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"A Nature Observer′s Scrapbook"

Flies - True, two winged flies of the order Diptera.

Page 1 - Crane flies, Midges and Mosquitoes.

Tipula maxima Tipula maxima larva Tipula maxima larva - detail

Crane-fly (sp)

Tipula maxima

This is the largest of the British Crane flies. It has a leg span of 100mm, i.e. 4 inches and it has quite distinctive, heavily patterned wings.

As with several other crane flies, dragonflies, midges and mosquitos it's development cycle includes an aquatic phase. The female lays her eggs in the damp mossy fringes of ponds, ditches and streams. On hatching, the larvae take to an aquatic existence just below the water surface, before continuing their development in submerged leaf litter.

The 50mm specimen shown alongside was found in February in a local drainage ditch. However, it would seem that in a very cold winter, a drop in water temperature may well cause their metabolism to slow down and their oxygen requirements to reduce, allowing them to sink to lower levels. Another smaller one was found in a very torpid condition at a depth of 600mm in a garden pond which had earlier been frozen over. When the latter was brought indoors, it became more active and in a shallow dish, raised the rear of its abdomen to the surface, (lower image), presumably to breathe.

In order to survive below water, the various species of aquatic insect larvae have developed their own unique breathing apparatus, ranging from gills to snorkel tubes. The detail of the posterior segment of this larva's abdomen shows its particular adaptation compared to the larvae of the 'terrestrial' crane flies.

The more commonly known terrestrial crane fly larvae, 'leather jackets', get themselves a bad name from gardeners and farmers by feeding on the root system of grasses. So this one, living on submerged decaying vegetable material, seems to be an environmental 'goodie'.

28.05.2000Imago on ditch side vegetation bordering western side of northern paddock.
23.06.2000Larva found in submerged leaf litter in bottom of ditch.
07.06.2000Imago on ditch side vegetation bordering western side of northern paddock.
16.01.2004Larva found in submerged leaf litter in flowing ditch opposite front door.
28.05.2004First adult of the season resting in a ditch side hedge.
30.09.2004 Three larvae found in submerged leaf litter in ditch bottom.
07.02.2005 Larva found in garden pond at depth of 600mm in root system of an aquatic iris.
02.05.2005First adult of the season seen after a heavy downpour of rain.
15.02.200650mm larva found in drainage ditch opposite front door.
27.04.2007First adult of the season flew indoors at night, attracted to light.
15.11.200748mm larva found in drainage ditch by garage.
19.05.2008Adult female found on Iris leaves by pond.
27.05.2012First adult female found near a lighted window.

Tipula vittata

a Cranefly

Tipula vittata

Like the previous species, Tipula maxima, this species, Tipula vittata, has characteristically marked wings that make it one of the easier Craneflies to identify. It is however much smaller that T. maxima so there should be no confusing these two species.

The wings have 'smoky' areas along the leading and trailing edges separated by a strikingly white streak at the wing tip. This one also sports a prominent dark 'Y' shaped vein towards the wing trailing edge.

The abdomen appears uniformly grey on top but has dark bars on the sides of each abdominal segment.

Tipula vittata shares the same damp environment as T. maxima e.g., water courses and pond margins, etc. but, in my experience, emerges a month earlier than Tipula maxima.

15.04.2011 Found close to a field drainage ditch, attracted to light at night.
08.05 to 27.05.2012 Good population seen daily in hay meadow and attracted to light at night..

Crane Fly
Limoniidae helius

(small) Crane Fly

Limoniidae helius

Just by way of comparing extremes within a family, against the 50mm larva of Tipula maxima above, this miniature version was no more than 15mm long.

And whereas the T. maxima larva was big and cumbersome - almost lethargic, this aquatic larva thrashed around like a mad thing and had to be constrained within a few drops of water for the photo session. But, free-swimming, it was so active that it looked very much like a midge larva.

This adult Crane-fly is one of many very similar delicate small flies which fold their wings over their abdomen.

