Wednesday 14 October 2015

Sunflower (part two)

The Sunflower continues to attract butterflies. This Red Admiral is the third species I have seen nectaring after the Small Tortoiseshell and Peacock last week. A passing Speckled Wood didn't seem so interested. I have seen  this butterfly on the flower for three consecutive days, now.

Red Admiral on the Sunflower
Red Admirals have two generations each year. The first generation is migrant from France (or perhaps even further south) in springtime, and their offspring feed on nettles, emerging from late August to October and then heading south. In recent years, however, adults have been found overwintering in the south of Ireland (and England), So, as warming takes hold, we're seeing a transition from solely migrant to partially resident populations.

Phenology has also changed in some moths. Some species were described by their flying (or emerging) dates. So we have August Thorn, September Thorn, Winter Moth, November Moth, December Moth, etc. But in the couple of hundred years since they were named, weather patterns have changed, and their names are not so accurate nowadays. This August Thorn is a new species for my list, and can be separated from the September Thorn by the kink in the rear band of the forewing (arrowed).

August Thorn moth
This is a locally common moth, feeding on larger broad-leaved trees.

I suppose it's worth pointing out that the season for September Moth often starts earlier than the August Moth! Of course, it isn't just moths that are altering emergence and migration patterns. Birds like the Redstart and Fieldfare that used to arrive as winter visitors have become very scarce nowadays, since they stay in situ and overwinter further north. Flowering plants are also extending their flowering season. Have a look in plant books from a few decades ago, and their 'flowering seasons' will surprise you.

Friday 2 October 2015

Sun!

Our summer has been one long stream of anticyclones coming in over the Atlantic, bringing high winds and rain for almost four months. As a result, flying insects have been far less frequent than usual, with hedgerows and verges almost deserted for much of the year. Flowering plants don't seem to suffer quite as much, but perhaps the number of blossoms is down.

Late September and early October have seen the arrival of a high-pressure system that has 'stuck' in place over the UK and Ireland, bringing dry days and colder nights. The circulating wind has brought warm southerly air to Ireland, leading to an influx of European species to supplement the meagre numbers of locals. At one point last week I had 7 specimens of Silver Y moth in my greenhouse.

By a strange coincidence, this is the time of year for the second generation some of our native butterflies to emerge and prepare for hibernation. A large Sunflower which I grew this year has been very attractive to Small Tortoiseshell and Peacock butterflies:

Small Tortoiseshell

Peacock
These will hibernate until March or April next year, when they will emerge to lay eggs, and the first 2016 generation will start. Both of these species use Nettles as their sole foodplant.

This is the first year for my new greenhouse and I tried different plants to see how they got on. I noticed after a while that pollination was largely being performed by a single male Episyrphus balteatus hoverfly:

Male Episyrphus balteatus
He was seen most days for perhaps 3 weeks, and made no attempt to escape through open vents or doors. Seems he was content to have a monopoly of the tomatoes, cucumbers, peppers and melons.