Surviving the bitter cold

Last Sunday’s sunshine and the relatively warm temperature was welcome especially after the cold wet days that we had been experiencing throughout most of this month. 

As I do on most Sundays I spent the morning photographing nature. I was not expecting any insects but was surprised to see a solitary asphodel bug (seffud tal-berwieq). 

This species which is usually seen from March to May is found mostly on asphodels. It was standing motionless on a leaf trying to warm up its body. It did not move away when I moved very close to it with my camera. 

This was not surprising as even though the low winter temperatures made it lethargic it normally does not bother to conceal itself or run away from danger as like other brightly coloured insects it felt secure in the knowledge that predators, especially birds are unlikely to harm it. Predators learn that animals with warning colours are inedible because they are either foul-tasting or poisonous.  

The presence of this insect made me think about how insects and other animals survive the winter. Many birds avoid cold weather by migrating to warmer parts of the world but in Europe very few insects migrate and their journeys are not as long and regular as those of birds. 

Some adult insects find a sheltered place usually underneath a stone or bark or in a crack in which to spend the winter. Others die as soon as the weather starts to cool but leave behind them eggs or pupae which will continue their lifecycle with the onset of warmer weather.

Malta’s only amphibian, the painted frog remains active throughout the winter as this is also the time when water, which is essential for this animal to survive, is present but the reptiles including the lizard, geckos and chameleon are inactive throughout most of the winter and venture out only on warmer days.

This article was published in The Times on 15.02.2012.

Grasshoppers

As autumn turns to winter one starts seeing less insects in the countryside. Last Sunday while taking pictures at Selmun the only insects I saw in any number were grasshoppers. Several jumped into the large spaces between the stones of an old wall and walked slowly on the white limestone dust into the inner part of the wall until they disappeared from view. 

Grasshoppers overwinter as eggs, nymphs or adults so the ones I was observing could be looking for a suitable place to lay eggs or to hibernate.

Grasshoppers are familiar insects with short antennae and large hind legs. Sometimes the hind legs have short projections that are rubbed against the lower edges of the forewing to make a noise during the day. The legs are hard and can exert a lot of force and this gave rise to the idea in Malta that grasshoppers are armed with a knife which they use for self defense.

It is estimated that there are about 11,000 species of grasshopper in the world. Most live in tropical areas especially in rain forests. About 25 species are found in the Maltese islands. Some species are very common and you will see them jumping away from you wherever you walk in the countryside. Most are greyish brown and blend perfectly well with their surroundings. 

Some species have brightly coloured hind wings which are normally kept hidden under the forewings. They are uncovered only when they are flying. Te bright colours have an important function. 

When danger approaches these insects rely on their excellent camouflage for protection but if a predator approaches too closely they fly away startling their enemy with their bright colour for long enough to be able to fly away. They do not fly very far away but as soon as they land they disappear again.

Grasshoppers eat mostly vegetation and some species can become pests.

They have an incomplete metamorphoses as when they hatch the young look like small wingless adults which grow progressively larger as they break out of one exoskeleton after the other until they reach adulthood.

In Africa and in other parts of the world where they occur in large numbers, grasshoppers can be an important source of proteins, minerals and vitamins especially in times of food shortage. 

This article was pubished in The Times on 8.12.10