Evolutionary history of tyrosine-supplementing endosymbionts in pollen-feeding beetles.

Many insects feeding on nutritionally challenging diets like plant sap, leaves, or wood engage in ancient associations with bacterial symbionts that supplement limiting nutrients or produce digestive or detoxifying enzymes. However, the distribution, function, and evolutionary dynamics of microbial symbionts in insects exploiting other plant tissues or relying on a predacious diet remain poorly understood. Here, we investigated the evolutionary history and function of the intracellular gamma-proteobacterial symbiont "Candidatus Dasytiphilus stammeri" in soft-winged flower beetles (Coleoptera, Melyridae, Dasytinae) that transition from saprophagy or carnivory to palynivory (pollen-feeding) between larval and adult stage. Reconstructing the distribution of the symbiont within the Dasytinae phylogeny unraveled not only a long-term coevolution, originating from a single acquisition event with subsequent host-symbiont codiversification, but also several independent symbiont losses. The analysis of 20 different symbiont genomes revealed that their genomes are severely eroded. However, the universally retained shikimate pathway indicates that the core metabolic contribution to their hosts is the provisioning of tyrosine for cuticle sclerotization and melanization. Despite the high degree of similarity in gene content and order across symbiont strains, the capacity to synthesize additional essential amino acids and vitamins and to recycle urea is retained in some but not all symbionts, suggesting ecological differences among host lineages. This report of tyrosine-provisioning symbionts in insects with saprophagous or carnivorous larvae and pollen-feeding adults expands our understanding of tyrosine supplementation as an important symbiont-provided benefit across a broad range of insects with diverse feeding ecologies.

First report of Austroporus doctus (Blackburn) from New Zealand and description of its larva (Coleoptera: Phalacridae)

The Australian species Austroporus doctus (Blackburn) is reported from New Zealand for the first time. Adults are illustrated and diagnosed, and late-instar larvae are fully described and illustrated. In addition, a summary of prior larval descriptions of Phalacridae is provided. This represents the first description of the morphology and habitat of the larvae within the genus Austroporus Gimmel and the Olibroporus-group of genera. Austroporus doctus is native to eastern Australia, where adults are distinguished from similar species by characters of the male genitalia and by a suite of external morphological features. There are no native members of Phalacridae known from New Zealand, but A. doctus represents the second introduced and established species there. A key is given to differentiate adult and larval A. doctus from the other introduced New Zealand species, Phalacrus uniformis (Blackburn).(AU)

First report of Austroporus doctus (Blackburn) from New Zealand and description of its larva (Coleoptera: Phalacridae)

Abstract The Australian species Austroporus doctus (Blackburn) is reported from New Zealand for the first time. Adults are illustrated and diagnosed, and late-instar larvae are fully described and illustrated. In addition, a summary of prior larval descriptions of Phalacridae is provided. This represents the first description of the morphology and habitat of the larvae within the genus Austroporus Gimmel and the Olibroporus-group of genera. Austroporus doctus is native to eastern Australia, where adults are distinguished from similar species by characters of the male genitalia and by a suite of external morphological features. There are no native members of Phalacridae known from New Zealand, but A. doctus represents the second introduced and established species there. A key is given to differentiate adult and larval A. doctus from the other introduced New Zealand species, Phalacrus uniformis (Blackburn).

First report of Austroporus doctus (Blackburn) from New Zealand and description of its larva (Coleoptera: Phalacridae)

The Australian species Austroporus doctus (Blackburn) is reported from New Zealand for the first time. Adults are illustrated and diagnosed, and late-instar larvae are fully described and illustrated. In addition, a summary of prior larval descriptions of Phalacridae is provided. This represents the first description of the morphology and habitat of the larvae within the genus Austroporus Gimmel and the Olibroporus-group of genera. Austroporus doctus is native to eastern Australia, where adults are distinguished from similar species by characters of the male genitalia and by a suite of external morphological features. There are no native members of Phalacridae known from New Zealand, but A. doctus represents the second introduced and established species there. A key is given to differentiate adult and larval A. doctus from the other introduced New Zealand species, Phalacrus uniformis (Blackburn).