The moth with golden wings

Goldwing (Synthymia fixa)

Moths are common insects but being nocturnal they are often unseen and unsung. 

Most moths spend the day resting in a safe place flying off at night in search of a partner or to lay eggs on the right food-plant. During the night some species also visit flowers to obtain nectar which provides them with energy.

For safety they rely on camouflage. Most moths are grey or brown and when resting remain motionless until approached too closely. Some also have brightly coloured underwings. These are the two wings which when the moth is resting are hidden under the forewings. In some species these wings are brightly coloured being yellow, orange, red or pink. 

When the moth is resting the colourful wings are well hidden but when the moth is disturbed it flies off uncovering the hind-wings and startling approaching predator which very often is too surprised to continue with its approach. This gives the moth enough time to fly away. 

The moth usually does not fly more than a couple of metres but as soon as it lands it hides the brightly coloured hindwings and again becomes practically invisible.

One such moth is the goldwing, which is known in Maltese as baħrija tas-silla tal-mogħoż.  The silla tal-mogħoż is the pitch trefoil, a common annual plant on which this species lays its eggs and thus on which the caterpillars feed. 

The adult moths can be seen in April and May It is a small moth with a wingspan of less than 40mm. It is native in southern Europe and North Africa.

The goldwing belongs to the owlet moth family; a large family with over 42,000 species. Of these 1,4500 are found in Europe of which just over 160 are found in the Maltese islands. Some of these are agricultural pests and can damage crops. 

This article was published in The Times on 23.05.2012

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

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