Articles in ‘Insects’

Wild couples in Barcelona

Written by Lucy Brzoska

In Barcelona, a sign that spring isn’t far away is an intensification of twig gathering by Monk parakeets (an activity they tend to do all year round). Away from their raucous nest colonies, built high up in the towering pines of Palau de Pedralbes park, a parakeet couple were snatching some quality time together.  Snuggled up close, they were taking it in turns to preen.

Another sign of incipient spring in the city is the sound of serins singing. The jangling, irrepressible song, delivered from a suitably high spot, can be traced to a small yellow-breasted bird – Europe’s smallest finch and close relation to the canary.

In a prelude to copulation, the more discretely coloured female serin leaned over to receive her mate’s gift of food.

On Montjuic, two large fuzzy black carpenter bees flew past in an embrace – the female had been seized by the male, recognisable by its smaller size and orange-tipped antennae. When they settled on a leaf, you could see another distinguishing feature: the male’s silvery grey mesosomal hairs.

It seems that carpenter bees are prone to overheating, as they fly slowly and are black, so the pale colour is thought to be useful in reflecting away sunlight. Males spend more time out in the open – territory patrolling, looking for females, and then feeding in the afternoons, when the females are back in their shelters. (See this study for more interesting info.)

Much of the private life of the Red squirrels in Palau de Pedralbes park goes on out of sight, very high up in the trees. They come down to earth to dig up their stashed autumnal loot or explore the rubbish bins. This one was pulling up dried grass.  With a very large mouthful, it ran up an Aleppo pine to furnish its drey, where it would soon be giving birth.

 

Pollen, this way . . .

Written by Lucy Brzoska

Wild weather of recent years has opened up Collserola’s woods, and one of the most rapid colonisers of the new clearings has been the rock rose, especially Sage-leaf Cistus.  This May everywhere you look, hundreds and hundreds of white flowers are shining in the sunlight.

The yellow base of each petal emphasizes the thick clump of stamen, creating a densely yellow heart.

Insects are drawn to the rich, easily accessible supplies of pollen. As well as bumblebees and white-spotted rose beetles I found this male Anthaxia hungarica, with enormous black eyes and green metallic sheen, dining in radiant surroundings.

Another member of the Rock rose family was in flower, Tuberaria guttata, with a strongly marked red-brown ring to guide pollinators to their target.

While holm oaks and pines predominate, in the north of Collserola there are many deciduous oaks. Here, under the shade of the new canopy, Granny’s Nightcaps (Aquilegia vulgaris) are blooming.  The elaborately structured flowers hang down, and the nectar is stowed deep within, at the end of narrow, neatly coiled spurs. Bumble bees were out foraging, but instead of disappearing inside the flower in search of their booty, and emerging dusted in pollen, they were settling on top.  Each spur had a small hole bitten out: the flowers were being cleaned out by backdoor thieves!

Iberian Blue-tailed Damselflies on Montjuic

Written by Lucy Brzoska

Large flocks of Blue-tailed damselflies (Ischnura graellsii) emerge from the ponds in Montjuic’s Jardins de Verdaguer.  They’re so tiny that in flight often all you can make out is a quivering blue blob.  When they settle, the spot of blue turns out to be the tail end of an endless abdomen (segment 8, to be precise).

the-tiny-iberian-blue-tailed-damselfly-ischnura-graellsii

Throughout the month of June the Blue-tails are harvested by House sparrows.  Bills bristling with wings,  the sparrows somehow manage to keep on collecting without dropping any of the existing catch.  You can imagine their nestlings getting fat on plentiful damselfly protein.

house-sparrow-hunts-for-damselflies-in-the-pond

By the end of July, the pond vegetation is full of Tree frogs (Hyla meridionalis),  perching motionless alongside the Blue-tails.  I found one very slowly ingesting its meal, till it seemed to be champing on a blue-tipped cigar.  One tremendous gulp and the rest was engulfed.

tree-frog-hyla-meridionalis-eats-bluetailed-damselfly-ischnura-graellsii

Food chains are long and complex.  Damselflies hunt small flies . . .

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. . . and each other.  As the sunlight broke free of the early morning clouds, it stirred the damsels from their resting places. A newly emerged Blue-tail on its maiden flight was immediately snatched, hoisted up and devoured by a mature female.

