Effects of Microclimate Condition Changes Due to Land Use and Land Cover Changes on the Survivorship of Malaria Vectors in China-Myanmar Border Region

Abstract

In the past decade, developing countries have been experiencing rapid land use and land cover changes, including deforestation and cultivation of previously forested land. However, little is known about the impact of deforestation and land-use changes on the life history of malaria vectors and their effects on malaria transmission. This study examined the effects of deforestation and crop cultivation on the adult survivorship of major malaria mosquitoes, Anopheles sinensis and An. minimus in the China-Myanmar border region. We examined three conditions: indoor, forested, and banana plantation. Mean survival time of An. sinensis in banana plantation environment was significantly longer than those in forested environment, and mosquitoes exhibited the longest longevity in the indoor environment. This pattern held for both males and females, and also for An. minimus. To further test the effect of temperature on mosquito survival, we used two study sites with different elevation and ambient temperatures. Significantly higher survivorship of both species was found in sites with lower elevation and higher ambient temperature. Increased vector survival in the deforested area could have an important impact on malaria transmission in Southeast Asia. Understanding how deforestation impacts vector survivorship can help combat malaria transmission.

Semi-field life-table studies of Aedes albopictus (Diptera: Culicidae) in Guangzhou, China

“…Because the average larval to adult -emergence rate was 43%, we collected an average of 344 adults out of 800 eggs, and we used 70% (240/344) of the already early or late emerged adults for the life-table study. Moreover, our method for selecting the adults was similar to that used in other studies [8,27]. The results are comparable because we used the same selection method in all the experiments.…”

“…The experiments were conducted in the same microcosms, set up in a greenhouse and covered with small nylon mesh tents ( Fig 3B), a setting similar to that described in previous studies [26,27]. The experiments were conducted from June to July 2018, i.e., early summer to mid-summer (Fig 4).…”

“…Newly emerged adults were used in the life-table studies with protocols similar to that described in previous studies [8,25,27]. Briefly, 30 female and 30 male adult mosquitoes within 24 h post-emergence were placed in a cage, which was an 85 oz popcorn bucket with 17.8 cm caliber, 14.5 cm bottom diameter, and 14.5 cm height.…”

“…To the best of our knowledge, no study has been conducted to evaluate how temperature variations affect reproduction in female mosquitoes [15]. Semi-field life-table studies have been frequently used to assess how environmental changes affect malaria vector fitness [24][25][26][27]. Few studies on Ae.…”

Experimental logging alters the abundance and community composition of ovipositing mosquitoes in the southern Appalachians

“…These abiotic differences can have direct effects on mosquito survival (e.g. Zhong et al, 2016) and larval development rate (e.g. Couret et al, 2014).…”