Beetle

The above photograph shows the pupal skin of a Cassida sp. of beetle. If I am correct it is of Cassida rubiginosa, the only type I have found as an adult,which is very similar to the Green Tortoise beetle. This tiny little creature gave us quite a surprise as we had never seen anything like it. 

It was identified for us by 'British Bugs' an internet based site I can heartily recommend.   E.G.

          Clearwing Moths

 

To many people, the general perception of a moth is of a drab brown insect fluttering around a lamp and being most unwelcome. The truth is that moths are very diverse in form and some are as colourful as the gaudiest butterfly.

  One group of moths stand out from the rest in that they closely resemble wasps in appearance and behaviour. The two larger members of the group are the Hornet Clearwings, stout rather plump moths, with a wingspan 15-20mm, and striking wasp-like bodies of a size similar to that of a Hornet but deeper yellow in colour.

   The majority of the group numbering no more than a mere twelve are much smaller and daintier resembling solitary wasps. As the name suggests, Clearwing moths have transparent narrow wings, the hind pair being broadest, and are held away from the body at rest. The few wing scales they have on emergence are mostly lost during their first flight, but have dark bands or blotches near their wing tips, sometimes reddish in colour. Prominent dark veins radiate the full length of the wing and the trailing edge is decorated with a fringe of hairs.

   The abdomen is narrow and black and may have bands of white, yellow or red, similar to a resistor used in electronic circuits. The tip of the abdomen is brush-like dipped in yellow or red.

   When trying to distinguish Clearwings from wasps there are several pointers to look for. In social wasp species the waist is very narrow and pinched at the union between thorax and abdomen, also, wings are folded longitudinally when at rest – not so in moths, head and eyes are also much larger in wasps.          

                                         

 

Like wasps and flies, clearwings are very active during daytime and are dependant on sunshine. They are rarely seen as adults, flying mostly high up amongst branches of trees in order to attract a mate. Occasionally you may encounter one sunning itself or nectaring at low levels, but they are easily disturbed and soon buzz off.

   The larval stage is as curious as the adult, being maggot-like and almost white. They feed internally in stems, trunks and upper roots of trees and shrubs. Poplar, Oak, Willow, Birch, Alder and a variety of fruit trees are colonised, inflicting serious damage to infected plants as the tunnelling larvae eat their way through conducting tissue for two years before emerging as adults. A few species prefer to feed inside stems of low plants like Thrift, Birds-foot-trefoil and Dock.

  Freshly cut stumps of Oak or Birch attract egg-laying females and present an opportunity to search for signs of habitation. Ejected frass, or empty pupae cases sometimes stand proud, in numbers, indicating that the adults have flown. Moth enthusiasts attract and record moth species after dark using a special lamp that emits ultra violet light, a form of light many moths can’t resist. Clearwings are not attracted this way as they are day flying and rarely seen, being under-recorded as a result. Science has come to aid of the recorder in the form of a man made pheromone, which is suspended in proximity of the food-plants during the flight period of May to August. This has proved very successful in increasing the records of clearwing moths as males arrive in hope of finding a mate.

 There are at best fourteen species in Britain and as many as one thousand worldwide, most in the tropics.

 

John Petyt

 

 

          Sleeping Lepidoptera

                                

 

When we think of butterflies we recall hot sunny weather, flower filled meadows and gardens alive with these charming colourful insects. Similarly, lovers of moths will remember those balmy warm evenings scented with the fragrance of honeysuckle.

   Each species has its own flight season, some only a few short weeks and others perhaps a few months. But sadly summer does not last forever and all species of Lepidoptera have to find a means of surviving the winter months.

How do they achieve this? Well for some they don’t!  Migrant species such as the Silver Y Moth, Deaths-Head Hawk-moth and Clouded Yellow Butterfly find our climate too wet and cold preferring a more Mediterranean climate. One exception is the Humming-bird Hawk-moth, which in recent years has managed to survive as an adult in unheated out-houses.

