The symbiosis between microorganisms and host arthropods can cause biological, physiological, and reproductive changes in the host population. The present study aimed to survey facultative symbionts of the genera Wolbachia, Arsenophonus, Cardinium, Rickettsia, and Nosema in Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) and Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) in the laboratory and evaluate the influence of infection on the fitness of these hosts. For this purpose, 16S rDNA primers were used to detect these facultative symbionts in the host species, and the hosts' biological and morphological features were evaluated for changes resulting from the infection caused by these microorganisms. The bacterial symbionts studied herein were not detected in the D. saccharalis samples analysed, but the endosymbiont Wolbachia was detected in C. flavipes and altered the biological and morphological aspects of this parasitoid insect. The results of this study may help to elucidate the role of Wolbachia in maintaining the quality of populations/lineages of C. flavipes.

Few studies have examined the genetic population structure of vector-borne microparasites in wildlife, making it unclear how much these systems can reveal about the movement of their associated hosts. This study examined the complex host–vector–microbe interactions in a system of bats, wingless ectoparasitic bat flies (Nycteribiidae), vector-borne microparasitic bacteria (Bartonella) and bacterial endosymbionts of flies (Enterobacterales) across an island chain in the Gulf of Guinea, West Africa. Limited population structure was found in bat flies and Enterobacterales symbionts compared to that of their hosts. Significant isolation by distance was observed in the dissimilarity of Bartonella communities detected in flies from sampled populations of Eidolon helvum bats. These patterns indicate that, while genetic dispersal of bats between islands is limited, some non-reproductive movements may lead to the dispersal of ectoparasites and associated microbes. This study deepens our knowledge of the phylogeography of African fruit bats, their ectoparasites and associated bacteria. The results presented could inform models of pathogen transmission in these bat populations and increase our theoretical understanding of community ecology in host–microbe systems.

The whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is one of the most important agricultural pests and virus vectors worldwide. Bemisia tabaci is considered a complex of cryptic species with at least 44 species. Among them, the species Middle East-Asia Minor 1 (MEAM1, formerly B biotype) and Mediterranean (MED, formerly Q biotype) are the most important, and they have attained global status. In Brazil, MEAM1 was first reported in the 1990s and is currently the predominant species in the country, meanwhile, MED was recently reported in the South and Southeast regions and was found to be mainly associated with ornamental plants. Currently, an increasing problem in the management of whitefly infestations in greenhouses associated with bell pepper was observed in São Paulo State, Brazil. The whiteflies were collected and identified based on a microsatellite locus (primer pair BEM23F and BEM23R) and the mitochondrial cytochrome oxidase I gene followed by restriction fragment length polymorphism analysis and sequencing. We observed that MED was the predominant species collected on bell pepper, but it was also found on tomato, cucumber, eggplant, and weeds grown in greenhouses. In open field, we found MED on tomatoes, bell peppers, and eggplants. In addition, MED was identified in Goiás State in association with ornamental plants. The begomovirus Tomato severe rugose virus and the crinivirus Tomato chlorosis virus was detected on bell pepper and tomato, respectively. Only MED specimens were found associated with the virus-infected plants. Moreover, we also investigated the endosymbionts present in the MED whiteflies. The collected populations of B. tabaci MED harbored a diversity of secondary endosymbionts, with Hamiltonella (H) found predominantly in 89 specimens of the 129 tested. These results represent a new concern for Brazilian agriculture, especially for the management of the newly introduced whitefly MED species, which must be implemented to limit the spreading and establishment of this pest in different crops in this country.

Spire-bearing brachiopods formally comprise four different rhynchonelliform orders. A calcified spiral brachidium (presumably supporting a spirolophe when alive) and variable median fold and sulcus (probably aiding separation of incurrent from excurrent flows) are peculiar characteristics they all share. Inferences regarding feeding current systems for these extinct taxa have long remained controversial. Two rival models (the Williams–Ager model and the Rudwick–Vogel model) have been developed, each of which has gained supporters as well as critics over the years. In this present paper they are both contrasted and reassessed on the basis of available evidence, together with a new approach that combines: (a) a morpho-functional analysis applying the plankton net as a suitable seston-collecting paradigm; (b) a review of actualistic data showing that all extant spirolophes are functionally inhalant (irrespective of water entering the valves laterally or not); (c) an evaluation of known outcomes from flume experiments yielding consistent empirical results where gaping shells are oriented transversally and dorsally upcurrent; and (d) a reappraisal of the distributions of certain epizoobionts and endosymbionts revealing compatible patterns. The evidence thus accumulated supports the main conclusion that, in most groups (with laterally tapering spiralia), the inhalant current was located medially with the exhalant currents on either side; only in atrypides (with centrally to dorsally tapering spiralia) does the reverse situation appear to have occurred.

The merging of two independent populations of heterotrophs and autotrophs into a single population of mixotrophs has occurred frequently in evolutionary history. It is an example of a wide class of related phenomena, known as symbiogenesis. The physiological basis is almost always (reciprocal) syntrophy, where each species uses the products of the other species. Symbiogenesis can repeat itself after specialization on particular assimilatory substrates. We discuss quantitative aspects and delineate eight steps from two free-living interacting populations to a single fully integrated endosymbiotic one. The whole process of gradual interlocking of the two populations could be mimicked by incremental changes of particular parameter values. The role of products gradually changes from an ecological to a physiological one. We found conditions where the free-living, epibiotic and endobiotic populations of symbionts can co-exist, as well as conditions where the endobiotic symbionts outcompete other symbionts. Our population dynamical analyses give new insights into the evolution of cellular homeostasis. We show how structural biomass with a constant chemical composition can evolve in a chemically varying environment if the parameters for the formation of products satisfy simple constraints. No additional regulation mechanisms are required for homeostasis within the context of the dynamic energy budget (DEB) theory for the uptake and use of substrates by organisms. The DEB model appears to be closed under endosymbiosis. This means that when each free-living partner follows DEB rules for substrate uptake and use, and they become engaged in an endosymbiotic relationship, a gradual transition to a single fully integrated system is possible that again follows DEB rules for substrate uptake and use.