Summer can be lovely – until a wasp turns up. Whether they present as an irritating picnic visitor or an uninvited loft guest, common social wasps are as much a part of our summer as festivals, sun cream and the growing despair of how to entertain children who’ve forgotten how to be bored.

But summer 2026 is breaking the norm, and there don’t seem to be many wasps about. As a wasp biologist, I’ve noticed it acutely, because my students need wasps for their experiments, and we simply can’t find them.

A second sign that something is wrong is the absence of wasp stories in the media. Wasps tend to be more active in warmer weather. Their colonies grow faster and bigger, and they end up making news headlines by bothering humans. This time last year – also a warm spring and hot summer – the media airwaves were filled with “plagues of wasps” stories. Now, even professional pest-controllers tell me it’s a quiet year with very few requests to remove wasp nests.

Admittedly, these are anecdotes not data: the Big Wasp Survey – the only national wasp monitoring survey – is yet to start sampling this summer. But the signs are not good.

If data back this up, their absence worries me greatly because – love them or hate them – wasps are important in ecosystems as pest-controllers, pollinators and decomposers.

So what’s happening?

Spring started well for wasps. In the warm, dry spring a glut of glorious foundresses – new queens – emerged from hibernation to start their nests alone, carrying out all the nest building, egg laying, foraging and brood rearing. This nest-founding period is a risky time. If a new queen survives until her first brood emerges as adult workers, though, then the odds are in her favour as she no longer needs to undertake risky foraging.

But spring 2026 was strange: the warm, dry start should have been good. Warm, dry spring weather improves a nest’s chance of survival as it ensures a good nectar supply for the queen to develop her ovaries and good prey populations for her to feed the brood. But we experienced unprecedented heat for the time of year, punctuated by cold, damp days and followed by unexpectedly chilly nights.

Such weather extremes may have caused queens to abandon their nests or die, reducing the initial spring queen bounty to a more modest population.

Temperature tolerance

And then came the heatwave. And another. And another. Some insects may benefit from this. Wildlife charity Butterfly Conservation is hoping 2026 could be a “bumper summer of butterflies” because warm, dry days mean uninterrupted foraging, mating and egg-laying.

But all insects have a thermal tolerance called critical thermal maximum (CTmax). If their CTmax is exceeded, insects succumb to desiccation, muscle spasms and eventual stupor.

For honeybees, this is around 49°C – which might sound high, yet ground surfaces exceeded 50°C in the UK heatwaves this summer. But the temperature doesn’t need to reach an animal’s CTmax to affect their productivity and behaviour. For example, bumblebee cognition and foraging efficiency are impaired by heatwaves of 32°C.

Bumblebee Conservation Trust raised concerns that 2026 may exacerbate a declining trend in bumblebee populations as flowers wither and bees fail to forage effectively.

Wasps are thought to be quite resilient to extreme weather. They are one of the most successful invasive species around the globe. And as a social insect, their thermoregulation behaviour (such as wing fanning to cool the larvae) and nest architecture (which has insulating envelopes surrounding the brood combs) may help buffer any environmental perturbations.

Insects also have waxy molecules called cuticular hydrocarbons that coat their exoskeletons protecting them from desiccation. Social wasp cuticular hydrocarbons change structure in response to heat, better protecting them from desiccation in excessive heat.

Their varied diets should also buffer them from imbalances in prey populations. However, their CTmax may be lower than other social insects – at around 45°C – which may have made them especially vulnerable to the high ground temperatures of the 2026 heatwaves.

Why are the wasps so small?

There’s something else that I’ve noticed: the few wasps I’ve seen are rather small. The adult size of many insects is fixed during their development, depending on the quality and quantity of food they receive as larvae. Wasps don’t get bigger once they’ve pupated.

The first workers to emerge in spring are usually small because the queen is limited in how much food she can provide for them alone. But by early August, the foraging capacity of the colony has increased exponentially, brood are better fed and the emerging workers are substantially larger.

So why are we still seeing “spring-sized” wasps? It’s possible that limited diversity and abundance of prey may mean their nutrition is restricted. The problem may also be more directly linked to heat. Insect larvae reared at higher temperatures will develop faster and reach pupation at a smaller size.

Global warming is thought to explain the trend in social wasps shrinking in size over the last 100 years. We could be seeing this in real-time this year.

How can you help wasps?

Share your alfresco meal with a wasp. When it approaches, don’t flap it away. Watch to see what it wants. In the absence of wild prey, it might be desperate for some protein (your picnic ham) to feed her brood. In the absence of flowers for nectar, it might be in need of something sugary (some jam) for her own nutrition.