06.05.2006 Found at Gibraltar Point Nature Reserve during a pond survey.

Tipula oleracea - female Common Crane fly

Common Crane-fly

Tipula oleracea

I am indebted to expert opinion for a positive identification of these images. There are two very similar Tipula species, T. oleracea and T. paludosa . Both are very common, both fly from April to September, and short of inspecting their antennae, are hard to tell apart. The T. oleracea population tends to peak in the early summer and the T. padulosa population tends to peak in the Autumn. It seems to me that, before heading off on their migration south, the Swallows wait for the autumn hatch and are often seen swooping low over the meadows feeding up prior to their long journey.

Neither adult species will eat more than a little nectar or pollen during their lifetime. They exist simply to mate and produce the next generation. ..... Something they are very good at.

As with all Crane flies, the females, prior to egg laying will be plump (they can carry several hundred eggs), and have pointed abdomens - all the better to insert eggs into damp soil. The males tend to be slim with squared off or club shaped abdomens.

The larvae of both species are the well known terrestrial 'leather jackets', brown legless grubs which spend their time below ground eating the root systems of grasses and root crops. After a shower of rain they often come close to the surface and fall prey to ground feeding birds.

15.05.2005 Large numbers found emerging from pupation in hay meadow.
Early Sept. 2005 T. padulosa being snapped up by swallows in hay meadow.

Tipula lunata m. Tipula lunata f.

Crane-fly, subgenus Lunatipula

Tipula lunata agg.

Tipula lunata is typical of the lunatipula sub-genus and flies during the months of May and June.

The reason that insects do not hybridise readily is that their genital organs develop in unique ways specific to each species. In many species that appear to be superficially similar, the only way to determine their true identity is to examine these organs.

So, without the benefit of such microscopic examination of the genital areas, at best, these images can only be claimed to be representative of an 'aggregate' group of species that bear a superficial resemblance to Tipula lunata, Hence the T. lunata agg. label.

In the Lunatipula subgenus of crane-flies, the males are easily recognised by their swollen, club-like lower abdomens, whereas the female abdomen terminates in a sharp pointed ovipositor, a probe to facilitate egg laying in the soil.

They are medium sized crane-flies, the males having a body length of about 18-20mm and the females 20-24mm.

The larvae feed on the roots of grasses.

14.05.2003 Female seen in hay meadow hedge.
end May 2005 Male seen in hay meadow hedge.

Tipula lateralis male Tipula lateralis female

Crane-fly, sub-genus Yamatotipula

Tipula lateralis

The Yamatotipula sub-genus is identified by the thin line running down the top of the thorax from just behind the head. Worldwide the sub-genus embraces many species but is quite limited within the UK.

The larvae of all this sub-genus are to be found in the saturated soil of marshy, waterside environments.

In common with all Crane-flies, the female T. lateralis is considerably larger than the male, the abdomen having to accommodate a huge number of fertile eggs.

05.09.2007 Male attracted to lighted window at night.
13.09.2007 Female attracted to lighted window at night.

Tipula vernalis m Tipula vernalis f

Crane-fly species

Tipula vernalis

Whereas the previous species favours a wet/moist environment, Tipula vernalis is to be found in dry calcareous grasslands mainly flying in the month of May - as was the case with these two individuals.

The main identification feature is the dark line that extends from the thorax all the way down the back of the abdomen. That coupled with the heavily veined and two tone smoky brown and clear wings and eyes with a green sheen on live specimens are diagnostic for the species. The tip of the females's abdomen is also noticeably less pointed than in other species.

It is described as 'common' throughout Europe and Northern Asia although a general small but steady annual decline in numbers has been detected since 1969.

On the web and in literature the following names, Tipula breviterebrata, T. lactipennis, T. lineola, T. nigricornis and T. pendens, may be regarded as synonyms for T. vernalis but only Tipula vernalis appears on the UK checklist of 100+ recorded cranefly species.

20.05.2005 Males and females seen at the edge of a calcareous grass meadow.

Spotted Crane-fly

a 'Tiger' Crane-fly

Nephrotoma flavescens

The crane-flies within the Nephrotoma genus are known as 'tiger' crane flies because of their vivid markings. But, if seen with folded wings, positive identification of the several species can be confusing as their thoracic markings are quite similar (eg N. quadrifaria and N. appendiculata). N. flavescens has a broad 'tear drop' black mark on top of it's head.

Nephrotomas will be seen from May to August and are quite common in gardens and grass fields. At about 18mm body length Nephrotomas fall in the mid range of crane fly size between the larger Tipula and smaller Limonia species.

