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"A Nature Observer′s Scrapbook"

Beetles page 2




Lily Beetle Lily Beetle eggs Lily Beetle larvae

Lily Beetle

Liliocerus lilii

It may only be 8mm long but, with its vivid red colouring, the Lily Beetle is really hard to miss. In my garden, it usually appears first feeding on the seed heads of the spring flowering Snakeshead Fritillary, Fritallaria meleagris, before moving to the later maturing oriental garden lilliums.


It is on the underside of the lily leaves that it lays its scarlet eggs (second image) in batches of up to 12 or so. These tend to darken as they mature and are almost black before hatching.


The tiny larvae commence grazing the surface of the leaves as soon as they emerge from the eggs. So, leaf damage is often seen surrounding empty egg cases. Eventually they will move to the choicer flower heads and it is the disfiguring damage that they cause there that earns them the wrath of keen gardeners.


It has to be said in their defence that the larvae are very environmentally conscious. They scrupulously gather up their own excreta and carry it around on their backs.
"Now, how do they do that?"
I'm glad you asked that.
They lie on their sides and gently back into and under their 'waste product' and nudge it into place. Yes, I know it is sad but I've watched them do it!



DateSighting
01.06.2007 Beetles found on Snakeshead Fritillary seedheads.
26.06.2007 Larvae grazing on lillium leaves and a further batches of eggs found.
05.05.2008 Two beetles found on Snakeshead Fritillary although seedheads not yet matured.
20.05.2010 First adult sighting of the year on Snakeshead Fritillary seedheads.



Thistle Tortoise beetle Thistle Tortoise beetle larva Thistle Tortoise beetle pupa

Thistle Tortoise beetle

Cassida rubiginosa

My attention to this species was attracted by the damage to the leaves of Creeping Thistle, Cirsium arvense. This led to the finding of the larvae which graze irregular shaped patches of the upper surface of the thistle leaves - and then to the discovery that the larvae adopt a similar habit to the Lily Beetle larvae in that they carry their excreta around on their backs. In common with many insect larvae, they have twin slim appendages (cerci) at the tip of the abdomen and in this species they are used to hold the accumulated waste on the upwards curving abdomen. The cerci can be seen clearly in the third image.


Prior to pupation, the waste is shed and the larvae start their metamorphosis with a motionless diapause period of a day or so. The outer skin then splits to reveal the emerging pupa but appears to abort, or so I thought, when only half way out of the larval skin (see third image). It was only after I had seen this happen three times that I realised it was normal for the species.


After some three weeks or so, the transformed adult emerges from the pupa, and the jet black body can easily be seen through a pale quite transparent thorax. Within 24 hours it starts to colour up but it takes nearly another ten days to take on its final opaque adult colouring.


The 7mm long adult is quite slow moving, often motionless. It has the ability to pull in its antennae and legs and closely hug the leaf surface like a large 'scale insect'. Against green leaves, it can be remarkably difficult to spot - even when one knows that it is there!


This species can be identified from its close relative, the Green Tortoise Beetle, Cassida viridis, by the brown rusty triangle at the front of the wing cases.



DateSighting
30.07.2007 Thirteen larvae found on two clumps of Creeping Thistle
09.08.2007 Two larvae entered pupation
31.08.2007 Adults emerged from pupation.



Longitarsus, 'Flea Beetle'

a Flea Beetle

Longitarsus sp.

This is a tiny little beetle - only about 3mm long, but the distinctive way that it's hind leg femurs stick out make it look just a bit different. And it is these hind femurs that are responsible for it's common name, 'Flea Beetle'. When the beetle is disturbed, they are able to propel the beetle in a huge 'flea like' jump. Definitely a case of 'now you see it, now you don't.'

There are some 40 different UK Longitarsus species and definitive identification requires microscopic examination so, this one remains anonymous.

Both larvae and adults are vegetarian and different species are found on a wide range of different food plants. But, this one was found on a white painted wall that was no help at all in identifying it.



DateSighting
16.03.2009 Found in warm sunshine on a white painted exterior wall.



Ocypus winkleri - possibly Ocypus winkleri - possibly

A Rove Beetle

Ocypus winkleri (pos)

When this wandered across the kitchen floor, my first impression was that it was the 'Devil's Coach-horse', Ocypus olens. But, apart from general similarities, it was obvious that it was not big enough or robust enough for that. While Ocypus olens can be 32mm long, this was only 20mm when active and 17mm at rest.

