A mystery Sawfly - and a new species for Essex

Just after writing the article about the uncertain hoverfly (see here), I came across a very uncertain sawfly.

Sawflies are a member of an Order of insects called the Hymenoptera, which includes bees, wasps and ants. Sawflies could be considered to be primitive wasps, but unlike wasps they have no waists. Hymenoptera are not  "true flies", as these comprise the Order Diptera which have just two wings. Hymenoptera have two pairs of wings.

On April 6th, 2011, I noticed a distinctive creature on some honeysuckle leaves in my garden, adjacent to Manor Park Cemetery. As I've stated before, I am far from experienced in the identification of insects, but immediately thought that it was probably a sawfly, and one that I hadn't been aware of before. I took a few photographs as it walked slowly around (mainly on the underside) of some honeysuckle leaves.

Zaraea loniceraeAfter some research, I determined that it looked most like a species of Abia, and accessed the Essex Field Club's website to see what the status of these were in Essex. The only Abia species was A. sericea, although the food plant was quite different. It was also on the Essex Red Data List, so I thought that I should contact an expert for assistance in case it was worthy of a record.

Not unexpectedly, my email – together with photographs – resulted in the response that it was virtually impossible to identify just from photographs, but with the suggestion that it looked more like a Zaraea species, perhaps Z. fasciata, Z. lonicerae or Z. aenea, which develop on plants such as honeysuckle and which are recorded as early as April.

Accordingly, I was asked for a specimen if possible, and much against the principles that I expounded in the article about hoverflies, the following day I managed to catch one of two specimens that were present in the garden, and posted it off. I had a restless night wondering whether the poor thing would survive First Class with a bit of honeysuckle as company in a plastic tube in a jiffy bag. It was confirmed the next day as Zaraea lonicerae. Lonicera, by the way, is honeysuckle - so there at least was a clue there! I didn't enquire whether it survived - or where it is now.

As far as is known this is the first record of this species in Essex; sawflies seem to have been a very neglected group, not just in Essex but generally, so any record such as this is valuable.

As an addendum to this, I was looking through my own photographs of sawflies, and found one that I had found in my garden on May 2nd 2006. I had tentatively identified this as an Abia species; it looks very like the recent ones, and was on honeysuckle!

Thanks to Peter Harvey of the Essex Field Club for his help and in finally identifying this species, and to Jerry Bowdrey at Colchester & Suffolk Museums for checking the Victoria County History and confirming that the species is not listed.

Paul Ferris. 11th April 2011

The beginning of April

From a week ago when I wrote about what was happening then, it's all happening now. (see previous article)

In anticipation of a pleasant day - as opposed to a cold drear one - I wandered into Wanstead Park on April 2nd for a quiet stroll. A text message reported a Ring Ouzel and a Redstart on nearby Wanstead Flats - both worthy of a twitchers presence - but I ain't really, and a stroll was more in mind. All the frog-spawn of 1st March has disappeared on 2nd April, but no sign of any tadpoles. No sign either of a Water Rail at the west end of Heronry Pond, but then I am surprised how late the one in Perch Pond has been seen - at least up until the last days of March.

Chiffchaffs are everywhere, it seems, now - and there are a number of Blackcaps singing, too. There was a brief song of a Willow Warbler by the Shoulder of Mutton, which is the first I have heard this year. But also there was quite a bit of alarm from various birds as a Sparrowhawk came down nearby. I didn't see the swans on the Shoulder of Mutton making a nest, but have been told that they've begun. Certainly a pair on Perch Pond look as though they may have settled down - or at least chosen a site as they are hardly settled;  they seem to be driving geese off the Perch and the Heronry Ponds!

Wood Anemones in Warren WoodThere are lots of trees bursting into leaf and bud at the moment: Field Maple and Norway Maple are particularly evident, and there are lots of flowering cherries in the streets and apple-blossom on the domesticated forms scattered around the Park. However, the Blackthorn is almost finished its flowering. as for flowers, Dandelions are profuse, the patch of Bugle near the Shoulder of Mutton is well in flower, but the glory was walking through Warren Wood to experience the Wood Anemones. I have never seen such large patches in the Park, and there are patches where I have never seen them before. If management took place to enhance these - requiring for example a lot of bramble-clearance - these could make the Park as famous for this species as it is fast becoming for Bluebells. And talking of Bluebells, there is already a haze of blue from the native ones in Chalet Wood, and the more vigorous Spanish ones are already in flower nearer the roadsides.

There are numbers of butterflies around too - those that I saw being Small White, Orange Tip, Speckled Wood and Peacock. Plenty of Bumble-bees - the species that I more readily identified appearing to be Bombus terrestris, but there were others, and other flying insects in the form of a species similar but smaller than the more familiar St. Mark's Fly, namely Bibio johannis, and a few of the interesting Bee-flys, Bombylius major. (more information)

Returning to birds, one of the Egyptian Geese was posing on the Ornamental Waters, but the other of the supposed pair was not in evidence. Might they be nesting? On the Plain - and audible from quite a distance - was a Lesser-spotted Woodpecker, drawing attention to itself by drumming for ages on a particularly resonant piece of wood. In amongst these Spring-like happenings, it was interesting to see that there were still a pair of Gadwall on Heronry Pond; this is a speceis that usually leaves for the summer.