    There are also several native species of butterfly capable of over-wintering as adults, and to do so have to seek suitable places such as amongst ivy foliage, under fallen leaves or in buildings, and when resting with closed wings are very well camouflaged. Typical butterfly species achieving this are Brimstone, Comma, Small Tortoiseshell, and Peacock and are capable of living for as long as ten months.

   Some moths also over-winter as adults finding similar places as butterflies, as well as behind loose bark. The Herald is a beautiful moth with cryptic colouring and several can be found together spending the winter in some cold outbuilding. The Grey Shoulder-knot hides behind loose bark whilst the Dark Chestnut remains active in mild weather, to mate, and lay eggs in December and January. The Satellite Moth adopts a similar tactic, but with the Red Green Carpet moth only the females attempt to pass the winter in hibernation, to emerge and lay eggs in spring. You would think that the aptly named Winter Moth would be active throughout winter; but only survives until January when the wingless female lays her eggs.

     The second option for surviving the winter is in the egg stage. Being extremely small, an egg laid singly or in small batches can be concealed in bark crevices or on terminal buds. The moths Mervelle du Jeur, Red Underwing and the Purple Hair-streak butterfly, adopt this strategy.  The Bulrush Wainscot moth cuts a slit in the stem of the food-plant before laying her eggs inside the plant tissues. The wingless female Vapourer Moth lays her complete batch of eggs on the outside of her pupal cocoon that she emerged from, attached to vegetation, walls or fences. In the case of the Lackey Moth, the egg batch is laid as a collar around a twig of the food-plant and is covered with a layer of gum to protect them. The Gypsy Moth conceals her eggs by covering them with a coating of hairs from her abdomen. Species over-wintering this way may be in this dormant state for as long as eight months.    

  The next strategy for over-wintering common to very many species of Lepidoptera is the larval stage. Of course this stage is at greater risk of predation then the egg, and so has to be well concealed or camouflaged to match the surrounding background. Larvae over-winter at various stages of development. In August, the Small Skipper butterfly larva eats the eggshell on emergence and then spins a small dense cocoon at the base of the grass food-plant and then settles down for the winter when it emerges the following April to feed. The Marsh Fritillary butterfly larvae feed communally inside a web until half grown during August when they construct a more substantial web in which to hibernate until early spring when they emerge to sun themselves before commencing feeding. The Speckled Wood butterfly over-winters as a small larva concealed at the base of its grass food-plant, but also as a pupa. This habit is unique amongst British butterflies. Some species over-winter as fully-grown larvae, the Chequered Skipper being an example, and after hibernation no feeding takes place before pupation in April.

  The Short-Cloaked moth larva, after feeding for a few weeks, hibernates in a bark crevice protected with a silken thread until the following April when feeding recommences: this species is in the larval stage for about ten months. The Ruby Tiger moth and Fox Moth spend the winter as fully-grown larvae concealed in leaf litter, to emerge in spring, not to feed but only to sun themselves before pupating. The Northern Eggar moth prefers to pass two winters resting, the first as small larva larva, and the second as a pupa.

  The wood boring species such as the Goat and Clearwing moths spend up to five years feeding to maturity as larvae inside the stems of their food-plants. The larvae of the Fiery Clearwing also feed internally, in this case inside thick roots of herbaceous plants such as Dock, whilst species such as the Turnip Moth, known to gardeners as ‘Cut Worms’, and members of the Swift family feed throughout winter, underground on the roots of grasses and herbaceous plants and inflict serious damage to crops.

  Probably the most common form of over-wintering used by moths and some Butterflies is in the pupal stage. When fully fed, the larva seeks a suitable place to pupate, hopefully out of the reach of hungry predators. The Orange-tip butterfly pupa is usually brown, occasionally green, and very angular in shape, and when attached to a dry stem by a girdle of silk is very difficult to detect. The Green Hairstreak pupa is brown and Slug-like and is held by silk to a dead leaf, then spends the winter amongst general litter under its food-plant. Cabbage White pupae can often be found resting on fences, sheds or walls of houses and often emerge quite early in spring when the chosen pupation site happens to face south and warms up rapidly on sunny days.

