Tuesday, August 27, 2013

Caper flies

Caper fly Capparimyia savastani
The caper fly is one of several species of insects that lives on the caper plant. It is a small fly that lives exclusively on caper plants and if you want to see one you need to look for it only on this host species.

This fly species is found in some Mediterranean countries and in parts of Asia. It has been recorded in Italy, France, Tunisia, Algeria, Libya, Egypt, Israel, Jordan, Oman and Pakistan. In 2008 it was found in large numbers on wild and cultivated caper plants on the Greek island of Milos and was immediately considered as a pest because of the potential damage it could cause to the caper production industry.

It is very similar to fruit flies such as the Mediterranean fruit fly (dubbiena tal-frott) which causes damage to fruit particularly oranges. It can be distinguished from the fruit flies by its yellow abdomen but the most important feature that would help you identify it from other flies is the fact that you will always find it resting on the leaves and flowers of the caper plant.

I have not found a Maltese name for the caper fly but dubbiena tal-kappar sounds like a good name for this species.

Female caper flies lay three to five eggs inside the buds and fruits of the caper plant. Once a fly has laid its eggs there is nothing to stop another fly from laying its eggs in the same bud or fruit and sometimes up to seven eggs can be found together in one bud or fruit.

The eggs hatch in two to ten days. The larva looks like a typical fruit-fly larva. The larva remains in the fruit or bud throughout its development which lasts from ten to eighteen days. When it is ready to pupate it emerges and falls onto the soil and digs itself in. The species probably has several broods per year. The adults can be seen only during the warmest months. It survives the winter as a pupa buried in the soil. 

This article was published in the Times of Malta on 14 August 2013.

White poplar

White poplar Populus alba
The white polar is the only native poplar of the Maltese islands. It is indigenous in southern and central Europe and to the east as far as Central Asia. It lives in moist habitats such as the sides of streams and rivers. In Malta it grows in valleys such as Chadwick Lakes and at Wied il-Luq which is Maltese for valley of the poplars.

In old English the white poplar was known as ‘Abele’ from the Latin albellus meaning white. Its scientific name is Populus alba which also means white polar.

The white poplar was introduced in North America in 1748. It is widely cultivated for its wood and in some areas it is considered as an invasive species. It is an invasive species also in many parts of Australia and in South Africa

The tree is easily recognised. The trunk is smooth greyish-white and the leaves appear white underneath. The white colour is a result of whitish-grey hair that grows on both sides of the leaves. The hair on the upper side of the leaves wears off uncovering the green surface of the leaves. That on the bottom remains on the leave until it falls off in late autumn.

In Ancient Greece the white poplar was dedicated to Hercules after he crowned himself with its branches to celebrate his victory over Cacus on Aventine Hill which was covered with white poplars. Those offering sacrifices to him bound their heads in a similar way as did those who conquered their enemies.

The white poplar is one of several species of poplars native to the Northern Hemisphere. The exact number of poplars is unknown mainly because of difficulties in distinguishing species and the existence of hybrids. It is believed that there are between twenty-five and thirty-five species.  

This article was published in the Times of Malta on 7 August 2013

Aggresive bulrush

Southern bulrush Typha domingensis
The lesser bulrush is a large aquatic plant found in southern Europe, North Africa and in many parts of Asia and the American continent.

It is rare in the Maltese islands because the aquatic habitat which it requires is very rare. One can see it in valleys behind man-made dams and in artificial ponds and pools.

About eleven species of bulrush can be found most of them restricted to the Northern Hemisphere. Only one of them occurs in the Maltese islands.

In Maltese the lesser bulrush is known as buda. In England bulrushes are also known as reedmace. In America they have several names including catnail and catninetail.

The plant grows from an underground rhizome. Above ground it consists of long sword-like leaves. The flowers consist of a thin vertical spike on which male flowers form. Beneath this is a thicker sausage-shaped inflorescence with female flowers. Female flowers form after the male flowers have shed their pollen, withered and died. This avoids self-fertilisation. 

In Turkey and some other countries the female inflorescence of the lesser bulrush is used to treat wounds. Recent studies have confirmed that these medicinal properties can be effective and are not just folk beliefs.

Bulrushes are aggressive, in some areas they can become the dominant species to the detriment of other plant species. Several species can grow in one area with the different species adapted to live at different depths.

The bulrush plant has many uses. It can be eaten, it has medicinal properties, and the leaves can be used as insulation for houses and to make decorative paper.

