males were purchased [(±)-3-hydroxyhexan-2-one], and synthesized [(S)-2-hydroxyoctan-3-one] and field-tested. Electroantennogram assays showed that antennae of the predatory beetle Clerus mutillarius F. (Coleoptera: Cleridae) also responded to the synthetic compounds. (3) Results: A two-component aggregation-sex pheromone consisting of (R)-3-hydroxyhexan-2-one and (S)-2-hydroxyoctan-3-one was identified for P. detritus. (±)-3-hydroxyhexan-2-one and (S)-2-hydroxyoctan-3-one attracted adults of P. detritus in field bioassays. Adults of the clerid C. mutillarius also were attracted to both compounds. The cerambycid Xylotrechus antilope Schönh was significantly attracted to traps baited with (S)-2-hydroxyoctan-3-one alone or the blend containing this compound. (4) Conclusions: Our data confirmed that 3-hydroxyhexan-2-one and 2-hydroxyoctan-3-one are male-produced pheromone components for P. detritus. These results show that both intraspecific and interspecific communication may play key roles in longhorn beetle life history and ecology, with closely and more distantly related species eavesdropping on each other’s signals.

Fur glowing under UV: a widespread consequence of porphyrin accumulation in mammals

Spectacular photoluminescence (PL) phenomena have been increasingly reported in various organisms from diverse ecosystems. However, the chemical basis of this PL remains poorly defined, and its potential ecological function is still blurry, especially in mammals. Here we used state-of-the-art spectroscopy and multispectral imaging techniques to document new cases of mammalian ultraviolet-induced PL (UV-PL) and to identify free-base porphyrins and natural derivatives as the organic compounds responsible for the reddish luminescence observed in the hairs and spines of distantly related species. We argue that pink to red UV-PL is predominantly observed in crepuscular and nocturnal mammals because porphyrins are photodegradable, and that this phenomenon might not have a specific function in intra- or interspecific communication but consists of a byproduct of a widespread physiological condition, overlooked in mammals.Co-first authors: Séverine Toussaint and Jasper Ponstein

An Ozonolysis Based Method and Applications for the Non-lethal Modification of Insect Cuticular Hydrocarbons

Cuticular hydrocarbons (CHCs) are important, multi-function components of the insect epicuticle. In Drosophila spp., CHCs provide protection from desiccation and serve as semiochemicals for both intra- and interspecific communication. We developed a non-lethal method for the modification of Drosophila CHCs profiles through the exposure of live insects to a high dose of ozone gas (~45,000 ppm). Drosophila suzukii that were treated with ozone showed a 1.63-3.10 fold reduction in unsaturated hydrocarbons with these CHCs shown to regenerate over 108 h. Changes in CHCs were correlated with significantly reduced desiccation resistance in both male and female D. suzukii at one h after ozone treatment. Interestingly, individuals treated with ozone showed increased desiccation resistance in comparison to controls at 108 h after ozone treatment. The methodology reported in this paper provides a novel approach to investigate the biosynthesis and functions of CHCs during the lifespan of an insect.

Homo Sapiens, Mnesitardigrada Class and Umwelt: A Dialogue on Interspecies Organic Data Flow

This article presents artistic research based on existing knowledge about interspecific communication and hypothesis about the spread of interplanetary civilizations. It is expressed as an imagined communication flow between a human earthling scientist and a Kquaanian–human hybrid who is an artist by earthly occupation. While these two species’ sensoria are too different to allow discussion, this consideration supports the poetic approach to interspecies understanding, through immersive interactive installations and a willingness to share thoughts and feelings, in answering questions about the world and our place in it. The organs, molecules and protein expression of tardigrades provide a point of departure.

Biology, sounds and vibratory signals of hooded katydids (Orthoptera: Tettigoniidae: Phyllophorinae)

