MODIRISK:Monitoring of Mosquito Vectors, Longitudinal study

Study Extent

Longitudinal studies were conducted in 3 selected sites across Belgium in the late summer of 2009 and the spring of 2010. The aim was to assess whether mosquito presence and abundance in the selected sites were correlated to those found in The Netherlands. It was assumed, though, that as the typical meadow landscapes as found in much of the North West of The Netherlands are not present in Belgium, differences in mosquito species composition and/or abundance might occur. Study site Maasmechelen (MA) The area surveyed was an old sand quarry near the national park Hoge Kempen and the industrial park of Maasmechelen, which harbours several recycling companies. One site was the initial reference site, a small mixed forest fragment with birch, oak and pine next to the industrial zone (MA1). The other subsite (MA2) was situated in the opposite of the road, in a narrow strip of mixed forest adjacent to a large nature reserve (heath). Land cover consists largely of mixed small forest, moorland, sand quarry and a large industrial zone. Study site Natoye (NT) The population of Aedes japonicus at Natoye was surveyed by UCL. Two Belgian second-hand tire companies located in the village of Natoye (Namur) were surveyed. Sites were named Natoye1 (50.3389587° N, 5.044879° E) and Natoye2 (50.33588° N, 5.0714698° E). The companies import mainly tires for trucks and heavy vehicles originating from various countries (only from Europe). Tires are stacked outside and many are exposed to rainfall and contain water and organic material like decomposing leaves. Landcover consists largely of deciduous forests, gardens, cultivated fields around Natoye1 and gardens, cultivated field and meadows around Natoye 2. Study Site Ruiselede (RL) & Study Site Torhout (TH) We sampled mosquitoes at two different localities in Western Flanders in the same ecoclimatic region, during one complete active season from May until October: - an urban-rural landscape was sampled: 2 sites at Torhout near Groenhove forest complex (TH01 and TH02) (Figure 24) - a natural landscape was sampled: 2 sites at Ruiselede, Vorte Bossen (RL01 and RL02) The sites were sampled two consecutive days (12:00 am-12:00 am) during 13 visits every two weeks from 20th of April 2009 until 5th of October 2009 with three types of traps (see 3.2).

Sampling

Mosquitoes were sampled with CO2 traps used throughout the Modirisk project. Each site was sampled for one week continuously, once between August and October 2009, and once again between April and June 2010. In this way, spring and fall populations of mosquitoes were expected to be found. Samples taken to Wageningen for taxonomic identification using the key provided by Schaffner (Schaffner 1993). Members of the An. maculipennis complex were further identified to species using a PCR of the ITS2 region (Marinucci et al. 1999). Each site or area was sampled thoroughly, with preferably each site/area consisting of different subsites. Each of this subsite was then again sampled with a minimum of 6 traps (3 types, 2 of each type). The traps chosen are: the Mosquito Magnet Liberty Plus (MMLP), the BG Sentinel and Gravid trap (CDC, J. Hocke model). MMLP were used because of the fact that these traps were used during the inventory whilst BG Sentinels are often used to attract Aedes species and Gravid traps for Culex species. The sites were sampled fortnightly during 14 visits every two weeks from the 20th of April 2009 until the 12th of October 2009. Study Sites 1 Maasmechelen The area surveyed was an old sand quarry near the national park Hoge Kempen and the industrial park of Maasmechelen, which harbours several recycling companies. One site was the initial reference site, a small mixed forest fragment with birch, oak and pine next to the industrial zone (MA1). The other subsite (MA2) was situated in the opposite of the road, in a narrow strip of mixed forest adjacent to a large nature reserve (heath). Land cover consists largely of mixed small forest, moorland, sand quarry and a large industrial zone. Study site 2 Two Belgian second-hand tire companies located in the village of Natoye (Namur) were surveyed. Sites were named Natoye1 (50.3389587° N, 5.044879° E) and Natoye2 (50.33588° N, 5.0714698° E). The companies import mainly tires for trucks and heavy vehicles originating from various countries (only from Europe). Tires are stacked outside and many are exposed to rainfall and contain water and organic material like decomposing leaves. Landcover consists largely of deciduous forests, gardens, cultivated fields around Natoye1 and gardens, cultivated field and meadows around Natoye 2. Study site 3 & 4 We sampled mosquitoes at two different localities in Western Flanders in the same ecoclimatic region, during one complete active season from May until October: - an urban-rural landscape was sampled: 2 sites at Torhout near Groenhove forest complex (TH01 and TH02) (Figure 24) - a natural landscape was sampled: 2 sites at Ruiselede, Vorte Bossen (RL01 and RL02)

Quality Control

Samples taken to Wageningen for taxonomic identification using the key provided by Schaffner (Schaffner 1993). Members of the An. maculipennis complex were further identified to species using a PCR of the ITS2 region (Marinucci et al. 1999).

Method steps

1. 1. Fieldwork 2. Validation 3. Analyse 4. Publication

Morphological identification of the Culicidae was done mainly using the electronic identification key of Schaffner et al. (2001) and the paper key of Becker et al. (2003). Data were stored into the web based data base as described above.

1. Diptera
   rank: order
2. Culicidae
   rank: family
3. Insecta
   rank: class

Belgium