  Moths choose a variety of places to hide their pupae. Most seek low herbage, under moss, or at various depths beneath the soil surface, and you have no doubt unearthed a few when turning over garden soil. Some moths prefer to pupate well above ground level fixing their cocoons to tree bark or stems. The Puss Moth when fully fed is a very dramatic creature, and prepares to pupate by chewing fragments of bark, which it mixes with silk resulting in a rock-hard elongated dome shaped case in which it over-winters. Both the Alder and Miller moths prefer to chew into soft wood before pupating.

  As you can see, there are several ways that Butterflies and Moths at various stages of development choose to spend the winter months. Not all survive; many larvae and pupae are dug up by birds such as Starlings and Crows or chiselled from their hiding places by Woodpeckers. Carnivores such as beetles often predate larvae, and if the winter is mild and damp then many succumb to diseases. Whatever strategy a species has chosen for its survival, its active stages can be very brief especially as an adult.

 

John Petyt

          Grubs Up

“Grubs Up”

 

When searching for the larvae of Butterflies and Moths you need to know the feeding season and what the favoured food source is of your target species. Of course you need to be aware of the life cycle of the species you are searching for and what part of the plant you are likely to find it. You may need a torch to search for many species as they feed only at night to avoid predation, and hide deep in low vegetation or rest amongst the twigs of their foodplant during daylight hours. The stick caterpillars are good at this, and the larva of the Swallow-tailed Moth become invisible when resting on the twigs of garden Privet. The larva of the Merveille du Jour feed on the foliage of Oak during the night but hides during the day in deep bark furrows and can be found quite low down on the trunk of the tree during daytime.

  95% of species feed on plant material, the majority on the foliage, either by chewing or feeding internally, tunnelling between the upper and lower layers of the leaf, some prefer to eat dead or decaying leaves. To a lesser degree, other parts of the plant are consumed. Flowers are often eaten as well as the foliage as with the Cinnabar Moth. The Foxglove Pug eats only the flower and so has to time its emergence with that of its foodplant. Fruits are attacked by species such as the Codlin Moth and the Lychnis and Netted Pug moths take ripening seeds of the Campion family. Not forgetting, of course, the damage done by the Pea moth. Moth larvae also eat stored grain, the Pale Mottled Willow being a culprit. The larvae of the Wainscot moths tunnel into the stems of the common reed whilst Leopard and Goat Moth larvae feed inside the trunks, branches and upper roots of trees and shrubs.  Roots of grasses and herbaceous plants are not safe from the attention of the Ghost and Swift moths. On emergence from an over wintering egg, the larva of the Purple Hairstreak butterfly chews into the terminal bud of the Oak tree. Footman larvae prefer to eat lichens and algae. Other food sources include fungi, mosses, and even cone wax in beehives. Unlikely foods taken are fur and feather of dead animals and also household furnishings! The most bizarre, perhaps, are the cannibals of the caterpillar kingdom- the Satellite and Dunbar moth larvae when not chewing foliage will readily consume each other! 

  Some larvae feed on a single species of plant, others on a particular family, grasses being preferred by many butterflies. I have found several winter pupae of the Speckled Wood on my garden ornamental grasses even the giant Miscanthus used as a bio fuel. Then there are the numerous species that feed on plants belonging to different families. Observations of the feeding habits of lepidopteron larvae have been made over many years and quite a comprehensive list of foodplants have been made with new discoveries being added occasionally. Recently I observed a Holly Blue butterfly laying eggs on the foliage of Dyer’s Greenweed (Genista tinctoria) in full flower- a later search revealed a single larva. Another find this year was of a well-grown larva of the Copper Underwing feeding on Rosebay Willowherb (Chamerion angustifolium), which I reared, to an adult moth. Another interesting find was of Eyed Hawkmoth larvae on Cherry Laurel (Prunus laurocerasus). If you fancy testing this yourself, remember that as the larvae chew the foliage they release cyanide gas so you must use a well-ventilated rearing cage.

In the 1980’s I worked in a local authority glasshouse nursery. One of the potted plants grown at that time was the Spider Flower (Cleome spinosa) family Capparidaceae and on this plant successfully fed Large, Small and Green-veined White Butterfly larvae previously only found on Cruciferous plants. It was at this time that my interest in moths really took off with the acquisition of my first moth trap. Moths were far more plentiful than they are now as were their larvae- it is a treat to find a single larva nowadays.

