Stylotermitidae appear peculiar among all termites, feeding in trunks of living trees in South Asia only. The difficulty to collect them limits the ability to study them, and they thus still belong to critically unknown groups in respect to their biology. We used a combination of microscopic observations, chemical analysis and behavioural tests, to determine the source and chemical nature of the trail-following pheromone of Stylotermes faveolus from India and S. halumicus from Taiwan. The sternal gland located at the 5th abdominal segment was the exclusive source of the trail-following pheromone in both S. faveolus and S. halumicus, and it is made up of class I, II and III secretory cells. Using gas chromatography coupled mass spectrometry, (3Z)-dodec-3-en-1-ol (DOE) was identified as the trail-following pheromone which elicits strong behavioural responses in workers at a threshold around 10- 4 ng/cm and 0.1 ng/gland. Our results confirm the switch from complex aldehyde trail-following pheromones occurring in the basal groups to simpler linear alcohols in the ancestor of Kalotermitidae and Neoisoptera.

• Keywords
• (3Z)-dodec-3-en-1-ol, Neoisoptera, Semiochemicals, sternal gland,
• MeSH
• Pheromones * chemistry   MeSH
• Animal Communication * MeSH
• Gas Chromatography-Mass Spectrometry MeSH
• Cockroaches * MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Pheromones * MeSH

Termites host diverse communities of gut microbes, including many bacterial lineages only found in this habitat. The bacteria endemic to termite guts are transmitted via two routes: a vertical route from parent colonies to daughter colonies and a horizontal route between colonies sometimes belonging to different termite species. The relative importance of both transmission routes in shaping the gut microbiota of termites remains unknown. Using bacterial marker genes derived from the gut metagenomes of 197 termites and one Cryptocercus cockroach, we show that bacteria endemic to termite guts are mostly transferred vertically. We identified 18 lineages of gut bacteria showing cophylogenetic patterns with termites over tens of millions of years. Horizontal transfer rates estimated for 16 bacterial lineages were within the range of those estimated for 15 mitochondrial genes, suggesting that horizontal transfers are uncommon and vertical transfers are the dominant transmission route in these lineages. Some of these associations probably date back more than 150 million years and are an order of magnitude older than the cophylogenetic patterns between mammalian hosts and their gut bacteria. Our results suggest that termites have cospeciated with their gut bacteria since first appearing in the geological record.

• Keywords
• cophylogeny, endosymbionts, isoptera, metagenomics, vertical inheritance,
• MeSH
• Bacteria genetics   MeSH
• Phylogeny MeSH
• Isoptera * MeSH
• Mammals MeSH
• Gastrointestinal Microbiome * MeSH
• Symbiosis MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Termites feed on vegetal matter at various stages of decomposition. Lineages of wood- and soil-feeding termites are distributed across terrestrial ecosystems located between 45°N and 45°S of latitude, a distribution they acquired through many transoceanic dispersal events. While wood-feeding termites often live in the wood on which they feed and are efficient at dispersing across oceans by rafting, soil-feeders are believed to be poor dispersers. Therefore, their distribution across multiple continents requires an explanation. Here, we reconstructed the historical biogeography and the ancestral diet of termites using mitochondrial genomes and δ13C and δ15N stable isotope measurements obtained from 324 termite samples collected in five biogeographic realms. Our biogeographic models showed that wood-feeders are better at dispersing across oceans than soil-feeders, further corroborated by the presence of wood-feeders on remote islands devoid of soil-feeders. However, our ancestral range reconstructions identified 33 dispersal events among biogeographic realms, 18 of which were performed by soil-feeders. Therefore, despite their lower dispersal ability, soil-feeders performed several transoceanic dispersals that shaped the distribution of modern termites.

• Keywords
• Isoptera, biogeography, ecology, feeding group, mitogenomes, stable isotopes,
• MeSH
• Diet MeSH
• Ecosystem MeSH
• Genome, Mitochondrial * MeSH
• Isoptera * genetics   MeSH
• Soil MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Soil MeSH

Colonies of social insects contain large amounts of resources often exploited by specialized social parasites. Although some termite species host numerous parasitic arthropod species, called termitophiles, others host none. The reason for this large variability remains unknown. Here, we report that the evolution of termitophily in rove beetles is linked to termite nesting strategies. We compared one-piece nesters, whose entire colony life is completed within a single wood piece, to foraging species, which exploit multiple physically separated food sources. Our epidemiological model predicts that characteristics related to foraging (e.g., extended colony longevity and frequent interactions with other colonies) increase the probability of parasitism by termitophiles. We tested our prediction using literature data. We found that foraging species are more likely to host termitophilous rove beetles than one-piece nesters: 99.6% of known termitophilous species were associated with foraging termites, whereas 0.4% were associated with one-piece nesters. Notably, the few one-piece nesting species hosting termitophiles were those having foraging potential and access to soil. Our phylogenetic analyses confirmed that termitophily primarily evolved with foraging termites. These results highlight that the evolution of complex termite societies fostered social parasitism, explaining why some species have more social parasites than others.

• Keywords
• nest, phylogenetic comparative analysis, sis model, social evolution, social parasitism,
• MeSH
• Coleoptera * MeSH
• Phylogeny MeSH
• Insecta MeSH
• Isoptera * MeSH
• Symbiosis MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH