Sunday, May 20, 2012

Beetle mania

Recently while taking some early morning pictures at Fiddien I found a species of black beetle that I had never seen before. A friend of mine, a specialist in beetles, identified it for me.

It was a nocturnal weevil known to entomologists as Otiorhynchus lugens but for which I could not find a common name.

Weevils are recognised by their long snout and small antennae which have small knobs at the end. They are plant feeders and are often found on or near their food plant.

The weevil family is very large. Over 40,000 species have been identified worldwide of which more than 120 species, including several endemics, are found in the Maltese islands.Most of the weevils I am familiar with are either a shade of brown or grey.

Being black and nocturnal this species made me think about the fact that although the most familiar beetles such as ladybirds and leaf beetles are brightly coloured, many beetles, many of which we do not often see, are black.

A study carried out about ten years ago in Brazil found that the body colour of beetles is strongly related to their daily activity pattern. In other words, nocturnal beetles are likely to be black while diurnal species are either brown or brightly coloured.

Bright colours are used to warn predators, especially birds, that that particular insect is either bad tasting, poisonous or that it can inflict a painful sting. Brown or grey colours camouflage them, making them difficult to see against their surroundings. On the other any brown or grey beetle would be easy to spot in the darkness so nocturnal beetles have evolved black bodies which makes them difficult to see at night.

This gives them an advantage over beetles that are not black, as, being more difficult to see there is a smaller chance that they are eaten by predators.

This article was published in The Times on 28.12.11

Of seeds with ‘papery wings’

The sandarac is Malta’s national tree. It was presumably chosen because of its rarity in the Maltese islands. 

Its main range is in the Atlas Mountains of Morocco, Algeria and Tunisia. Outside North West Africa it is found only in Malta and Cartagena in southeast Spain.

It is a conifer and like all conifers the seeds are produced in cones. 

In this species the cones are between ten and fifteen millimetres long. When young they are green, turning brown as they age. 

They consist of four thick scales arranged in pairs to form an uneven sphere. When the cones open, the seeds which have papery wings float gently to the ground.

In Maltese the sandarac is known as għargħar, a semitic name that indicates that this tree was already present when the when the islands were occupied by the Arabs. 

Up to about thirty years ago it was thought that this tree grew only at Maqluba, near Qrendi, but a small grove was found near Mellieħa. 

In the past this tree was said to have been much more common especially in the area around Birkirkara and around the village of Għargħur.

It is a tree adapted to the hot dry summers of the Mediterranean. It can survive burning and can re-grow from cut or burnt stumps. Trees that have been burnt repeatedly over a long period of time form burrs known as lupias. 

Burrs are stress-induced deformations usually in the form of rounded outgrowths of the trunk. Burrs are usually highly prized and sought by furniture makers and artists. To obtain the lupias the sandarac trees are destroyed and this has led to large parts of Morocco being deforested.

The tree produces a resin which is used to make a varnish which was used to protect paintings and antiques. For many centuries sandarac was the only varnish in use until it was replaced by cheaper varnishes. 

In parts of North Africa the resin is traditionally used to make a liquor and as a remedy in cases of difficult childbirth as well as to reduce cramps. Sandarac is burned to treat colds or taken internally to treat roundworms and tapeworms.

The wood of the sandarac is known as citron. In Romans times it was often used in house building and is still used in cabinetry and to make decorative objects. 

This article was published in The Times on 21.12.11.

Fly that pretends to buzz like a bee

Hoverflies, as their name suggests, are well known for their habit of hovering in front of flowers. 

Many adult hoverflies feed on nectar and pollen while the larvae feed on a variety of animal and plant material. 

In some species the larvae are insectivores. These are now being used to control plant-sucking insects such as aphids which can cause widespread damage to agricultural crops.

Hoverflies are found on all continents except Antarctica. 

At least six thousand species have been identified and named of these about 30 species have been recorded in Malta but I would not be surprised if more species are discovered in the future.

Hoverflies rely on mimicry to protect themselves from predators. 

They resemble dangerous insects especially bees and wasps and even hover and buzz like them. Their mimicry is so good that predators mistake them for dangerous insects and leave them alone even though they are not dangerous as they do not sting. 

Hoverflies are so confident of their mimicry that unlike most other insects they do not fly away when approached and one can get many opportunities to get good close up pictures of them. 

Pictures can be useful when trying to identify this group of insects as unless one is a specialist it can be very difficult to tell species apart in the field.

Many species of hoverflies can be seen on flowers on warm spring days but even at this time of the year one can observe a number of species feeding on pollen produced by autumn and early winter flowering plants such as the daisies which are already in flower. 