Their larvae are virtually indistinguishable from small Tipula leather-jacket grubs.

27.06.2005 Well defined against the dark foliage of a garden Berberis bush.

Limonia nubeculosa

'Folded-wing' Crane-fly

Limonia nubeculosa agg.

This is one of several very similar speckled wing species which tend to be somewhat smaller than the previous species (body length about 10mm, wing length about 15mm) and they are always seen at rest with their wings folded over the abdomen.

They are to be found all year round, weather permitting and tend to favour the shelter of woods and thick hedges.

02.10.2004 Found taking shelter indoors.

Ptychoptera contaminata - female

no common name

Ptychoptera contaminata

This Cranefly belongs to a small and distinctive family that only has about seven species in it. The scientific generic name, 'Ptychoptera' refers to their 'folded' wings, ie, a crease in the wing that can make the wing appear very narrow.

They frequent water margins and marshy areas, the larvae being aquatic, living in mud and litter in shallow water. They resemble long thin terrestrial 'leather jackets' with long thin breathing tube tails that extend to the surface of the water.

The adults, normally about 10mm body length, are to be seen flying from May to October. The image is of a female, recognised by the swollen abdomen and pointed ovipositor used to probe the mud to lay her eggs. The male abdomen, like many male Craneflies, is slender and ends in a swollen stump.

02.08.2008 Found on vegetation by garden pond.

Ptychoptera albimana - female

No common name

Ptychoptera albimana

Of the seven species in this genera, this and the previous species are perhaps the most common. They are found in wetland habitats where the aquatic larvae, like short pale worms, thrive in the shallows, burrowing in the mud and breathing through long thin tubes that reach up to the surface.

Whereas P. contaminata was characterised by it's prominently marked wings, the wing markings of P.albimana are much reduced and may even be absent altogether - as seen here. But, it's unique distinguishing feature is the pale terminal (tarsus) segment of the hind leg. Hardly an obvious characteristic but, it sets it apart from its relatives. The adults fly from April to October.

Two features set this genera apart from other Craneflies. The outstretched wings are creased longitudinally causing the wings to be twisted upwards making them appear un-naturally thin. And the legs bear short 'spurs' at the tibia/tarsus (ankle) joints which are not seen on the majority of other Craneflies.

20.04.2011 Attracted to outside window.

St Mark's Fly St Mark's Fly detail

St Mark's Fly

Bibio marci

St Mark's fly owes it's common name to its annual habit of appearing around St Mark's day, 25th April.

It seems odd to me that an insect as substantial as this should be deemed to be a 'midge'. This is the largest of the 18 strong Bibionidae family of black day flying midges. The females are about 13mm in length and the males about 10mm.

It is slow and cumbersome in flight with its legs dangling clumsily - and that is while it is on it's own. When they are mating, it is not unusual to find them in even more unwieldly flight, still coupled together with the larger female dragging the hapless male to the next resting place.

The differences between male and female can clearly be seen in the upper image. The female is significantly larger but has a much smaller head with smaller eyes set on either side of the head. The male on the other hand has large eyes touching each other.

The single, strong, forward pointing spine on the outside of the tibia of the front legs (highlighted in the lower image) is an identifying feature of the Bibio family, helping to distinguish it from the similar Dilophus family - to which the fever-fly (see below) belongs.

The conformation of the wings is such that when folded, one wing completely overlays the other.

It breeds underground and the larvae feed largely on decaying vegetation but are also blamed for damage to crop roots.

One 'oddity' of Bibio species is that the larval structure appears to be more primitive than the adult fly conformation would lead one to expect, indicating some evolutionary aberration in their development.

01.05.2005 Several found in the act of mating.
24.04.2009 One day ahead of schedule, I find five males emerging from soil disturbed when weeding.

Bibio johannis

no common name

Bibio johannis

There are many UK species of Bibio flies and most of them have all black legs. The fact that the lower segments of this one's legs are an orange/brown colour, help to set it apart. The black spot on the wing is usually better defined than in other species - but that only helps if you have something to compare it with.

The image is of a male. All Bibio species females have much smaller eyes.

The larvae live underground and feed on decayed vegetation and grass roots.

