Butterfly as Pests

A butterfly causing concern in Europe is the Geranium Bronze (Cacyreus Marshalli) which is the family lycaenidae. Originally from South Africa wehre its larval food plant was the geranium or pelargonium somehow it was introduced into Europe, where it is wreaking havoc amongst growers of its food plants. It is an unusual and attractive butterfly so its presence won’t break the hearts of many lepidopterists unless they happen to grow geraniums or pelargoniums. 

Butterflies and moths can be both pets and instrumental in the control of pests. Mostly they’re pests causing untold amounts of damage to agriculture. The most notorious is of course, the Cabbage White, which is a general name given to many similar species of Pierids, including the small white (Pieris Rapae), the large white (Pieris brassicae), and the Green veined or Mustard White (Pieris napi) of these three only the first two are pest species. 

Two moths have been instrumental in the control of rogue plant species. These’re the Crimson Speckled Footman (Utetheisa Pulchella), which was used in Australia to bring the prickly pear cactus under control. The other is the Cinnabar moth, Tyria jacobaeae, which feeds among other things, on ragwort a poisonus plant found in cattle fields. These represent a serious threat to any animal that eats them. However every year the caterpillars strip the foliage usually so severely that the plant can’t seed

Perhaps the most serious lepidopterous agricultural pest is the Gypsy Moth (Porthetria dispar), which causes untold economic damage to forested areas. It was introduced to the U.S. from Europe in 1869 when some were sent to an amateur entomologist in Medford, Massachusetts. Some of these were accidentally allowed to reach the wild, from where they started to colonize the New England states. The moth quickly established itself as there were no natural parasites to limit its spread. This combined with the fact that each female lays up to a thousand eggs made it a very successful immigrant. Another reason why it has managed to spread throughout the United States is that its larvae will eat many hundreds of different plants, and if its preferred choices are not available it will eat almost anything. 

Several different methods have been tried to wipe out this pest, but none of them has been anything more than a passing success. In the 1960s one of its natural parasites, a braconid wasp (Rogas indescretus) was released in yet another attempt. Unfortunately though, it is not limited to the Gyspy moth and has been found parasitizing a related species. This cross over from pests to the indigenous fauna is a serious problem and needs to be addressed whenever a non-active parasite or predator is introduced to a new locality. 

 

Other control methods tried include pesticides diseases, diseases, pheromone traps, and encouraging natural predators. Of these, only the traps are ecologically sound, with no impact on the species. Controlling pests without damaging the local habitat is a real problem sometimes releasing infertile male’s works and other times parasitic nematode worms will drastically reduce numbers. The answer probably lies with more research, but that suffers from the opposite problem survival in a harsh economic climate severely limits the number of research scientists.

Source: Charismatic Planet

Butterflies and moths can be both pets and instrumental in the control of pests

Barberry (Berberis) is popular garden specimens

The barberry that grows wild in my neighborhood “Berberis Vulgaris” is one of the first plants to leaf out in the woods and fields. In mid spring tiny yellow flowers appear on its arching stems they’re only ¼ inch wide, but if you look closely they resemble miniature roses. In fall the plant turns a brilliant red-orange and bright red berries appear; these last so long that they’re sometimes still dangling there when it’s time for the flowers. What more could you ask of an ornamental scorned because it is thorny and weedy. It’s one of the first shrubs to take over neglected fields, along with such bad company as sumac, red cedar, multiflora rose and poison ivy. Barberry is even the host of a rust disease that afflicts wheat crops in some areas it is illegal to plant it.

Nonetheless, some of the more civilized forms of barberry are popular garden specimens. Their berries and fall color make them attractive hedge plants; their thorns and dense habit make them practical ones. The most common cultivated form is Japanese barberry (Berberies thunbergii), which usually grows to about six feet and is hardy to zone 4. More compact varieties include “Aurea” a 2 foot plant with yellow foliage, “Kobold” a compact two to three foot mound that is a hardy substitute for boxwood or Japanese holly, and the very popular “Crimson Pygmy” “Little Gem” which usually stays about two feet tall and has purple red leaves all summer, especially when grown in full sun.

Several other barberries are garden worthy. Some are evergreen, such as warty barberry (B. Verruculosa), which has black berries and quite showy yellow flowers and is hardy to zone 6. Korean barberry (B.Koreana), with dangling yellow flowers and red berries, and mentor barberry (B.Mentorensis), both hardy to at least Zone 5, are thorny shrubs that make good barriers.
 