Common species in Malta include the drone-fly (dubbiena dakar), the lesser drone-fly (dubbiena ta’ l-għajnejn irrigati), the common yellow-banded hoverfly (dubbiena żunżanija) and the slender hover-fly (dubbiena tal-fjuri). 

This article was published in The Times on 14.12.2011

The shell that lets in light

I spent an enjoyable afternoon last Sunday taking pictures of sea snails and shells washed ashore during the recent stormy weather.

I found several interesting species which are normally associated with a sandy sea bottom.

The Maltese islands do not have regular tides, but the sea level sometimes goes down by a few centimetres, which in places like Għadira Bay can result in a considerable retreat comparable to a tide.

When this happens one gets the chance to observe more specimens of marine flora and fauna.

The most common seashell on the beach was that of the rayed trough-shell (Mactra stultorum), which is known in Maltese as arzella tal-baħar.

This species belongs to a family of bivalve molluscs commonly known as trough shells or duck clams.

Ten members of this family are found in the Mediterranean but only four species have been recorded around the Maltese islands.

The rayed trough-shell is found in the north, from Norway down the west coast of Europe to the Iberian Peninsula and along the African coasts as far south as Senegal. It is also found along the Mediterranean and Black Sea coasts.

It lives in sandy bottoms from five to 30 metres deep and is often found cast up on beaches. It has a thin and delicate shell through which light can pass, providing one with many opportunities to create beautiful pictures especially early in the morning or late afternoon.

Like many other species of molluscs, the rayed trough-shell is edible and in some places it is collected and sold in markets.

This article was published in The Times on 7.12.11

The healing field marigold

The field marigold is a member of the daisy family. It is native to central and southern Europe including the Maltese islands. 

It has now been introduced in many countries throughout the world in some of places it is considered as a pest. 

In Malta we find two subspecies of field marigold one of which even exists in two varieties. 

This makes identification of this species somewhat confusing a situation which is not made any easier by the fact that the daisy family which is made up of over 20,000 species is the largest plant family. In Malta the daisy family is represented by about 120 species.

The two races of field marigold are known in Maltese as suffejra tar-raba’ and suffejra kbira tar-raba’. The variety being shown in the picture has been named suffejra tar-raba’ ta’ ġiex kuluri.

The field marigold is widely cultivated as a garden plant but it is better known for its medicinal properties. 

It is said to have antibacterial and anti-inflammatory properties and has been used extensively to heal wounds. It is believed that its anti-bacterial properties are partially a result of the structure of its sugar which stimulates the body’s immune system. 

To heal minor wounds the leaves and petals can be ground or crushed into a paste, mixed with water and applied to the wounds. The flowers have also been used to treat stomach ulcers and gastrointestinal problems for hundreds of years.

Plant identification is an interesting and sometimes challenging task. Until the invention of modern pharmaceuticals most people interested in plants were pharmacists and doctors who studied botany because many plants were used for medical purposes. 

Botanists today still study plants because of their medicinal value but a growing number of enthusiasts are taking an interest in wild plants as a hobby. 

This article was written in The Times on 30.11.11

The leaf beetle family

Chrysolina variolosa
Leaf beetles are members of an insect family represented  by about sixty species in Malta

The one pictured with this article is known simply as a leaf beetle and in Maltese as żabbella a name that was used also for the ladybirds. The scientific name which distinguishes this beetle from all other leaf beetles is Chrysolina variolosa.

This species is frequent although not common. 

It is usually found on the spiny asparagus, (spraġġ in Maltese) as it probably eats its leaves.

But the specimen I photographed last Sunday at Mistra Bay was walking on rocks far from any asparagus plant.

The leaf beetle family is the largest and most commonly encountered beetle family. It is estimated that there are over 35,000 species in this family. Several species are of economic importance because of their impact on agricultural produce. 

Some have been used to control weeds biologically especially in Australia and in California.

But the greatest impact is probably that of another species - the Colorado potato beetle which can devastate entire crops of potato.

The Colorado potato beetle is indigenous to the Americas but it was not until 1840 that it started to become a pest of the potato plant. 

It appeared in Germany in Germany in 1877 but was soon eradicated from there. It reappeared in Europe sometime during World War I. It was first observed near American military bases in Bordeaux and from there it spread to Belgium, the Netherlands and Spain eating its way through potato fields.

Soon after the Colorado potato beetle started to spread in Europe the Maltese Government, prohibited the importation of crops from any areas where this beetle was present and managed to keep the Maltese islands free from this pest.

In 2008 the European Union issued a Directive by means of which Malta was declared a protected zone and was thus given special protection to be able to take measures such as plant quarantine to keep the Colorado potato beetle away from the islands. 

