What bees do in autumn
A colony changing its own physiology for winter, a bumblebee colony dying, and the last generation of solitary bees sealing their nests.
Honey bees
The colony raises a physiologically different kind of worker in late autumn. Winter bees carry elevated levels of vitellogenin, a storage protein that lets them live for four to six months rather than six weeks, and they are reared on the last good pollen of the year — which is why autumn pollen matters so much more than autumn nectar. The colony also expels the drones, which have no function once mating season is over, and contracts into a cluster. Ivy provides both nectar and pollen in quantity from September to November and is the single most important autumn plant in Britain and northern Europe.
Bumblebees
The colony dies. Workers, males and the old queen all die with the first hard frosts, and only the new queens — mated in late summer — survive, each finding a hole in the ground to hibernate alone until spring. That means an autumn bumblebee is almost always a new queen feeding up for hibernation, and what she finds in September and October determines whether she has the fat reserves to survive six months underground. Ivy again does most of the work.
Solitary bees
Nearly all are already dead. The generation now underground or in stems is a set of provisioned cells containing larvae or pre-pupae that will not emerge until spring. That has one very practical consequence: an autumn tidy-up that cuts and burns hollow stems, clears leaf litter or turns over bare soil destroys next year's bees, invisibly, and nothing about the garden looks any different.
What actually helps in autumn
Leave the ivy alone and let it flower. Do not cut hollow stems until spring. Leave leaf litter. Autumn is the season where doing less is the whole of the advice, and where the most damage is done with a tidy conscience.
Social bees flying now
- Western honey beeApis melliferaEusocial, colony survives the winter
- Asian honey beeApis ceranaEusocial, colony survives the winter
- BumblebeesBombusEusocial, colony dies each autumn
- Stingless beesMeliponiniEusocial, colony survives the winter
- Africanized honey beeApis mellifera scutellata hybridsEusocial, colony survives the winter
- Giant honey beeApis dorsataEusocial, colony survives the winter
- Himalayan giant honey beeApis laboriosaEusocial, colony survives the winter
- Dwarf honey beeApis floreaEusocial, colony survives the winter
- Buff-tailed bumblebeeBombus terrestrisEusocial, colony dies each autumn
Solitary bees flying now
23in the catalogue, showing the first nine. Around ninety per cent of the world’s bee species are solitary, so this is the normal way to be a bee rather than the exception.
- Leafcutter beesMegachileVery efficient, for the same physical reason as mason bees: dry abdominal pollen sheds readily. Megachile rotundata, the alfalfa leafcutter bee, is managed at industrial scale for lucerne seed production in North America because honey bees pollinate alfalfa badly — the flower's tripping mechanism strikes them on the head, and they learn to avoid it. Leafcutters are undeterred.
- Carpenter beesXylocopaGenuinely mixed. Important and effective pollinators of large open flowers and of several tropical crops including passionfruit, and capable buzz-pollinators. On deep tubular flowers they frequently rob rather than pollinate. The honest summary is that they matter, and not uniformly.
- Ivy beeColletes hederaeAn almost complete specialist on ivy, which makes it a good pollinator of ivy and of very little else. It illustrates a general point better than most species: specialists are efficient and fragile, and the more tightly an insect is tied to one plant the more completely its fate is that plant's.
- Yellow-faced beesHylaeusModest per individual and genuinely useful in aggregate, particularly for small-flowered plants that attract little else. Internal pollen transport reduces incidental transfer compared with a dry-scopa bee, so they are less efficient pollinators than mason bees for the same number of visits — a direct consequence of how they carry the load.
- Squash beesEucera subgenus Peponapis and XenoglossaHighly effective specialists. Cucurbita pollen is large, spiny and heavy and needs an insect that carries a lot of it; squash bees are built for exactly that plant and visit nothing else, so every grain they move goes somewhere useful. Multiple studies have found that where squash bee populations are healthy, they provide full pollination of a squash crop with no contribution from honey bees at all — which makes them one of the clearest cases in agriculture of a managed pollinator being unnecessary.
- Long-horned beesEucera and MelissodesImportant pollinators of legumes in Europe and of composites — sunflowers above all — in the Americas. Melissodes species are significant wild pollinators of commercial sunflower and cotton, and their presence measurably increases seed set alongside managed honey bees. Their role in the Ophrys orchid system is ecologically small and biologically remarkable: the orchid gets pollinated, the bee gets nothing at all, and the whole arrangement depends on the male emerging first.
- Plasterer beesColletesEfficient pollinators, with the specialists particularly effective on their host plants. Their short tongues restrict them to open and shallow flowers, so they concentrate on composites, umbellifers, heathers, ivy and willow rather than on deep-tubed plants.
- Small carpenter beesCeratinaUseful generalist pollinators, particularly of small-flowered plants that larger bees find uneconomic. Their abundance makes them collectively significant even though no individual carries much pollen.
- Orchid beesEuglossiniKeystone pollinators of neotropical forest. Their long tongues open up deep flowers nothing else can reach, and their range links widely scattered individual trees. Around 700 orchid species depend on male euglossine bees exclusively for pollination, attaching pollen packets to the bee while it collects perfume and offering no nectar reward at all — a pure deception system built entirely on the perfume behaviour. Brazil nut trees are the best-known economic case: they require large-bodied euglossine and related bees, and the crop cannot be grown in plantations without them.
Cuckoo bees flying in autumn
6 cleptoparasitic species in the catalogue fly now: Cuckoo bees, Cuckoo bumblebees, Sharp-tailed bees, Blood bees, Nomad bees, Vestal cuckoo bumblebee. They build no nest and gather no pollen for their own young, laying instead in another bee’s provisioned cell — and their presence is a sign of a healthy host population rather than a problem with it.
Guides that go deeper
- What is a honey bee?A specific insect, not a category. Nearly everything people know about bees is drawn from one species out of roughly twenty thousand.
- Inside a honey bee colonyQueen, workers and drones — three castes with different bodies, different lifespans and different jobs, two of which come from identical eggs.
- How bees communicate and find their wayThe waggle dance encodes direction and distance in a figure of eight. It is one of the most sophisticated communication systems outside human language, and it is only part of how a colony makes decisions.
- Why bees store honeyHoney is a winter fuel supply for an animal that stays awake and warm through it. Almost no other bee needs one.
- Most bees are not honey beesAround 20,000 bee species exist. Roughly 90% are solitary, almost none make honey, and most of the ones in genuine trouble are not the one on the jar.
- Why bees swarm, and what to do if you see oneA swarm is a colony reproducing, not a colony attacking. It is also the calmest a large group of honey bees ever is, and the correct response is to leave it alone and make one phone call.
Questions people ask
The rest of the bee year
Months here are northern-hemisphere temperate. Southern-hemisphere readers should shift by roughly six months — but that shift is an approximation rather than a translation, because day length, rainfall pattern and the local flora do not shift with it. Records that genuinely span both hemispheres say so.
Plan for them
- Seasonal bee planner
It is this season and I want to do this — what should I plant?
- Flowering calendar
What should I plant so that something is always in flower for bees?
- Bee-friendly garden planner
What should I plant in the space I actually have?