How to Grow

All the barberries are easy to grow in most soils and are drought tolerant. They’ll grow in sun or shade, but foliage colors are more pronounced in sun. They transplant easily and respond well to shearing, either to create a hedger or in the red leaved varieties, to produce more colorful growth. They look best in their natural arching form; however, old, overgrown plants can be thinned at the base. Shear or cut back in early spring, while the plants are dormant.

Ceropegia Ampliata - Bushmans Pipe (Asclepiadaceae)

Ceropegia ampliata is a perennial twiner or scrambler with a succulent stem arising from a fleshy, tuberous rootstock. Plants occasionally branch at the nodes and can grow up to 2 m and more in length. The stems are hairless and sometimes have longitudinal grooves. The lovely plants have fleshy tuft roots from germinating seed or fibrous roots form at the nodes where the stem touches the soil surface. Therefore leaves are borne on terminal growth; they're very small, up to about 3 mm long, and are lanceolate or heart-shaped. The leaves are shed early and the stem is the main organ used for photosynthesis. Bushman's pipe is commonly found on dry, stony hillsides, twining in other vegetation. The plant is found in the Limpopo Province, Mpumalanga, KwaZulu-Natal, the Eastern Cape and southern parts of the Western Cape, extending northwards as far as Tanzania. It also occurs in Madagascar.

Harmless Mimics

The benefit of looking utterly repellent

Camouflage allows an animal to blend in with or resemble the prevailing background but this is not enough for some creatures who wish to disguise the fact that they are edible. So they adopt the look of something clearly inedible, such stones, twigs thorns and even fresh bird droppings. There is little more unappealing than a fresh bird dropping and any creature that mimics one will avoid being eaten by all but the most desperate of predators.

The Chinese character moth, for example, which lives in hawthorn hedges, looks very like a shiny, rather watery, bird-dropping. Making no attempt to conceal itself, the moth sits among the foliage with wings closed, ignored by even the hungriest predator. The nymph of a species of bush cricket, or katydid, a native of Trinidad, takes the impersonation of bird-droppings even further. It splays its hind legs to that, from above, it looks as if it has dropped from a height and splashed all over the leaf. It polishes the disguise with a realistic uric acid glint and “dribble” effect that give the bush cricket a high degree of security.

Animals that act their way out of danger

As well as adopting a disguise as a means of eluding predators, some creatures have enhanced their deception by the way in which they behave. Among such actors is a stick insect that lives in New Guinea. Its flattened, frayed body looks like a leaf in the last stages of insect-chewed dilapidation. It adds to this impression by suspending itself from a bush by one of its legs, and spinning in the breeze like a leaf that is about to fall off.

Another actor is a Kenyan beetle. Active at night, it spends, its days among drifts of last year’s seeds and is no more likely to move unaided than they are. If it does stir at all, it is only by being moved by the same breeze that is blowing the seeds about. Some insects have assumed double disguises. There’re some species of praying mantis that live in thorn bushes and look like twigs, while their offspring resemble thorns. Similarly, the tortoise beetle of Trinidad has the appearance of a seed while sitting on the ground but on a twig it presents another aspect of itself and looks like a thorn.

Animals that blend with their backgrounds are to some extent imprisoned by them since they’d be dangerously conspicuous elsewhere. A creature resembling a blade of grass for example, would be an easy prey if it spent much of its time sitting on a slab of concrete. Another example is the leafy sea dragon, a form of sea horse. This astonishing fish lives among kelp beds off the coast of eastern Australia and its trailing weed like appendages so resemble the surrounding plants fronds as to be practically indistinguishable from them. Outside the kelp however its disguise would be both conspicuous and a hazard.

Many amphibians also have to live amid the background they mimic. The casque-headed frog of Ecuador is exclusively a ground dweller that blends so closely with the forest floor vegetation that it is virtually invisible. Horned toads are equally convincing as leaf litter until the males piercing calls uttered in the breeding season betray their presence.

The World of a Sandy Beaches

The beach is a product of weathering rock and the seas drift. Countless molluscs and worms live inside the sand, while animals on its surface range from tiny sand hoppers to birds and seals. Sand consists of tiny particles of rock and shell, and is the result of years of erosion and weathering by the sea. The erosion begins with the sea gnawing away at cliffs and breaking off rocks and stones. These are carried away by the sea and waves batter them against rocky foreshores, breaking them and their attached shells into ever smaller pieces. Thus the sea produces the raw materials for a sandy beach.

The next stage in the creation of a sandy beach takes place once the particles of rock and shell are small enough to be suspended in the water, when they are carried along the coast by a process known as “Longshore drift”. The direction from which waves approach a stretch of coast is determined by the direction of the prevailing wind, since the waves are created by winds out at sea. As the waves hit the shore they run up the beach, usually obliquely (depending on the wind direction), carrying their cargo of sand with them. This is called the swash. The water returns (the backwash) by the line of least resistance, which is straight down the beach. By this to and fro action, wave after wave, the sand is shifted along, guided by the direction of the prevailing wind. 

