Ray Collier Country Diary - Moths
24th December - Moths
Different moths have various ways of overcoming the winter months with its vagaries of weather. Some moths, such as the aptly named winter moth, the mottled umber and the spring usher, actually emerge during the winter months and most of these have a special adaptation in that the females either have no wings or the wings are so stunted they cannot be used for flight. The lack of wings may have evolved so that the females are not blown away by winter gales. There is also the advantage of not having to find the food plant for the caterpillars as the female is resting on the plant on which she hatched. Another theory is that being wingless they are at less risk from birds as they would be more noticeable in flight. The wingless females release insect hormones as soon as they hatch and this attracts the flying males from some distance.
Some moths such as the garden tiger spend the winter as caterpillars, sometimes in crevices and sometimes underground. The photograph of an attractive adult garden tiger was taken in a garden near Inverness. Other caterpillars like the large emerald over winter by securing themselves to a pad of silk attached to a twig. Some of the larger moths over winter as a chrysalis and spend the cold winter months underground. The recent run of milder winters may have helped many moths survive the cold but unfortunately the down side is that in milder weather the many types of parasites also thrive. One of the larger moths whose chrysalis stays underground for the winter months is very attractive and is a very unusual colour as an adult as it is predominantly pink. The elephant hawk moth has pink wings, body and antennae and this overall colour contrast strongly against its white legs. As if to enhance the colouration of the moth even further there are olive green markings on the body and wings and a black patch on both the hindwings. The males and female moths are similar and there is very little colour variation.
These attractive moths have an intriguing distribution in the Highlands as prior to 1990 there were very few records and those were well scattered. Then the Highland Biological Recording Group started moth recording and the results were quite remarkable. New records show the main distribution centres on Inverness, the Black Isle and Easter Ross right up to Lairg and to a lesser degree around Skye and Lochalsh. Either the moth has been overlooked in the past or it is rapidly extending its range for some unknown reason. The adult moths feed on nectar at night time and they have a long flight season from May to early August. They can occasionally be found at rest during the day but they fly from dusk onwards feeding on the wing like miniature humming birds on long nectar flowers such as honeysuckle. The spectacular looking large caterpillar is more often seen than the moth particularly when they are found wandering before they pupate. Unlike most moth caterpillars there are two colour forms. The usual one is brown grey but there is also a green form but both are able to protect themselves from would be predators by changing their shape which causes the false eyes on the head to expand and then it looks menacing although it is quite harmless. Around Inverness the moths and caterpillars can be found in a wide variety of places including rough grassland often with disturbed or burnt ground where rosebay willow herb occurs as this is the main food plant of the caterpillars.
Different moths have various ways of overcoming the winter months with its vagaries of weather. Some moths, such as the aptly named winter moth, the mottled umber and the spring usher, actually emerge during the winter months and most of these have a special adaptation in that the females either have no wings or the wings are so stunted they cannot be used for flight. The lack of wings may have evolved so that the females are not blown away by winter gales. There is also the advantage of not having to find the food plant for the caterpillars as the female is resting on the plant on which she hatched. Another theory is that being wingless they are at less risk from birds as they would be more noticeable in flight. The wingless females release insect hormones as soon as they hatch and this attracts the flying males from some distance.
Some moths such as the garden tiger spend the winter as caterpillars, sometimes in crevices and sometimes underground. The photograph of an attractive adult garden tiger was taken in a garden near Inverness. Other caterpillars like the large emerald over winter by securing themselves to a pad of silk attached to a twig. Some of the larger moths over winter as a chrysalis and spend the cold winter months underground. The recent run of milder winters may have helped many moths survive the cold but unfortunately the down side is that in milder weather the many types of parasites also thrive. One of the larger moths whose chrysalis stays underground for the winter months is very attractive and is a very unusual colour as an adult as it is predominantly pink. The elephant hawk moth has pink wings, body and antennae and this overall colour contrast strongly against its white legs. As if to enhance the colouration of the moth even further there are olive green markings on the body and wings and a black patch on both the hindwings. The males and female moths are similar and there is very little colour variation.
These attractive moths have an intriguing distribution in the Highlands as prior to 1990 there were very few records and those were well scattered. Then the Highland Biological Recording Group started moth recording and the results were quite remarkable. New records show the main distribution centres on Inverness, the Black Isle and Easter Ross right up to Lairg and to a lesser degree around Skye and Lochalsh. Either the moth has been overlooked in the past or it is rapidly extending its range for some unknown reason. The adult moths feed on nectar at night time and they have a long flight season from May to early August. They can occasionally be found at rest during the day but they fly from dusk onwards feeding on the wing like miniature humming birds on long nectar flowers such as honeysuckle. The spectacular looking large caterpillar is more often seen than the moth particularly when they are found wandering before they pupate. Unlike most moth caterpillars there are two colour forms. The usual one is brown grey but there is also a green form but both are able to protect themselves from would be predators by changing their shape which causes the false eyes on the head to expand and then it looks menacing although it is quite harmless. Around Inverness the moths and caterpillars can be found in a wide variety of places including rough grassland often with disturbed or burnt ground where rosebay willow herb occurs as this is the main food plant of the caterpillars.
posted by Corinne @ 3:27 PM
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