Overwintering in the Bamboo Mosquito Tripteroides bambusa (Diptera: Culicidae) During a Warm, But Unpredictably Changing, Winter

The assumption that vector abundance differences might drive spatial and temporal heterogeneities in vector-borne disease transmission is common, though data supporting it is scarce. Here, we present data from two common mosquito species Aedes aegypti (Linnaeus) and Culex quinquefasciatus Say, biweekly sampled as adults, from March 2016 through December 2017, with BG-sentinel traps in two neighboring districts of Kaohsiung City (KC), Taiwan. One district has historically been a dengue transmission hotspot (Sanmin), and the other a coldspot (Nanzih). We collected a total 41,027 mosquitoes, and we found that average mosquito abundance (mean ± S.D.) was higher in Sanmin (Ae. aegypti: 9.03 ± 1.46; Cx. quinquefasciatus: 142.57 ± 14.38) than Nanzih (Ae. aegypti: 6.21 ± 0.47; Cx. quinquefasciatus: 63.37 ± 8.71) during the study period. In both districts, Ae. aegypti and Cx. quinquefasciatus population dynamics were sensitive to changes in temperature, the most platykurtic environmental variable at KC during the study period, a pattern predicted by Schmalhausen’s law, which states that organisms are more sensitive to small changes in environmental variables whose average value is more uncertain than its extremes. Our results also suggest that differences in Ae. aegypti abundance might be responsible for spatial differences in dengue transmission at KC. Our comparative approach, where we also observed a significant increment in the abundance of Cx. quinquefasciatus in the dengue transmission hotspot, suggests this area might be more likely to experience outbreaks of other vector borne diseases and should become a primary focus for vector surveillance and control.

Section: Discussionsupporting

confidence: 82%

Section: Discussionmentioning

confidence: 99%

Increased Adult Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae) Abundance in a Dengue Transmission Hotspot, Compared to a Coldspot, within Kaohsiung City, Taiwan

Chaves

Tsai

et al. 2018

“…Although it has been suggested that human landing catch is the best method to sample adult mosquitoes in the Neotropics [42], we think our study could have benefited by using other sampling methods for the adult populations, such as Mosquito Magnet ® traps [102]. Also, our environmental data could have been more descriptive of the local environmental conditions of our sampling sites if our budget had allowed us to use data loggers measuring local weather variables [103] instead of resorting to spatially coarsely grained records from gridded databases. We also think that a more frequent sampling, for example, biweekly instead of monthly, could have been helpful to straightforwardly link patterns of larvae and adult abundance, which at the monthly time scale, were not significantly correlated with each other.…”

Section: Discussionmentioning

confidence: 99%

Population Dynamics of Anopheles albimanus (Diptera: Culicidae) at Ipetí-Guna, a Village in a Region Targeted for Malaria Elimination in Panamá

Hurtado

Rigg

Calzada

et al. 2018

Anopheles albimanus Wiedemann is a major malaria vector in Mesoamerica and the Caribbean whose population dynamics, in response to changing environments, has been relatively poorly studied. Here, we present monthly adult and larvae data collected from May 2016 to December 2017 in Ipetí-Guna, a village within an area targeted for malaria elimination in the República de Panamá. During the study period we collected a total of 1678 Anopheles spp. mosquitoes (1602 adults and 76 larvae). Over 95% of the collected Anopheles spp. mosquitoes were An. albimanus. Using time series analysis techniques, we found that population dynamics of larvae and adults were not significantly correlated with each other at any time lag, though correlations were highest at one month lag between larvae and adults and four months lag between adults and larvae. Larvae population dynamics had cycles of three months and were sensitive to changes in temperature with 5 months lag, while adult abundance was correlated with itself (1 month lag) and with the normalized difference vegetation index (NDVI) with three months lag. A key observation from our study is the absence of both larvae and adults of An. albimanus between January and April from environments associated with Guna population’s daily activities, which suggests this time window could be the best time to implement elimination campaigns aimed at clearing Plasmodium spp. parasites from Guna populations using, for example, mass drug administration.

“…Aquatic stages, i.e., pupae, large (4th instar) and small (1st, 2nd and 3rd instar) larvae, were sampled between 14 June 2014, and 24 June 2015 (28 sampling sessions), provided Tr. bambusa overwinters as larvae [77]. Fourteen sampling sessions, conducted between 18 May and 15 November 2014, covered the adult activity season [14].…”

Section: Methodsmentioning

confidence: 99%

“…bambusa adults have a crucial trait that is characteristic of major zoonotic pathogen vectors, the ability to bloodfeed on diverse host species [73]: humans, domestic mammals, birds, and reptiles [74]. Also, the bamboo mosquito seems to have a very plastic biology, as it can reproduce autogenously, i.e., without bloodfeeding on a vertebrate host [75] and overwinter as both eggs and 4th instar larvae [76,77].…”

Section: Introductionmentioning

confidence: 99%

Landscape and Environmental Factors Influencing Stage Persistence and Abundance of the Bamboo Mosquito, Tripteroides bambusa (Diptera: Culicidae), across an Altitudinal Gradient

Chaves

Friberg

Jian

et al. 2019

Self Cite

The bamboo mosquito, Tripteroides bambusa (Yamada) (Diptera: Culicidae), is a common insect across East Asia. Several studies have looked at the ecology of Tr. bambusa developmental stages separately, but little is known about the factors associated with the persistence (how often) and abundance (how many individuals) of Tr. bambusa stages simultaneously studied across a heterogeneous landscape. Here, we ask what environmental and landscape factors are associated with the persistence and abundance of Tr. bambusa stages across the altitudinal gradient of Mt. Konpira, Nagasaki City, Japan. During a season-long study we counted 8065 (7297 4th instar larvae, 670 pupae and 98 adults) Tr. bambusa mosquitoes. We found that persistence and abundance patterns were not associated among stages, with the exception of large (4th instar) and small (1st to 3rd instars) larvae persistence, which were positively correlated. We also found that relative humidity was associated with the persistence of Tr. bambusa aquatic stages, being positively associated with large and small larvae, but negatively with pupae. Similarly, landscape aspect changed from positive to negative the sign of its association with Tr. bambusa pupae and adults, highlighting that environmental associations change with life stage. Meanwhile, Tr. bambusa abundance patterns were negatively impacted by more variable microenvironments, as measured by the negative impacts of kurtosis and standard deviation (SD) of environmental variables, indicating Tr. bambusa thrives in stable environments, suggesting this mosquito species has a finely grained response to environmental changes.