Snapping nature at home

Nature photography is generally defined as the photographing of landscapes as well as plants and animals in their natural habitats. Purists do not consider any picture that includes man-made objects as a nature picture.

Some nature photography competitions stipulate that an image cannot be allowed to compete if it includes non-natural objects. This attitude would be commendable were it not for the fact that nowadays none of us live in untouched surroundings. Most of us live in towns and villages surrounded by buildings with little or no greenery.

For many the only nature they regularly come in contact is found in gardens and other man-made open spaces.  For them, nature consists of cultivated flowers, trees and nature programs on television.

On the other hand for those who are tuned to nature there is much more. As they walk through a street, they see wild plants growing wherever there is some soil. Wild plants grow even in cracks on pavements. Vegetation attracts wildlife and though we do not have large animals we have an interesting variety of insects and other arthropods. Some of which even enter buildings including our home.    

Sometimes unusual and interesting species such as the ant-lion end up in houses. Should one photograph an ant-lion on a wall? Yes, because although ant-lions normally spend the day resting on vegetation, the fact that it sometimes spends the day resting on a wall is of interest and worth recording.

This long-winged insect is active mostly in the evening and is more commonly found in sandy areas. The larva lives at the bottom of a funnel-like pit where it spends the day waiting for unwary ants to venture over the edge of the pit. The ants are unable climb out of the pit and fall to the bottom and are eaten by the ant-lion.

About 2,000 species of ant-lion are found world wide. 

This article was published in the Times of Malta on 21 August 2013

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

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 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

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

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

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

The island bluetail damselfly

Island bluetail damselfly (Ischnura genei)

The island bluetail damselfly is a delicate insect known in Maltese as damigella. It is closely related to the more robust dragonflies. 

It lives in valleys with running water and near ponds, pools and reservoirs. 

It is a weak flyer and does not stray too far from aquatic habitats on which it depends throughout its life cycle. Like dragonflies the damselfly lays its eggs in water. The larva spends its entire life under water feeding on smaller organisms.

Two forms of this species are found in two colour forms: green and reddish-brown. Both forms can occur in a particular place and the colour might a result of different environmental temperature during the larval stage of the damselfly. 

In other insect species larvae that are developing later in the season, when the temperature is higher give rise to brown adults which are thus better camouflaged in the dry summer vegetation. As far as I know this has not been investigated in damselflies but a future study might show such a link.

Like dragonflies, it has very interesting courtship and mating habits, quite different from that of other insects.

The genital opening is near the tip of the tail, but before mating the male transfers his sperm to an accessory genital organ on the underside of his abdomen, just behind the thorax. 

He then finds a female and seizes her by the neck with a pair of claspers situated at the hind end of his body. They then fly in tandem and settle, linked together in this way.

When mating takes place, the female bends her body around under the male’s body and the sperm is transferred for fertilization.

Damselflies and dragonflies use different methods to lay eggs. Some insert them in the plants of aquatic plants or in vegetation at the water’s edge. 

Others fly over the water and drop them, while others dip the abdomen into the water to wash the eggs off the tip. Some species remain in tandem whilst the female is laying.

Their larvae or nymphs spend all their time under water hunting smaller animals. A hunting larva stalks its prey to within a centimetre or less, than shoots out the labium and seizes its prey with its claws. 

The victims are mostly insects, but large well-grown larvae can even catch tadpoles and small fish. The labium is a segmented organ, found in all insects below the mouth. In dragonfly larvae this organ bears a pair of pincer-like jaws near the tip and is elongated and hinged so that it can be extended in front of the head.

This article was published in The Times on 20.04.2011

Three species of hawk moths in different localities

Caterpillar of the Convolvulus Hawk moth (Agrius convolvuli)
 

In the past few days I found the caterpillars of three species of hawk moths in different localities around Malta. They belonged to the death’s head hawk moth, the convolvulus hawk moth and the Maltese spurge hawk moth. The first two are the largest moths in the Maltese islands. 

Hawk moths are medium sized to large moths with narrow wings and streamlined abdomens that make it possible for them to fly rapidly and for long distances. Some hawk moths can fly at 50 kilometres per hour and are among the fastest insects.