In the jungle – Mediterranean insects

Written by Lucy Brzoska

It’s the month of May and plants are fighting for space. In the dense, overgrown jungle roams a large yellow beast (well, 2-3 cm long). It has the silhouette of an anteater, except for those antennae sprouting out of the snout.  The Yellow Weevil eats plant matter with mouthparts at the end of its “nose”.  The length of the snout allows it to bore where other insects can’t reach.

yellow-weevil-in-thistle-lixus-pulverulentus

Two Longhorned beetles mate, antennae mingling.  They look a bit like chamois, except their “horns” are flexible and longer than their own bodies.

longhorn-beetles-mating-agapantia-cardui-suturalis

Flowers are for eating – this pollen-consuming jewel beetle (Anthaxia hungarica) is attracted to Compositae . . . .

anthaxia-hungarica-jewel-beetle

. . . . or for lurking in.  A napoleon crab spider, sprinkled with pollen, waits to ambush its prey.  It’s common to see the lifeless form of  a bee hanging from a flower, as the spider sucks it dry.  Sometimes the venom takes a while to work, and the spider clings on, going for a flight with its victim, not knowing where it will land.

napolon-crab-spider-synaema-globosum-covered-in-pollen

The vibrancy of this Spotted Fritillary (Melitaea didyma) reminded me of a tiger. On this windless cloudy day, the butterfly remained motionless.

spotted-fritillary-melitaea-didyma

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.

Autumn colours in Collserola

Written by Lucy Brzoska

Though its woods are mainly evergreen, Collserola is livid with colour in the autumn. Blue-violet Rosemary flowers hum densely with bees, and yellow Mediterranean gorse shines against the rich blue sky of San Martín. As if decorated for Christmas, the Strawberry trees are hung with glowing red and orange fruit and clusters of bell-shaped flowers, creamy white like candles.

rosemary-bush-and-strawberry-tree

I found a Praying Mantis in almost exactly the same spot as last year, lightly clinging to a Narrow-leaved Cistus.  It had a contented post-meal air, probably having dined on the bees in the Rosemary bush next door. After cleaning them, it neatly folded its spiky “arms” and remained motionless.

praying-mantis-mantis-religiosa-cleans-itself

Under the dense Holm oak canopy, in the dark, boar-raked mulch, knots of scarlet tentacles emerge:  Latticed Stinkhorns (Clathrus ruber), or in Catalan Guita de Bruixa – “Witch’s Vomit”. A fungal wonder, it attracts flies with its rotten stench to act as spore-dispersers.

latticed-stinkhorn-clathrus-ruber

From a fallen tree comes the sound of Pekin Robins – or Red-Billed Leiothrix – who are hiding among the dried branches and leaves. This escapee cagebird, native to the jungles of Southern Asia, feels at home in Collserola, with its overgrown gullies and impenetrable tangles of creepers and brambles.

When disturbed they can’t seem to control their curiosity. One by one, Pekin Robins begin emerging from the dead tree to get a closer look at the intruder, all the time scolding vigorously. I got a noisy close-up of coral-red bills, yellow throats and bright black eyes.   With a steadily expanding population, their colonisation of other areas in Catalonia is imminent.

leiothrix-lutea-pekin-robin-in-collserola

Close encounter on Montjuic: a Cone-head Mantis

Written by Lucy Brzoska

The prohibitively steep slope falls away to the ring road below, where traffic crawls day and night. This is the wildest, most inaccessible side of Montjuic, covered in grass, broom, the occasional stunted pine and mast-like agave cactus.  There are contrasting views of the colourful containers stacked in the port and the shining sea beyond.

On a warm, drowsy late October day I was wandering about on the edge of the hill side and noticed a delicate Green Lacewing perched on a stem. I was pushing aside the grass for a better view when suddenly a twisted bit of straw quivered and move away on all sixes.

cone-head-mantis-nymph-empusa-pennata

It was the legendary Cone-head mantis (Empusa pennata).  The last time I’d seen something so uncanny and brittle-looking was the skeleton army in Jason and the Argonauts.  Close up it seemed wizard-like, with the eyes of an alien.

pointed-head-of-a-cone-head-mantis

Coloured like dead plant matter, its camouflage was perfected by long, sharp-angled legs that repeated the criss-cross pattern of surrounding stems. It was a risk to look away even for a second – the diminutive mantis might merge back into the grass, never to be seen again.

cone-head-mantis-camouflage

Only about 3 cm-long, the creature was a nymph, as evidenced by its curled rutted “tail”.  If it survives, it’ll acquire a winged adult form next spring.  Other features that distinguish the Cone-head Mantis from the more commonly seen Praying Mantis, whose eggs hatch in spring, is a preference for smaller prey.  The females show no penchant for eating their mates.