One very successful method I used then to attract females of Poplar Hawkmoth and Puss Moth was to plant a row of poplars. For Poplar Hawkmoth choose the hybrid Black Poplar and also a few White Poplars, which between them produce some interesting larval colour variations. The inclusion of Grey Sallow will encourage additional species of moth. For the Puss Moth I used Populus x candicans “Aurora” a conspicuously variegated form with spring foliage of white and pink later turning green. I have seen as many as three eggs laid on the upper surface of a single leaf, these look very conspicuous against the variegated background.

The length of the row will depend upon space available. Simply push well into the ground hard wood cuttings up to 1cm thick and 60 cm long in early winter. These will root quickly in spring and grow to 2m in a couple of years when they are pruned down to 30cm from ground level every winter, the resulting new growth being very attractive to Poplar Hawkmoths. Because the Puss Moth emerges early it is best not to prune the Variety “Aurora” hard down but to leave a 1.5m stem and cut back all the branches.

And finally a tale of a Grey Dagger larva I collected to rear a few years ago only to be disappointed when a single parasitic wasp emerged – but the larva managed to pupate. The following June a perfect moth emerged. How’s that for economy!   

 

John Petyt      2008

          Cut Worms

                              BEWARE OF CUT WORMS!

 

 Many a keen gardener when sowing seeds of their favourite vegetables, dream of harvesting a bumper crop, then imagine their despair when they find their beloved seedling transplants toppled over, severed from the infant root: then you have probably fallen foul of the dreaded “Cutworm”!

  If you are now imagining a chainsaw–crazed earthworm, you would be wrong; the culprits are nothing more than the larval stages of some of our most common moths.

   The name cutworm is given to these caterpillars because they frequently feed on plants at ground level severing them from their taproot. They generally spend the day in the surface layers of the soil, or hidden under leaves or stones and come out to feed at night, sometimes on the foliage, but more often on stems above and below soil level. Cutworms often work along a row of plants cutting them off one after another – hence their name. Larger roots such as turnips and potatoes are also attacked, the larvae burrowing into the root or tuber to hollow out the interior in a similar way to garden slugs.

  It is now time to name and shame. All the offenders belong to the family Noctuidae and are mostly rather drab moths. The four most serious species are the Turnip Moth, Heart and Dart, Garden Dart and the Large Yellow Underwing. Their caterpillars are also rather drab in colour making them very difficult to see in the soil, but can sometimes be found by day just beneath the soil surface near the attacked plant. Being nocturnal, detection of the caterpillars may be easier after dark if searched for with the aid of a torch.

  The adult moths start to emerge in late may and some may produce a second brood in September, but in both cases over-winter as caterpillars which feed when mild weather permits. The Garden Dart has a single brood and over-winters as an egg, and on hatching feeds from spring to early summer.

  It gets worse!! Just when you think you have survived the Cutworms and the plants are well established and leafy, then in comes the foliage champers. This time the villain is a micro moth, the Diamond Backed Moth, only about 6 mm long, brown grey in colour with long white marks along the inner margins of each forewing forming a diamond pattern. Appearing in May and June, sometimes augmented in great numbers by moths arriving from the continent, they lay their eggs on cultivated and native plants of the cabbage family, and on hatching the larvae feed on the underside of the leaf rejecting the upper surface and main veins. 

 Then there’s the Butterflies known as the ‘Cabbage Whites’, which need no description--- it seems that you can’t win! But don’t despair, with a bit   (a lot) of luck, there will always be enough to harvest.

When it comes to controlling these ‘Pests’ don’t bother serving ‘ASBOS’, they don’t work and don’t consider inflicting pain for fear of being arrested for assault. After all, these insects are essential in the environment and if you don’t want these crawlers on your plot then gather them up and relocate them on native wild plants where they can take there chances in the natural world.

 

John Petyt

          The Butterfly Bush

When it comes to providing a source of nectar in the garden for visiting Butterflies and Moths, many will agree that by far the best choice is the Butterfly Bush or Buddleia.

