The rapid development of analytical methods in the last four decades has led to the discovery of a fascinating diversity of defensive chemicals used by termites. The last exhaustive review on termite defensive chemicals was published by G.D. Prestwich in 1984. In this text, we aim to fill the gap of the past 25 years and overview all of the relevant primary sources about the chemistry of termite defense (126 original papers, see Fig. 1 and online supplementary material) along with related biological aspects, such as the anatomy of defensive glands and their functional mechanisms, alarm communication, and the evolutionary significance of these defensive elements.

• MeSH
• biologická evoluce * MeSH
• biosyntetické dráhy fyziologie   MeSH
• chování zvířat fyziologie   MeSH
• diterpeny metabolismus   MeSH
• Isoptera chemie   fyziologie   MeSH
• komunikace zvířat * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• diterpeny MeSH

Despite their ecological importance, nothing is known about the diversity and abundance of RNA viruses in termites (Termitoidae). We used a metatranscriptomics approach to determine the RNA virome structure of 50 diverse species of termite that differ in both phylogenetic position and colony composition. From these samples, we identified 67 novel RNA viruses, characterized their genomes, quantified their abundance and inferred their evolutionary history. These viruses were found within or similar to those from the Togaviridae, Iflaviridae, Polycipiviridae, Flaviviridae, Leviviridae, Narnaviridae, Mitoviridae, Lispivirdae, Phasmaviridae, Picobirnaviridae and Partitiviridae. However, all viruses identified were novel and divergent, exhibiting only 20% to 45% amino acid identity to previously identified viruses. Our analysis suggested that 17 of the viruses identified were termite-infecting, with the remainder likely associated with the termite microbiome or diet. Unclassified sobemo-like and bunya-like viruses dominated termite viromes, while most of the phylogenetic diversity was provided by the picobirna- and mitovirus-like viruses. Of note was the identification of a novel flavi-like virus most closely related to those found in marine vertebrates and invertebrates. Notably, the sampling procedure had the strongest association with virome composition, with greater RNA virome diversity in libraries prepared from whole termite bodies than those that only sampled heads.

• Klíčová slova
• RNA sequencing, RNA viruses, ecology, evolution, metatranscriptomics, termites,
• MeSH
• genetická variace MeSH
• genom virový genetika   MeSH
• Isoptera virologie   MeSH
• RNA virová genetika   MeSH
• RNA-viry klasifikace   genetika   izolace a purifikace   MeSH
• virom genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• RNA virová MeSH

Termites (Blattodea: Isoptera) have evolved specialized defensive strategies for colony protection. Alarm communication enables workers to escape threats while soldiers are recruited to the source of disturbance. Here, we study the vibroacoustic and chemical alarm communication in the wood roach Cryptocercus and in 20 termite species including seven of the nine termite families, all life-types, and all feeding and nesting habits. Our multidisciplinary approach shows that vibratory alarm signals represent an ethological synapomorphy of termites and Cryptocercus. In contrast, chemical alarms have evolved independently in several cockroach groups and at least twice in termites. Vibroacoustic alarm signaling patterns are the most complex in Neoisoptera, in which they are often combined with chemical signals. The alarm characters correlate to phylogenetic position, food type and hardness, foraging area size, and nesting habits. Overall, species of Neoisoptera have developed the most sophisticated communication system amongst termites, potentially contributing to their ecological success.

• MeSH
• etologie MeSH
• fylogeneze MeSH
• Isoptera * MeSH
• komunikace MeSH
• lidé MeSH
• švábi * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

It is long established that queens of social insects, including termites, maintain their reproductive dominance with queen primer pheromones (QPPs). Yet, the QPP chemistry has only been elucidated in a single species of lower termites. By contrast, the most diversified termite family Termitidae (higher termites), comprising over 70% of termite species, has so far resisted all attempts at QPP identification. Here, we show that the queen- and egg-specific sesquiterpene (3R,6E)-nerolidol acts as the QPP in the higher termite Embiratermes neotenicus. This species has a polygynous breeding system, in which the primary queen is replaced by multiple neotenic queens of parthenogenetic origin. We demonstrate that (3R,6E)-nerolidol suppresses the development of these parthenogenetic queens and thus mimics the presence of mature queen(s). It acts as an airborne signal and may be used to optimize the number of queens, thus being the key regulatory element in the special breeding system of E. neotenicus.

