Page 66 - State of Biodiversity 2023-2024

64 STATE OF BIODIVERSITY REPORT 2023/2024
Durban Natural Science Museum’s Mosquito
Surveillance Programme Compiled by Natasha Govender, Durban Natural Science Museum
Mosquitoes are important vectors for infectious diseases which pose ongoing risks to human and animal health. Understanding mosquito community composition is crucial, particularly as mosquito diversity and abundance are a key indicators of disease risk.
In 2020, the Entomology Department at Durban Natural Science Museum (DNSM) embarked on a mosquito surveillance programme, to gather foundational data to inform future disease management. Field surveys were conducted by the DNSM Entomology team over two years in urban green spaces, including five municipal managed reserves and gardens (listed in Table 1). Adults were trapped monthly, using specialised CO2 baited traps at the surveillance sites. Mosquitoes were identified to species and distributed to collaborating institutions for pathogen screening which is still ongoing.
In total, 3064 mosquitoes representing 33 species in 8 genera were collected (Figure 1), accounting for approximately 1% of the 3,500 mosquito species recorded globally. Culex (Cux.) pipiens, commonly known as the Common House Mosquito, is the most dominant species in eThekwini, accounting for 66% of the total catch (Table 1). This species is remarkably adaptable in its choice of
host range and breeding sites, allowing it to thrive in both natural and urban settings, including ponds, marshes and artificial containers like discarded tyres and storm drains.
The proportion of the dominant species increases to 82% when Culex (Cux.) neavei and Aedes (Stg.) aegypti are included. These three species are considered the most significant non-malaria vectors in South Africa and are highly capable of transmitting a range of arboviruses, microfilarial nematode worms, and other parasites.
Despite their implication in disease transmission, it is important to note that mosquitoes play a vital role as indicators of habitat health and provide ecosystem services such as pollination, nutrient cycling and as a food source for wildlife. Understanding these positive aspects can provide a more balanced perspective on their role in nature, even as we manage their health risks.
This short-term monitoring programme provides valuable baseline data for future mosquito surveillance monitoring in eThekwini, particularly considering environmental changes that may be brought about by urbanisation and climate change.