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

  • Similar initiatives have been launched from Barcelona to Bogotá, but they have misinformation, political pressure and vested interests stacked against them

    Ten years ago, Alastair Harper was an advocate for young people’s health sitting in a stuffy meeting room in London planning an air pollution campaign. “My phone started buzzing,” he said. “I took the call, and then told the room I needed to leave immediately.

    “I had to get to UCLH [one of London’s major hospitals]. My own child was headed there in a blue-lit ambulance because she was struggling to breathe London’s toxic air.”

    Continue reading...

  • Surge in proposals follows Labour’s lifting of de facto ban, with about 45 plans submitted in the year to March

    Plans for new onshore windfarms in England have reached their highest annual level in a decade, after the government overturned the Conservatives’ de facto ban in 2015.

    About 45 applications for new onshore windfarms were submitted in the year to March,according to a Guardian analysis of government data.

    Continue reading...

  • North Sea oil, once the driving force of the UK economy, may be dwindling but it remains a symbol of prestige and a rich resource for political debate

    When oil was first discovered off the north-east coast of Scotland in September 1969, industry folklore has it that the duty superintendent on the rig carefully poured it into a pickle jar commandeered from the canteen and took it back to Amoco’s Great Yarmouth office in Norfolk. There, it was emptied into an ash tray, sniffed and then set alight.

    From that modest start, North Sea oil – as the huge basin of oil and gas reserves quickly became known – emerged as a driving force of the British economy and a symbol of national power and renewal as the UK emerged from the Opec oil crisis.

    Continue reading...

  • Exclusive: campaigners warn 600-year-old New Barn at Harmondsworth could be ‘shaken to pieces’ by vibrations

    Six hundred years after it was built, England’s largest surviving medieval timber-framed barn could now be “shaken to pieces” by aircraft vibrations, campaigners warn.

    The public has until 1 September to submit objections to the Heathrow airport expansion, which could threaten the survival of the New Barn at Harmondsworth, considered a remarkable example of medieval architecture.

    Continue reading...

  • Experts say fires caused by wrongly discarded lithium batteries, such as those in vapes, are putting lives at risk

    Fires at recycling centres caused by wrongly discarded lithium batteries such as those found in vapes are occurring at the rate of more than 10 a week, according to new figures.

    Experts say the sheer volume of battery fires now occurring at waste facilities has reached a crisis that is putting lives at risk, costing £1bn a year and frustrating fire chiefs.

    Continue reading...

  • Athletes faced last-minute cancelling of 2.4-mile swim, as experts say pollution and extreme heat are causing blooms

    As far as athletic accomplishments go, few are held in higher regard than completing an Ironman triathlon.

    The amount of training required to tackle the 2.4-mile swim, 112-mile bike ride and 26-mile run that make up the course, as well as the expensive equipment required to train in the first place, means that only about 50,000 people in the world complete a full race and earn the title of Ironman every year.

    Continue reading...

  • Experts say more must be done to adapt to changing climate, after two trains derailed within 24 hours during a recent heatwave

    Railway companies are racing to prepare for another brutal summer next year, as a developing El Niño could see 2027 break more heat-related records.

    Britain’s railway system has already been under stress from extreme heat this summer, with several operators reducing timetables and train speeds.

    Continue reading...

  • Since Hurricane Sandy in 2012, a growing labor movement has addressed the climate crisis and economic inequality

    Ryan McElroen had spent years repairing the New York City subway underground when he got the opportunity to work in the middle of the ocean.

    “I had no views other than the darkness at work,” he said. “Then I went polar opposite.”

    Continue reading...

  • The state’s bird emblem is an indicator species for H5N1, with high visibility populations and low survival rates. Experts are warning of ‘significant mortality’

    When the black swans start dying, Western Australians will know that bird flu has truly arrived.

    The birds are an “indicator species” because once they are infected with the H5N1 virus, they are more likely to die than survive, according to the University of Queensland virologist Kirsty Short.

    Continue reading...

  • Beach patrols report hundreds of stings a day as warmer waters and drought create favorable conditions for jellyfish

    An unusually high number of jellyfish are crowding Delaware’s beaches this summer amid climate change and other environmental factors – keeping some beachgoers out of the ocean and stinging lifeguards as well as bathers.

    Beach safety patrols in the state have reported hundreds of daily stings as the jellyfish have increased with intensifying environmental factors, including warmer waters, hot and dry conditions, and water circulation favorable to the invertebrates.

    Continue reading...

Novosti: Cybermed.hr

Novosti: Biologija.com