Spring has arrived, bringing warmer weather and the revival of all things. Yet springtime "pests" like willow catkins, pollen, and flying insects disrupt many lives. But are common beliefs about these nuisances accurate?
Wind-pollinated flowers are the culprits
Spring brings widespread pollen dispersal, triggering allergies in many.Some believe that brightly colored flowers like peach blossoms and rapeseed flowers, with their high pollen counts, are the culprits. Others argue that wind-pollinated plants like trees, grasses, and wildflowers are the main cause. Which view is correct?
"It's a common misconception that spring pollen allergies stem from vibrant blooms,"Zhu Rongfei, Director of the Allergy Department at Tongji Hospital affiliated with Tongji Medical College of Huazhong University of Science and Technology, explains that brightly colored flowers like peach blossoms and rapeseed flowers are not likely to cause allergies. These are "insect-pollinated flowers" whose pollen grains are large, heavy, and sticky. They cannot float in the air and rely on bees for pollination, causing allergies in only a very small number of people.Pollen from trees, grasses, and wildflowers, known as "wind-pollinated flowers," are the primary culprits behind pollen allergies. These pollen grains are microscopic, lightweight, and abundant. When wind blows, vast quantities float in the air, easily causing sensitization upon contact or inhalation.
Only female poplar and willow trees produce fluff
Beyond pollen, many people also find themselves troubled by the poplar and willow fluff that dances through the streets in spring. Pear blossoms are pale white, willow leaves deep green; when willow fluff flies, flowers fill the city. In this season of spring outings, the poplar and willow fluff arrives "as promised."Some believe that all poplar and willow trees produce fluff. Is this true?
"Not all poplar and willow trees produce fluff."Li Lianghou, a researcher at the Henan Academy of Forestry Sciences, explains that the fluff originates exclusively from female poplar and willow trees. The fluff drifting through the air in spring is actually the seeds and derivatives of female poplar and willow trees. To propagate the next generation, these trees "dispatch" these white, fluffy seeds each spring. Carried by the wind, they scatter across the sky.
Both poplar and willow trees are dioecious species. Li Lianghou further explained that in spring, pollen from male trees drifts onto the sticky stigma of female trees. After fertilization, fruits develop. The seeds are enclosed within these fruits, and the fluff visible to the naked eye is actually the seed's pappus.From a biological perspective, the buoyancy of these pappus enables poplars and willows to achieve natural propagation.
It is understood that a mature female tree can produce approximately 1 kilogram of fluff.
Insects also have their color preferences
On spring evenings or near dense vegetation, one might notice numerous flying insects swarming nearby. The number of insects around you correlates significantly with the color of your clothing. If you appear in bright yellow near grassy areas, you'll inevitably be "surrounded" by many "followers."
Professor Xue Fangsen from Jiangxi Agricultural University explains that the "tiny flying insects" commonly seen in residential gardens and green belts—also known as honey bugs or sticky bugs—belong to a species of aphids called winged aphids. They often cluster on leaves, tender stems, flower buds, and terminal buds, feeding on plant sap and harming plant growth.These "tiny flying insects" do exhibit a tendency to be attracted to yellow, so it's best to avoid wearing yellow clothing in areas with abundant vegetation.
"Different insects exhibit preferences for different wavelengths of light, meaning each species favors specific colors," Xue Fangsen noted. Scientific research reveals aphids are most sensitive to yellow light in the 600–550 nanometer range, exhibiting a yellow attraction response. This explains why these common "flying bugs" are particularly drawn to yellow objects, actively pursuing them.
"Mosquitoes, however, have a particular fondness for black. People wearing black clothing are prime targets for mosquito attacks," Xue Fangsen noted. This is because mosquitoes generally prefer dim light, disliking both complete darkness and intense brightness. Different mosquito species also exhibit varying preferences for light intensity. For instance, Aedes mosquitoes are mostly active during the day, while Culex and Anopheles mosquitoes are primarily active at dusk or dawn.However, whether diurnal or nocturnal, mosquitoes generally avoid intense light. Even Aedes mosquitoes, active during the day, typically begin their activity around 3 or 4 p.m.
Xue Fangsen advised that to minimize mosquito bites, people should avoid wearing black clothing. Besides black, mosquitoes are also drawn to colors like red and green, which emit dimmer light at night.(By Ma Aiping, this newspaper's reporter) Further Reading Should you stay indoors during aerial pesticide spraying? Urban pest control doesn't work that way. Spring plowing season is upon us, marking the busiest time of year for farmers.With spring's arrival, many pests have emerged. Social media feeds frequently circulate messages warning of aerial pesticide spraying in certain areas, advising residents to take precautions and avoid going out.Are these warnings legitimate?
In fact, this rumor has circulated multiple times since 2016, resurfacing annually during spring. Forestry departments in Dalian, Hefei, and other cities have previously clarified that aerial spraying is exclusively used for large-scale forest pest outbreaks, strictly controlled to avoid harming residential areas. This method is never employed for urban pest control.Furthermore, forestry authorities follow extremely strict procedures for approving, pre-announcing, and implementing such forest pest control measures, which are never disseminated via mass online messaging. Whether aerial spraying over forests or ground-based pesticide application, only pesticides safe for humans, livestock, and poultry are selected, so citizens need not panic.
Huang Xiuzhu, Deputy Director of the Department of Agricultural Product Quality Safety Supervision at the Ministry of Agriculture and Rural Affairs, also noted that based on random inspections, the quality of China's major agricultural supplies is assured. In 2019, the pass rate for veterinary drugs was 98%, while that for pesticides was 91%.