The convolvulus hawk moth is found throughout Europe and Africa. Its caterpillar (photograph) feeds on bindweeds which are known scientifically as Convolvulaceae hence the English name of this moth. 

In Maltese it is known as baħrija tal-leblieb. Leblieb is bindweed in Maltese. 

The caterpillar of this species, like that of most other hawk moths, has a horn-like structure at the posterior end of its body. It is dark in colour unlike the caterpillars of the two other species I found which are both very brightly coloured. 

The caterpillar of the convolvulus was crossing a path at Il-Majjistral Park. It was probably searching for a place to pupate. Hawk moths spend the winter months as a pupa.

 Before turning into a pupa the caterpillars of these moths burrow into the soil and remain under the surface or in a small chamber until they metamorphose into an adult moth. In topical species the change can take place in about three weeks but in colder parts of the world the adult emerges in spring or summer.

The adult convolvulus moth  is grey with pink, black and white spots on both sides of the abdomen. It spends the day on a wall or tree bark where it can be very well camouflaged. When disturbed it humps its thorax to scare any predator away.

This article was published in The Times on 10.11.10

The scarab beetles

Some days ago I found several beetles along the water’s edge at Mellieha Bay. Several more were floating on the water. 

All were dead except for a couple which I collected and moved to a safer place. 

These beetles, like many other insects are attracted to light and they must have been confused by some lights after having emerged from their cocoon and fell in the sea.

The beetles belonged to a very common species of the scarab family. Like many members of this family it does not have a common English name and is known as a scarab beetle.

 In Maltese most beetles are known as ħanfus. Like every identified plant and animal it has a unique scientific name - Phyllognathus excavatus. The males of this species have a structure on their head that resembles the horn of a rhinoceros. There are other scarab beetles with such a horn on their head which are popularly known as rhinoceros beetles.

At this time of the year it is the most common scarab beetle. It is found throughout the Mediterranean to the as to Iran and Crimea and in Senegal.

The scarab beetle family consists of over 30,000 species. Many of these beetles have bright metallic colours ranging in size from 1.5 to 160 mm. The larvae are soft bodied pale yellow or white grubs. 

Most live underground or under leaves away from sunlight. The majority are scavengers and many species live on dung, dead animals or decaying vegetation.

One of the best known species of scarab is the dung beetle which was revered as sacred in ancient Egypt. Dung beetles collect dung which they shape into the shape of a ball and then roll to an underground nest. They lay eggs in it so that on hatching the larvae find a readily available rich source of food. 

This article was published in The Times on 30.09.2010

The oak eggar

The oak eggar is a beautiful large moth. It is seen in August and September mainly in Buskett and its surroundings. 

The males are red brown and fly during the day and many people mistake them for butterflies.

 Last Sunday, while watching the migration of raptors at Buskett I saw at least three oak eggars being caught and eaten by bee eaters, the brightly coloured migratory birds that specialise in hunting flying insects especially bees.

Female oak eggars are larger and paler than males and are nocturnal. It is said that females fly slowly at dusk dropping eggs on the vegetation below but I still have to see this interesting behaviour.

The eggs are laid on ivy which grows in abundance especially on the north-facing walls in Buskett. In Maltese the oak eggar is known as baħrija tal-ballut but it should be pointed out that despite its name, this species does not feed on oak, but is called so because its cocoon is shaped like an acorn.

The caterpillar is covered in brown hairs and has a black line between each segment on each of which there is a small tuft of white hair along the sides. I have seen and photographed the caterpillar on the leaves of the bramble at Wied il-Luq and also walking on the ground in the vicinity of this common plant.

The oak eggar belongs to the Lasiocampidae family of moths which has over 2000 species worldwide. These are usually large moths with feather-like antennae. The caterpillars are covered in long hair. Four species are found in the Maltese islands. 

This article was published in The Times on 22.0./2010

The sounds of Malta's summer

Cicada (Cicada orni)

This year, summer started later than usual and it seems that it is ending earlier as well. It has already rained and the temperature is going down but summer is not just sunny days and high temperatures. Summer, like every other season has its characteristic sounds and smells which together differentiate it from every other season.

