Culture-Independent Characterization of the Microbiota of the Ant LionMyrmeleon mobilis(Neuroptera: Myrmeleontidae)

Abstract

Ant lions are insect larvae that feed on the liquefied internal components of insect prey. Prey capture is assisted by the injection of toxins that are reportedly derived from both the insect and bacterial symbionts. These larvae display interesting gut physiology where the midgut is not connected to the hindgut, preventing elimination of solid waste until adulthood. The presence of a discontinuous gut and the potential involvement of bacteria in prey paralyzation suggest an interesting microbial role in ant lion biology; however, the ant lion microbiota has not been described in detail. We therefore performed culture-independent 16S rRNA gene sequence analysis of the bacteria associated with tissues of an ant lion, Myrmeleon mobilis. All 222 sequences were identified as Proteobacteria and could be subdivided into two main groups, the ␣-Proteobacteria with similarity to Wolbachia spp. (75 clones) and the ␥-Proteobacteria with similarity to the family Enterobacteriaceae (144 clones). The Enterobacteriaceae-like 16S rRNA gene sequences were most commonly isolated from gut tissue, and Wolbachia-like sequences were predominant in the head and body tissue. Fluorescence in situ hybridization analyses supported the localization of enterics to gut tissue and Wolbachia to nongut tissue. The diversity of sequences isolated from freshly caught, laboratory-fed, and laboratory-starved ant lions were qualitatively similar, although the libraries from each treatment were significantly different (P ‫؍‬ 0.05). These results represent the first culture-independent analysis of the microbiota associated with a discontinuous insect gut and suggest that the ant lion microbial community is relatively simple, which may be a reflection of the diet and gut physiology of these insects.

Geographical Distribution and Diversity of Bacteria Associated with Natural Populations of Drosophila melanogaster

“…They hypothesized that this pattern could be due to the humid environments that ticks prefer, which are more permissive conditions for desiccation-sensitive microbes such as proteobacteria. The prevalence of proteobacteria has also been shown for several other species of insects, including Culicoides sonorensis, an orbivirus vector (11); the honeybee Apis mellifera (34); and the ant lion, Myrmeleon mobilis (20). In contrast, bacterial communities associated with certain species of wood-and soil-feeding termites tend to be biased towards gram-positive microorganisms (29,65).…”

“…The same techniques are currently being applied to understanding the microbiota of a range of insects (11,29,34,47,53,55,56,65). For example, using such sequence-based approaches, Dunn and Stabb (20) found that the ant lion, Myrmeleon mobilis, harbors a relatively simple microbial community, represented mostly by Enterobacteriaceaeand Wolbachia-like microorganisms. In contrast, Campbell et al (11) found a more diverse microbiota in the biting midge, Culicoides sonorensis, comprised of genera from five different bacterial divisions.…”

Bacterial Diversity Analysis of Huanglongbing Pathogen-Infected Citrus, Using PhyloChip Arrays and 16S rRNA Gene Clone Library Sequencing

“…Most of the clones in the 16S rRNA gene library were closely related to bacteria reported to be endosymbionts of various insects (17,20,21,46). Lacava et al (31) have reported similarity between the endophytes of host plants and bacteria inhabiting the head region of the glassy-winged sharpshooter, Homalodisca vitripennis, an important vector of various strains of X. fastidiosa.…”

Microbial diversity in the larval gut of field and laboratory populations of the sugarcane weevil Sphenophorus levis (Coleoptera, Curculionidae)

“…Organisms from the Enterobacteriaceae family that have the ability to ferment sugar (Ewing, 1986) seem to play a key role in the S. levis field population as they represent 70% of the total sequences found in the 16S rRNA gene library. Weevils and other insects harbor various maternally transmitted Enterobacteriaceae (Lefèvre et al, 2004); members of the Enterobacteriaceae are found in many environments, including the guts of other termite and insect species (Dillon and Dillon, 2004;Delalibera et al, 2005;Dunn and Stabb, 2005). The desert locust, Schistocerca gregaria, also possesses an abundant gut microbiota consisting predominantly of Enterobacteriaceae (Hunt and Charnley, 1981).…”