Sunday, December 7, 2014

Digging their way out of soil

Autumn marks the appearance of large numbers of fairly large brown beetles with a noticeable horn like that of a rhinoceros on their head. The beetles appear after sunset and disappear before dawn. In some areas these insects concentrate in such large numbers that anybody passing by would find it difficult not to notice them.

This beetle, which belongs to the scarab family known scientifically as Phyllognathus excavatus. This species is found in southern Europe and North Africa and to the east in Asia all the way to Crimea.

They emerge from beneath the soil surface usually in the days following the first rains of the season. After mating they dig their way back into the soil using their shovel-like front legs to dig their way in. by dawn they all disappear except for those which find themselves on a hard surface such as roads and tiled areas.

Once back in the soil the female lays its eggs in rotting vegetation. The eggs hatch after about two weeks and the soft-bodied white larva which emerges grows slowly in the soil taking about two and a half years to reach a length of five centimetres. When it is fully grown it is ready change into a pupa inside which the body of the larva breaks down completely and rebuilds itself into a six-legged winged adult. The whole process is known as metamorphoses.
The scarab family is represented in the Maltese islands by more than thirty species. These include the rhinoceros beetle, known in Maltese as buqarn kbir, the dung beetle known as ħanfusa barri tad-demel  and the chafer called the għawwar dehbi because of its golden coloured body.

In Maltese the general term for beetles is ħanfus. Over the years entomologists have coined descriptive names for the many species that did not have a common name but they seem to have missed giving a name to this species of beetle for which the name ħanfusa tal-qarn seems to be very appropriate.

This article was published in The Times of Malta on 16 October 2014. 

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