Friday, 30 June 2017

Roosting Wool Carder Bees

After a warm couple of weeks the temperature dropped suddenly on Tuesday and we've had quite a long of rain. From the conservatory window, I noticed a roosting Wool carder bee (Anthidium manicatum) on a Purple Toadflax flower spike, one of their favourite flowers. As I took a photo I saw there were actually three others roosting nearby, all females. Today it was far too cold for them to be active, so they are braving the weather holding onto the flowers with their jaws, so when the sun shines again they should be ready to feed straight away.
 Although we've had a few poor years for wool carder bees, this year they have come back en force and two males have been defending their territory in the garden.
Spot the roosting bees. A carder bee, Bombus pascuorum, feeds on the flowers unmolested. Bumblebees generate their own body heat and their dense hair coat helps them retain it so they can be active at lower temperatures than the wool carder bees.

Wednesday, 14 June 2017

The cost of long-horned moths long antennae?

As I walked past the university woodland area, in the usual clearing, a swarm of 7-8 Yellow-barred Long-horn moths, Nemophora degeerella in their bobbing flight. A few other males sat on the leaves facing the swarm. I searched for females to no avail, but something caught my eye, a male that had been caught in a spider web by his antennae (top shot), still alive, but kicking hopelessly. I have covered these moths in previous posts, the extraordinary antennae of their names only applies to males: the females have a much shorter antennae. This sexual dimorphism suggests that the male's antennae have evolved in response to sexual selection, possibly in relation to pheromone detection by males.
Two males rest on leaves (1/06/2017).

The evolution of exaggerated sexually-selected traits often is accompanied by costs and in the case of these moths, increased predation risk is a likely prize the males are paying for their oversized antennae.
A large swarm of long horned moths on 1/06/17.