The Green Meshweaver gets to Hull

 

Another post on a rapidly expanding species, this time a small spider, the Green Meshweaver, Nigma walckenaeri. All started on Saturday, during the YNU AGM in the University of Hull, where spider expert  Geoff Oxford, showed us a specimen he had just collected from the university grounds, a tiny green spider that is currently expanding its range across the UK and now colonising Yorkshire. We all admired the individual, which had been collected with its web on a leaf. 

The first Nigma walckenaeri record from Hull.

After returning from the meeting, I searched the garden ivy, and since I've been searching ivy and holly, which are favoured leaves to weave it's mesh. Nigma walckenaeri  chooses curled leaves, so it can take advantage of this to hide under its little web. As other regular character in this blog, Amaurobius, Nigma is a cribellate silk weaver. 

Today, I took a local walk and came across a magnificent mature ivy, south east facing. I started searching its leaves, wondering if I had the wrong search image in my mind. It didn't take long to find a Nigma.

Nigma walckenaeri  habitat.

There it was! A light-touch web of blueish threads with the green spider sitting, well camouflaged, underneath.

I moved part of the web aside to have a closer look (also top shot). This is a female, with her whole body green. Once I had seen one, I found another, and another, almost every ivy leaf had it's little Nigma in it. 

A male, with its brown cephalothorax.

This individual was busy weaving its web.

I even spotted a male (with reddish-brown opistosoma) on the edge of a female's web.

Until 1993 it was only found in London and the home counties, and it is associated to parks and gardens. Since then it has been steadily spreading north. I'll keep a look for it in the garden!

Hull Dragons 2020: June summary

June has been a much more variable month than the dry and sunny May, with some rain, storms, more windy and more cloud. There were some good days for dragonfly watching, including a heat wave on the 3rd week, when temperatures reached 29°C in Hull. A total of 142 records of 13 species have been submitted during the month by 11 contributors. Foredyke Green Pond and East Park, with 7 species each, were the best sites in number of species. The only species recorded in May with no June records is the Large Red Damselfly. The Red-eyed Damselfly, Black-tailed Skimmer and Southern Hawker were added to the year list. An unidentified darter was recorded on the 25th June. 

My June odonate highlights

• Watching a female Hairy Dragonfly coming to the shore by my feet at Noddle Hill fishing lake and start ovipositing on a dead branch was my highlight of the month. She moved on pretty fast before I could set the camera on her. As far as I know, this is the first time the species has been recorded ovipositing in the Hull area. 
• Spotting a Red-eyed Damselfly at Foredyke Green, a new location for the species. 
• At Ennerdale South Pond there was a strong damselfly emergence on the 2nd June. House Sparrows were feeding on them, sometime as I disturbed them and they flew up. As I watched and followed a female Banded Demoiselle by the river Hull, a house sparrow chased her and captured her!

• Watching an ovipositing Broad-bodied chaser at Foredyke Green Pond.
• Watching an Emperor and Hairy Dragonfly males patrolling and hunting on a stretch of the Beverley and Barmston drain, occasionally clashing.

• As I was examining an emperor exuviae, I was surprised to see it moving, and a lodger emerged: a Larinioides cornutus spider! I had never seen spiders using dragonfly exuviae as retreats.

June species and breeding evidence

Southern Hawker. First and only record so far on the 26th June.

An emperor dragonfly resting briefly on plants near Foredyke Green pond.

Emperor Dragonfly. 13 records. Exuviae found at Foredyke Green Pond and Ennerdale South Pond.

Hairy Dragonfly. 2 records, with ovipositing female at Noddle Hill Lake.

Banded Demoiselle. 4 records from the 2nd June from River Hull, Ennerdale S Pond and Cottingham. Several records from Wawne.

Azure Damselfly. 30 records. Teneral at Beverley and Barmston Drain and Setting Dike. Oviposition noted at Pearson Park and Beverley and Barmston Drain.

Common Blue Damselfly. 19 records. Tenerals at Ennerdale S Pond. Mating pairs at Foredyke Green Pond and Ennerdale Pond.

Red-eyed Damselfly. Four records from four sites, the first on the 1st of June. They include a new site for the species, Foredyke Green Pond.

Female Blue-tailed Damselfly with Arrenurus mites (17th June).

Male Blue-tailed Damselfly with mites. Both at Foredyke Green pond (14th June). These are parasitic mites that feed on the host blood and drop to water once the host comes to mate to water. 

Blue-tailed Damselflies mating.

Blue-tailed Damselfly.

Blue-tailed Damselfly. 33 records, the most commonly recorded species. Tenerals were found at Oak Road, Ennerdale S Pond and Setting Dyke, oviposition was recorded at Beverley and Barmston Drain and Noddle Hill Lake.

Broad-bodied Chaser. 5 records. Oviposition at Foredyke Green Pond, where the photo above was taken.

Four-spotted Chaser. 12 records from 5 sites, including individuals emerging in a private garden.

Black-tailed Skimmer. 8 records from 6 sites, the first of the year on the 2nd June. A female was seen ovipositing at Snuff Mill Lane.

Hull Dragons: September summary

I didn't think I would write a September summary for Hull Dragons. However, the first three weeks of September were generally dry, sunny and warm - though breezy at times - allowing for plentiful dragonfly surveys. In contrast, the end of the month was very overcast, wet and the temperatures plummeted. Overall, 134 records were submitted to iRecord from 9 species in September by 4 observers. Although fewer species have been active in September compared to August (9 compared to 13), and the general diversity is lower, the spread of the records is increased, with the records coming from 30 km2. 83% of the records were for Common Darter and Migrant Hawker. There were 8 Southern Hawker records and 5 Ruddy Darter records, the remaining species having one or two records each in the month. Most notably, however, a male Willow Emerald was first recorded at East Park. This is not only a great addition to the Hull Dragons survey, but it is the first record for all of East Yorkshire (see my previous post about it here).

