New record of Anopheles superpictus (Diptera: Culicidae) in central Italy (Tuscany): resting adults and evidence of natural breeding sites.

BACKGROUND

Anopheles superpictus (subgenus Cellia) plays an efficient role in malaria transmission in countries of the Mediterranean basin, Eastern Europe, and the Caucasus region, where it has been involved in the transmission of both Plasmodium falciparum and P. vivax. In Italy, this species was historically considered a secondary malaria vector, primarily recorded in the South including Sicily, along small rivers. It was less frequently observed in central Italy, only rarely reported in the North. Between 2022 and 2024, as part of routine investigations on residual anophelism, An. superpictus specimens were collected for the first time in the southern Maremma Plain (Magliano in Toscana, Grosseto, Tuscany).

METHODS

Adult mosquitoes were collected in animal shelters and tool premises of two farms using traps and manual aspiration methods. Larval sampling was performed by exploring potential breeding sites along the Albegna riverbed. Anophelinae adults and larvae were morphologically identified at the species level, and subsamples were molecularly confirmed by sequencing the cytochrome c oxidase subunit 1 gene and the ribosomal DNA internal transcribed spacer 2 region.

RESULTS

A total of 1,106 adult mosquitoes were collected from July to October 2022. Anopheles superpictus was the most abundant species recorded (n = 512; 46%), peaking in August and found in sympatry with An. labranchiae, the main historical malaria vector in Maremma Plain. Anopheles superpictus larvae were found in seven of the twelve investigated sites, with 50 specimens collected (mean density: 0.1-0.2 larvae per dip). Snapshot surveys in September 2023 and 2024 confirmed the stable occurrence of the species in the area.

CONCLUSIONS

Anopheles superpictus was consistently recorded in an area where it had not been previously documented. These findings provide new insights into the current presence and distribution of the species in Italy and at the European level, notably including the first recent identification of natural breeding sites. Furthermore, the results highlight the importance of residual anophelism surveys in malaria surveillance, supporting the development of targeted control strategies and preparedness plans for potential malaria reintroduction in at-risk regions.