Sunday, May 20, 2012

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

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