Here comes the hawthorn fly
NOT many of us are good at entomology. My knowledge has been improved by fly fishing, but is, at best, basic. I do know, however, that this week heralds the arrival of the unmistakable hawthorn—or St Mark’s—fly, which traditionally appears on April 25, the Saint’s Day.
Black, about a third of an inch long, with clear wings and telltale trailing legs, they hatch in their millions and are a favourite food of trout when blown onto the water before the even bigger mayflies appear in late May. The male’s eyes are split and have separate connections to the brain, which allows them to hover, looking upward for females and downward to monitor their position on the ground—a neat trick. They’re ugly and a swarm can be disconcerting, although they don’t bite, but they are among the most important pollinators of fruit trees at this time of year as apples and pears come into blossom.
Of the other insects, we have more orange tip but fewer brimstone butterflies than a year ago, plus the odd tattered small tortoiseshell that has hibernated over the winter. The bumblebees are becoming busy, but, alas, there seem to be very few honeybees. MH