Sunday, 27 March 2016

Adonis Blue male

A stunning little butterfly of chalk land habitat and is becoming quite scarce compared to a few years ago. They are doubled brooded, flying about the 2nd week of May to the end of June,  and again from early August to the end of September. It prefers herb rich grassland on south facing hills. The  females lay their ovum on the undersides of Horseshoe Vetch leaves.
The males being very distinctive with their bright blue upper wings while the colours of the wing undersides
can vary
2nd brood Male wing undersides 
1st brood male wing undersides

Friday, 18 March 2016

Small Heath

This beautiful little insect is one of our commoner grassland butterflies. And is found in a selection of habitats, including grass verges, meadows, woodland rides and clearings, etc But not so often seen, as they tend to fly low down in amongst the vegetation, and always rest with their wings closed. The female is larger and paler in colour than the male.

Female Small Heath
The smaller male where you would normally find them, down in amongst the vegetation
There are 2-3 broods a year, depending on how far south or north they are, with the ovum being laid on various meadow grasses, Fescues and Bents. In the summer the transformation from egg to butterfly takes about 8-9 weeks. They also overwinter as a larva.

Sunday, 13 March 2016

Butterflies copulating overnight

Small Tortoiseshells were believed to be the only British species of butterfly that copulated overnight. Well new evidence has proved otherwise. On 29th April 2014 i found a pair of mating Orange-tips close to my home at about 5pm and they were still joined the following morning at 7am. Meaning they had been joined for at least 14 hours and, maybe a possible two more hours [my thinking is that they only parted when it was warm enough] making it at least 16 hours of mating. I have since learnt that Nigel Kitely has photographed a copulating pair of Meadow Browns that were covered in dew, which he found early morning in some long grass. Which indicates that the Meadow Browns also copulated overnight.

This pair of Orange-tips mated overnight, just like the Small Tortoiseshells

I believe that this happens when butterflies mate/join late afternoon. The sun goes in, becoming cold, so they roost where they are and stay joined overnight. The following day they go their separate ways, once its warm enough. It is thought that mating saps the males energy, which is why males tend to take in salts/minerals from Horse droppings, damp soil etc., to build-up their energy levels. Mating for the average species of butterfly probably only lasts between 40-60min. So why mate all night? As this act could well prove to be fatal to the male butterfly. Both male and female Orange-tips flew off after their marathon copulation.

Unable to complete metamorphosis

A gene named Broad is found in caterpillars and, is essential for the change from larva to pupa to complete the metamorphosis. If a caterpillar is without this gene it is incapable of developing, and making the important change to a pupa. And, so fails in its quest to become a butterfly.

Reference, Scientific American, [for the information on the Broad Gene]. All photographs are the copyright of Nick Broomer

The 1st photo depicts a small White larva at 25mm in length, and 2-3mm wide. This is the normal size of a 4th instar larva that is ready to pupate.

A final instar Small White larva at 25mm in length and, ready to pupate

The 2nd photo depicts another 4th instar Small white larva that has grown to the enormous size of 35mm in length [10mm above the normal size for pupation for this species] and, 5mm wide. Far to big to pupate. If this larva had managed to complete its journey and become a butterfly, it probably would of been called a Large Small White. The reason for this abnormality is that this larva was missing that vital gene, the Broad gene and carried on eating until it died without developing any further and not being able to pupate.
A final instar Small White larva at 35mm in length, should only grow to 25mm in length
I n the 3rd photo [just for comparison] it depicts a Small White larva preparing to pupate, now only 19mm in length, the actual size of a fully pupated pupa, [bottom left of the photo]. Whilst in the top right of the photo, you have the overgrown larva at 35mm. Which is genetically incapable of pupating.

Two Small White final instar larva, the one on the left is ready to pupate
the one on the right has failed to pupate and carried on eating
and eventually dies
The 4th photo depicts a final instar White Admiral larva that is probably also missing the Broad gene. Instead of pupating at this stage of it's life, which it should of done, it just stayed on it's leaf without eating until it also died because it was unable to pupate.
Final instar White Admiral larva that failed to pupate

Tuesday, 8 March 2016

A closer look at the eye of a butterfly

Ultrastructure and adaption in the Rectina of Aglais Urticae, Ledidoptera. By, Springer. Also a big thank you, to Iris Scientist for pointing this out to me.

Some butterfly's eyes are covered in tiny hairs, known as Interfacial hairs. These hairs are believed to help orientate light which penetrates the butterfly's eye and, so are expected to perform like that of Corneal Nipples. [Springer] For more information, please go to...

This Peacock Butterfly's eye showing the Interfacial hairs covering the
surface area of the eye, also showing some minuscule particles of debris
caught up with-in the interfacial hairs.
I always thought that these hairs were to protect the delicate eye of the Butterfly from tiny particles found floating in the atmosphere, as minuscule particles of dust/debris have shown-up in amongst these hairs in the few photographs i have taken of Butterfly eyes. So this seems to be another effective use for these Interfacial hairs.
The eye of the Red Admiral butterfly, again the hairs
covering the surface area of the eye acting as a trap
for tiny particles of debris.