Revision of Hypoxys Amyot amp; Serville, 1843 stat. rest. (Heteroptera Pentatomidae).

Hypoxys is one of four subgenera of Edessa (Fabricius, 1787) together with Aceratodes (De Geer, 1773), Dorypleura (Lepeletier Serville, 1825) and Edessa (Fabricius, 1787). This taxon has a very confusing taxonomy due to incorrect use of the names available, imprecise descriptions, and large number of very similar species. To illustrate the confusion, Hypoxys potentially includes a large number of species of Edessa, but actually contains only the type species, according to the most recent catalogue. The name E. quadridens Fabricius, 1803, type species of Hypoxys, was used for more than a century as a label to identify a large group of similar species. In this work we continue revising Edessa elevating Hypoxys to genus based on the following morphological characters: proximal part of costal margin black; evaporatorium with a deep notch on lateral margin; anterior arms of metasternal process acuminate; pygophore longer than wide and subrectangular or barrel-shaped in dorsal view; dorsal rim of pygophore well-projected, almost reaching posterolateral angles and finishing in a small lobe; and posterolateral angles of pygophore not developed. Hypoxys is being divided in four species groups to include 17 species transferred from Edessa. H. quadridens group comprises: Hypoxys quadridens (Fabricius, 1803) (type species), H. boerneri (Breddin, 1904) comb. nov., H. claricolor (Breddin, 1907) comb. nov., H. dolosus (Breddin, 1907) comb. nov., H. eburatulus (Breddin, 1907) comb. nov., H. necopinatus (Breddin, 1907) comb. nov., H. offuscatus (Breddin, 1907) comb. nov. and H. trabeculus (Breddin, 1907) comb. nov. H. triangularis group comprises: H. triangularis (Dallas, 1851) comb. nov. (type species), H. capito (Breddin, 1904) comb. nov. and H. subrastratus (Bergroth, 1891) comb. nov. H. oxyacanthus group comprises: H. oxyacanthus (Breddin, 1904) comb. nov. (type species), H. brachyacanthus (Breddin, 1904) comb. nov., H. infulatus (Breddin, 1904) comb. nov., H. leptacanthus (Breddin, 1904) comb. nov. and H. tragelaphus (Breddin, 1903) comb. nov. H. balteatus group comprises only H. balteatus (Walker, 1868) comb. nov. These groups of species will be useful to organize the new species of Hypoxys that will be described in upcoming papers. Descriptions, measurements, photos of genitalia of both sexes; photos in dorsal and ventral views of the species; and distribution maps are provided. Males of H. capito, H. claricolor, H. eburatulus, H. infulatus, and H. subrastratus are described for the first time. Female of H. necopinatus is described for the first time. Edessa jugalis is considered a junior synonym of H. quadridens; E. rimata a junior synonym of H. offuscatus; E. scabriventris and E. leprosula junior synonyms of H. triangularis; E. pachyacantha a junior synonym of H. tragelaphus; E. orba a junior synonym of E. oxyacanthus. A key to the species of Hypoxys is also provided.

Seasonal and regional dynamics of M. ulcerans transmission in environmental context: deciphering the role of water bugs as hosts and vectors.

BACKGROUND: Buruli ulcer, the third mycobacterial disease after tuberculosis and leprosy, is caused by the environmental mycobacterium M. ulcerans. Various modes of transmission have been suspected for this disease, with no general consensus acceptance for any of them up to now. Since laboratory models demonstrated the ability of water bugs to transmit M. ulcerans, a particular attention is focused on the transmission of the bacilli by water bugs as hosts and vectors. However, it is only through detailed knowledge of the biodiversity and ecology of water bugs that the importance of this mode of transmission can be fully assessed. It is the objective of the work here to decipher the role of water bugs in M. ulcerans ecology and transmission, based on large-scale field studies. METHODOLOGY/PRINCIPAL FINDINGS: The distribution of M. ulcerans-hosting water bugs was monitored on previously unprecedented time and space scales: a total of 7,407 water bugs, belonging to large number of different families, were collected over one year, in Buruli ulcer endemic and non endemic areas in central Cameroon. This study demonstrated the presence of M. ulcerans in insect saliva. In addition, the field results provided a full picture of the ecology of transmission in terms of biodiversity and detailed specification of seasonal and regional dynamics, with large temporal heterogeneity in the insect tissue colonization rate and detection of M. ulcerans only in water bug tissues collected in Buruli ulcer endemic areas. CONCLUSION/SIGNIFICANCE: The large-scale detection of bacilli in saliva of biting water bugs gives enhanced weight to their role in M. ulcerans transmission. On practical grounds, beyond the ecological interest, the results concerning seasonal and regional dynamics can provide an efficient tool in the hands of sanitary authorities to monitor environmental risks associated with Buruli ulcer.

Early trafficking events of Mycobacterium ulcerans within Naucoris cimicoides.

The severe skin-destructive disease caused by Mycobacterium ulcerans, named Buruli ulcer, is the third most important mycobacterial disease in humans after tuberculosis and leprosy. Recently we demonstrated that M. ulcerans could colonize the salivary glands of the water bug, Naucoris cimicoides. In this study, we report that M. ulcerans may be delivered from the digested prey aspirate to the coelomic cavity via a unique headspace, the head capsule (HC). During the infected meal, we observed that M. ulcerans clusters adhered to the stylets that were retracted in the HC at the end of the meal. M. ulcerans was able to translocate from the HC to the coelomic cavity where it is phagocytosed by the plasmatocytes. These cells are subverted as shuttle cells and deliver M. ulcerans to the salivary glands. At this early stage of its parasitic life style, two other important features of M. ulcerans can be documented: first, mycolactone is not required for translocation of M. ulcerans into the HC, in contrast to the next step, colonization of the salivary glands; second, M. ulcerans clusters bind a member of the serpin protein family present in the salivary gland homogenate.

Colonization of the salivary glands of Naucoris cimicoides by Mycobacterium ulcerans requires host plasmatocytes and a macrolide toxin, mycolactone.

Mycobacterium ulcerans was first identified as the causative agent of Buruli ulcer; this cutaneous tissue-destructive process represents the third most important mycobacterial disease in humans after tuberculosis and leprosy. More recently other life traits were documented. M. ulcerans is mainly detected in humid tropical zones as part of a complex ecosystem comprising algae, aquatic insect predators of the genus Naucoris, and very likely their vegetarian preys. Coelomic plasmatocytes could be the first cells of Naucoris cimicoides to be involved in the infection process, acting as shuttle cells that deliver M. ulcerans to the salivary glands as suggested by both in vitro and in vivo approaches. Furthermore, a key element for the early and long-term establishment of M. ulcerans in Naucoridae is demonstrated by the fact that only mycolactone toxin-producing M. ulcerans isolates are able to invade the salivary glands, a site where they proliferate. Later, the raptorial legs of Naucoris are covered by M. ulcerans-containing material that displays features of biofilms.