This article was published in The Times on 23.11.11)

Of gourd ladybirds and the squirting cucumbers

Many species of animals and plants are closely linked together. In some cases the relationship benefits one species only and in others both species benefit from the relationship. 

This relationship often means that if one species had to disappear the other would not be able to survive on its own and would cease to exist as well. 

One such relationship is that existing between the squirting cucumber (faqqus il-ħmir) and the gourd ladybird (nannakola tal-faqus il-ħmir).

The squirting cucumber is a common plant with large leaves and yellow flowers. The fruit are oval and when ripe they shoot out the seeds. The seeds emerge with such force that they can land up to one metre away from the parent plant thus helping the plant to disperse. 

The squirting cucumber grows in disturbed habitats along country lanes and in urban areas.

Whenever you find a squirting cucumber you are also likely to find the gourd ladybird. This species of ladybird spends its entire life on the squirting cucumber. Ladybirds are known to be predators. 

Most feed on insects especially aphids but I have never seen this species eating other insects. I have often seen the adults in the flower of the squirting cucumber probably eating pollen. 

Adult ladybirds often carry a sprinkling of pollen on their wings which indicates that they could be transferring pollen from one flower to another thus aiding pollination.

The eggs are laid on the plant and the larvae spend their entire life on it. I have not found any literature on the life cycle of this species but I have seen small parts of the surface of the leaf on which a larva of this ladybird is living eaten away which indicates that the larvae feed on the leaves on which they live.

My observations indicate that the relationship between these two species is beneficial to both species. The plant provides the food for the larvae and adults while the adult ladybirds help to pollinate the flowers. 

This article was published in The Times on 16.11.11

Wasps: Close encounter of a painful kind

The common and the large paper wasps are the most familiar wasps in the Maltese islands. 

Although a relatively small number of persons have ever been stung by one of these insects practically everybody is aware of this insect’s ability to defend itself by inflicting a painful sting. 

The yellow and black stripes are a form of warning colouration which informs potential predators that trying to eat a wasp will result in pain.

Both of these species are very common in the Maltese islands and can be found practically in every corner of the countryside sometimes very close to human habitats. 

They build a distinctive nest made of a paper-like material which they produce by chewing wood particles and mixing them with saliva to produce a thick fluid which dries on exposure to air. 

The nests are anchored to a vertical solid object such as a wall, rock face or tree trunk by means of a stalk. After building the nest they secrete an ant repelling chemical which they spread around the base of the stalk to prevent them from stealing the eggs or brood from the nest.

The nests of the two species look very similar and are built in similar places. 

The large paper wasp is slightly larger than the common paper wasp and builds a larger nest hence their Maltese names: żunżan tax-xehda (common paper wasp) and żunżan tax-xehda kbira (large paper wasp).

Paper wasps are predators. They hunt other insects which are then carried to the nest to provide food for the larvae. 

Wasps and are very important biological pest control agents and should not be destroyed.

Paper wasps are usually not very aggressive and will attack only if they or their nests are threatened. 

I have taken many close-up pictures of their nests and I have never been stung. The only trick is to move slowly away if they start behaving nervously and appear agitated. 

This article was published in The Times on 9.11.11

Saturday, May 19, 2012

The common autumn squill

This common flower is so difficult to notice. It is about five centimetres high with very small light pink flowers that blend perfectly with the light coloured soil common in the arid rocky areas where this plant grows. 

It is also difficult to see it because when it is blooming there are no green leaves to attract your attention. The leaves appear above ground after the end of the flowering season.

The flowers appear in the autumn soon after the first rains. Like other species of autumn-flowering plants it is able to do so because of the food stored in the bulb which had been manufactured by the plant during the previous season.

The autumn squill is known in Maltese as għansal tax-xitwa. It is widespread in Mediterranean countries from Turkey to Spain as well as further north as far as southern England and the Middle East all the way to northern Iraq. In Malta it is common in the right habitat

Two other species of squill are known in the Maltese islands. The large squill, known in Maltese as għansal selvaġġ, is probably extinct from the Maltese islands. The Sicilian squill, għansal ikħal in Maltese, is a regional endemic found only in the Maltese islands and neighbouring islands including Sicily.

Until some years ago the autumn squill belonged to the same group of plants as the other two locally occurring squills but recently its name was changed from Scilla autumnalis to Prospero autumnalis

Prospero is the main character in The Tempest one of Shakespeare play. 

I had read this play when I was still at school but I cannot imagine why this tiny flowering plant was named after this character. Perhaps if I re-read the play I could get some clues that would help me solve this problem! 