 

Belonging to the family BUDDLEJACEAE  (LOGANIACEAE) the genus Buddleia consists of about 100 species occurring in Africa, Asia and both American continents.

 

Buddleia davidii was discovered in 1876 growing in river gravel beds in southern China, by the French naturalist and missionary, Father Pierre David, after whom the species was named.  The generic name originates from the 17^th century naturalist, the Reverend Adam Buddle, vicar of Farnsbridge in Essex who had no connection with the plant at all, but some kind person thought it would be rather nice to attribute the plant to him.  Today the accepted spelling of “Buddleja” is the one used by Linnaeus.

 

It was first grown in Kew Gardens in 1896 and the first reported ‘Garden escape’ noted in the wild was in Harlech, North Wales c 1921 and many would agree that this plant is a welcome alien in our countryside.

 

The species davidii is the best for attracting Lepidoptera.  It is a hardy shrub with ribbed stems and long lanceolate leaves capable of growing to five metres, but when pruned correctly, usually only half this height.  The flowers are small, orange eyed in the original form, very nectar rich and borne in clusters grouped in long tapering fragrant spikes or ‘Panicles’.

 

Buddlejas are easily grown in any light soils, including chalk – though not having a preference for this mineral – in full sun.  Seeds are produced in large numbers which are sometimes carried to derelict sites and unlikely places such as old walls and neglected guttering where they grow into stunted plants.

 

Vegetative propagation couldn’t be easier.  Simply cut the current season’s growth into lengths of about 30 to 45 cm and pushed into light soil to about two thirds of their length they will root readily the following spring.  I find that pruning to within 15 cm of the previous season’s growth is best done in mid April as this induces flowering when the bulk of summer butterflies are on the wing.  Removal of dead flower spikes can prolong the flowering season.

 

The colour range of Buddlejas is quite wide, including mauves, crimson-purple, violet blue, white and pink.  Variegated varieties are also available.

 

Buddleja globosa is a tall species from South America producing orange yellow globular flowers about 20 mm in diameter and of little attraction to butterflies.  However this species has been crossed with B. davidii x B. weyeriana and the varieties Golden Glow and Sunglow are very similar to B. davidii, but are a rich golden yellow and very attractive to butterflies.  Another virtue is that it will continue to flower well into late autumn producing nectar for late flying species such as Comma, Painted Lady, Red Admiral and Peacock.

 

As well as attracting butterflies, Buddlejas are much loved by both day and night flying moths and to see a Hummingbird Hawk moth taking nectar on a sunny day is a delight.

 

The flowers are not the only part of the plant attractive to Lepidoptera as it is claimed that 23 species of moth larvae feed on the foliage, ignoring their native foodplant in preference for this alien plant.

 

The only species I am aware of feeding in this manner is the Mullein moth, feeding naturally on Mulleins and Figworts, both of which are members of the family Scrophulariaceae.  Interestingly these plants contain the chemical compound Catalposide which was first discovered in the American plant Catalpa bignonioides also known as the Indian Bean Tree and is also present in the leaves of Buddleja. Catalposide  seems to stimulate the larvae to feed and it is said that an extract of Catalpa applied to the foliage of other species will render them palatable to these species of moth.

 

The Holly Blue butterfly larva has also been reported feeding on Buddleja – but in this case on the flower head, and may account for the increase in Holly Blue numbers as the plant has become more popular in gardens.

 

          Scarce Vapourer

The SSSI status of the Messingham Sand Quarry Nature Reserve was awarded, in part, due to the presence of a rare and fascinating day flying moth; the Scarce Vapourer, Orgyia recens.  Not the largest of moths - the males have a wingspan of about 15 mm – orange brown in colour with white marks near the tips of the forewings.  The female is very nearly wingless, with a swollen abdomen when holding four to five hundred eggs which are deposited on emergence on the exterior of the pupal cocoon.

 

Being wingless the female is unable to disperse her eggs.  This is achieved by the tiny larvae being carried on the wind on a thread of silk, or by crawling, resulting in small and vulnerable colonies.

