Ray Collier Country Diary- Butterflies
Butterflies - 8th September 2009
Butterflies need two types of food, nectar or other liquids for the adults and food, mainly in the form of leaves, for the caterpillars. Nectars come from a range of flowers with some butterflies seeking only one or two species of flowers whilst others take a wider range. Most of the thistles found in the Highlands, including the white form of the marsh thistle in the photograph, provide a nectar source for a wide range of butterflies. Areas with thistles at this time of the year are well worth looking at when the sun is shining. One of the commonest garden butterflies, the green veined white, uses a wide range but is particularly attracted, for some unknown reason, to both white and pink flowers. In contrast the dingy skipper, which is rare around Inverness but found at Nairn dunes, mainly seeks nectar from common bird’s foot trefoil. We are all used to a range of butterflies such as red admiral, small tortoiseshell, peacock and painted lady using Buddleia but some butterflies will look elsewhere for substitutes.
A good example is red admirals that will freely go to any fallen apples as juices are available after they have rotted slightly or have been attacked by birds or insects. A more specialised source is obtained by such butterflies as the speckled wood that in recent years has spread to new areas of the Highlands. The adults will seek nectar from ragwort and other wild flowers but the main source of food comes from honeydew from aphids found on ash, birch and oak. The purple hairstreak, that has only recently been recorded in the Highlands, goes one further in that it drinks the honeydew from aphids only on oak trees. It is perhaps not surprising then that the food plants of the caterpillars of the purple hairstreak are the leaves of the oak. Sap oozing from trees is often visited by butterflies and some of the old collectors used to attract some butterflies such as the red admiral and purple emperor by putting out decaying meat, such as rabbit, along woodland rides. In periods of hot weather, certainly not like this summer in the Highlands, butterflies will often freely go to water, such as puddles, to drink.
One critical part of the butterflies life cycle is finding the correct food plant for the caterpillar stage and some butterflies accept a wide range of plants whilst others, as with the nectar source, are more specialised. One of the commonest butterflies in the Highland is the Scotch argus and the caterpillars feed on virtually any of the broader leaved grasses. They have even been seen laying their eggs as the adult female flies just above the vegetation such as a roadside verge. White butterflies such as the large white and small white will feed on a wide range of brassicas which is one of the reasons they are so successful. Six species of fritillary, including the two pearl bordered fritillaries, that occur in the Highlands all feed on various species of violets. In contrast 12 species of butterflies that occur in Britain are reliant upon single caterpillar food plants.
One aspect of the life cycle of butterflies is why some species have an association with ants. This is particularly the case with members of the "blue family", which in the Highlands includes the common blue, which is widespread. What happens is that the caterpillar emits sweet liquids from a gland that attracts ants day and night and they simply drink the liquid. The attendance of the ants helps the caterpillars chances of survival because the ants keep predators and parasites away.
Butterflies need two types of food, nectar or other liquids for the adults and food, mainly in the form of leaves, for the caterpillars. Nectars come from a range of flowers with some butterflies seeking only one or two species of flowers whilst others take a wider range. Most of the thistles found in the Highlands, including the white form of the marsh thistle in the photograph, provide a nectar source for a wide range of butterflies. Areas with thistles at this time of the year are well worth looking at when the sun is shining. One of the commonest garden butterflies, the green veined white, uses a wide range but is particularly attracted, for some unknown reason, to both white and pink flowers. In contrast the dingy skipper, which is rare around Inverness but found at Nairn dunes, mainly seeks nectar from common bird’s foot trefoil. We are all used to a range of butterflies such as red admiral, small tortoiseshell, peacock and painted lady using Buddleia but some butterflies will look elsewhere for substitutes.
A good example is red admirals that will freely go to any fallen apples as juices are available after they have rotted slightly or have been attacked by birds or insects. A more specialised source is obtained by such butterflies as the speckled wood that in recent years has spread to new areas of the Highlands. The adults will seek nectar from ragwort and other wild flowers but the main source of food comes from honeydew from aphids found on ash, birch and oak. The purple hairstreak, that has only recently been recorded in the Highlands, goes one further in that it drinks the honeydew from aphids only on oak trees. It is perhaps not surprising then that the food plants of the caterpillars of the purple hairstreak are the leaves of the oak. Sap oozing from trees is often visited by butterflies and some of the old collectors used to attract some butterflies such as the red admiral and purple emperor by putting out decaying meat, such as rabbit, along woodland rides. In periods of hot weather, certainly not like this summer in the Highlands, butterflies will often freely go to water, such as puddles, to drink.
One critical part of the butterflies life cycle is finding the correct food plant for the caterpillar stage and some butterflies accept a wide range of plants whilst others, as with the nectar source, are more specialised. One of the commonest butterflies in the Highland is the Scotch argus and the caterpillars feed on virtually any of the broader leaved grasses. They have even been seen laying their eggs as the adult female flies just above the vegetation such as a roadside verge. White butterflies such as the large white and small white will feed on a wide range of brassicas which is one of the reasons they are so successful. Six species of fritillary, including the two pearl bordered fritillaries, that occur in the Highlands all feed on various species of violets. In contrast 12 species of butterflies that occur in Britain are reliant upon single caterpillar food plants.
One aspect of the life cycle of butterflies is why some species have an association with ants. This is particularly the case with members of the "blue family", which in the Highlands includes the common blue, which is widespread. What happens is that the caterpillar emits sweet liquids from a gland that attracts ants day and night and they simply drink the liquid. The attendance of the ants helps the caterpillars chances of survival because the ants keep predators and parasites away.
posted by Corinne @ 6:38 AM
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