The plants’ rhizomes are rich in starch. They are edible and can be ground into a powder. Starchy remains of ground bulrush tubers have been found on prehistoric grinding stones suggesting that they have been consumed in Europe for as far back as 30,000 years ago. Other communities eat other parts of the plants. The developing flower-heads can be boiled and eaten like corn on the cob. The seeds are rich in linoleic acid and are used as cattle and chicken feed.

This article was published in The Times of Malta on 31 July 2013.

The entwining climbing plant

Morning glory Ipomea purpurea
The common morning glory is a familiar garden plant. It requires a moist rich soil and when seeds from cultivated plants reach the countryside they survive only in valleys with water courses which remain humid throughout most of the year.

This species is native to Mexico and Central America but it has become established in many countries outside its normal range. In some countries it is considered a pest but in Malta it does not grow in large numbers as in the summer months few places have enough water to support it.

The plant entwines itself around branches and other structures and can climb up to three metres high.

The large flowers are usually blue to purple but white, pink and red cultivars have been developed by gardeners with some varieties having more than one colour.

The seeds contain a substance similar to lysergic acid diethylamide known in short as LSD and have been used in the past as psychedelic agents.

The morning glory forms part of the genus Ipomea which belongs to the bindweed family. Several species of bindweed known in Maltese as leblieb are indigenous to the Maltese islands.

At least four species of morning glory have been found growing in the Maltese countryside. None of them is indigenous to the Maltese islands and all have been introduced to Malta as garden plants.

The Ipomea is a large genus. The members of the genus are native to the tropical and subtropical parts of the world. Most species are annual twining climbing plants but some are perennials that can take the shape of small trees. The large flowers of Ipomeas are often pollinated by hawk moths and in the Americas by hummingbirds.

Many members of the genus have medicinal value and some are used as food.  The seeds of some South American species were used by the Aztecs in religious, shamanic and spiritual rituals. 

This article was published in The Times of Malta on 24 July 2013

Sunday, August 25, 2013

Savi’s pipistrelle

Savi's pipistrelle Hypsugo savii
The Savi’s pipistrelle is the latest addition to the list of bats of the Maltese islands. In 2011 it was discovered roosting in the Vilhena Palace at Mdina.

This new species of bat was discovered by means of a bat detector. This is a device that is used by chiropterologists (people who study bats) and naturalists to detect the presence of bats and to identify them. Most bat detectors work by converting the ultrasound signals bats make to fly in the dark into audible frequencies. Different species make different sounds making it possible to identify them although closely related species sometimes can be hard to tell apart.

The Savi’s pipistrelle is found in the countries surrounding the Mediterranean. It is also found west of the Mediterranean in the Canary Islands and the Cape Verde Islands and to the east and south east as far as northern India.

Savi’s pipistrelles roost during the day under bark, in cracks in old buildings and rock faces and come out at night to feed on flying insects. In winter they seek caves, underground vaults and other places where the temperature is more stable.

The Savi’s pipistrelle belongs to a family of bats known as the vesper or evening bats. The vesper family is the largest bat family. It consists of over 300 species found on every continent except Antarctica.

Twelve species of bats have been recorded in the Maltese islands. One species, the Schreiber’s bent-winged bat, was recorded only twice in the 1950s.

All bats are protected in the Maltese islands and it is illegal to kill or harm them. Bats are protected internationally through a number of conventions such as the Bonn Convention and in Europe through the EU Habitats and Species Directive. 

This article was published in The Times of Malta 17 July 2013

The common hollyhock

Common hollyhock Alcea rosea
The common hollyhock is indigenous to southwestern China. It was brought to Europe in the 15th century or even earlier. It was originally named ‘holyoke’ from which name the current name hollyhock is derived.

The original name was given to it by William Turner, a 16th century English Anglican cleric and natural historian who studied medicine in Italy.

Until today, the hollyhock, which is a member of the mallow family, is grown mainly as an ornamental plant for its large flowers. In Malta it can sometimes be found growing wild often close to human habitation. It is thus considered as a rare alien species.

In Maltese it is known as bastun ta’ San Ġużepp meaning St Joseph’s walking cane.

The hollyhock has been used medicinally and is edible. I have never tasted it but it is said that it does not have a good taste. The flowers are emollient, demulcent and have diuretic properties. These properties are similar to those of other members of the mallow family.

About sixty species of hollyhock are known to exist. Most of them are found in Asia and Europe.

 They can be annual, biennial or perennial plants and they usually grow vertically without much branching. The flowers are formed on an erect stalk hence the common hollyhock’s Maltese name.

