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My daughter and her partner have a raised flower bed in their garden near Cambridge, built from old railway sleepers, and yesterday large numbers of the alate (winged) form of black ants emerged from their underground nest, for their nuptial flight.
They swarmed on a day of classic flying ant conditions - hot, almost windless and sultry - and several hundred took to the air in the space of about fifteen minutes. These were either males or new queens, which would shed their wings and found a new colony after they had been fertilised.
These spectacular flights of black ants provide a valuable food source for birds. Fortunately there were still swifts, swallows and house martins flying around the village, be benefit from this sudden abundance of food.
One interesting aspect of this event was that the winged ants seemed to be under attack from the much smaller workers from the moment they appeared above ground. The smaller ants constantly harassed the alates, nipping at their head and wings with their jaws, until the took to the air. Once the winged forms were all airborne the workers disappeared below ground again.
A few of the winged forms seemed to be weakened or killed by the attacks.
In this image you can see a worker gripping an alate's wing with its jaws.
A ripening field of wheat, as harvest time approaches, is an impressive sight - the culmination of 10,000 years of selective plant breeding, aided by the finest agricultural technology that modern science can provide. It's also one of the most hostile environments for native wild flowers.
In winter the soil is ploughed every year and then selective herbicides are used to destroy any wild plant species that manage to germinate. but around the edges of the crop, where the herbicide spray doesn't quite reach, and where there is more light and less competition with the wheat, a select assemblage of annual arable weeds often persists. There presence in arable fields is as old as agriculture itself.
Corn poppy Papaver rhoeas depends on the plough to bring its tiny buried seeds to the surface, exposing them to the light that they need for triggering germination. Most scatter their seeds from their pepper pot seed capsules long before the combine harvester arrives.
Field pansy Viola arvensis is a frequent annual arable seed of crop edges. Its dome-shaped seed capsules split into three boat-shaped segments. They immediately begin to shrink as they dry in the sun, squeezing the seeds - which as smooth and slippery as wet soap - until their are fired out into the surrounding crop.
Most of these arable weeds have small flowers, nonetheless beautiful when you take a close look. This is cut-leaved cranesbill Geranium dissectum. Its tiny flowers are attractive but .....
.... its fruits are exquisite too. Here they are, ripe and ready to go - five seeds each in their own capsule, attracted to a strip of tissue that runs right to the tip of that beak-shaped structure. It becomes as tense as a clock spring as it dries, until the capsules break free and are flicked upwards, hurling out their seeds like a medieval siege catapult.
After the seeds have been discharged the fruits remain attached to the plant, like miniature chandeliers.
Most of these small arable weeds have no impact on crop yield, but sometimes more serious agricultural weeds survive and can become a problem - this is wild oat Avena fatua, whose seeds have a remarkable ability to drill themselves into the soil, which you can see by visiting this post.
When we first came to live in Co. Durham in 1975 several butterflies that I had been familiar with in the south of the country were nowhere to be seen. Commas had been extinct here for a century and speckled woods, small skippers and ringlets were very uncommon. Since then they have all become common and speckled woods even breed in my garden.
But in all that time holly blues remained rare. Until 2014, when I found one under the Byker viaducts in Newcastle, of all places, I hadn't seen any. Then in 2017 I saw another in Sunderland.
This year they turned up in my garden in Durham in spring and it's clear that they must have laid eggs on the holly hedge, because the summer generation has now emerged. This one seemed attracted to a few alkanet flowers that were still in bloom in the garden, but it has also been nectaring on devil's bit scabious, marjoram and thyme flowers.
I'm hoping that this will be the start of a long-lasting colony here. There were numerous other reports on Twitter of holly blues in the North east this spring.
The change in fortunes of these five butterfly species here suggests that the theory that climate change, bringing a lengthening breeding season, is a factor allowing them to extend their range northwards might well be true.
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