Bulletin 34 - March 1988: Some Butterflies of Das Island

Some Butterflies of Das Island

There are two fairly common blue butterflies resident on the island throughout the year in greater or lesser numbers. They are similar in shape and pattern but one is almost twice as large as the other.

The larger has been identified with the aid of Torben Larsen's Butterflies of Saudi Arabia and its Neighbours (an excellent publication, on sale in Abu Dhabi) as the Pea Blue Lampides boeticus, or in England, where it is a rare migrant, the Long-tailed Blue. This species is considered a serious pest on leguminous plants; it lays the eggs on pods and the larvae burrow into and live inside the ripe fruit, eating the seeds. On Das one of their main hosts is the tree Prosopis juliflora. The young creature eventually eats its way out, leaving an empty, riddled pod, and pupates on the plant. The male is much bluer than the female and on the underside of the hind wing are two tiny black dots.

The smaller butterfly has been identified from the same book as the Asian Grass Blue Zizeeria karsandra, a non-migratory species fairly common in the eastern Gulf region. The African Grass Blue, very similar in appearance, is found in the west of Arabia, but the two species apparently do not meet in the peninsula. Unlike the Pea Blue, the Asian Grass Blue is reckoned to be too small to be an agricultural pest. The male upperside has a distinct dark, almost black, border, and the blue sheen is clear. It is virtually absent in winter.

The Pea Blue is common throughout Oman, indeed the whole world, whereas the Asian Grass Blue has a more restricted global distribution. Besides Oman and Eastern Arabia it is found in Australasia, Iraq and parts of North Africa.

During early February 1987 the odd suspected Small Cabbage White Artogeia rapae was recorded flying past but apparently not settling. This is a butterfly of temperate climates, very common in Europe, but migrants regularly reach Arabia. Those that remain, after perhaps breeding on Cruciferous weeds, will be killed by the heat of late Spring or early summer. It has not been recorded from Oman and it would be interesting to discover whether it has been seen in mainland Abu Dhabi.