AUTHOR=Dally Maria , Izraeli Yehuda , Belausov Eduard , Mozes-Daube Netta , Coll Moshe , Zchori-Fein Einat 

TITLE=Rickettsia association with two Macrolophus (Heteroptera: Miridae) species: A comparative study of phylogenies and within-host localization patterns

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1107153

DOI=10.3389/fmicb.2022.1107153

ISSN=1664-302X

ABSTRACT=<p>Many arthropods host bacterial symbionts, some of which are known to influence host nutrition and diet breadth. Omnivorous bugs of the genus <italic>Macrolophus</italic> (Heteroptera: Miridae) are mainly predatory, but may also feed on plants. The species <italic>M. pygma</italic>eus and <italic>M. melanotoma</italic> (=<italic>M. caliginosus</italic>) are key natural enemies of various economically important agricultural pests, and are known to harbor two <italic>Rickettsia</italic> species, <italic>R. bellii</italic> and <italic>R. limoniae</italic>. To test for possible involvement of symbiotic bacteria in the nutritional ecology of these biocontrol agents, the abundance, phylogeny, and distribution patterns of the two <italic>Rickettsia</italic> species in <italic>M. pygmaeus</italic> and <italic>M. melanotoma</italic> were studied. Both of the <italic>Rickettsia</italic> species were found in 100 and 84% of all tested individuals of <italic>M. pygmaeus</italic> and <italic>M. melanotoma,</italic> respectively. Phylogenetic analysis showed that a co-evolutionary process between <italic>Macrolophus</italic> species and their <italic>Rickettsia</italic> is infrequent. Localization of <italic>R. bellii</italic> and <italic>R. limoniae</italic> has been detected in both female and male of <italic>M. pygmaeus</italic> and <italic>M. melanotoma</italic>. FISH analysis of female gonads revealed the presence of both <italic>Rickettsia</italic> species in the germarium of both bug species. Each of the two <italic>Rickettsia</italic> species displayed a unique distribution pattern along the digestive system of the bugs, mostly occupying separate epithelial cells, unknown caeca-like organs, the Malpighian tubules and the salivary glands. This pattern differed between the two <italic>Macrolophus</italic> species: in <italic>M. pygmaeus, R. limoniae</italic> was distributed more broadly along the host digestive system and <italic>R. bellii</italic> was located primarily in the foregut and midgut. In contrast, in <italic>M. melanotoma</italic>, <italic>R. bellii</italic> was more broadly distributed along the digestive system than the clustered <italic>R. limoniae</italic>. Taken together, these results suggest that <italic>Rickettsia</italic> may have a role in the nutritional ecology of their plant-and prey-consuming hosts.</p>