This is long shore drift. If the swash is more powerful than the backwash then the sand gradually builds up to form a beach. If the backwash is dominant the sand moves on along the coast, round the headland, and perhaps the next until it comes across a bay in which the conditions are right for the formation of a beach.
Beneath the surface like all habitats dominated by the tides, sandy beaches have their favorable and unfavorable periods for the creatures that live there. The water brings a fresh source of food on each tide but when it retreats the inhabitants invertebrates such as worms, crustaceans and molluscs have to seek shelter against the sun, the wind and predators. For this reason the great majority live beneath the surface of the sand.

One of the most obvious inhabitants is the common lugworm, which advertises its presence with the familiar coiled worm casts. This worm lives permanently in a U-shaped burrow, where it swallows sand to extract the organic content, after which the sandy waste is ejected as the cast. A few inches away from the cast a shallow round depression in the sand marks the entrance to the worm’s burrow, where the feeding activities of the head end are causing the sand to sink. The only way you can see the worm itself is to dig for it as anglers do for bait or hope to see it being dragged out by an oystercatcher or a gull feeding at low water.

The damp sand of the inter-tidal region contains many different marine worms besides the lugworms. The tube building worms are particularly satisfying to find because they build beautiful shelters against the difficult environment. The sand mason, for example, secretes sticky mucus from its body, to which sand grains adhere. This sandy tube extends down into the sand and also pokes above the surface. When the tide is out the worm withdraws, leaving only the top of the tube open. As the tide comes in the worm extends itself up the tube to collect tiny food particles drifting past its waving tentacles. The tube provides the worm with a fixed home in unstable medium of sand and allows the worm easy movement up and down in response to the changing rhythm of the tide.

Burrowing bivalves type of movement up and down in the sands in response to the tide is also performed by many different molluscs. The molluscs of the sand are mostly bivalves, in contrast to those of rocky shores which are mainly creatures such as limpets and winkles, which seal their single shells to the rock surface to keep in moisture and maintain an anchorage during the hazardous period of exposure. The bivalves have a different strategy to survive this dangerous period they burrow, using a powerful “foot muscle to drag them out of sight into the damp sand.

A good example of a burrowing bivalve is the common cockle. When the tide is in the cockle lies half buried at the surface with its two shells slightly apart to permits its two shells slightly apart to allow its siphons to extend into the water for feeding and respiration.  One siphon ejects the sieved water as waste. When the ebbing tide signals the end of cockle’s feeding time it tightly clamps its two shells, sealing itself in until the next flood tide, and hides itself just below the surface of the sand.
Hidden Predators; the sand also harbors some active hunters, such as the masked crab and the burrowing starfish. When the tide is in the masked crab digs and scoops its way into the sand with its powerful hind legs. Once hidden it breathes by drawing water down through long, tubed antennae and waits for the tide to go out so it can begin hunting. It is active only at night along the lower shore and shallow water, walking without the sideways scuttle typical of most crabs.

The burrowing starfish adopts a different strategy. It hides just below the surface of the sand and seizes whole molluscs or worms, swallowing them into its central stomach. A bivalve may seem indigestible, but the starfish has a way of dealing with it. It succeeds in prising open the mollusc’s and inserting its own stomach. The starfish’s digestive juices then reduce the meat inside to a ready meal. In due course the empty shell is rejected on to the surface of the sand.

Birds on the beach birds too are on the lookout for molluscs, and they’ve some highly successful methods of extracting the meat from within the shells. Even the tough shell of a cockle is no protection against the powerful bill of an oystercatcher. Hunting in the shallows, just before the cockle runs out of feeding time on a falling tide, or before the incoming tide renders the water too deep for the bird to wade, the oystercatcher looks for an open gaping shell. When it sees one it strikes the mollusc’s muscle, after which the mollusc is unable to close its shell in self-defense. Even if the shell does manage to close round the beak, the strong red bill can easily force it open again. Alternatively the oystercatcher can smash its way into the shell by using its beak like a hammer.

Gulls also use brute force when feeding on molluscs, but a certain amount of cunning as well. Herring gulls sometimes force cockles to the surface by paddling their fet up and down on the surface of the sand. They’ve also learned to pick up cockles from soft sand, fly with them until they are above a hard surface such as a rock or even a promenade, and then drop them so that they smash open below.