• MeSH
• feromony MeSH
• Isoptera * MeSH
• partenogeneze MeSH
• seskviterpeny * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• feromony MeSH
• nerolidol MeSH Prohlížeč
• seskviterpeny * MeSH

All termites have established a wide range of associations with symbiotic microbes in their guts. Some termite species are also associated with microbes that grow in their nests, but the prevalence of these associations remains largely unknown. Here, we studied the bacterial communities associated with the termites and galleries of three wood-feeding termite species by using 16S rRNA gene amplicon sequencing. We found that the compositions of bacterial communities among termite bodies, termite galleries, and control wood fragments devoid of termite activities differ in a species-specific manner. Termite galleries were enriched in bacterial operational taxonomic units (OTUs) belonging to Rhizobiales and Actinobacteria, which were often shared by several termite species. The abundance of several bacterial OTUs, such as Bacillus, Clostridium, Corynebacterium, and Staphylococcus, was reduced in termite galleries. Our results demonstrate that both termite guts and termite galleries harbor unique bacterial communities.IMPORTANCE As is the case for all ecosystem engineers, termites impact their habitat by their activities, potentially affecting bacterial communities. Here, we studied three wood-feeding termite species and found that they influence the composition of the bacterial communities in their surrounding environment. Termite activities have positive effects on Rhizobiales and Actinobacteria abundance and negative effects on the abundance of several ubiquitous genera, such as Bacillus, Clostridium, Corynebacterium, and Staphylococcus Our results demonstrate that termite galleries harbor unique bacterial communities.

• Klíčová slova
• Coptotermes, Heterotermes, Nasutitermes, ectosymbionts, symbiosis,
• MeSH
• Bacteria klasifikace   genetika   MeSH
• biodiverzita MeSH
• druhová specificita MeSH
• Isoptera mikrobiologie   MeSH
• mikrobiota * MeSH
• RNA ribozomální 16S genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• RNA ribozomální 16S MeSH

BACKGROUND: A decade ago, the mixed reproductive strategy Asexual Queen Succession (AQS) was first described in termites. In AQS species, the workers, soldiers and dispersing reproductives are produced through sexual reproduction, while non-dispersing (neotenic) queens arise through automictic thelytokous parthenogenesis, replace the founding queen and mate with the founding king. As yet, AQS has been documented in six species from three lineages of lower (Rhinotermitidae) and higher (Termitinae: Termes group and Syntermitinae) termites. Independent evolution of the capacity of thelytoky as a preadaptation to AQS is supported by different mechanisms of automixis in each of the three clades. These pioneering discoveries prompt the question on the extent of thelytoky and AQS in the diversified family of higher termites. RESULTS: Here, we investigated the capacity of thelytoky and occurrence of AQS in three species from the phylogenetic proximity of the neotropical AQS species Cavitermes tuberosus (Termitinae: Termes group): Palmitermes impostor, Spinitermes trispinosus, and Inquilinitermes inquilinus. We show that queens of all three species are able to lay unfertilized eggs, which undergo thelytokous parthenogenesis (via gamete duplication as in C. tuberosus) and develop through the transitional stage of aspirants into replacement neotenic queens. CONCLUSIONS: The breeding system in P. impostor is very reminiscent of that described in C. tuberosus and can be characterized as AQS. In the remaining two species, our limited data do not allow classifying the breeding system as AQS; yet, also in these species the thelytokous production of neotenic females appears to be a systematic element of reproductive strategies. It appears likely that the capacity of thelytokous parthenogenesis evolved once in the Termes group, and may ultimately be found more widely, well beyond these Neotropical species.

• Klíčová slova
• Asexual queen succession, Gamete duplication, South America, Termes-group, Termites, Thelytokous parthenogenesis,
• MeSH
• fylogeneze MeSH
• Isoptera klasifikace   genetika   fyziologie   MeSH
• mikrosatelitní repetice MeSH
• nepohlavní rozmnožování MeSH
• partenogeneze MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Termites have a rich set of exocrine glands. These glands are located all over the body, appearing in the head, thorax, legs and abdomen. Here, we describe the oral gland, a new gland formed by no more than a few tens of Class I secretory cells. The gland is divided into two secretory regions located just behind the mouth, on the dorsal and ventral side of the pharynx, respectively. The dominant secretory organelle is a smooth endoplasmic reticulum. Secretion release is under direct control of axons located within basal invaginations of the secretory cells. The secretion is released through a modified porous cuticle located at the mouth opening. We confirmed the presence of the oral gland in workers and soldiers of several wood- and soil-feeding species of Rhinotermitidae and Termitidae, suggesting a broader distribution of the oral gland among termites. The oral gland is the smallest exocrine gland described in termites so far. We hypothesise that the oily secretion can either ease the passage of food or serve as a primer pheromone.