This article was published in The Times on 2.11.11

Appreciating the richness of our country’s biodiversity

Autumn grape hyacinth
Last Sunday I was at l-Aħrax tal-Mellieħa taking pictures of the fauna and flora. Until fifty years ago the area consisted mostly of garigue habitat. This habitat consists of rocky ground with depressions and fissures containing a thin layer of soil. 

Many species of aromatic shrubs such as the Mediterranean thyme grows in such a habitat. The thyme provided nectar to bees which produced the much sought after thyme honey for which the area around Mellieħa was well known. 

A few decades ago it was decided to replace this important habitat with woodland. Most of L-Aħrax nowadays consists of low trees under which grow non-indigenous plants especially the Cape sorrel (ħaxixa ngliża).

Here and there one still finds small patches with plants that must have been present when the area was still garigue.

Among these patches last Sunday I found the autumn narcissus (narċis imwaħħar) and the autumn grape hyacinth (ġjaċint tal-ħarifa). The latter is a small plant with blue bell-shaped flowers. This is the only species of grape hyacinth that flowers in the autumn. It grows in patches of soil in garigue habitat in a small number of localities and I had not seen it for a number of years so I spent some time taking pictures of the small interesting flowers.

What struck me most during day was that as people arrived to picnics at L-Aħrax most of them seemed oblivious of their surroundings. They saw the trees but did not distinguish between the different species and I was sure that they had not heard the robins singing loudly in the trees beneath which they were sitting and they did not notice the different flowers some of which ended up crushed under their feet. 

I do not expect others to be expert naturalists but I realised that by not being aware of the fauna and flora of the Maltese islands many fail to fully appreciate the richness of their country’s biodiversity. 

This article was written in The Times on 26.10.11

The shiny yellow autumn buttercup

Autumn buttercup (Ranunculus bullatus)
During the past few days summer gave way to autumn. The air became cooler and enough rain fell to stimulate bulbs, corms and tubers to start growing leaves and to initiate the process of germination of those seeds that had been lying dormant in the soil from last spring or earlier. 

The change from parched brown to fresh green takes place incredibly fast and the change from green to bright yellow which will take place within a few weeks time is even faster.

Plants with underground storage organs have an advantage over plants which have to germinate from a seed.

This advantage makes it possible for them to flower soon after the arrival of the first rains. This weekend I found one of the first plants to flower in autumn, the autumn buttercup.

This plant, which is known in Maltese as ċifolloq, has shiny yellow flowers. It can be found growing in garigue, maquis and steppe.

In the next few days the flowers of the autumn narcissus (narċis imwaħħar) will also appear in the same habitats. These will be followed by the yellow-throated crocus (żagħfran salvaġġ) which is found mainly in garigue and steppe habitats in the Buskett and Dingli area. 

There will also be less showy plants for which you will need to look more carefully. Among these is a small orchid known as autumn lady’s tresses (ħajja u mejta). Most of these flowers will disappear by the time winter officially starts by which time many other species of winter flowering plants will be in bloom.

Autumn in Malta is a time of rebirth. The autumn rains give life to the countryside and many species of plants make the most out of the available water and sunlight to grow rapidly before the arrival of the colder and darker winter months.

This article was published in The Times on 19.10.11

The rat that lacks pigment

Some time ago I photographed a strange looking rat that was so tame that it came to within two or three metres of me and allowed me to take many pictures of it before it walked calmly away. 

The rat had white markings on the face showing that it was an albinoid rat.

Albinism is characterised by complete or partial absence of pigment in the skin. It can occur in all vertebrates including humans. The lack of pigment can be partial or complete and can also effect the hair and eyes.

Albinism is not often seen in nature. The lack of pigment results in loss of camouflage and albinistic animals are easily spotted by predators. In areas with no predators albino animals can have a normal life expectancy. A Spanish sparrow (għammiel tal-bejt) with large patches of white on its wings used to breed in a ventilator close to where I live and managed to survive for many years.

Several albino animals have been purposely bred for particular characteristics. The best known are albino rabbits and rats. Albino rabbits are said to have a better taste while albino rats are used extensively in laboratories for biomedical studies and experimentation.

It is said that these rats are the descendants of rats caught around 1800 by English rat-catchers for ratting, a blood sport in which trained dogs were lowered in pits full of rats to kill as many as possible in the shortest time possible. Rats which exhibited any albinism, instead of being thrown in the pits, were kept for breeding and exhibition and these became the stock from which today’s laboratory rats are descended.

Two species of rat are found in the Maltese islands; the brown rat (far tal-kampanja) and the black rat (far iswed). Both species of rat can by found in urban and rural areas. 

