Poland's mosquitoes and blackflies emerged from winter unscathed and summer rainfall will be the decisive factor in how bad the season gets, according to entomologist Prof. Stanisław Ignatowicz of the Warsaw University of Life Sciences.
"If we're asking whether cold winters can effectively limit insect populations, we should ask ourselves how it is that in Siberia, where frosts are incomparably greater, a person in summer cannot endure the swarms of mosquitoes and blackflies", Ignatowicz told Polish Press Agency (PAP).
He explained that insects have spent millions of years developing survival mechanisms for harsh conditions. As temperatures drop gradually, they find shelter and their body fluids produce substances that act similarly to antifreeze, forming tiny ice crystals that do not damage cells.
Summer conditions matter far more than winter cold. "If prolonged rainfall appears, stagnant water and long-lasting puddles, mosquitoes can reproduce en masse", he said.
Ignatowicz drew particular attention to blackflies, which despite their small size can be lethal to livestock. Their danger lies not in blood loss but in their saliva. During mass swarms, thousands of insects can simultaneously attack a single animal, triggering a severe systemic reaction and potentially fatal pulmonary edema.
The professor also addressed the growing presence of deer keds — commonly called flying ticks, though they are actually flies — which were rarely seen in Poland a decade or two ago. "Today they are recorded more and more frequently, and much indicates that this is connected to climate warming", he said. Researchers have detected genetic material from Anaplasma and Bartonella bacteria in deer keds, but there is still no definitive evidence they transmit these pathogens to humans.
On personal protection, Ignatowicz said there is no credible evidence that ultrasonic repellent devices work. Repellents containing DEET, icaridin or IR3535, as well as certain essential oils, are considerably more effective. "A mosquito flies, seeking a person by their characteristic scent. Then it encounters someone smelling intensely of mint or lavender. The scent that would normally lead it to a victim gets drowned out", he explained.
(jh)
Source: PAP