Well, here I am once again examining some unusual phenomenon that appears in Wicklow in June, and can now be seen everywhere. What am I looking at?
Anyhow, this strange phenomenon is the rather unpleasant-looking ‘spit’ that appears on the leaves of low-growing plants at this time of year:
This spit is known traditionally as ‘cuckoo-spit’ because it appears after the arrival of cuckoos. In modern times cuckoos are a lot less common that cuckoo-spit. If you want to solve the mystery you need to be a bit brave and run your fingers through it, revealing…
This little bug is actually a species of insect known, appropriately, as ‘spittle bugs’. There are many species the most common being the so-called Froghopper, which somewhat resembles a miniature frog, and it really can hop, further than any frog I’ve seen. The larva is known as the Cuckoo-spit Aphid, which is actually a misnomer, as these bugs are not true aphids. The spittle is caused by the little bug sucking sap out of the plant it is living on and then blowing the sap out through its backside in the form of bubbles until it is completely enclosed in a shroud of bubbles which protect it from predators and parasites. But these bubbles might also distract potential predators, as I have seen quite a few creatures apparently feeding on the bubbles. Perhaps it tastes sweet like honeydew, which true aphids blow out of their butts as bubbles. The photo below was the first time I had ever witnessed a predatory insect feeding on the cuckoo-spit bubbles. But maybe it was trying to get at the little bug beneath…
Right now Cuckoo-spit is appearing on the flowers of meadows and hedgerows. At first glance it looks like someone came along and spat on the plants, but on closer inspection it appears to be more like washing-up liquid foam.
And you might be thinking, because of its name, that Cuckoo-spit is the saliva of the cuckoo bird. It’s not, but get’s its name because you usually hear the cuckoo around the same time you begin seeing this “spittle”. It is in fact an elaborate defence mechanism of a tiny creature that lives beneath the Cuckoo-spit. This insect is known as the Cuckoo-spit Aphid, but is actually a juvenile Froghopper or Spittle-bug.
This little insect cannot hop to escape predators like the adult bug, so instead it blows bubbles of water, from its backside. These rigid little bubbles cover it, but also allow air between them so that the nymph (juvenile bug) can breathe. A truly fascinating defence-mechanism.
There are several species ranging in size from a few millimetres to about 1.5 cm in length.
As April draws to a close we have reached high Spring, and this year has been a superb one. The steady weather conditions and good levels of sunlight have transformed the landscape. The shrubs and trees are beginning to bloom, adding to those of the undergrowth. This year the lilac trees have been early and especially impressive due to the dryness – in wet years the fleshy, fragrant flower-spikes rot rapidly. This year they are the magnificent ornaments they are meant to be.
But the undergrowth is only really getting started. In woodlands, and on the narrow lanes of Wicklow you will find intoxicating seas of Ramsons (Allium ursinum), the wild garlic. Driving along these lanes with the car window rolled down can be something of an aromatic adventure in springtime.
The flowering plants depend on sunlight, and in turn the invertebrates, particularly insects, depend on the flowering plants to provide serious energy, in the form of nectar and pollen. Of course, the plants are equally dependent on the insects to fertilise them so there will be more plants, and insects, next year. Away from the trees the Daisy (Bellis perennis) are one of the most important nectar-producing species, supporting every conceiveable pollinating creature, and reaping the rewards. Wild meadows are very important habitats for this reason.
As the length of days and exposure to sunlight increases the number of plant species in bloom greatly increases, which in turn supports more and more pollen and nectar-dependent organisms.
This, in turn, leads to an increase in predator numbers. One of the most interesting and unusual predators of other insects is the Yellow Dung-Fly. These flies are normally seen perched on cow dung in huge numbers, where they mate, lay eggs, and attack and eat other insects attracted to the dung. However, in spring they feed mostly on pollen, because there is so much of it about, and their prey numbers are still growing. The fly in the photo is covered in pollen, having clearly gorged, probably on daisies.
Because of predators nectar and pollen-feeders have to be able to defend themselves: in spring you will see many species of bee, all armed with potent stings.
However, many of the bees you will see in Wicklow are not bees at all. Instead of developing toxins, many species of fly have opted to imitate bees, and it is difficult even for naturalists to tell them apart. The trick is to look at the heads: the flies have large round heads with little or no fur, and they have only stubby antennae, whereas bees always have long antennae curling from their heads.
However, flowers do sometimes get more than they bargained for, slugs will also happily eat pollen, and the entire flowerhead. But only very, very slowly, and very occasionally.
Thanks to the abundance of nectar many insects can take time off to find mates and breed, something that would be impossible to do if they didn’t make a profit when it comes to feeding. The beautiful little Orange-tip butterflies are only with us for about four or five more weeks, so watch out for them in gardens, along roads and flower-filled meadows with good hedgerows. They are now taking the time to find mates and breed, and the sight of a pair of them dancing over hedges is a strong sign you will very soon witness a marvellous event: I saw Orange-tips mating for the first time in my life this week. They are so common at this time of year, it is strange how well they hide their social lives. Maybe they’re marvellous camouflage prevents the casual observer from noticing. However, I’m not a casual observer, so it is rare: if you do witness this event you are one of a lucky few.