Search Results (5)

Anthropic activities such as agriculture, livestock, and wastewater discharges affect water quality in the Tlapaneco River in the mountain region of the state of Guerrero, México, which is a tributary of the Balsas. The river flows from the mountain region and discharges into the Pacific Ocean; the water resource in the localities mentioned is used for agriculture, recreation, and domestic activities. The aim of this study was to evaluate water quality in the stretch of influence of two localities, Patlicha and Copanatoyac. The instrument used was the Biological Monitoring Working Party biotic index (BMWP) and physicochemical parameters. Nine sampling sites were selected according to the perception of the local community with respect to disturbance; the study area was divided into three parts: high, medium, and low. Twenty-seven collections of macroinvertebrates and water were analyzed, in dry and rainy seasons, through the presence–absence of these organisms and physicochemical analysis, to evaluate water quality. The results showed that the conditions of the riverbed associated with daily activities and domestic discharges are important factors in the composition of the families. Water quality was very poor to regular, according to the macroinvertebrate assemblages collected. The BMWP index was of acceptable quality when the orders (Family) Ephemeroptera (Leptohyphidae; Leptophlebiidae; Baetidae; Ephemerellidae), Diptera (Chironomidae; Simulidae), Trichoptera (Hydropsychidae), Hemiptera (Veliidae; Corixidae), Coleoptera (Hydrophylidae), and Odonata (Lestidae) were present; in sites with poor quality, the families Chironomidae, Leptophlebiidae, Veliidae, Corixidae, Hydropsychidae, Leptohyphidae, Hydrophilidae, Baetidae, and Simuliidae were found, while in very poor quality water, only family Corixidae was present. Full article

The broad-shouldered water-strider genus Paravelia Breddin, 1898 (Hemiptera: Heteroptera: Veliidae: Veliinae) is currently represented in Brazil by 38 species. Although the diversity of the genus in the country is relatively well known, eight states remain with no records of any species: Acre, Alagoas, Ceará (CE), Paraíba, Paraná, Pernambuco (PE), Piauí (PI), and Tocantins. Aiming to fill these gaps, several expeditions were carried out at conservation areas of the Caatinga biome between 2018 and 2021: Aiuaba Ecological Station (CE), Catimbau National Park (PE), and Serra das Confusões National Park (PI). Paravelia luisi sp. nov., a new species from PE, is described and illustrated. In addition, new records of P. bilobata Rodrigues, Moreira, Nieser, Chen & Melo, 2014, P. digitata Rodrigues & Moreira, 2016, and P. nieseri Moreira & Barbosa, 2012, and an updated key to the Brazilian species of Paravelia are provided. This study increases the number of species of Paravelia known in Brazil to 39 and provides the first records of the genus from three states: PE, with two species, and CE and PI, with one species each. Full article

The Gerromorpha assemblages in mangroves located in the central and eastern regions of Thailand were examined, and a total of nine species belonging to six genera and three families were discovered. Four of the recorded species are new records for Thailand. Asclepios annandalei Distant, 1915 was the most common species and widely distributed throughout the study area. The most diverse genus was Xenobates, which consisted of Xenobates argentatus Andersen, 2000, Xenobates mandai Andersen, 2000, Xenobates murphyi Andersen, 2000, and Xenobates singaporensis Andersen, 2000. Three of these species are new country records. Here, we present taxonomic and ecological information of mangrove gerromorphans in the central and eastern regions of Thailand. Full article

Semiaquatic bugs (Hemiptera: Heteroptera: Gerromorpha) are mostly wing-polymorphic species with flight dispersal as an important life history trait, but the specific flight ability and dispersal pattern remain unexplored in most species. This report presents the results of a long-term survey based on the individual marking of more than 23,000 specimens of eight water striders (Gerridae) and a water cricket Velia caprai (Veliidae). Three distinct lentic habitats were sampled (solitary fishponds, systems of nearby fishponds and systems of small, often temporary pools) and one lotic habitat—a small forest stream. Recaptures revealed that three gerrid species tend to stay at the breeding site, but can differ in dispersal via the water surface. Reproductive flightless females disperse most actively via the water surface, possibly bypassing the trade-off between dispersal and reproduction. One species has a sex-dependent dispersal pattern, with females being rather philopatric, whereas males often disperse. Three other gerrid species are highly dispersive and tend to change breeding site. V. caprai, the only lotic species included in this survey, tend to move upstream and possibly compensate for the downstream drift. Full article

Buruli ulcer (BU), caused by Mycobacterium ulcerans, is a neglected tropical disease associated with freshwater habitats. A variety of limnic organisms harbor this pathogen, including aquatic bugs (Hemiptera: Heteroptera), which have been hypothesized to be epidemiologically important reservoirs. Aquatic Hemiptera exhibit high levels of diversity in the tropics, but species identification remains challenging. In this study, we collected aquatic bugs from emerging foci of BU in the Southwest Region of Cameroon, which were identified using morphological and molecular methods. The bugs were screened for mycobacterial DNA and a selection of 20 mycobacteria-positive specimens from the families Gerridae and Veliidae were subjected to next-generation sequencing. Only one individual revealed putative M. ulcerans DNA, but all specimens contained sequences from the widespread alpha-proteobacterial symbiont, Wolbachia. Phylogenetic analysis placed the Wolbachia sequences into supergroups A, B, and F. Circularized mitogenomes were obtained for seven gerrids and two veliids, the first from these families for the African continent. This study suggests that aquatic Hemiptera may have a minor role (if any) in the spread of BU in Southwest Cameroon. Our metagenomic analysis provides new insights into the incursion of Wolbachia into aquatic environments and generated valuable resources to aid molecular taxonomic studies of aquatic Hemiptera. Full article