Tuesday, 24 May 2016

Cryptic Wood White survey in Craigavon

It has recently been discovered that Ireland has two species of Wood White butterfly: Leptidea sinapis, which is restricted to the Burren and nearby areas (and is the same species as that found in Great Britain) and the Cryptic Wood White - Leptidea juvernica - which is found in the rest of Ireland, including Northern Ireland, but is absent from GB.

Resolution of the conflicting and confusing identifications and distributions was temporarily further confused by the suggestion that one of the species was Leptidea reali, which is found in France. It seems that the situation has now been satisfactorily resolved, and it now remains to examine local populations to be sure we have the correct distributions. There is no sure way of separating the species by morphological characters, although differences have been proposed, so the only way to be sure is to sample populations and examine the genitalia.

The purpose of yesterday's visit to Craigavon was to train recorders in the identification of Cryptic Wood White (CWW) and to demonstrate a recording system for subsequent use in tracking this (and other) species.

But me being me, I didn't restrict myself to CWW, and I recorded more or less everything else we encountered.

First, though, a shot of the courtship behaviour of CWW:

Courtship behaviour in Cryptic Wood White, Leptidea juvernica
The male (left) usually sits higher and repeatedly swipes his antennae and proboscis over the face of the female. This courtship can take up to 30 minutes to complete. If the female accepts him, mating takes place. We saw one recently-emerged female being courted by two successive males before her wings had even fully inflated.

Gorse bushes were very fruitful, and were covered with Gorse Shieldbug:
Gorse Shieldbug
And their eggs: 

Eggs of Gorse Shieldbug

I also found many specimens of the minute (3 mm.) Gorse Weevil, Exapion ulicis:

Gorse Weevil, Exapion ulicis

New to my Species List.

There were a great many Common Blue damselflies: 
Common Blue damselfly (Enallagma cyathigerum)
And a few Blue-tailed damsels:

Blue-tailed Damsel

I found a few galls of the mite Eriophyes pyri quite early on in the walk:

The gall mite Eriophyes pyri on Rowan.

This appears to be the first record for NI, with one previous record from Ireland, and new to my Species List.

A record shot of the Mirid bug Harpocera thoracica. The male antennae have an interesting 'structure'.
Mirid bug Harpocera thoracica (male)
New to my Species List.

The day-flying Mother Shipton moth caught my eye, and it posed conveniently for a few shots:

Mother Shipton moth
I have seen the Lacehopper Tachycixius pilosus quite a few times, but this one seems to have a mite of some kind under the left wing. Mites usually position themselves in places where they can't be scratched off.
The Lacebug, Tachycixius pilosus

Finally, a Tetragnatha sp. 'Stretch Spider'. There are a couple of these that can't be separated without a microscope:

Tetragnatha sp. 'Stretch Spider'
Not bad for around 2 hours work, and we did count around 25 CWW. 

Monday, 16 May 2016

Benburb bioblitz

This bioblitz was based around Benburb castle, but also included the grounds of what is now known as Benburb Priory. The 17th century castle is being restored and the priory was formerly a manor house built in the 1880's.

The underlying geology is limestone and the site slopes downwards towards a river which is extensively engineered with cuts and sluices, and could almost be regarded as a canal. The riverside area has been allowed to run wild and is covered with Giant Hogweed, Bamboo, Japanese knotweed, Laurel and Himalayan Balsam. The grounds closer to the Priory are maintained as a decorative garden, but again, large areas are running wild, with a collapsed victorian greenhouse/orangery attached to outbuildings. This feature runs for some 50 metres and was clearly an important structure in its day. This is a shot of the old glasshouse:

Part of the glasshouse area with priory in the background
The south-facing glasshouse area contained a mixture of wild and cultivated plants, notably an overgrown herb garden, and attracted a huge number of hoverflies, butterflies, solitary bees and bumblebees.

Here's a shot of a Holly Blue on the approach path: 

Holly Blue butterfly
We made a quick survey to see where we should concentrate our efforts and it was clear that the riverside paths would be most productive. When I noticed that the area was limestone, we looked for Garlic Mustard, since this is a host plant for the Orange Tip butterfly and we immediately found an occupied flower:

Orange Tip egg on Garlic Mustard
We saw many Orange Tips, both male and female along the river bank. This female was nectaring on Herb Robert:
Female Orange Tip on Herb Robert
The same area yielded 14-spot Ladybird:

14 spot Ladybird

And a 10-spot ladybird with the rear spots missing. The 10-spot must be the ladybird with most variation in the spotting:

10-spot ladybird
Also from this area were the hoverfly Leucozona lucorum:

The hoverfly Leucozona lucorum landing on Bush Vetch

And I caught a glimpse of a huge pond skater down below in the cut next to the river. It's a poor shot, but there is only one pond skater this size. It's Aquarius najas, and is around 5 cm long from front foot to rear foot:

The River Skater Aquarius najas
New to my Species List.

We found a couple of leaf miners in the wooded area closer to the castle:

Phytomyza chaerophylli on Cow Parsley

Phytomyza ranunculi on Celandine
Phytomyza ranunculi was also found on Creeping Buttercup.

Closer to the castle, I found a moth larva grazing on lichen on a fence post. It's Brussels Lace, Cleorodes lichenaria:

Larva of the Brussels Lace moth

That's a good example of the formal name clearly stating the nature of a species.

A final shot of Lords-and-Ladies or Cuckoo Pint, which I only ever find on lime:

Arum maculatum
Overall we submitted perhaps a hundred species on the day. This is far fewer than I would normally expect on a day's hunting, especially on a bright sunny day, but the habitat is essentially 'cultivated but abandoned', so the biodiversity could be expected to be low.