Tag Archives: Eristalis pertinax

The birds and the bees

Insects have been hit hard by climatic aberrations in recent years and on my meanderings around the Cambridgeshire countryside this year numbers of bees and butterflies sightings have been down compared to previous years. It’s now the middle of June and I saw the first dragons of the year today; two damselflies. I also read this week in ‘The Guardian‘ newspaper that a third of managed honeybee colonies in the USA were wiped out in 2012. This article makes very sobering reading. And it’s a similar story in Europe, but in Europe neonicotinoid pesticides, which have been implicated in colony collapse disorder, have been banned for two years to evaluate their effect on honeybees. My concern is that the onslaught on the bees is complicated and removing one variable may not show a significant effect in the limited two year duration of the ban. But I hope it does!

Early last month the sun finally broke through and gave us some insect friendly weather and it was remarkable how quickly the microfauna emerged.

Beefly – Bombylius major

Beeflies are found over large parts of the globe and can be seen hovering in sunny glades from the springtime. The narwhal of the Dipteran world, the spike looks fearsome but is only used to probe flowers for nectar, there is  no sting. Beeflies procreate by flicking their eggs into the entrance to the burrows of wasps and bees where the larvae feed on the grubs of the occupants.

A pair of hoverflies doing their best to rectify the decline in the insect population

I think these hoverflies are ‘Eristalis pertinax’ but I’m not certain. It was good to see them though, especially as they were taking their biological responsibilities so seriously.
Addendum: on the subject of climatic aberration mentioned at the top of this post I just found and read with increasing concern this link:

http://robertscribbler.wordpress.com/2013/04/12/human-climate-change-is-wrecking-the-jet-stream-uk-met-office-calls-emergency-meeting/

which my blogging buddy Sam posted on her excellent WP blog ‘Science on the Land‘. This provides a chilling insight (in every sense) into why the weather in the northern hemisphere is behaving the way it is. And it doesn’t look as though it’s going to get any better folks.

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Anachronous insecta

A few posts ago I showed you some of the spider I encountered in the short spell of good weather we had in the late summer and early autumn. I think maybe some species were making hay whilst the sun was shining because there were also a lot of hoverflies around at that time too. And here are  three of the species I found. It’s the wrong time of year to be posting about hoverflies, hence the title of the post, but I haven’t been able to get out with my camera so I reckon a hoverfly post is better than none at all! Identifying hoverflies can be tricky because there are species which look very similar to each other and I’m no expert, so I hope my identifications are accurate but if any of you spot an error please let me know.

Eristalis tenax

Eristalis tenax is a type of hoverfly known as a ‘drone fly’, so called because they mimic honey bee drones. They are common throughout the UK and the females, which mate before overwintering and laying their eggs in the springtime, can be seen in any month of the year because they emerge from hibernation to feed when the weather warms up sufficiently. The larvae of this species are called ‘rat-tailed maggots’ and feed in sewage outflows and rotting carcasses – the more putrid it is the more they seem to like it! They are aquatic and the reason they are called ‘rat-tailed’ is that they have an extendable tube which can protrude up to around 5cm which they poke out of the water and use to breath air.

Tapered drone fly – Eristalis pertinax

The tapered drone fly is so called because the male has a tapered abdomen which is visible on this individual. It is otherwise a similar species to E. tenax and it’s larvae are also known as rat-tailed maggots. Apart from the taper it’s also distinguishable from E. tenax by it front legs which are pale.

My favourite hoverfly I found this year is this one:

The footballer – Helophilus pendulus

It’s called ‘the footballer’ because it’s colours are likened to a football shirt. It’s scientific name means ‘dangling sun lover’. The larvae of this species feed on detritus and have been found in wet manure, drains and in very wet sawdust. It’s widespread throughout the UK and can be seen throughout the summer in bright sunny locations in hedgerows. Despite the unsavoury but indispensable habits of the larvae of all of these species they transform into the most handsome adults.

I haven’t done a dedicated Christmas post this year so here’s wishing you all a very merry Christmas and a happy and healthy 2013!