The years 2025 and 2026 began with almost identical warm and dry springs, conditions that should have been equally favorable for wasp queens. However, the subsequent weather patterns took very different turns. In 2025, the warmth persisted through summer, resulting in a highly productive year. By contrast, 2026 experienced sudden extreme heat spikes and sharp cold snaps, disrupting the initial promising start.
Generally, wasps are quite resilient to heat. Their colonies use wing-fanning to cool the brood, nests are insulated, and their cuticles contain waxy substances that change structure to minimize water loss in high temperatures. However, this resilience has its limits. Rapid shifts between extreme conditions, as opposed to consistent heat, may disturb the sensitive timing of young colonies during their crucial early weeks.
Stress
Currently, it is challenging to accurately assess the impact of this year’s volatile weather on wasps due to insufficient research. A study conducted in 2024, surveying wasp and bee researchers, highlighted that media coverage of wasps is significantly more negative than that of bees, often overlooking their roles as pollinators and natural pest controllers. This imbalance extends beyond media representation.
Another study found that the pollination effectiveness of wasps is comparable to bees. However, public perception of wasps is considerably less favorable compared to other pollinators, leading to fewer studies and less funding dedicated to wasp research. A broader review of pollinator ecology bias shows a similar trend: research is heavily focused on a small number of appealing and commercially important species, primarily honeybees and a few bumblebee species, while non-bee pollinators, including wasps, remain underexplored.
Research on bees has already shown that heat stress adversely affects them, even if it does not lead to immediate mortality.
Threat
The most compelling evidence comes from a trial where bumblebee colonies were kept at a constant temperature of 35°C. The colonies could not maintain their internal temperature, leading workers to abandon the colony. The issue was not direct mortality from heat but the difficult choice between cooling the brood and continuing to forage. If such heat stress affects bees, the most studied and protected insect group, it is unlikely that wasps, sharing similar vulnerabilities, are unaffected. The more plausible explanation is the lack of monitoring infrastructure to detect these impacts.
Besides climate volatility, there are other pressures on wasp queens in spring. Efforts to manage the invasive Asian hornet, which has been spreading across parts of Britain and threatens native pollinators, include spring trapping of queens to prevent new colonies.
Pest
These traps are indiscriminate, capturing native wasp queens as well, at a time when the population bottleneck is already dependent on a few individuals. Simon Spratley from Bounty Pest Control stated, “This spring clean-up is doing real damage to native wasps. While selective traps have been increasingly encouraged in recent years, plenty of local beekeepers still rely on older, traditional traps that catch and kill any queen that enters, native or not.”
Currently, there is no tracking of how much this bycatch adds to losses already caused by erratic weather, raising a genuine question about whether the trapping strategy should be more targeted as climate pressures on native wasps increase.
Beyond just the impact on wasps, there is a broader argument for addressing this issue. Wasps are effective, unpaid pest controllers, providing meat and other insects, including flies, to their larvae throughout the summer.
Volatile
Pest controllers and some entomologists have anecdotally linked years with low wasp activity to increased problems with flies and midges, reasoning that the absence of wasps removes a key check on fly populations. While this connection has not been rigorously tested, it is a plausible theory.
Sumner Lab at CBER, UCL is conducting a public wasp survey this summer — Ham or Jam Picnic Wasp Survey — inviting people to observe what attracts wasps at their picnics and to note any changes in wasp populations over the years. This low-cost initiative aims to create a year-on-year dataset for wasps, similar to what exists for bees. Given the unpredictability of the past two summers, this data could help determine if 2026 is an isolated incident or the beginning of a more volatile trend.
This Author
Femi Ezhuthupallickal Benny is a doctoral researcher specializing in wasp ecology at the Center for Biodiversity and Environment Research (CBER), University College London.