They are very common animals that can be carriers of disease and can cause a lot of damage to crops and stored food. 

This article was published in The Times on 12.10.11

The amazing praying mantis

Last Sunday I was photographing a dragonfly resting on top of a dry plant when out of the corner of my eye I saw a brown praying mantis. 

Praying mantises are amazing insects. They are long and as thin as a stick with a pair of large eyes on the sides of a flexible head. The head can swivel in many directions which allow the mantis to scan its surroundings for predators and prey. The most unusual feature of these insect is that the front legs have been modified into very effective hunting instruments.

The praying mantis is known in Maltese as debba tax-xitan , devil’s mare in English. Mantis is derived from the Greek word for prophet. Three species of praying mantises are found in the Maltese islands. 

This is a very small number when compared to the approximately 2,200 species found in the world. Some of the larger species are capable of catching larger animals including lizards, frogs, fish rodents and even birds.

Most species are diurnal, that is, they are active during the day, but the males of some species fly at night to visit females which they detect by means of pheromones. 

By flying at night they can avoid day-flying predatory birds and to avoid bats some have organs capable of detecting the echolocation sounds of bat which allows them to take evasive action when bats are hunting in the vicinity. 

After all the effort and risks incurred to find a female, most male praying mantises make the ultimate sacrifice by allowing the female with which they had just copulated to eat them and so providing her with nutrients to produce the eggs. 

This article was published in The Times on 5.10.11

Flesh flies breed on living or dead organic material

Flesh flies, as their name implies, breed on living or dead organic material, mainly flesh. Their maggots live in dead animals, dung or decaying vegetable matter and sometimes in open wounds of mammalian species. 

Some species are internal parasites especially of beetles and grasshoppers while others live in bees and wasps’ nests.

About 30 species are found in the Maltese islands. Most are dark with light stripes but in many cases it is difficult to tell species apart unless they are studied microscopically. 

In many species the female is larger than the male. The most common species, known in Maltese as dubbiena tal-laħam, is larger than the common house fly. It can be found on decomposing organic material as well as on flowers.

These insects which are found throughout most of the world are not only a nuisance but can also be important vectors of diseases including leprosy. Sometimes they are also important as pest control agents and can be beneficial in fruit tree orchards and in forestry plantations.

Flesh flies have been extensively studied especially because of their importance in forensic science. Flesh flies do not lay eggs. The eggs hatch inside the female fly which then ‘gives birth’ to the maggots. 

Different species place their young in animals that are at different stages of decomposition ranging from freshly dead to bloated or decaying. This makes it possible for entomologist to accurately give the date or sometimes even the time of death of a corpse.

There is a tendency to classify insects as being either good or bad. Flies are automatically deemed as bad and therefore to be annihilated. But the living world is not that simple. 

Many species of flies can cause problems but at the same time they also help to break down organic matter and help to recycle it. 

Flies reduce the time required for a corpse to decompose and without them we would see more dead animals lying around. 

This article was written in The Times on 28.09.11

Watching raptors migrating is a rewarding experience

Honey buzzard (Pernis apivorus)
September is raptor migration month. Every year large numbers of birds of prey such as honey buzzards (kuċċard), several species of harriers (bugħadan), eagles (ajkli) and falcons (isqra) fly over the Maltese islands while travelling from their breeding grounds in Europe to their wintering grounds in Africa. 

Malta is on one of their routes because these birds travel on land and avoid as much as possible crossing large stretches of open water. 

Raptors travel mostly by making use of hot air currents, known as thermals, to soar with the minimum of effort. We are all familiar with films and documentaries showing vultures soaring in search of dead animals.

Migrating raptors tend to congregate mainly but not solely at Buskett. Birdwatchers have been monitoring these magnificent birds for more than three decades and have become experts at raptor identification, being able to not only to tell species apart but also sexing and aging migrating birds.

Raptor watching in Malta has become very interesting and exciting. Thirty years ago the challenge was to count the birds including the large numbers that were illegally shot while avoiding being shot yourself. This situation has changed and bird shooting in and around Buskett is mostly under control. As a result of this the number of migrating raptors has increased and birdwatchers are getting spectacular views of these birds as they fly low in search of a place to land.

Watching raptors on migration is an incredibly rewarding experience and I urge readers to go to Buskett to experience this natural phenomenon. Anybody wishing to give it a try should go to Buskett this afternoon from three o’clock onward where a group of experienced birdwatchers will be near the cart ruts site known as Clapham Junction to help those present to get the most out of the experience.