The tettigoniid subfamily Phyllophorinae, distributed in Southeast Asia and Australia, is poorly known. Our study of the biology of Giant Katydid Siliquofera grandis (Blanchard, 1853) from a laboratory culture has shown that these insects mate more than once, the females lay a total of up to 400 eggs during their life, and these hatch after 2–2.5 months. The life cycle from egg to death takes longer than one year. In the laboratory, the insects fed mainly on leaves of various Rosaceae, Ficus, and lettuce, and on fruits. It is known that the males of hooded katydids lack the tegminal stridulatory apparatus typical for Tettigoniidae, but are capable of producing protest sounds using their coxosternal sound-producing organs for stridulation. Here, protest stridulation of the males and females and the sound-producing organs used to produce it have been analyzed in Phyllophorina kotoshoensis Shiraki, 1930 and S. grandis. In addition, nymphal protest sounds produced by friction of the metafemur against the edge of the pronotum and adult protest signals produced with the wings are described. In S. grandis, vibratory signals have been described and studied for the first time: territorial, protest, drumming and rhythmic low-amplitude vibrations emitted by adults and nymphs and pre- and postcopulatory vibrations of the males and females. The territorial signals not accompanied with visible movements of the body may be produced by contracting the antagonist muscles of the thorax and possibly of the legs. Using their coxosternal sound-producing organs males of S. grandis produced also an audible courtship song lasting for several seconds. Acoustic signals may thus both regulate intrapopulation relations and serve for interspecific communication (protest signals). The acoustic communication in Phyllophorinae is probably especially important during mating behavior.

Semiotic alignment: Towards a dialogical model of interspecific communication

Communicative interactions across different species have so far received relatively little attention from cognitive or behavioral scientists. Most research in this area views the process of communication as the adaptive interaction of manipulative signalers and information-assessing receivers. This paper discusses some shortcomings of the information/influence model of communication, particularly in the empirical study of interspecific communicative interactions. It then presents an alternative theoretical model, based on recent contributions in psycholinguistics and semiotics. The semiotic alignment model views communication as a dynamic process of joint semiosis resulting in the alignment of the interactants’ own-worlds (Umwelten). It is argued that this model can improve our understanding of communicative interactions between heterospecifics and provide the basis for future work in the empirical study of interspecific communication.

‘Crystal Macrosetae’: Novel Scales and Bristles in Male Arctiine Moths (Lepidoptera: Erebidae: Arctiinae) Filled with Crystallizing Material

Scales, exoskeletal features characteristic of the Lepidoptera, occur in enormous structural and functional diversity. They cover the wing membranes and other body parts and give butterflies and moths their often stunning appearance. Generally, the patterns made by scales are visual signals for intra- and interspecific communication. In males, scales and/or bristles also make up the androconial organs, which emit volatile signals during courtship. Here, a structurally and putative functionally novel type of scales and bristles is reported: ‘crystal macrosetae’. These lack trabeculae and windows, are made up by a very thin and flexible envelope only and contain crystallizing material. In ‘crystal scales’, there is a flat surface ornamentation of modified ridges, while ‘crystal bristles’ often show large protrusions. Crystal macrosetae usually cannot be reliably recognized without destruction. Apparently, they serve as containers for large amounts of material that is viscous in living moths, highly hygroscopic, crystallizes when specimens dry up, and can be visualized by scanning electron microscopy. Crystal macrosetae occur in males only, always associated with or making up androconial organs located on various parts of the body, and have numerous forms with diverse surface ornamentation across many species and genera. The newly identified structures and the discovery of crystallizing material in scales and bristles raise many questions and could shed new light on ontogenetic development of macrosetae, and on the biology and physiology as well as the evolution and systematics of Arctiinae. There is evidence that crystal macrosetae occur in other moths too.

Free-ranging dogs are capable of comprehending complex human pointing cues

Dogs are the most common species to be found as pets and have been subjects of human curiosity leading to extensive research on their socialization with humans. One of the dominant themes in dog cognition pertains to their capacity of understanding and responding to human referential gestures. The remarkable socio-cognitive skills of pet dogs, while interacting with humans, is quite well established. However, studies regarding the free-ranging subpopulations are greatly lacking. Free-ranging dogs represent an ideal system to investigate interspecific communication with unfamiliar humans, nullifying any contribution of indirect conditioning. The interactions of these dogs with humans are quite complex and multidimensional. For the first time, we tested free-ranging dogs’ ability to understand relatively complex human referential gestures using dynamic and momentary distal pointing cues. We found that these dogs are capable of apprehending distal pointing cues from humans. However, approximately half of the population tested showed a lack of tendency to participate even after successful familiarization with the experimental set-up. A closer inspection revealed anxious behavioural states of the individuals were responsible for such an outcome. We assume that life experiences with humans probably shape personalities of free-ranging dogs, which in turn influence their responsiveness to human communicative gestures.