The sound I associate most with a Maltese summer is that of the cicada the large insect that looks like a fly that spends days on end making a loud buzzing noise. 

During the night, when the cicada stops singing, the cricket takes over. This nocturnal insect used to be very common but like many other insects, especially those that live in agricultural areas, it has decreased in number probably because of the use of pesticides. 

Country people used to catch crickets and take them home to hear them sing. They caught them by placing a wet cloth on the ground in a field in which tomatoes were being grown. In the morning they collected the crickets from beneath the cloth and placed them in special cages or in a tin can.

Those walk in parts of the countryside where the bear’s breaches grows can also hear the sound of its seed pods as they crack open in the heat. The sound which resembles that of a small pistol is followed by that of its large seeds of falling on the large dry leaves of this plant.

Spanish sparrows gather in large trees to roost every evening but in summer their numbers and the noise they make reaches a peak as the population is augmented by the recently fledged birds.

In early July the first autumn migrants appear in the Maltese islands. The first birds to arrive are the waders which leave their breeding grounds in the far north immediately as soon as their short breeding season is over. They have to move south as weather at such latitudes is very unpredictable and it can snow even in August.

For those with trained ears the shrill call of another migrant bird, the kingfisher, becomes another common summer sound. Kingfishers arrive in August. They often perch on a rock along the coast waiting for a right-sized fish to swim by. It flies low over the water often making a short sharp whistle, chee, repeated two or three times. 

The most common sound nowadays is that of the ubiquitous car which can be heard even from Comino where no cars are present and because of this we often miss the beautiful natural sounds which were once part of the Maltese environment.

This article was published in The Times on 15.09.2010

The rosemary leaf beetle lives on herbs

Rosemary leaf beetle (Chrysolina americana)

The rosemary leaf beetle is a common beetle that lives on rosemary and other herbs. Its scientific name is Chrysolina americana. Despite its scientific name, it is a native of southern Europe. In the early 1990s it appeared in Britain and during the last decade it has become an established pest on rosemary, lavender and related plants.

It is an attractive beetle with metallic green and purple stripes down its back. . In the sunlight these stripes reflect all the colours of the rainbow - rather like oil on water. This effect is very beautiful to see but difficult to capture on camera.

It is usually found in groups on stems or feeding on the new growth of plants. The larvae are small slug-like grubs which are usually found on the underside of leaves. They are light grey with horizontal dark stripes running the length of their body.

Their favourite food plant, the rosemary is a medium-sized bush of the Mediterranean, recognised by its narrow fleshy leaves, small pale blue flowers and more than anything else by its typical aromatic smell. The bush is usually about one metre high but when hanging down from a vertical rock face it can grow up to two metres. It flowers throughout the year.

The rosemary leaf beetle, known in Maltese as żabbella tal-klin, belongs to the Chrysomelidae family, a group of beetles known as the leaf beetles. This is a family of over 35,000 species, one of the largest and most commonly-encountered of all beetle families. About 60 of these species are found in the Maltese islands. Another common member of this large family is the red leaf beetle, żabbella ħamra in Maltese, which is found in vegetation in the countryside. Adult and larval leaf beetles feed on all sorts of plant tissue. Many are economically important pests of agriculture. 

This article was published in The Times on 05.01.2010

A true predator kills and eats another organism

In ecological terms predation is described as the interaction whereby one organism feeds on its prey. Predators may or may not kill their prey before eating them but the end result is beneficial to the predator and harmful to the prey. This has led to selective pressures on one another which have lead to an evolutionary arms race between the predator and prey resulting in various anti-predator adaptations.

Predators are usually classified by the way they feed and the way they interact with their prey. A true predator is one which kills and eat anther organism. It may hunt actively for its prey or sit and wait for it to approach within striking distance. Some predators such as the lion kill larger prey which they dismember and chew while others like dolphins eat their prey whole. Some predators like snakes poison their prey to subdue it or kill it before eating it.

Prey species have evolved several ways to avoid being preyed upon. One common form of defence is aggression. The electric eel uses an electric current to kill prey and to defend itself from other predators. Others animals use their tusks, horns and hoofs to defend themselves.