With the addition of these records and the dragonfly records submitted through Birdtrack, HullDragons has now accumulated over 500 records, which are far more than I would have anticipated at the start of the survey.

Other than my Willow Emerald twitch, my favourite dragonfly trip this month was at Noddle Hill. The sheltered 'Snake Pass' ride is a favourite haunt of Migrant and Southern Hawker, hunting and sunbathing and both Common and Ruddy darters also favour it. The NW corner of the lake, with a wide belt of marginal vegetation, in a sunny, sheltered corner, had plenty of Migrant Hawker activity, with several mating pairs, two of them sitting close to each other. A male Ruddy Darter was also on territory. The following are some photos of that survey on the 18th of September.

Female Migrant Hawker.

Male Southern Hawker.

Mating Migrant Hawkers.

Mating Common Darter.

The patrolling Migrant Hawker males over the water offered some opportunities for in flight photography.

Male Ruddy Darter on territory.

 List of species recorded on September

1. Southern Hawker
2. Brown Hawker
3. Migrant Hawker
4. Ruddy darter
5. Common Darter
6. Small Red-eyed damselfly
7. WILLOW EMERALD
8. Black-tailed skimmer
9. Common blue damselfly

Note: this will be the last monthly summary for HullDragons this year

Hull Dragons: July summary

July is peak dragonfly season, most of the early species are still on the wing, and the last of the high summer species have emerged too. Hull Dragons has now a total of 180 records in iRecord, from 34 km2 surveyed (28 of them in July) yielding a grand total of 15 species. All but Broad-bodied Chaser, an early season species, have been recorded during July at iRecord.

Survey coverage: 34 km2.

Four new species have been added to the survey this month: Southern Hawker, Common Darter, Brown Hawker and Small Red-eyed Damselfly. Evidence of breeding has been obtained for all four but Brown Hawker.

Southern Hawker
The first record of Southern Hawker was at Pearson park Wildlife Garden pond. A number of fresh exuviae were collected between the 2nd and the 8th of July from the emergent vegetation in and around the pond.

Southern Hawker exuviae, Pearson Park wildlife garden.

Two exuviae and observations of an individual getting into a house were obtained at a private Avenues pond. Other records include an individual flying by Oak Road and two or three at Noddle Hill Lake.

Immature Southern Hawker at Noddle Hill Lake.

Banded Demoiselle

The excellent Banded Demoiselle year continues, with more records and additional sites for this species by the River Hull at Thearne, at Mill Beck, Cottingham and at the Boating Lake at Peter Pan Park (Costello Stadium).

Female Banded Demoiselle by the River Hull at Ennerdale.

Emperor Dragonfly
After a few sightings in the last week of June, it is peak season for this species, which has now been recorded at 10 sites. Males were patrolling and defending territories at East Park, Pickering Park, Foredyke Green, Ennerdale South pond and Beverley and Barmston Drain. A female was observed ovipositing at Ennerdale South pond

Male Emperor by the Beverley and Barmston drain.

Female Emperor ovipositing, Costello Stadium boating lake.

Black-tailed Skimmers
The first Black-tailed skimmer record was at the end of June, but it is in this month that they become more common. They have been recorded at 4 sites, with 8 records: Ennerdale South pond, East Park, Noddle Hill LNR and a private avenues pond. Ovipositing was observed at Ennerdale South Pond.

Ovipositing female and guarding male Black-tailed skimmer at Ennerdale South Pond. The male confronted the resident Emperor while the female oviposited.

One of several territorial male Black-tailed Skimmers at East Park.

Azure Damselfly

Azure Damselflies have now been recorded in 13 km2. Evidence of breeding in the form of mating and ovipositing has been obtained in several sites.

Azure Damselflies mating, Pearson Park wildlife garden.

Ruddy darter

Ruddy darters have been found in Noddle Hill LNR, Oak Road Lake, Midmeredales Pond (several tenerals) and a private pond in the Avenues.

Ruddy Darter, Oak Road Lake.

Common Darter

The first Common Darter in the area was at Ennerdale S Pond on the 4th July, where several tenerals were found in the vegetation by the pond. More tenerals and darter exuviae were found at an avenues private garden where both Ruddy and Common Darters have been recorded. At least two individuals and three exuviae were found at Pearson Park Wildlife Garden. This species has a long flight season and roams away from water before settling to breed so hopefully more records will be added as the season progresses.

Common darter, private avenues pond.

Blue-tailed damselfly

No matter the weather, even during cloudy or muggy days or the habitat, which includes polluted water or fish ponds, the Blue-tailed damselfly always saves the day. I was pleased to find the 'rufescens' female form at the pond in the Museums Garden in the city centre, where the species is very abundant. This form also occurs at East Park. We now have records from 18 squares in the recording area.

Small red-eyed damselflies

The first sighting of this species this year was at East Park, with dozens of pairs ovipositing in both main lake and boating lake on 13th and 25th of July. Two individuals were recorded at St Andrew’s Quay pond and there is also a record at a garden pond at Skidby. The new locations indicate that this species is likely to become more common and widespread.

Resting male.

Small red-eyed damselflies ovipositing, East Park boating lake.

Red-eyed Damselfly
More records for this species were obtained for East Park and Noddle Hill. A teneral female at Noddle Hill provided evidence of successful breeding at this site.

Red-eyed Damselfly, Noddle Hill Lake.

Teneral female Red-eyed Damselfly, Noddle Hill lake.