[Incidence and damages inflicted by simuliid flies in the GDR district of Schwerin].

This research paper presents an in-depth study carried out in Schwerin, Germany where the existence, causes and impact of simuliid flies (black flies) were analyzed during the 1967-1971 period. It documented the species of simuliid flies found, the extent of damage to livestock, and the economic significance of these attacks on the local agriculture industry.

Survey of Simuliid Fly Species and their Habitat

• The study conducted faunal surveys in the district of Schwerin to establish the presence of simuliid flies. The research identified various black fly species such as Boophthora erythrocephala, Wilhelmia salopiensis, Wilhelmia equina, Odagmia ornata, Eusimulium aureum and Eusimulium lundstroemi.
• The research further categorized the habitats of these insects based on their nature of existence. It seems five river sources were identified as regular breeding grounds. We also learn that five other locations were categorized as temporary habitats, and two were ephemeral, meaning infrequent or short-lived.
• In three other areas, environmental pollution such as effluent hindered the water flow of the rivers and the resulting environmental conditions were unobserved or not documented.

Impact on Livestock Health

• The study provides comprehensive statistics on how simuliid flies inflicted severe damage to farm animals. Between 1966 and 1971, 38 cattle died, and 170 fell gravely ill due to simuliid fly attacks.
• In 1967, five horses were recorded as seriously ill, and in 1971, three pigs died and 27 were seriously ill due to these attacks.
• The symptoms observed in affected livestock included petechiae (tiny, circular non-raised patches that appear on the skin or in a mucous or serous membrane), scabs, and edema (fluid accumulation in body tissues causing swelling).
• Severe cases exhibited heart and circulatory system failures, leading to paralysis, coma, and death.

Economic Implications

• The study emphasized the economic implications of simuliid flies’ infestation, beyond the immediate physiological impact on the animals.
• The continuous disturbance caused by the flies greatly affected young animals, retarding their growth and performance which is an additional concern for the farming industry.
• Dairy cattle showed significant and irreparable performance deterioration when they were infected, which directly affected the productivity and potential income of the farmers.

Overall, the research highlighted the problematic issue of simuliid flies infestation and the significant health and economic consequences it had on the livestock sector in Schwerin district.