The seeds germinate very easily but the seedlings attract snails and slugs. In a pot or in a garden it would be easy to protect the seedlings from snails and slugs but in the wild few of the seedlings would manage to survive and grow. This probably explains why this species is not more widespread in the countryside.  The slugs and snails are a form of biological control and stop this alien species from taking over the countryside. Other alien species such as the cape sorrel (ħaxixa ngliża) and the castor oil tree (siġra tar-riġnu) are not kept in check naturally and have taken over large parts of the Maltese countryside to the detriment of indigenous species. 

This article was published in The Times of Malta 10 July 2013

The sea daffodil

Sea daffodil Pancratium maritimum
The sea daffodil is one of the most beautiful of Malta’s indigenous flowers. It grows in the most unexpected of places and flowers during the hottest and driest months of the year.

It is very well adapted to live in sand, close to the sea. It manages to do so by having a large bulb which stores enough food and water to help it survive in difficult conditions. The bulb is buried at least half a metre underground. This ensures that the bulb is not uncovered even when strong wind is blowing the sand around. As it grows in loose sand it is not difficult for the shoots to push their way through half a metre of sand.

The sea daffodil often grows in dense clumps. It has several common names including sea lily and sand lily. In Maltese it also has several names indicating its popularity. It is known as ġilju tar-ramel, narċis tar-ramel and pankrazju.

The latter name is used mostly by people familiar with its scientific name, Pancratium maritimum. Pancratium is a Greek word meaning strength. It probably refers to the ability of this plant to live in a difficult environment although it could also be a reference to the tonic properties of the plant. Maritimum is an obvious reference to its ability to live close to the sea.

A fertilised flower produces a large seed capsule which, when mature breaks open releasing 10 to 40 irregularly-shaped black seeds that look like charcoal. The seeds are very light and can float. They probably disperse by the action of waves and wind.

The sea daffodil has an interesting mode of fertilisation. The flowers of the sea daffodil open in the late afternoon and evening and close the following afternoon. They are large and pure white which makes them easier to see at night. They also have a strong scent. All this indicates that they are pollinated by night-flying moths.

Studies carried out a few years ago have shown that the pollinators are the large hawk moths particularly the convolvulus hawk moth, known in Maltese as baħrija tal-leblieb.

Another interesting investigation showed that the moths visited the flowers when there was little or no wind. Flowers that opened on windy days remained unpollinated and did not produce seeds.

This article was published in The Times of Malta on 3 July 2013

Beautiful primrose

Primrose tree Lagunaria patersonia
The primrose tree is an evergreen tree native of Lord Howe Island and Norfolk Island, two small islands lying between Australia and New Zealand. It is also found along parts of coast of Queensland in northwest Australia.
It has been introduced in many tropical and sub-tropical countries.  It is a popular street and park tree in warmer parts of the United States of America such as California, Florida and Hawaii as well as in South Africa.

It grows well in Malta but is not very popular and is not often planted.
The flowers are pale pink or mauve, fading to white, and have a waxy texture. In Malta it is in bloom from late spring to early autumn. It has been recorded growing on its own but I have not yet seen any self-seeded specimens.
The primrose tree belongs to the mallow family. In Malta we have several species of indigenous mallows such as the tree mallow (ħobbejża tas-siġra). We also have a number of species such as the hibiscus which are not indigenous. The flowers of the primrose tree do in fact have a superficial resemblance to the flowers of many of the more familiar mallow species.
This beautiful tree is known by several names including the pyramid tree, the Norfolk Island hibiscus and the Queensland white oak. It is also known as the cow itch tree because its seed pods are full of irritating hairs. Luckily Maltese boys do not know about this characteristic as they would undoubtedly be used as an itching powder by the more mischievous of them.
Its scientific name is Lagunaria patersonia. It was named after Andrés Laguna de Segovia who lived between 1499 and 1559. Laguna de Segovia was a Spanish botanist and physician to Pope Julius III and after Colonel William Paterson (1755 -1810), a Scottish soldier, explorer and botanist, who collected the first seeds that were sent to England. 

This article was published in The Times of Malta 26 June 2013

Protecting our trees

Trees play a very important role in rural and urban areas. They filter air, and provide shelter and food to animals. They also provide shade and recreational areas. They reduce air temperature, slow down wind speed and mitigate the effects of extreme climate. They also actively reduce pollutants from the air.

Trees also reduce stress and are beneficial to health in more ways than one.

Trees or the lack of trees in the Maltese islands can bring about extreme reactions ranging from that of persons who want to save trees at all costs to those who want to move or remove trees from particular areas.

These reactions are understandable. Those who believe that there should be more trees in our towns and villages are hurt when they see trees being removed while ignoring the fact that trees can cause damage to buildings and underground structures and must be replaced or removed. 