Beach plants: Sandy beaches do not exist in isolation but are flanked by rocky headlands or shallow rocky foreshores. In sheltered parts of the beach, where the water currents are slacks, the sea often carries a large cargo of debris from these neighboring habitats, and from further out at sea itself; seaweed, dead animals and shells, for instance. At the high water mark much of this organic material piles up to form the familiar strandline with its own wildlife of scavenging sand hoppers, kelp flies, turnstones, crows, rats and foxes. The same strandline also supports most of the few plants found on the lower reaches of a sandy beach. Here you may find plants such as saltwort, sea rocket and orache.

Further inland above the high tide level, the most obvious sign of plant life is often sand dunes. There is an extension of the sandy beach formed when onshore winds carry the sand inland. Once there maritime plants notably mar-ram grass stabilize the sand to form semi-permanent dunes.

Offshore seals going in the other direction, away from the land, low tides sometimes create temporary offshore island which, because of their isolation, are excellent habitats for seals. Common seals often give birth to pups on such islands, even though the pups must be able to swim before the next tide comes in to engulf them. Once in the water the baby swims with its mother and then both return suckling on the sand bank or in the shallows when the island revels itself again. Common seals spend a lot of time out of the water, humping on to the sand in large social gatherings as well as to drop pups. Their passage along the sand is marked by the characteristic tracks created by their bodies and flippers. As the tide drops the seals move with it towards the water.

From the seals point of view, one stretch of sand is as good as another for their purposes their preference for offshore banks is a direct response to human disturbances, for on land people are their only major enemies, and people flock to beaches in their thousands for the recreation they offer so well.
 

Source: Charismatic Planet

Secrets of the Seashore

From dramatic, wave-battered rocky shores to gently flowing brackish creeks and lagoons, Britain’s coastline provides over 5000 miles of varied habitats for a huge assemblage of animal and plant life, as well as an unrivalled hunting ground for the naturalist. And, whatever the interest of the naturalist, it seems the seashore can cater for it birds, mammals, fishes and a myriad of worms, shellfish and other invertebrates all find rich pickings on the seashore. 

Geological upheavals in the past have determined the overall nature of our coastline, but the sea is a constantly modifying agent, and by a relentless programme of erosion on the one hand and deposition on the other, we’re witnessing long term re-shaping by the action of water. Nevertheless, whatever the forces of nature, animals and plants seem infinitely adaptable, and there is scarcely and outcrop of rock or a patch of shifting shingle that is not inhabited. 

Unlike several other habitats, the seashore supports a constant community of plants and animals which are always on view. There is some seasonal variation but overall the seasons are of less significance than the tides. At times of low tide the naturalist can pick among the seaweeds and rock crevices for molluscs worms echinoderms and other small animals, or wait quietly by rock pools for the inhabitants to show themselves. The cliffs are often rich in wild flowers, and provide superb vantage points from which to watch seabirds such as gulls and fulmars wheeling and soaring on the thermals. Estuaries, too can provide many hours of rewarding investigation, especially even the tide is out and the wading birds flock into feed. 

The Evolution of Butterflies

The story of butterfly evolution is incomplete; butterflies are inherently so delicate that their remains are very rarely preserved there’re therefore several gaps in our knowledge. Insects first made an appearance about 400 million years ago, having evolved from the same ancestral line as the spiders and centipedes. This was back in the Devonian period, in the Paleozoic era. Winged insects made an appearance soon after; somewhere around 50 million years later; during the Carboniferous period. Moths evolved before butterflies, but it is actually very difficult to say when. This is because they developed out of caddis-flies (Order Trichoptera), and there’s no single stage where they stopped being cadis-flies, and started being moths. Butterflies evolved about 40 million years later; during the Cretaceous period.

Finding a fossil butterfly is a very rare even less than 50 have been found to date, including those preserved in amber. The best fossil butterflies have been found at the Florissant Fossil Beds National Monument in central Colorado, which is world renowned for the quality of its fossils. The beds there produce fossils that are in the order of 35 million years old. The oldest conclusive lepidopteran fossil found, however was in England at Charmouth. This was a moth called Archaeolepis mane, and is from the lower Jurassic, which makes it about 185 million years old.

The evolution of butterflies was directly linked to that of flowering plants. This is because of mutual interdependence; the butterflies need the flowers to feed on, and the plants need the butterflies to act as pollinators. This is achieved when butterflies travel between flowers to feed. As they do so, they also transfer pollen; this is sometimes so specific that only one species of plant can feed the butterfly, and conversely the butterfly may be the only species that can pollinate the plant. The consequence of this is that if one becomes extinct, so does the other.