Seasonal life cycle of Pintomyia longiflocosa (Diptera: Psychodidae) under semi-controlled conditions in the Huila state, Colombia.

BACKGROUND: Pintomyia longiflocosa is considered a vector of etiological agents of cutaneous leishmaniasis. The objective of this research was to establish the parameters of the life cycle of Pi. longiflocosa in semi-controlled conditions in a rural area of the Campoalegre municipality, Huila, Colombia. METHODOLOGY/PRINCIPAL FINDINGS: The life cycle of individuals of Pi. longiflocosa, obtained from two cohorts of collected, fed, and individualized females, was monitored during two different times of the year (between February and August 2020 and between July 2020 and January 2021, respectively). Determining parameters associated with the fertility and fecundity, time and attributes of development and survival, and its association with abiotic variables. The average duration of Cycle 1 (C1) and Cycle 2 (C2) was 134.9 and 148.78 days, respectively. The gonotrophic cycle of parental females presented significant differences (p-value <0.05) between C1 and C2 (8.47 and 11.42 days) as well as between fecundity and fertility parameters. The number of days it takes the development of the immature stages between the two cycles studied, also showed significant differences in the larvae II (15.21 and 22.23), larvae III (11.93 and 17.56), and pupae (24.48 and 22.9) stages. During C1, the survival rate was higher and consistent with the productivity of adult individuals (F1), compared to C2. Fecundity and fertility values were significantly higher in C2. Finally, a significant correlation between the number of individuals and temperature was evidenced in C1 while, for C2, there was a negative correlation with precipitation. CONCLUSIONS/SIGNIFICANCE: Significant differences were found in several biological and reproductive parameters between the two cycles monitored. The parameters of the life cycle of Pi. longiflocosa in its natural habitat would be influenced by environmental factors related to the annual seasonality in the sub-Andean rural area, conditioning the temporal distribution of this species and, consequently, the possible transmission of causative agents of cutaneous leishmaniasis.

Spatio-Temporal distribution of a vector of cutaneous leishmaniasis: Pintomyia longiflocosa, in a population from the Colombian Andean Mountains.

BACKGROUND: Leishmaniasis, a neglected disease and public health concern, is associated with various factors such as biological, social, economical conditions and climate, increasing the risk of human infection. Understanding the population dynamics of the vectors, like Pintomyia longiflocosa, and its relationship with ecological variables is crucial for developing effective strategies to control sand fly populations and combat cutaneous leishmaniasis in a tropical country like Colombia. METHODOLOGY: Adult sand flies were collected in three different sample locations: outdoor, indoor, and peri-domestic areas in three houses located in the rural settlement of Campoalegre (Huila) between February 2020 and February 2021, using the CDC light traps. The sand fly density was quantified and associated with the sample locations and the sampling months using Analysis of Variance and Pearson correlations. PRINCIPAL FINDINGS: In the period of the sample, 98.86% of sand fly collected was identified as Pi. longiflocosa. The density of this species was significantly different between males and females, the latter contributing more to density in all sample locations (P<0.0001). The outdoor was the sample location with the highest and most significative density in this study (70%, P = 0.04). The density of these sand flies is related to the seasonality of Campoalegre, revealing a density peak from February and June to October (P < 0.05). Finally, precipitation is the environmental variable prominently linked to the density pattern, showing a negative correlation with it. Months with the highest precipitations show the lowest values of Pi. longiflocosa abundance. CONCLUSIONS/SIGNICANCE: Our investigation reveals a inverse correlation between precipitation levels and the abundance of Pi. longiflocosa in Campoalegre (Huila), particularly in outdoor areas. This suggests that vector control strategies to periods of reduced precipitation in outdoor settings could offer an effective approach to minimizing cases of cutaneous leishmaniasis in the region.

Lutzomyia antunesi, probable vector de leishmaniasis cutánea en el área rural de Villavicencio / Lutzomyia antunesi as suspected vector of cutaneous leishmaniasis in the Orinoquian region of Colombia

Objetivo Definir los posibles vectores de leishmaniasis, teniendo en cuenta su abundancia e infección natural con Leishmania spp. en un área endémica de la zona rural de Villavicencio, Meta. Materiales y Métodos En la vereda La Reforma, donde se presentaron casos de leishmaniasis cutánea en caninos y humanos, se recolectaron con trampas CDC los flebótomos en el intra, peri y extradomicilio de 15 viviendas. Grupos de 1 a 3 hembras de la misma especie fueron procesados por PCR para la detección de parásitos de Leishmania spp. Resultados Se capturaron 1 304 flebótomos distribuidos en 9 especies de las cuales L. antunesi (75,6 por ciento) y L. walkeri (19,2 por ciento) fueron las más abundantes. Otras especies reconocidas como antropofílicas (L. panamensis y L. gomezi), se presentaron con abundancias muy bajas (< 2,4). La PCR detectó infección con Leishmania spp. en dos grupos de L. antunesi (total= 123 hembras procesadas). Conclusiones L. antunesi por su abundancia e infección natural con Leishmania spp. podría estar involucrada en la transmisión de la leishmaniasis cutánea en un área rural al suroeste del municipio de Villavicencio.

Objective Identifying probable cutaneous leishmaniasis vectors in a rural area a few kilometres from the city of Villavicencio, taking the relative abundance of sand-flies and their natural infection with Leishmania spphaving into account. Materials and Methods A CDC trap was used for sampling sand-flies in and around 15 dwellings. Pools of three females from the most abundant Lutzomyia species were used for identifying Leishmania spp. by PCR, with OL1 and OL2 primers. Results 1 304 sand-flies from nine species were captured, of which L. antunesi (75,6 percent) and L. walkeri (19,2 percent) were the most abundant. These was a low abundance of L. panamensis and L. gomezi anthropophilic species (<2,4 percent). PCR detected Leishmania spp. infection in two L. antunesi groups (total=123 processed females). Conclusions Due to the fact that L. antunesi was the most abundant species and was found to have Leishmania infection, it may be considered to be the main suspected cutaneous leishmaniasis vector in the rural area being studied. It is recommended that detailed studies of this species’ biology (including biting and resting behaviour) should be carried out, aimed at furthering vector control measures.

[Lutzomyia antunesi as suspected vector of cutaneous leishmaniasis in the Orinoquian region of Colombia]. / Lutzomyia antunesi, probable vector de leishmaniasis cutánea en el area rural de villavicencio.

OBJECTIVE: Identifying probable cutaneous leishmaniasis vectors in a rural area a few kilometres from the city of Villavicencio, taking the relative abundance of sand-flies and their natural infection with Leishmania spphaving into account. MATERIALS AND METHODS: A CDC trap was used for sampling sand-flies in and around 15 dwellings. Pools of three females from the most abundant Lutzomyia species were used for identifying Leishmania spp. by PCR, with OL1 and OL2 primers. RESULTS: 1 304 sand-flies from nine species were captured, of which L. antunesi (75,6 %) and L. walkeri (19,2 %) were the most abundant. These was a low abundance of L. panamensis and L. gomezi anthropophilic species (<2,4 %). PCR detected Leishmania spp. infection in two L. antunesi groups (total=123 processed females). CONCLUSIONS: Due to the fact that L. antunesi was the most abundant species and was found to have Leishmania infection, it may be considered to be the main suspected cutaneous leishmaniasis vector in the rural area being studied. It is recommended that detailed studies of this species' biology (including biting and resting behaviour) should be carried out, aimed at furthering vector control measures.