• Klíčová slova
• Blattodea, Isoptera, Pharynx, Smooth endoplasmic reticulum, Termitoidae,
• MeSH
• exokrinní žlázy ultrastruktura   MeSH
• Isoptera ultrastruktura   MeSH
• transmisní elektronová mikroskopie MeSH
• ústa ultrastruktura   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Termites are dominant animals of tropical terrestrial ecosystems. Their success is due to their eusocial organization as well as their ability to digest dead plant tissues. While being extremely abundant, the termite diet is poor in crucial nutrients, such as fatty acids. Linoleic acid (LA) is a precursor for many vital biomolecules, and most animals depend on its dietary supply. Termites count among the exceptions known to produce LA de novo, presumably via the action of an unknown Δ12 fatty acyl desaturase (FAD) introducing the second double bond into monounsaturated oleic acid. Here, we search for the evolutionary origin of LA biosynthesis in termites. To this end, we compile the repertoire of FAD homologs from 57 species of termites and their closest relatives, the cockroaches, analyze FAD phylogeny, and identify a potential Δ12 FAD branch, which arose through duplication of a likely Δ9 FAD. We functionally characterize both paralogs and identify the Δ9 activity in the ancestral FAD-A1a and the Δ12 activity responsible for LA biosynthesis in FAD-A1b. Through the combination of homology modeling and site-directed mutagenesis, we pinpoint structural features possibly contributing to the distinct functions, regiospecificities, and substrate preferences of the two enzymes. We confirm the presence of both paralogs in all 36 studied species of the Blattoidea lineage (Blattidae, Lamproblattidae, Cryptocercidae, and termites) and conclude that we identified an evolutionary event important for the ecological success of termites, which took place in their cockroach ancestors roughly 160 My and remained conserved throughout termite diversification into 3,000 extant species.

• Klíčová slova
• Blattodea, Isoptera, biosynthesis, fatty acyl desaturases, linoleic acid, termites,
• MeSH
• ekosystém MeSH
• fylogeneze MeSH
• Isoptera * genetika   MeSH
• kyselina linolová MeSH
• mastné kyseliny MeSH
• švábi * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyselina linolová MeSH
• mastné kyseliny MeSH

Distribution of neurones detectable with antisera to the corazonin (Crz) and the pigment-dispersing factor (PDF) was mapped in the workers or pseudergates of 10 species representing six out of seven termite families. All species contained two triads of Crz-immunoreactive (Crz-ir) neurones in the protocerebrum. Their fibres were linked to the opposite hemisphere, formed a network in the fronto-lateral protocerebrum, and projected to the corpora cardiaca (CC); in most species the fibres also supplied the deuto- and tritocerebrum and the frontal ganglion. Some species possessed additional Crz-ir perikarya in the protocerebrum and the suboesophageal ganglion (SOG). The PDF-ir somata were primarily located in the optic lobe (OL) and SOG. OL harboured a group (3 groups in Coptotermes) of 2-6 PDF-ir cells with processes extending to the medulla, connecting to the contralateral OL, forming 1-2 networks in the protocerebrum, and in most species running also to CC. Such a PDF-ir system associated with the OL was missing in Reticulitermes. Except for Mastotermes, the termites contained 1-2 PDF-ir cell pairs in the SOG and two species had additional perikarya in the protocerebrum. The results are consistent with the view of a monophyletic termite origin and demonstrate how the Crz-ir and PDF-ir systems diversified in the course of termite phylogeny.

• MeSH
• druhová specificita MeSH
• ganglia metabolismus   MeSH
• hmyzí proteiny metabolismus   MeSH
• Isoptera anatomie a histologie   klasifikace   metabolismus   MeSH
• neuropeptidy metabolismus   MeSH
• peptidy metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• corazonin protein, insect MeSH Prohlížeč
• hmyzí proteiny MeSH
• melanophore-dispersing hormone MeSH Prohlížeč
• neuropeptidy MeSH
• peptidy MeSH

The queens of advanced social insects maintain their reproductive monopoly by using exocrine chemicals. The chemistry of these "queen pheromones" in termites is poorly known. We show that primary queens of four higher termites from the subfamily Syntermitinae (Embiratermes neotenicus, Silvestritermes heyeri, Labiotermes labralis, and Cyrilliotermes angulariceps) emit significant amounts of the sesquiterpene alcohol (E)-nerolidol. It is the dominant analyte in queen body washes; it is present on the surface of eggs, but absent in kings, workers, and soldiers. In E. neotenicus, it is also produced by replacement neotenic queens, in quantities correlated with their fertility. Using newly synthesised (3R,6E)-nerolidol, we demonstrate that the queens of this species produce only the (R) enantiomer. It is distributed over the surface of their abdomen, in internal tissues, and in the haemolymph, as well as in the headspace of the queens. Both (R) and (S) enantiomers are perceived by the antennae of E. neotenicus workers. The naturally occurring (R) enantiomer elicited a significantly larger antennal response, but it did not show any behavioural effect. In spite of technical difficulties encountered in long-term experiments with the studied species, (3R,6E)-nerolidol remains among eventual candidates for the role in queen fertility signalling.

• Klíčová slova
• (E)-nerolidol, Syntermitinae, fertility signalling, higher termites, social insects,
• MeSH
• feromony chemie   metabolismus   MeSH
• fertilita MeSH
• Isoptera metabolismus   fyziologie   MeSH
• komunikace zvířat MeSH
• seskviterpeny chemie   metabolismus   MeSH
• sociální chování MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• feromony MeSH
• nerolidol MeSH Prohlížeč
• seskviterpeny MeSH