Just lastly, there are two patches of a rather strange member of the onion family in Wanstead Park, one of which is near the WansteadPark/Northumberland Avenue entrance. I was interested to see a number of people take a closer look at it. and indeed one group asked me if I knew what it was. It is Few-flowered Garlic, Allium paradoxum. (photo)

I don't feel that I missed out on the Ring Ouzel and Redstart, having experienced so much else in a stroll .

Paul Ferris, 2nd April 2011

A question-mark after Syrphus torvus (?)

One of my principles relating to wildlife has been to try where possible to avoid disturbance - where possible being the get-out, I suppose. If I were to stick to the principle, for example, I would never get involved in any practical work. Two big downsides of such a principle are that it has inhibited me in my early years from learning about the nesting habits of birds, and in latter years has prohibited the identification of some similar or closely related species.

The former is quite well known. Many of our best birders have been people who actually started out by collecting bird's eggs - thankfully not so common a pastime, these days! But when identifying species such as the hoverfly that I saw the other day, the only way to be reasonably certain of its identity would have been to capture it and put it under close examination. For one thing I am not prone to running about with a net, and for another it was busy doing its own thing and doubtless would have been less than happy to have been put in a plastic tube.

The hoverfly - on 28th March - was the first that I've seen this year and was settled on a willow catkin in the City of London Cemetery . As I so often do these days, I took some photos for examination later. It looked like one of the Syrphus species, but that was only hazarding a guess. At home, I found that the photographs were reasonably clear, showing some detail of the insect viewed from above and some viewed partly side-on. I am really not familiar with all the scientific terminology relating to the structure of a hoverfly, so it is difficult for me to follow a key through without referring back to the meanings of the descriptive terms. In addition, of course, I just had my photographs to go by.

Anyway, I deduced just from its general appearance (birders "jiz") that it was probably a member of the genus Syrphus. Wikipedia say of this genus: "Syrphus is a genus of hoverflies. It can be distinguished from other genera of the tribe Syrphini because it is the only genus that has long hairs on the upper surface of the lower lobe of the calypter. (as well as hairs on the rear margin of the calypter as in most Syrphini)." which - unless you are already an expert - shows you what I'm up against. There are six species of Syrphus in Britain. To start with, I could see that the specimen was a male; that's easy enough as in males the eyes meet on top of the head, in females the eyes are widely separated. I use a book called British Hoverflies, by Stubbs and Falk* as my guide, and the colour of the hind femur (part of the leg) is an important factor. Mine appeared to be slightly more than half-yellow, the rest black. Well, according to the book, that could mean that it was either S. ribesii or S. torvus. S. ribesii is a very common species, and may be seen from March to November, and might be expected in this area. S. torvus was described as being "easily overlooked amongst other Syrphus species, but should be found in most districts, especially about woodland." Another important distinction of species separation is the fact that S. torvus has hairy eyes, but that this can be inconspicuous. Looking closely at my photographs, the eyes do appear hairy, so that might help. One aspect of the description of torvus states "... often one of the common species at sallow catkins before other Syrphus have emerged." As I said, it's the first hoverfly I've seen, and it was on a sallow catkin! That is not confirmation, nor are my other indicators, but I do tend to think it may be the first specimen of Syrphus torvus that I have recognised in this area. I'd appreciate an expert comment.

Paul Ferris, 30th March 2011

* Reference: British Hoverflies, Alan E. Stubbs and Steven J. Falk, British Entomological and Natural History Society, November 2002

Bombylius in the Cemetery

A rather strange, but attractive, little creature is paying its annual visit to our area. In the City of London Cemetery - and almost certainly elsewhere - Bombylius is flying around. There were a number of them in the cemetery on 23rd March.

Bombylius is the bee-fly - its name describes it quite well. It is actually a true fly - a member of the Order Diptera. These "True Flies" are the ones that have just two wings; other insects that might have the name of "fly" attached - such as Damselfly - have four wings. In the true flies, the second pair of wings have been reduced to small stabilizing appendages called "halteres".

So what does Bombylius look like? Well, at first sight it might appear to be a bee; they are somewhat stout and somewhat hairy. They move about feeding in a similar way to bees, have a somewhat darting movement, and often fly close to the ground. They can also hover remarkably well - in this case resembling Hover-flies. Perhaps the most distinguishing feature, however, is the long proboscis - giving a somewhat Pinocchio-like appearance. A closer view will show that their legs - unlike bumble-bees, are long and slender. Of course they use this to probe for nectar in flowers, and whilst doing so sometimes appear to hover by the flower. In fact - although they do hover - very often they are using a pair of these slender legs to attach to the plant. There are apparently 12 species in Britain, but the most common is Bombylius major and, with my limited knowledge of these, the ones I am seeing certainly look like that species.

I tend to see them first in the latter part of March and during April, but not much after. As with a number of insects with a long proboscis, they may be thought to sting. However they are completely harmless and one of my favourite insects.

Paul Ferris, 24th March 2011

The Bee-fly, Bombylius major, in the City of London Cemetery on 24th March

The Bee-fly - showing the proboscis