Biology subjects

Torrez, L.

Publications and source records attributed to Torrez, L..

3 recordsLinked to original sources

bioRxiv2025

Culex (Culex) acharistus, Root, 1927 (Diptera: Culicidae), a new record for Bolivia

This study reports the first confirmed records of Culex (Culex) acharistus, Root, 1927 in Bolivia, based on both morphological examination and biomolecular identification using the cytochrome c oxidase subunit I (COI) marker. Specimens were collected in four localities representing diverse environmental settings: La Paz (urban environment, {asymp}3600 m), the nearby high-altitude city of El Alto ({asymp}4000 m), Cochabamba (semi-rural and urban habitats, {asymp}2600 m), and Licoma a large village in the Yungas region (subtropical environment, {asymp}1900 m). The larval habitats where the species was found closely match those reported in neighboring countries where Cx. acharistus also occurs, ranging from typical small peridomestic sites to ponds, ditches, and river seepages in semi-rural areas. All identification methods yielded unambiguous results, confirming the species presence in Bolivia and extending its known distribution in South America. This finding highlights the importance of integrating morphological and molecular approaches to achieve accurate and reliable mosquito species identification.

ecology↗

bioRxiv2025

Detection of Anopheles pseudopunctipennis (Diptera: Culicidae) in Cochabamba, Bolivia, after 90 years of suspected presence

Objectives.This study provides the first confirmed record of the malaria vector Anopheles pseudopunctipennis in Cochabamba city, Bolivia, ending nearly 90 years of suspected presence since the malaria epidemics of the 1930s and 1940s. Additionally, it assesses the potential suitability of the region for this mosquito species. MethodsMosquito larvae were collected as part of a comprehensive survey of Culicidae in Cochabamba city and its suburbs. Larvae of An. pseudopunctipennis were collected on April 16, 2024, and reared to the fourth instar in the laboratory. One male specimen obtained from collected larvae was pinned. Specimens were morphologically identified using a standard identification key and species re-description. The larval identification was based on its unique spiracular apparatus, while adults were identified by their characteristic black hind tarsomeres and unspotted wing costa. The specimens are preserved in the Laboratory of Medical Entomology at UMSS, Cochabamba. ResultsA single larval habitat was identified in Lincoln Park, in the center of Cochabamba. It consisted of a 184 m{superscript 2} pond with a cement bottom, clear water with very slow flow from a small spring, and abundant Rhizoclonium algae. A Maxent habitat suitability model indicated that the Cochabamba Valley provides suitable environmental conditions for An. pseudopunctipennis. ConclusionsThis study provides the first concrete evidence of An. pseudopunctipennis in Cochabamba city, confirming its presence after decades of speculation. However, its low abundance and limited larval habitats due to urbanization and pollution suggest that it poses no significant malaria transmission risk in the area.

ecology↗

bioRxiv2025

Statistical analysis of larval postspiracular filament length reveals continuous variation in Bolivian Anopheles pseudopunctipennis (Diptera: Culicidae)

Anopheles pseudopunctipennis is a neotropical malaria vector widely distributed from northern Argentina and Chile to the southern United States. At the larval stage, it is characterized by posterior-lateral caudal filaments, which vary markedly in length within the same samples in Bolivia, with some individuals displaying unusually long filaments. The coexistence of individuals with relatively long and relatively short filaments raises the question of whether at least two distinct populations could be differentiated based on caudal filament length. This study examined filament-length distributions in two Bolivian dry-valley populations, El Chaco and Mataral, to determine whether variation reflects distinct subpopulations or continuous phenotypic variation within a single population. Distributions deviated from normality, exhibiting moderate skewness and tail heaviness, and the Generalized Error Distribution provided the best statistical fit. Examination of outliers and a targeted analysis of the distribution tail using multiple complementary methods showed that extreme values did not form a discrete secondary cluster but rather represented the upper continuum of the trait range. The two sites showed broadly comparable distributions, consistent with similar environmental conditions. These results emphasize the importance of using appropriate distributional models for continuous traits, highlight the occurrence of rare extreme phenotypes within otherwise homogeneous populations, and provide a baseline for future studies on the ecological and genetic determinants of caudal filament variation in An. pseudopunctipennis.

zoology↗