This article was published in The Times on 21.09.11

The moonflower – an alien species

The moonflower is another alien species that first came to Malta as a cultivated garden plant and which is now thriving in the Maltese countryside. Although it is not as common as some other alien species such as the ubiquitous Cape sorrel (ħaxixa ngliża), when present, it is very noticeable because of its large leaves and white or pink flowers.

The flowers of the moonflower open at night and close early in the morning. Their light colour, large size and fragrance make it easier for the flowers to be seen in the dark especially by moths particularly the hawk moths.

The moonflower is a native of the tropical and sub-tropical parts of the American continent. It can be found all the way from northern Argentina to Mexico and Florida.

In Malta this species usually flowers between March and July but in gardens, where it is watered in summer, and in humid valley bottoms it can continue blooming until much later.

This plant is rich in sulfur, an element which is still used in vulcanisation of rubber, a process discovered by Charles Goodyear in 1839 but in southern America, the natives had been using the moonflower to vulcanise the latex of two plants to make bouncing rubber balls 3,000 years before him.

The moon flower belongs to the convolvulus or bindweed family the group in which we find many species of bindweeds which are known in Maltese as leblieb as well as the morning glories. It is in fact it is most closely related to the garden morning glory, the popular garden plant. 

A number of closely related species are used as food while others are used medicinally. Others contain psychoactive substances which were used in religious and spiritual ceremonies to induce an altered mental state similar to that from modern drugs such as LSD, opium and some mushrooms. 

This article was published in The Times on 14.09.11

The flower that blooms at 4 p.m.

Marvel of Peru (Mirabilis jalapa)
The marvel-of-Peru or as it is known the four o'clock flower gets its English names from its country of origin and from its habit of opening its flowers in the late afternoon. 

It is a widely cultivated plant that is also found growing wild in the Maltese countryside. In Maltese it is known as ħummejr

It is believed that this plant was first exported from the Peruvian Andes in 1540.

The plant grows along country roads and lanes and can be easily recognised by its large number of brightly coloured flowers. 

The flowers can be of different colours ranging from yellow to red with some flowers being white, striped or marked with different colours. Sometimes differently coloured flowers grow simultaneously from the same plant. More surprisingly the colour of the flowers growing on a particular plant change in colour as the plant matures. Thus a plant that starts off by having yellow flowers ends with dark pink flowers while a plant with white flowers starts producing light violet flowers.

The marvel of Peru flowers from late spring to early autumn. The flowers remain open well after sunset and are pollinated by long-tongued moths such as the hawkmoths which are attracted to the flowers by a strong sweet-smelling fragrance.

Parts of the plant are said to be very toxic and can have effects similar to that of LSD. They can cause digestive disorders and abortion. 

As with many poisonous plants this species also has medicinal value. It is used as a laxative, or to treat constipation and to expel intestinal worms. The flowers are used in food colouring particularly as a crimson dye which is used to colour cakes and jellies. 

This article was published in The Times on 07.09.11

The protein-rich pecan nut

Pecan (Carya illinoinensis)
The pecan, is a large tree indigenous to the southern states of America and Mexico. 

The Spaniards brought the tree to Europe in the 16th century. It was later planted in parts of Africa and Asia. This tree is best known for its fruit which is referred to as a pecan nut. In Malta the tree has been planted in a number of places including Buskett Gardens. Several large specimens can be seen along the path leading to the valley known as Wied il-Luq as well as in Wied il-Luq itself.

The pecan tree is a deciduous tree. The flowers, which are wind pollinated, appear in spring. Fertilised flowers produce an elongated fruit consisting of a green husk surrounding a structure known as a nut. As the fruit matures the husk becomes dark brown. In October and November the fruit drop onto the ground.

Although this species is not well known in Malta, some people know exactly when to visit Buskett gardens to collect pecan nuts. Pecan trees can produce large quantities of fruit and some manage to fill up whole baskets with this edible fruit.

In Maltese the pecan tree is known as siġra tal-pekan and the fruit is called ġewż tal-pekan.

The nuts can be eaten fresh. In other parts of the world they are used as an ingredient for several desserts the best known being the pecan pie.

The trees that grow at Buskett Gardens are very large. Although they must have been planted several decades ago they are likely to be around for many more as in good conditions pecan trees can live for more than 300 years.

Pecan nuts, like walnuts (to which they are related) are protein-rich and a good source of unsaturated fats. Eating pecans reduces the levels of LDL cholesterol and in women the risk of gallstones. 

This article was published in The Times on 31.08.11

Seed dispersal to germinate away from parent plant

Squirting cucumber (Ecballium elaterium)
Most plants have strategies to disperse their seeds which ensures that they germinate away from the parent plant. 

Seed dispersal is important because most plants have little or no mobility and thus would not be able to colonise new areas and habitats. 

