Dragonflies, info request

Objavljeno u Vaša pisma

Can anyone help with information about dragonflies on Hvar?

Dragonfly Dragonfly Steve Jones

Steve from Dol has sent us the following query by email on 23rd September 2016:

'Do you know much about dragonflies on the Island?

Over the Summer I have seen several and I know Norman nearby has also seen similar.

While I know a few of the more obvious ones I am puzzled, one thing I do know is that they like water in which to lay. The dragonfly life cycle is for the most part spent underwater and they only emerge as what we see towards the end of their life and to mate.

I am puzzled as to where they can possibly lay eggs, I only know one source of water down near the airfield and I don’t believe from there they would travel up to Dol. I often think they could be laying in the numerous wells/water storage places in the field but most are covered and I don’t know how they would emerge. One species described to me was the Golden Ringed Dragonfly and this as I read likes fast flowing water so I even more at a loss.

I was down near the airfield yesterday and several of just two species that I could tell were flying the one species tended to be flying joined to his mate, there were several of these

Didn’t know whether or not you can shed any light on this for me? I know of someone in the UK who specialises in Dragonflies, I may email him and see what comes of it.'

Eco Hvar's reply, 23rd September 2016:

Yes, actually there are many more sources of water than you'd think, off the beaten tracks, but also in the fields.

One of Hvar's 'secret' pools. Photo Vivian Grisogono

A lot of the enclosed wells have open basin on top,which can be home to all sorts of insects, including water snakes. Unless the fields around the wells have been doused in herbicide of course. There was a superb little water snake in the open part of the well by my field one year. It would curl itself round and round very lazily, right up to the time the basin went dry. I was afraid 'my' snake had died, lying there quietly, but it then discreetly disappeared, re-appearing a cuple of times in the grass above the well, presumably looking forward to the winter rains which would replenish its basking place. 

Talking about herbicide, did you see that the sale of Cidokor/Roundup is to be banned from October 1st, together with 12 other glyphosate-based herbicides? Good as far as it goes, but it still leaves 12 other glyphosate herbicides on the market!

We''ll look forward to hearing the results of your dragonfly investigations. A good place to see them is in the environs of Humac, where there are some lovely natural pools where the horses and some hunting dogs drink and butterflies abound, as there are no poisoned fields in the vicinity.

Nalazite se ovdje: Home vaša pisma Dragonflies, info request

Novosti: Ekologija.hr

  • Ex-energy secretary Ed Miliband’s agenda appears undermined as money is diverted from renewables to defence

    Britain is unlikely to hit its targets on green heating after the cuts announced by John Healey this week, experts have warned, as critics of Ed Miliband claim the former energy secretary’s green agenda is being dismantled.

    The chancellor unveiled more than £3bn worth of cuts to the energy department’s budget this week, much of which will pay for higher defence spending.

    Continue reading...

  • This week’s best wildlife photographs from around the world

    Continue reading...

  • Turkey has been hit by powerful thunderstorms and a fatal tornado this week with more heavy rain expected

    Heavy rain and strong winds will continue to affect parts of south-eastern Europe and Turkey over the next few days, as an area of low pressure in the region has allowed for the formation of powerful thunderstorms. During a particularly intense thunderstorm in Antalya, a coastal city in the south-west of Turkey, the formation of a tornado resulted in the deaths of four construction workers on Tuesday. Authorities in Greece and Turkey have released severe rainfall and flooding warnings, as a further 100-150mm (nearly 4-6in) of rain is expected this week in central Greece and western parts of Turkey, with locally higher totals possible.

    Travelling eastwards towards south Asia, strong winds and heavy rainfall have swept across the Indian regions of Odisha and Andhra Pradesh as Cyclone Arnab made landfall. With wind gusts in excess of 85mph (140km/h) and rainfall totals in some regions exceeding 200mm, the severe storm has prompted mass evacuations of more than 180,000 people, as well as widespread disruption to energy and transport infrastructure. The cyclone will weaken as it continues to traverse northwards over the coming days, though will continue to deliver heavy rain to parts of northern and central India as it does so.

    Continue reading...

