Zooming in on Montjuic (iv): early insects

Written by Lucy Brzoska

It was the first really warm day in February and quantities of Hummingbird Hawkmoths (Macroglossum stellatarum) were restlessly hovering in front of the castle wall, as if searching for something. They engage in this mysterious activity every year when they reappear at the end of winter. I spotted one sitting quietly, something apparently rare, but who knows how many others there were, flattened on the wall, blending in with beige-grey wings and just a hint of iridescence.

hummingbird-hawkmoth-sunbathing-on-wall

When a Hummingbird Hawkmoth feeds, it slings in its lengthy proboscis from a distance.  Not so the Carpenter Bee (Xylocopa violacea), who hugs the flower close. These gentle giants were also out in numbers, bumping into each other around the Common Borage. Their wings are brown like old film negatives, until the light catches them and they turn blue. The males signal their sex with orange antennae tips.

carpenter-bee-xylocopa-violacea-showing-blue-wings

Judging by the constant rustle of Chiffchaffs in the small evergreen oaks by the castle, there were plenty of small bugs to feast on.  They were being deftly picked off the leaves or snapped up mid-flight as the restless birds forayed out of the trees to retrieve them.

chiffchaff-picking-off-bugs

Natur-al-Andalus has an interesting post on Chiffchaffs, whose hovering skills allow them to exploit the nectar of extensions of introduced South African aloe that bloom in the mild Gibraltan winters.

The Hummingbird Hawkmoth and the Wood Spurge

Written by Lucy Brzoska

hummingbird hawkmoth

On a path in Collserola I came across a whir of wings near a Wood Spurge (Euphorbia amygdaloides).  My camera caught the Hummingbird Hawkmoth (Macroglossum stellatarum) uncoiling its lengthy proboscis to dip into the glistening nectar.

hummingbird hawkmoth uncoils proboscis

At rest, the moth is a non-descript brown, but in flight you can see its orange hindwings, albeit in a blur. So much movement requires copious quantities of nectar, so they are restless foragers. They are also strong migrators, crossing the Alps to reach central and northern Europe.

Though innately attracted to blue, Hummingbird Hawkmoths soon discover that flowers of other colours can be profitable too, including the inconspicuous yellow-green Wood Spurge. A long proboscis is not really necessary with this plant, which serves nectar up on a plate.

What the Wood Spurge lacks in colour it compensates with elegance. Each cyathium contains four nectar-secreting glands in the shape of half-moons. They encircle the male and female flowers, although young plants are sometimes male only, like this one.  The whole structure is about to be repeated as two pale green cyathia are poised to unfurl.

detail of wood spurge