Dispersal is also important as it takes seeds away from areas where they would face stiff competition from plants of the same species.

Plants use both internal and external forces to scatter their seeds far and wide. These include gravity, wind, water, explosive forces, and dispersion by animals including humans. Sometimes dispersal can be by more than one means thus a plant might allow a seed to fall onto the ground so that late it would be carried away by water. This often happens when coconuts fall to the ground along the coast and then carried away when the tide rises.

Some species can forcefully discharge their seeds long over large distances. The seed pods of the bear’s breaches (ħannewija) open with such force that they make a sound like a small pistol shot. 

The squirting cucumber, known in Maltese as faqqus il-ħmir, belongs to the cucumber family. During the summer months it forms a green-yellow fruit about the size of a large olive. 

It gets its name from the fact that when ripe the fruit ejects the seeds out together with a stream of thick liquid. When very ripe the slightest touch is enough for the fruit to explode. 

Children sometimes play with these fruit shooting the seeds and liquid at each other or throwing them in the direction of each other to see them explode and hitting each other with the seeds. 

The liquid that forms in the fruit is highly toxic but it has been used medicinally since classic times. It can act as a laxative and is known as a violent purgative. In parts of Cyprus and Turkey the juice is believed to cure cases of sinusitis, hepatitis and earache.

This article was published in The Times on 24.08.11

The lappet moth family

Lappet Moth (Gastropacha quercifolia)
The lappet is a large moth that is found in all of Europe as well as in northern and eastern Asia. It belongs to a large family of about 2,000 species known as the eggars, snout moths or lappet moths. 

The family is characterised by having feather-shaped antennae, and an atrophied proboscis. The caterpillars are covered in short hair which is used as a defense mechanism as well as to build the cocoon in which they turn into a pupa. Four members of this family have been recorded in the Maltese islands.

The lappet is very common throughout the islands between May and June and from August to October. The caterpillar has decorative skin flaps on some of its legs hence the name lappet. 

It feeds on the leaves of fruit trees and is sometimes considered as a pest. When fully grown the caterpillar descends to the ground and builds a cocoon in which to pupate. The caterpillar is covered in short hair. This hair, together with silk which the caterpillar itself produces is used to build the cocoon.

Female lappet moths are larger than males. They produce a pheromone which smells of charcoal or burnt wood to attract males. When resting, lappet moths are very well camouflaged. They fold their wings in the shape of a tent to look like oak leaves hence its Maltese name werqa niexfa.

In the lappet, the snout, which is a characteristic of members of the snout family, resembles a petiole (the part of the leave attached to the twig or branch). This adds to the resemblance of the moth to a dried leaf and enhances its camouflage.

In the same family as the lappet we also find the oak eggar (baħrija tal-ballut) which is common especially at Buskett and its surroundings, the grass eggar (baħrija tas-silla) which is also common and the lackey moth (malacosoma) which has been recorded in Malta once in 1956. 

This article was published in The Times on 17.08.11

The field bindweed: A bright funnel-shaped attractive flower

Field bindweed (Convolvulus arvensis)
Maltese summers are characterized by high temperatures and lack of rain. Many plants survive this difficult time as seeds. This results in a dry brown countryside. Where it not for the thousands of trees that have been planted during the past fifty years or so it would be very difficult to find any green vegetation. 

Few species of plants are able to flower but those that do immediately catch one’s attention. One of these species is the field bindweed (leblieb tar-raba’). This species grows in fields and gardens from early summer to early autumn. It also grows in similar habitats such as patches of soil in centre strips and along roads.

The flowers of this plant can have different colours. They are usually white or pink but can also be striped white and pink. As practically no other plant is in flower the bright funnel-shaped flowers are very conspicuous and often attract one’s attention to their beauty. Flowers come in a variety of colours, shapes, sizes and scent but their beauty is not there to please us but to attract insects especially bees which are essential for pollination. 

The most attractive part of flowers are the petals which induce insects to land on them and to visit the nectaries from which they obtain nectar.

To make it easier for the insects to locate the nectaries, many flowers have lines or other markings called nectar guides which lead the bees to the centre of the flower where the flowers’ reproductive structures are found. 

Some of the guides are visible to humans while others can only be seen in ultraviolet light which is invisible to humans but which bees can detect. The nectar guides make it possible for the bees to collect nectar faster and more efficiently. This is advantageous for the plant because of more efficient pollination. 

This article was published in The Times on 10.08.11

Moths on the Maltese islands

Moths are far more common than most people believe. They are not as familiar as the closely related butterflies because with the exception of a very small number they are nocturnal insects. They spend the day trying to be as inconspicuous as possible. They often settle on a surface with the same colour as their body, they place the antennae close to their body and keep their wings flat and close to the surface to avoid making a shadow.