  • After UK’s hottest summer on record, Ardingly near Haywards Heath is just 19% full – and next-closest reservoir is unusable due to broken treatment works

    “You can see the water level at Ardingly going down and down. I don’t remember ever seeing it this low,” says Caroline Allan, a lifetime resident of Haywards Heath, the nearest town to one of England’s most depleted reservoirs.

    The Ardingly reservoir, managed by South East Water and serving about 95,000 properties in and around Haywards Heath and Uckfield in Sussex, is currently 19% full.

    Continue reading...

  • Scientists call for incentives to preserve vegetation as study highlights benefits of plentiful planting in London

    Your front garden could be a first line of defence against air pollution, according to a year-long field study in two London neighbourhoods.

    The UK’s 26m gardens cover nearly 5% of the country’s land area, but they account for a much larger share in urban areas. In Greater London, domestic gardens cover 41% of the city, compared with 27% of Cardiff and 23% of Edinburgh.

    Continue reading...

  • In this week’s newsletter: There are too many meetings, and not enough decisions, say experts – and time is running out

    • Don’t get Down to Earth delivered to your inbox? Sign up here

    When things are not going well at an environmental summit, organisers often tell delegates that the “world is watching” in an attempt to focus minds. But spend any time at biodiversity Cop17 in Armenia and it is clear that the world’s attention is elsewhere.

    The negotiating halls of Yerevan’s Meridian centre are subdued. Environment ministers have arrived from all corners of the world to plan their response to being so far behind the biodiversity targets they agreed four years ago. Right now, they appear on track to miss nearly all of them. They risk continuing the miserable record of never having met a biodiversity target they have set for themselves.

    The climate crisis will destroy our economies – we learned this 20 years ago. When will we act?

    Heat killed ‘staggering’ 50,000 people in Europe’s cities this summer, scientists warn

    Angry Labour MPs urge leadership not to overrule energy secretary on Rosebank

    Continue reading...

  • As many as 8 million people have been affected by food shortages, electricity blackouts and health clinic closures

    Extreme drought driven by an historic El Niño is affecting as many as 8 million people in Papua New Guinea, causing a cascade of issues from shortages of food and water, to electricity scarcity and schooling disruption.

    An influential coalition that includes churches, trade unions and business groups has said the Pacific nation is in the midst of a “national crisis”, but there appears to be “no coordinated plan to protect vulnerable communities from the worsening impacts of El Niño.”

    Continue reading...

  • Keen to join in the revelry but don’t have a costume? You can still fashion a get-up without buying – or wasting – anything

    • Change by degrees offers life hacks and sustainable living tips each Saturday to help reduce your household’s carbon footprint

    • Got a question or tip for reducing household emissions? Email us at [email protected]

    The thrill of an event like Halloween doesn’t come from a brand new costume or “two pillowcases’ worth of sweets”, says play specialist Cat Sewell.

    The fun comes from carving out the time to play, making ridiculous outfits, and the terror and delight of haunting the neighbourhood, says the artistic director and co-CEO of Polyglot Theatre, a company that creates participatory, immersive, child-led theatre.

    Continue reading...

  • There is no end in sight for the drivers of illegal mining, while police action appears ineffective

    Cora Bailey has been encountering illegal miners ever since she first started treating injured animals in the townships around Roodepoort, west of Johannesburg, in 1991. But as the price of gold has soared, so too has activity in the abandoned mine shafts that mark the area.

    In late September, dozens of zama zamas – the name given to illegal miners in South Africa, meaning roughly “to take a chance” in Zulu – arrived to dig for gold across the dirt road from her charity, Claw (Community Led Animal Welfare).

    Continue reading...

  • Replacing diesel-powered ferries with electric vessels could reduce emissions and improve air quality

    Cutting through New York Harbor in the shadow of the Statue of Liberty, the small white boat we were riding on caught the attention of passengers aboard a nearby sightseeing ferry.

    “It’s quite a curiosity at the moment,” Eric Laakmann, the chief executive and co-founder of Vessev, said.

    Climate Central is an independent group of scientists and communicators who research and report the facts about our changing climate and how it affects people’s lives.

    Continue reading...

Novosti: Cybermed.hr

Novosti: Biologija.com