Collserola gothic: Calopteryx haemorrhoidalis

Written by Lucy Brzoska

In July the shadowy halls of Collserola’s shallow, trickling streams are filled with a spooky, fluttering presence.Groups of dark insects flicker in the half-light, or perch on isolated vantage points.

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These are the male Copper Demoiselles, staking a claim for a stretch of stream. Their wings are black, and their bodies darkly iridescent, tinged purple like blackberries.When impressing the females, they kink their abdomens, revealing a red under-tip.This has saddled the species with the Latin name Calopteryx haemorrhoidalis

The common name, though, is inspired by the rich coppery tones of the female.She signals from a distance with white spots on sepia-coloured wings.

copper-demoiselle-female-showing-wing-spots

When a male, from his prominent lookout post, sees a female enter his zone, he’s immediately in attendance, serenading her in semaphore.The hovering wings form a cross, a performance being repeated up and down the stream.

male-copper-demoiselle-courtship

After a successful courtship, the female is whisked up to a twig.

mating-copper-demoiselles-calopteryx-haemorrhoidalis

Eggs are deposited in a tangle of pink roots at the water’s edge.

copperdemoiselle-female-ovipositing

 

Black-tailed Skimmers at lunchtime

Written by Lucy Brzoska

With parallel worlds evolving in the park, it’s amazing what can be happening by your elbow, unnoticed.

I’ve seen squirrels hanging upside down on the tree trunks, looking down at oblivious heads only inches away.  Or Black rats bursting out of the hedge, flying straight into a litter bin, while people chat or have lunch nearby, none the wiser. And the other day it was the Black-tailed Skimmers.

A pair were trying to mate in the wide expanse of the palace forecourt, getting pestered by a lone marauding male.   The couple finally found some peace and quiet on the stone balustrade that runs behind the semi circle of benches.

black-tailed-skimmers-orthetrum-cancellatum

You could clearly see the way the male folds the darkened tip of his flexible abdomen over the head of the female, to secure her in position.  Or the way the female uses four legs to hold onto her partner, while the third pair gets tucked right back, neatly out of the way.

Perhaps I disturbed them, because the Skimmers flew over to a flowering bush, next to a woman absorbed in her newspaper. The dragonflies, their green eyes like aviator goggles, held on tight, as the twig swung in the breeze.

black-tailed-skimmers-in-wheel-position

After separating, the female rested on the ground for a while.  Female Black-tailed Skimmers emerge into the world bright yellow, but with age can change colour.  This one had an indeterminate grey green shimmer.

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I saw her zipping over the ornamental fountain, dropping off eggs at a terrific speed.  The only pity is it wasn’t the pond, where chances of hatching are significantly higher.

A new generation of damselflies

Written by Lucy Brzoska

All round the pond, firmly stuck to the low concrete wall, were quantities of papery husks.  I immediately suspected what they might be, remembering the concentration of mating Western Willow Spreadwings (Lestes viridis) in the park last autumn.  It must have been a spectacular sight to see the nymphs emerge from the pond in such numbers and burst out of their unravelling skins.

One damselfly was still clinging to an exuvia, much smaller than itself. How could it fit inside?  Reading up, I found that once half out, they pause and inflate their wings and abdomen into shape with hemolymph, the insect equivalent of blood.

lestes-viridis-damselfly-with-exuvia

Looking closely at one of the exuvia, it appears like a Mutoid Waste sculpture. The long “snout” is the labial mask, or lower lip, which the nymph flips open to grab passing prey.

lestes-viridis-exuvia-showing-labial-mask

The nymphs do their work well. The two biology students who volunteer to keep algae levels at a  level acceptable for park authorities found no mosquito larvae in the pond at all.

After the mass metamorphosis, the damselflies had dispersed, but I did find one pristine young female clinging to a leaf.  Her wings had a pink shimmer and were still held close together, not at the 45 degree angle that gives the species its name.  With any luck, in a few weeks she would be laying eggs in the bamboo grove by the water’s edge.

lestes-viridis-damselfy-recently-emerged