My research team would also like you to share your wasp observations with us, so that we can better understand these important insects. Snap a photo of her eating and submit your data to the Wasp Picnic Survey 2026: Ham or Jam?. Keep the observations coming all summer. The wasps (and wasp scientists) will thank you.

Seirian Sumner receives funding from the UK government's Natural Environment Research Council (NERC) and the Biotechnology and Biological Sciences Research Council (BBSRC). She is a Trustee and Fellow of the Royal Entomological Society, and author of the book 'Endless Forms: Why We Should Love Wasps'

Hearing that a new primate species has been named is exciting news for scientists because primates across the world are in decline. According to the IUCN Red list, a global inventory of animal extinction risk, 44.4% of primate species are classed as endangered or critically endangered (versus 13.2% of all mammals).

In most cases when the number of primate species increases, it is because a known species has been upgraded from the status of subspecies to species, or two populations that were previously considered the same species are re-classified into two separate ones. The African monkey Likweli (Colobus congoensis), however, is a completely new addition to the primate family tree, which makes this news particularly interesting.

Likweli is a colobus monkey. The word colobus stems from the ancient Greek word κολοβός, meaning truncated, because they don’t have much of a thumb. It has an orange mouth, lives in the Democratic Republic of Congo and is part of the large subfamily colobines. Colobines are found in both Asia and Africa, but not in the Americas.

Three colobine genera are found in Africa. The olive colobus genus, has one species (a small monkey with drab olive-brown fur and a grey-black face). The red colobus genus and the black-and-white colobus genus, that Likweli belongs to. What is interesting about Likweli is that its closest relative is the black colobus (Colobus satanas), which has two subspecies – the critically endangered Bioko black colobus on the Island Bioko (20 miles off the coast of Cameron) and the Gabon black colobus on the nearby mainland. Their nearest range is 1,200km away from the range of Likweli monkeys.

Colobines have specialist digestive adaptations, including multi-chambered stomachs, that allow them to digest high fibre leaves and toxic seeds. To accommodate their large gut, many colobines are relatively large for monkeys. Likweli is smaller than the other colobus species though, and more comparable to some Asian colobines (like langurs and leafmonkeys). African colobines depend on forests and rarely come to the ground, but they can survive in small forest fragments and mangroves.

Likweli’s orange tinted mouth resembles that of some Asian langurs. But members of the Colobus genus have all black faces, making it almost impossible for human observers to recognise individuals based on their facial features. This also makes it hard to see their facial expressions. Scientists believe these monkeys’ more subtle facial expressions are related to the relatively low levels of competition within groups and less stringent social hierarchies.

Relationships between groups, however, can involve threats, loud roars and sometimes fights. Colobus males produce a loud roar to warn group members of danger, scare off predators, or during encounters with other groups of the same species. Likweli monkeys produce a similar roar although the researchers were unable to determine the sex of the callers. Likweli’s roar resembles that of the black colobus, but is distinctly different from that of other nearby colobus species.

It is not surprising that the central African region is providing new scientific discoveries. The area has been politically unstable for decades and a difficult place to conduct scientific work in. Working in these forests as a scientist means a risk of running into rebels, soldiers and professional poachers.

But the area is not only under-studied, it also represents a birthplace for many new species because the region has diverse soil including one of the largest peatlands on the globe. Plus, the landscape has been shaped and reshaped over centuries by a combination of tectonic plate movement, climatic changes, human influences and changes in its wetlands and rivers. Current climate change forecasts suggest that the area will remain suitable for colobus species in the future.

Some forests in this region contain around 20 species of primate, a value only matched by some Amazonian regions.

Most of those species are cercopithecids, the sister sub-family of the colobines. Likweli also shares its range with the striking Angola colobus, Colobus angolensis and the Lomami red colobus (Piliocolobus parmentieri). Likweli, like many red colobus species, has often been found mingled in with groups of other primates (up to six species), like guenons and sometimes Angola colobus or Lomami red colobus.

There are also apes (gorillas, chimpanzees and bonobos) in the region. Chimpanzees in other regions are well known to hunt red and black-and-white colobus monkeys for meat.

Likweli lives in small groups (a mean of six but this can range from one to 20). All Colobus species typically live in units of multiple females together with one male and their offspring. Multi-male groups are rare. Some Colobus species, like the Angola colobus, can form large aggregations of over 200 monkeys, consisting of multiple smaller one-male units travelling together.

