2012 was marked by one of our articles entitled ‘’A Celebration of Butterflies in Malta’’ as the year of Maltese butterflies as last September most species showed up in abundance. However most of which were, if not all, from local stock.
2013 will top up the latter event by far because Malta`s second largest butterfly the Plain Tiger, Danaus chrysippus, Farfett ta` Danaus has hit local records by the number of specimens that have immigrated locally. Although the Plain Tiger or African Monarch, is a frequent butterfly in it's normal ranges from Africa and southern Europe, eastwards via Sri Lanka, India, and Myanmar to China, Java and Sulawesi, local records are a handful throughout the years.
It has been first recorded in 1923 by Col.Hartford and was not seen up to 1952 by Mr Valletta or at least not recorded officially. 1979 was marked the year of this species, as it was seen 23 times. From then onwards, almost every year, skipping one or two, the species was seen locally through single specimens or very small groups by several naturalists.
When we were children, we remember seeing a preserved specimen at the natural history museum and wondered if we could ever see this species locally. We were lucky enough in November 1997 to observe a specimen in San Anton Gardens, and as we grew up we observed a handful of single records, some of which we did publish.
On 13 October 2005, we thought we reached a climax, as 26 specimens flew over us crossing Blue Lagoon area between Comino and Cominotto Island. However, by far, this year topped to the maximum. On 6 November 2013, one of us encountered three specimens at tas-Sellum area, Mellieha, as they were settling on Fennel twigs just before dusk. We happily informed local nature lovers on FaceBook and a number of good records started coming in accompanied by images from all over the island. Thanks to a friend of ours we found the jackpot!
The following day on the7th, at Bahrija a population of about over a hundred of these were fluttering around a male flowering Carob tree. It was an unbelievable sight, as if experiencing one of the popular migrations of The Monarch butterfly (Danaus plexippus) in the Americas. The butterflies seem very docile and approachable, gliding around this tree feeding on the nectar, accompanied by several other local butterflies species namely the Painted lady, Red Admiral, Clouded Yellow, Large and Small white.
Along with the latter the beautiful Crimson Speckled Moth, Utetheisa pulchella , Sbejha was also noted. This species was recorded vaguely in the past and almost disappeared in the 1990`s but recently has increased in numbers and was noted by us on several Mediterranean islands and islets to be on the increase.
Plain Tiger butterflies are protected from predatory attacks due to the unpalatable alkaloids ingested during the larval stages. The butterfly therefore flies slowly and leisurely without fear, generally close to the ground and in a straight line. This gives a would-be predator ample time to recognise and avoid attacking it. Inexperienced predators will try attacking it, but will learn soon enough to avoid this butterfly as the chemicals in its body cause vomiting. Three subspecies and several forms are recognized worldwide. It is a shame that this species does not have a lot of options on what to lay its eggs on. Although breeding records of this species locally exist, they are truly rare. This is partly due to the species being rare locally itself, but mainly because the Maltese Islands lack the vegetation that the species breeds on. Although it may breed on several plant species from several families its main are plant food is from the genus Asclepias L. ie: the Milk weeds.
A total of 357 specimens were recorded in 5 days by several contributors and this makes this year the highest record of this species locally. It is also of no doubt that the same specimens may have been recorded more than once in different locations by different individuals while other specimens were overlooked. The general influx of this species was greatly observed in good numbers in the north of the Malta, but on the whole it was observed all over the archipelago. Malta is not the only place in the Mediterranean to receive an increase of this butterfly. On the Iberian peninsula, this butterfly is becoming more common every year, though partially due to an increase of the food plant over there, which is not the case of Malta yet.
On this note, a species which may be a wild food source is the Cotton-Balloon Asclepias physocarpa, which is found in small numbers at Ghajn Zejtuna in Mellieha, and if such a plant, despite being an alien species, becomes widespread, than maybe one day this magnificent butterfly may become a local resident. We would like to conclude by thanking all those that provided us with their records particularly Ms Corinne Caruana who guided us to the Bahrija occurrence.