11.04.2011 Found basking in sunshine on a white painted wall.

Fever fly - side view Fever fly profile

Fever Fly

Dilophus fibrilis

Fever flies are smaller versions of the St. Marks-fly with more transparent wings and have a ring of spines around the bottom of the front leg tibia.

As with the previous species, the females (as illustrated on the right), although having a bigger body size (about 9mm), have smaller heads and eyes than the males (about 7mm).

These images were taken through a window and the bright background has washed out much of the detail but, since the insect is totally black, little, apart from wing venation, has been lost.

And a final word of reassurance, there appears to be no evidence that they cause fever!

22.04.2005 On a window - one day before St. Mark's Day.

Owl Midge Owl Midge Owl Midge

Owl Midge

family Psychodidae

The Owl midges, or Moth flies as they are sometimes known, are very small hairy, almost fluffy, winged insects.

73 different species are acknowledged. And while they are easy to identify as Owl midges, they can be extremely difficult to identify as individual species.

The largest has a wing length of no more than 4mm which would totally obscure the 2-3mm body. The smaller ones usually come in uniform shades of grey but should not be confused with the even smaller 'Whitefly' pests of the vegetable garden and greenhouse.

The Owl midges breed in decaying matter and fly most abundantly in Spring and Summer.

I am sure you will see the owl in the lower i(midge).

19.05.2005 Found on the shady side of a Salix caprea tree.
18.09.2005 Again, found on the shady side of a Salix caprea.
02.10.2005 And yet again, found on Salix caprea.

Non-biting Midge 'Bloodworm' larva

Non-biting Midge 1

Chironomus plumosus ?

This is another species which has several look-a-likes, so a positive identification would be 'optimistic'.

With regard to the 'non-biting' epithet, it seems that, in general, the non-biting species tend to hold their bodies parallel to the surface they are on whereas the biting types, incline their bodies at a head down angle of some 30 degrees - all the better to drive home their spear like proboscis.

The pointed abdomen and lack of feathering on the antennae indicate that the illustrated 10mm specimen is female.

These midges are common everywhere and on the wing from April to September and the adults seem to feed very little, if at all.

The larvae are of the aquatic bloodworm type, and have a group of little hooks just below the mouth parts which they use to anchor themselves while browsing.

27.04.2005 Found on north facing window cill.
03.04.2006 Bloodworm larva found in nearby ditch.

Chironomus luridus

Non-biting Midge 2

Chironomus luridus ?

Another of the Chironomus family, showing the similarity of body shape and wing venation (notice the dark junction of the veins half way down the wing) but with several green forms there can be no certainty of species identification.

However, on the positive side, with feathery antennae this one is obviously a male.

The flight season is from April to September and at the end of the long dry summer of 2004, the image on the right was taken on 28th September.

28.09.2004 An evening visitor to the backdoor light.


Aedes punctor

This one bites,
....... at least the female does, but it is not a malaria carrier.

The complex 'head gear' of this specimen comprises an outer pair of antennae, an inner pair of palps (sensors for determining food sources) and the long central proboscis used for sucking blood or nectar.

The squared off tip of the abdomen and the feathery antennae of the image on the right indicates that this specimen is a male and his proboscis is used solely for nectar gathering.

The aquatic larvae thrive in pools of static water and the adults are active from March to October.

30.09.2004 Found on side of garage wall close to ditch.

Sylvicola fenestralis Sylvicola fenestralis

Window Midge

Sylvicola fenestralis

Sylvicola fenestralis is one of several similar looking small flies generally known in the UK as 'midges'or 'gnats' and since this one is commonly found around windows, it is often known as the 'Window Midge' or 'Window Gnat'.

With long legs, long narrow wings and its small round head, it can be seen to resemble a small Crane Fly - and was originally known as Tipula fenestralis (fenestralis being derived from the latin for window). They are very common throughout the UK and can be found most months of the year.

Although the adults are non biting, they tend to lay their eggs around decaying material so, like most flies, they could be considered to be a health risk. The larvae will thrive in compost heaps, stagnant water and other waste material.

The upper image gives some indication of size and the lower image indicates the 'closed discal cell' in the wing venation, one of the distinctive identifying features that helps to distinguish it from similar species.

17.04.2007 Attracted to lighted window.
17.05.2012 Attracted to lighted window.
11.04.2013 Found indoors on inside of window.

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