The Likweli is only the fifth new African monkey species to have been described since 1975, one of which was a local guenon, the Lesula (Cercopithecus lomamiensis). Meanwhile, Miss Waldron’s red colobus has probably gone extinct as there have been no conclusive sightings since 1978, despite intense searching after some unconfirmed sightings in 2000 and 2001.

The Likweli is already considered endangered and protection of this hotspot for biodiversity is urgently needed.

There may well be more undescribed primates (although another monkey species is unlikely) hiding in these forests. It is nice to imagine that these African forests still contain hidden secrets.

Amanda Korstjens does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

What happens when a leader suddenly disappears? In politics, business and other human organisations, leadership transitions can trigger intense power struggles. Rivals compete for control, alliances shift and institutions can become unstable.

Similar dynamics occur throughout the animal kingdom. Our new research on tropical paper wasps, published in the journal Animal Behaviour, shows just how chaotic leadership struggles can be – but also how societies can remain stable even while conflict rages.

Many animal societies revolve around a single dominant breeder. In cooperative paper wasps, as in many other social wasp species, dozens or even hundreds of females live together in a colony. But reproduction is usually controlled by one dominant individual: the queen. The other females help raise her offspring by foraging for food, feeding larvae and defending the nest.

Unlike in honeybee, yellowjacket wasp or ant colonies, however, these helpers are not sterile. If the queen disappears, any of them could potentially take over and become the next breeder. Often there is a queue – ladies-in-waiting, hoping to be queen. But succession isn’t always predetermined, and in some cases, it can become a contest.

How is the contest settled?

It was in a derelict building in Panama that we found the answer to this question. We experimentally removed queens from 19 wild colonies of the tropical paper wasp, Polistes canadensis, and watched to see what happened next.

The effects were immediate. Aggressive interactions between females increased sharply as several of them competed for dominance. The colony’s usual patterns of behaviour broke down and its dominance hierarchies rapidly became unstable. Rather than a smooth transfer of power, succession turned into a period of widespread conflict involving many members of the colony.

At first glance, this kind of turmoil looks risky. Fighting takes time and energy, and wasps distracted by conflict might neglect essential tasks such as foraging for prey, feeding larvae and maintaining nest structure and hygiene. Violent fights over leadership have been reported in other paper wasps, resulting in societal collapse.

But that wasn’t what we observed.

Despite the chaos, the colonies continued functioning. While some wasps fought to be queen, others avoided the conflict and instead stepped up their investment in foraging and brood care. They ignored the conflict and kept the colony running.

Cooperation didn’t disappear – it was redistributed.

One surprising finding was that the peaceful wasps didn’t appear biologically different from the fighters. In many animal societies, traits such as body size, age or position in the hierarchy help predict who will compete for leadership. For example, in meerkats the largest and oldest females are most likely to inherit the dominant breeding role. In naked mole rats, females already high in the hierarchy fight hardest when the queen dies.

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Read more: Of mice and matriarchs: the female-led societies of the animal kingdom

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But in our wasp colonies we found no clear differences in body size, age or previous status between individuals that fought and those that stepped back.

This suggests the behaviour may reflect strategic decisions rather than fixed roles. Some wasps may judge that competing for dominance offers them a good chance of producing their own young, while others may gain more by assuring the survival of the brood, which are typically the wasps’ siblings. Investing in the survival of your close relatives is an alternative reproductive strategy and explains the evolution of helping behaviour in animal societies.

Cooperation during conflict

Social insects are often portrayed as perfectly organised societies with rigid rules. Honeybee and ant colonies, for example, typically have sterile workers, leaving little competition over who becomes the next queen. But paper wasps are different. Workers retain the ability to reproduce, and in the tropical species we studied there appears to be no “next in line” when the queen disappears.

Aggression-driven succession might seem too costly for a society to tolerate. Yet our results show it can work, so long as some animals compensate for the disruption by maintaining essential tasks. Even during intense leadership battles, cooperation can persist if some members adjust their behaviour to keep the system functioning.

The balance the wasps in our study maintained may be a common feature of social systems more broadly. When power struggles intensify, stability depends upon those who keep crucial work going in the background.

It’s easy to get distracted when political rivals are fighting it out, but, perhaps we should be shining a light on the unsung heroes who quietly keep things ticking over.

Seirian Sumner receives funding from UK government's Natural Environment Research Council (NERC) and the Biotechnology and Biological Sciences Research Council (BBSRC). She is a Trustee and Fellow of the Royal Entomological Society, and author of the book 'Endless Forms: Why We Should Love Wasps'.

Owen Corbett receives funding from the UK government's Natural Environment Research Council (NERC).