Several hundred species of moths have been recorded from the Maltese islands. Some of which are endemic to Malta, that is they are found only on the Maltese islands. Some are very common while others have been seen only once or twice and more species will be added the list as this group of insects is still being studied by lepidopterists.

For many Maltese a moth is a baħrija but for others especially country people who learnt about nature from their parents, moths are known as farfett ta’ billejl (butterfly of the night) or just farfett. For them the baħrija is a hawk moth. 

Moreover the baħrija was associated with either good or evil. If a hawk moth entered a house it meant that somebody was about to die. 

There are several species of hawk moths in the Maltese islands but the one which was believed to be the portent of death was probably the humming bird hawk moth which is known in Maltese as ħabbara (messenger). This species is one of the few day-flying moths and often enters houses.

Many species of moths that are plant pests are known as susa a word that is more widely used for the woodworm (susa tal-injam). 

The caterpillar of these moths lives in the branches, leaves or fruit of plants and like the woodworm feeds on the plant inside which it lives. 

This article was published in The Times on 20.07.2011

Butterfly diversity peaks in June

Butterfly numbers and diversity reach their peak in June. After that month, the number of butterflies in the Maltese countryside start to decrease.
By now, many species have disappeared and will not be seen again, until next spring. At the moment the most common species and the one most likely to be seen is the small white butterfly which happens to be one of the most common butterflies during the rest of the year.
Another common species is the large white butterfly which looks very much like the small white but is usually much larger.
These two species are common because they feed on, among other things, on the leaves of wild and cultivated members of the cabbage family such as cauliflowers, kohlrabi and of course cabbages.
Up to 40 or 50 years ago in some villages in Malta children trapped these butterflies using the same methods that adults used to trap birds.
Their aim was not just to catch the butterflies.
They used to catch them by using very crude methods such as hitting them with a piece of cardboard while they were resting on a flower.
The trapping was a serious exercise which taught them the skills required, later in life, when they would start to trap birds.
In their play they copied adult bird trappers.
They prepared a trapping site by clearing it of vegetation, levelled the ground and removed all stones.
They then laid down two pieces of cloth on the ground. The cloth was attached to two thin sticks to which they attached a long piece of string.
When the string thread was pulled the sticks and cloth flipped onto to butterflies preventing them from escaping.
To make the site more authentic they even had a decoy butterfly attached to a stick by a thread. The stick could be moved up and down by means of a string to make the butterfly flutter as if it was flying. Some boys even had decoy butterflies tied to sticks stuck in the ground around their trapping site.
When caught the butterflies were placed in a carton box or tin can as trophies to be shown to their friends who had also been trapping butterflies.
The best trappers enjoyed a high status and would boast and brag about the number of butterflies they caught and recount stories about the ones that got away...

This article  was published in The Times on 03.08.2011

Rare ferns

Several species of ferns have been recorded from the Maltese islands. Most are rare or very rare. On the other hand one species, the maiden hair fern, known in Maltese as tursin il-bir, is relatively common. It can be found in caves, wells, in valley bottoms and in damp courtyards of old buildings. 

Like many other ferns it thrives in humid habitat away from direct sunshine although some species such as the rusty-back fern (felċi tal ħitan tas-sejjieħ) can live in full sun and requires little humidity. This species is found in Western and Central Europe including the Mediterranean. In Malta it is very rare. The only time I saw it, it was growing on a large boulder in the middle of a dry valley in a spot not reached by the rays of the sun. In some parts of Europe it was used medicinally as a diuretic.

Most other ferns recorded in the Maltese island are also very rare with some species not having been seen for decades. Two or three species are aliens, that is, they were imported into Malta, probably as cultivated species, and can now be found growing wild.

Ferns are primitive plants. They have stems, leaves and roots like other vascular plants but instead of seeds they produce spores and thus do not have flowers. About 12,000 species are found in the world. About twelve have been recorded in the Maltese islands.

The oldest fern fossil records are from 360 million years ago. In geological terms this would be the beginning of the Carboniferous period which lasted until 299 million years ago. The name of this period comes from ‘carbo’ which is the Latin word for coal as during this period many of the coal beds were laid. 

The coal formed because of the appearance on earth of bark bearing trees which found the right climatic conditions for growth and possibly also because the animals and decomposing bacteria which can digest lignin, the main component of wood had not yet evolved with the result that the wood remained on the ground until it was covered by sediment and eventually changed into coal 

This article was published in The Times on 27/07/2011