In the countryside trees are an important tool for soil conservation. Their roots hold the soil in place and help rainwater seep into the ground. They slow down the flow of water and help reduce flooding.

The leaves and flowers of many species provide food for insects such as bees and butterflies.

There are those who insist that any tree planted in the Maltese islands whether in urban or rural area should be indigenous to the islands. Indigenous species are those that have been growing in the Maltese islands for thousands of years and came here without human intervention. These trees are usually very well adapted to the local climate and conditions and provide the best possible habitat for indigenous fauna.

The number of indigenous trees is very small. Species that nowadays form an integral part of the Maltese countryside such as the carob, almond and olive trees, in spite of what many people think, are not indigenous.

Several species of alien trees grow in the Maltese countryside. Some species such as the castor oil tree are aggressive invaders and in many areas have taken over vast tracts of ground at the cost of local species. These species need to be eradicated from the Maltese countryside and replaced by local species.

Much needs to be done to protect trees and increase their numbers in the Maltese islands.
Any action that is taken should be based on sound principles and should not be based solely on emotional reactions.

This article was published in The Times of Malta on 19 June 2013

The mammoth wasp

Mammoth wasp Megascolia flavifrons
The mammoth wasp is the largest wasp you will encounter in Malta or for that matter anywhere in Europe. It is also known as the large yellow-banded scolid wasp or just as the scolid wasp.

It belongs to a family of wasps known as scolid wasps. About 200 species are known to exist in the world. Most are predators of beetle larvae and some are important biocontrol agents.

The female mammoth wasp can grow up to 40 or 45 mm long. Males are smaller, reaching a maximum of 30 mm.

It is a very conspicuous insect. It is seen from late spring to early autumn especially in valleys and garigue areas with wild artichoke (qaqoċċ tax-xewk) plants growing in the vicinity. I have also seen on the large pink flowers of the kaffir fig (xuxet San Ġwann).
In spite of its large size and warning colours it is not dangerous and does not pose any threat to humans

Only females have stings. The sting is used mainly to paralyse the white larvae of Europe’s largest beetle; the rhinoceros beetle. She then lays a single egg in the larva’s body. When the egg hatches, the wasp larva starts to feed on the larva’s internal tissues. It eventually kills it and continues eating it until nothing is left but an empty skin. When fully grown the larva forms a cocoon and emerges in spring when the air has warmed up sufficiently.

In Maltese the mammoth wasp is known as qerd iż-żaqquq. Qerd is Maltese for destroyer but I could not find the meaning of żaqquq. I assume that as this wasp kills the larvae of the rhinoceros beetle żaqquq could be a lost name for this insect which nowadays is known as buqarn kbir

This article was published in The Times of Malta on 12 June 2013 

Striking bird breeding at GħadiraB

Black winged stilt Himantopus himantopus
The black winged stilt is known in Maltese as fras-servjent. It is an uncommon spring and autumn migrant that is sometimes seen in small flocks. It is easily recognised by its striking white and black pattern and long beak and pink legs.

Several years ago I predicted that some day the black winged stilt would start breeding in Malta. It is common in wetlands around the Mediterranean and couples had been seen taking part in courtship displays at the Għadira Nature Reserve.

In 2011 a pair did build a nest and successfully raising their young in the reserve. Last year no black winged stilts bred at Għadira but this year not one, but three pairs are breeding in the reserve.

This augurs well for the future of this bird as a regular breeder in the Maltese islands.

Black winged stilts are not the only waders to breed at Għadira. In 1995 a pair of little ringed plovers, monakella in Maltese, bred on one of the islands in the reserve. Since then this species has bred successfully every year. An average of six pairs breed in the reserve every year. The little ringed plover can now be listed as a breeding species.

The Għadira and the Simar nature reserves have been instrumental in attracting new breeding aquatic birds such as the coot and little grebe to the Maltese islands.

Other birds such as the little bittern bred once or twice and might become regular breeders in the future while others such as the moorhen and reed warbler had bred outside the reserve before but have now established strong breeding populations in the reserves.

 The success of these reserves is that they have provided habitats which previously did not exist in the Maltese islands. They also provide a safe haven where they can breed without being shot.

Nature reserves are important because they tend to encourage birds to breed in new areas or in new countries. In the UK nature reserves are sometimes called ‘welcome door mats’ because several species breed for the first times in nature reserve and from there move to new areas to establish breeding populations outside the boundaries of the nature reserves.

This article was published in The Times of Malta on 5 June 2013