 

The larvae feed from July, resting for winter hibernation, and recommence feeding in the spring.  The adults emerge in June with a second brood of adults occasionally in August.

 

The main foodplants are Hawthorn, Oak, Sallow and Bramble, but it is also found on other species of trees and shrubs as well as on herbaceous plants such as Meadowsweet and Water Dock.

 

The adults may not be the most striking of moths, but the fully grown larva is superb!

The body is black, up to 35 mm in length, covered with tufts of whitish hairs arising from small warts in a double row along the back.  Tufts of greyish hairs decorate the sides.  It has a pair of long forward pointing black tufts on the first segment with a smaller single tuft at the rear.  A double row of orange-red spots extend along the back with a broad red line along each side.  The head is black.  The most striking features however are the orange-brown “shaving brushes” on segments four to seven.

 

This is a Red Data book species in steep decline and has been lost from its sites in the southern counties, and is now restricted to few sites in South Yorkshire, North and South Lincolnshire, Nottinghamshire and Norfolk.  Once plentiful in the Scunthorpe area, even occurring in gardens on ornamental shrubs it is now, sadly, very rare indeed, and the last record for feeding larvae at Messingham was on the 22^nd May 1998.

 

Fortunately this rare British species ranges through Europe and as far as the Far East and Japan, but on the reserve at Messingham may now be extinct, a fate suffered at many other sites in Britain.

 

John Petyt.

          Apples or Marbles?

Our two native Oak trees, the Sessile and the Pedunculate play host to many species of insects providing nutrient and shelter.  Two of these are tiny gall-wasps resembling small ants and cause the host tree to produce abnormal growths known as galls.

 

The first of these, the Oak Apple or King Charles’ Apple is a growth, spongy in texture, often rose pink and up to 4 cm in diameter.  It can be found in June-July singly or in clusters and contain an average 150 larval chambers with each apple containing, usually, a single sex.  The life cycles of these galls are complicated having sexual and asexual alternative generations.

 

The Oak Apple starts its life with a wingless female gall-wasp laying in mid winter, unfertilized eggs in terminal or auxillary buds.  The gall appears in April, produced by the host tree in response to the stimuli secreted by the digestive glands of the feeding larvae.  The adult gall-wasps emerge from the mature Oak Apples in July, males a day or so before females, and after mating the females of this sexual generation fly to oak tree roots exposed or just beneath the soil surface and deposit eggs into the surface tissues.

 

The resulting galls appear towards the end of August and are brownish in colour and about 10 mm in diameter, sometimes merging into a single mass.  Each gall contains a single larva developing after some 16 months into wingless females which ascend the trunks of oaks in mid winter to deposit their eggs thereby completing their bizarre life-cycle.

 

Other species of insects inhabit the galls. Some are parasites, others simply lodgers, making the gall a complex community.

 

May 29^th is Oak Apple day, commemorating the restoration of Charles the second to the throne and coincides with the colourful development on the summer gall.

 

The Marble Gall - Bullet Gall – Oak Nut or Devonshire Gall (Take yer Pick) is quite unlike the soft fleshy Oak Apple, being round, quite hard and woody, about 1.5 cm in diameter.

 

Like the Apple Gall the Marble Gall has alternating sexual and asexual generations.  The familiar summer gall develops from eggs laid by a sexual female in the developing buds of our two native oaks in May or June; the host trees usually being immature or retarded specimens. The developing spherical galls are green at first, brown later, and mature in August.

 

Each gall contains a central chamber, with a single female wasp larva of the asexual generation, which emerges as an adult winged gall-wasp in September.  These asexual females lay unfertilized eggs between the embryonic bud leaves of the Turkey Oak, with galls slowly developing during winter, and are visible in March and April as small oval structures between the bud scales.  The emerging adult gall-wasps in spring are the asexual generation, producing both males and females, which fly to the Common Oaks to initiate the formation of the summer Marble Gall.

 

The Marble Gall-wasp is not native to this country, being introduced about 1830 when galls, which are rich in tannic acid, were imported from the Middle East into Devon for dying cloth and ink making.

 

John Petyt