An interesting form of defence, common in birds, is mobbing. This is when animals attack and harass a predator to drive it away. This can be seen in many species of birds such as gulls which attach predator, including men, when these get anywhere near their nests.

Some animals are camouflaged to avoid being seen while others are brightly coloured and do not bother to hide themselves. Their colouration is recognised and remembered by predators as a danger signal and are left alone. These animals such as the ladybirds, wasps and the caterpillars of the spurge hawkmoths, are usually poisonous or bad tasting.

The humped crab spider is an aggressive predator that lives on flowers with which it easily blends. It prefers the large yellow flowers of the crown daisy, which are now in flower. It lies motionless in wait for an insect to land on the flower and then catches it with its forelegs. It bites it to inject a poison and holds on to it until it is paralysed or dead before it starts to suck its body. 

This article was published in The Times on 20.01.2010

The predatory red assassin bug

The red assassin bug belongs to a large family of predatory insects which have an elongated head, narrowed neck and long legs. They also have a prominent tube which they use for sucking the liquidised contents of their prey. The family consists of about 7,000 species found in most parts of the world including Europe, North and South America and Africa. Twelve species are found in the Maltese islands. The red assassin bug, known in Maltese as seffud tal-assalt is the most common and easily recognised species.
This species can often be found waiting for its prey underneath the flowers of a number of summer-flowering plants especially fennel (busbies), samphire (xorbett) and fleabane (tulliera).
I photographed this specimen last Sunday at Fiddien Valley near Rabat. It had just caught a small bee as it was visiting the flowers of a sticky fleabane (tulliera komuni). The bug inserted its segmented proboscis in the space between the head and the thorax to inject it with a lethal toxin that dissolves its tissue. It then starts to suck up the liquefied tissues through its long proboscis. This process takes several minutes and so I had enough time to take several pictures of the bug as it was feeding.
Assassin bugs are aggressive insects and sometimes capture insects that are larger than themselves. They manage to subdue and kill them by means of their poisonous saliva. Some species of assassin bug feed on cockroaches or bedbugs. Some are beneficial to agriculture as they attack insect pests. In some parts of the world people breed assassin bugs as pets or for insect control.
Some species are notorious for biting humans and one species found mostly in South America can transmit the potentially fatal Chagas disease. (This article was published in The Times on 25.08.2010)

Butterflies need protection

Anthony Valletta was a keen lepidopterist. He spent most of his life collecting and studying butterflies and other insects and was one of the first people in Malta to talk and write about the need to protect Malta’s natural environment. He wrote a number of books for children and adults as well as articles in newspapers and magazines.

In 1980 he wrote an article about the butterflies of the Maltese islands and their dwindling habitats, in which he expressed concern about an alarming decrease in the number of individuals of certain butterflies which he was noticing. He wrote that complete colonies had disappeared from newly built up areas. He noted that in the 48 years during which he had been studying butterflies the colourful abundance of these beautiful insects had become a thing of the past. As is the situation today the most common butterflies were the migrants who every year augmented the local population.

Lately I have been talking a lot with Maltese farmers especially elderly ones who remember the countryside as it was sixty or seventy years ago and what all of them told me sadly reflects what Valletta wrote thirty years ago. Mr Valletta believed that the decline was being caused by the destruction of the butterflies’ habitats because of new residential areas. He also blamed the planting of ornamental trees along the sides of valleys which were replacing local flora. The farmers blame the large quantities of pesticides that they use for the decline.

I am not aware of any studies that have been carried out to monitor the butterfly decline and their causes. It is already late to save the butterflies but it is better late than never and we can if we want to, halt the decline and even to reverse the trend. We owe the butterflies to future generations of Maltese people. We also have a responsibility to conserve local races such as that of the swallowtail butterfly which is endemic to the Maltese islands.

Mr Valletta wrote that many of the natural habitats would continue to disappear but he hoped that those in a position to do so will encourage the preservation of all existing species by ensuring that the necessary food plants are not entirely eradicated from the countryside and in some cases that these would be deliberately propagated.

Unfortunately, many species that Mr Valletta once enjoyed have become a rarity and might soon become extinct from the Maltese islands unless urgent action is taken to save them.

This article was published in The Times on 18.August.2010)