It belongs to a group of very similar species (the Ocypus globulifer group) that can only be positively identified by microscopic examination. Of that group O. winkleri is the most common in the UK and therefore the most likely candidate.

Whereas the abdomen of most beetles is covered by smooth wing cases (elytra), the greater part of the rove beetles abdomen, which is covered by short bristly hairs, is exposed behind very short elytra that never-the-less cover fully functioning wings which make them proficient fliers. The wing folding process after flight is interesting to watch, if you get the chance.

They live in cool damp places at ground level - usually in garden or woodland habitats, hiding under fallen wood or stones by day and feeding on small insects and grubs.

To a greater or lesser degree, all the rove beetles adopt a 'scorpion like' posture when alarmed. They stand their ground, raise the rear abdomen up and forwards and open their jaws in a threatening display. If provoked enough, they will actually bite - which is usually enough for most humans to 'back off' although the damage is likely to be only superficial.



DateSighting
26.10.2007 Found indoors late at night.



Rove beetle, Coprophilus striatulus

a Rove Beetle

Coprophilus striatulus

This, like the previous species, is another member of the huge Staphilinidae family of Rove beetles, of which some 900 species are found in the UK. They range in size from 2mm to 32mm. This one was 6mm in length and is the only Coprophilus species to be found in the UK.

Although the Coprophilus genera name implies that it feeds on dung, it is commonly found around compost heaps and decaying vegetation. The adult beetle is normally only seen during the springtime breeding season. Beetle larvae are invariably small white grubs and are notoriously difficult to identify.



DateSighting
16.03.2009 Found in warm sunshine on a white painted exterior wall.



Demetrias articapillus

no common name

Demetrias articapillus

When I first saw this, I honestly did not know what it was. It was the wrong season for flying ants and yet it didn't look right for a fly. Only when the photograph was enlarged did I realise that the visible wing should have been tucked away and that it was a beetle.

It turned out that it was Demetrias articapillus, a 6mm member of the 'Ground Beetle' family. It is very common in Eastern and Southern England, confined to coastal lowland Wales and, apparently, not found in Scotland at all. Being an aphid eater it is regarded as a farmer's friend.

Although it was found in bright daylight it was very active in its attempts to hide and proved difficult to photograph. But one can see that the left elytra, displaced by the un-retracted wing, is almost transparent and does not cover the full length of the abdomen - and that is a trait of the Lebiini tribe of the Carabidae family. In sunshine the elytra appeared to be golden.



DateSighting
10.05.2009 Found on top of a garden waste bin.



Carpet / Museum beetle

Carpet / Museum beetle

Anthrenus verbasci


Anthrenus verbasci is a slow moving, small beetle, no more than 4mm long. Unless seen in good light, it's body markings can be quite indistinct and it really needs a lens to see them clearly. It is a member of the Dermestidae family of beetles, some 30 of which are to be found in the UK and many are considered to be household pests.


Despite it's common names of Carpet or Museum Beetle the adults feed on pollen and all the adults that I have come across have been found on white external window ledges or indoor window sills. While this would seem to testify to their ability to fly, it also poses the question of how many escaped my attention wandering over dark surfaces.


Carpet / Museum beetle larva

It is the 3 - 4mm long larvae of the species that have earned a bad reputation by feeding on keratin and chetin. A very good image of a well fed larva is to be seen here.

Keratin is a constituent of hair, fibre and woolen textiles - commonly found in carpets and clothing. The larvae are small, slow moving, hairy, and dark in colour and so are easily overlooked. It is only when damage has been done that attention is focussed on them.

Chetin, on the otherhand, is found in dead skin, nails and claws and this is what attracts the beetles to museum collections. Such collections are usually static and are often housed in drawers and cabinets so that damage usually goes un-noticed over time until the exhibits start falling apart.

Given that the adults are capable of distributing eggs over a wide area and that the larvae are difficult to see means that once they become well established they can be quite difficult to eradicate.



DateSighting
26.05.2009 Adult beetle found on an outdoor window ledge.
08.06.2010 Adult beetle found on an indoor window sill.
19.11.2010 Larva found on same indoor window sill as the adult above.




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