Spiked Shieldbugs found in the Carlisle area of Cumbria in 2015: Overview
Spiked Shieldbugs found in the Carlisle area of Cumbria in 2015 - Overview.
Spiked Shieldbugs are very common in the Carlisle area, in particular in my local Kingmoor Nature Reserve. However, although I saw plenty of adults in the autumn of last year - when I first developed a keen interest in shieldbugs - I didn't see any nymphs. This was partly due to the fact that this species overwinters in egg form, which means that the nymphs reach peak population level fairly early in the year, and there are relatively few of them left by the end of the summertime.
To give myself the best chance of catching as many of the nymphal stages as possible, I started checking out the broad-leaved low-lying vegetation on every outing from early May onwards. As the previous earliest record for a Spiked Shieldbug nymph in Cumbria was 20 June, this was probably a bit OTT, but as I did find several Blue Shieldbugs during these searches the time wasn't completely wasted!
I was beginning to lose hope, when on 21 June I stumbled across three clusters of nymphs just a few metres apart in Kingmoor North (two on different leaves of the same plant), containing about 40 or so individuals in all, spanning several stages of development; then two days later a further group of about 20 early-instars was found in Kingmoor Sidings. Unfortunately, I never located the Sidings group again, but thankfully the Kingmoor North specimens were seen on several further occasions, but the last time in cluster form on 27 June. Although fourth and final-instar nymphs were later found at High Stand Plantation, Glasson Moss, Drumburgh Moss and Sowerby Wood, early-instars were only found in Kingmoor.
The first sighting of a fourth-instar nymph was made on 21 June, when one was seen amongst one of the Kingmoor North clusters; the last sighting was on 25 August in High Stand Plantation. The first sighting of a final-instar nymph was on 7 July in Kingmoor North, and the last on 5 September on Glasson Moss. Adults were seen from 21 July to 24 October.
A number of length measurements of the earlier-instar nymphs were carried out, and although I accept that these may be of limited value, for the record the results were as follows:
First-instar: 1.7mm (25 Jun)
Second-instar: 2.8mm, 2.8mm (23/24 Jun)
Third-instar: 4.4mm, 4.7mm (23/24 Jun)
Fourth-instar: 6.0mm (25 Jun), 6.5mm (26 Jun), 6.0mm (23 Aug)
All Spiked Shieldbug photos taken this year and submitted to Flickr are included in my Spiked shieldbug (Year 2015) album, where more detailed information can be found. All of the shots included in the montage are taken from here. The contents of the montage are as follow:
Photo 1: Early-instar nymphs with a first-instar inset, Kingmoor North, 25 June
Photo 2: Second and third-instar nymphs, Kingmoor North, 23/24 June
Photo 3: Fourth-instar nymph, Kingmoor North, 23 August
Photo 4: Final-instar nymph with prey, Kingmoor North, 2 August
Photo 5: Adult teneral, Kingmoor North, 16 August
Photo 6: Adults with prey, Kingmoor North, 11 September
Photo 7: A mating pair, High Stand Plantation, 25 September
Spiked Shieldbugs found in the Carlisle area of Cumbria in 2015: Overview
Spiked Shieldbugs found in the Carlisle area of Cumbria in 2015 - Overview.
Spiked Shieldbugs are very common in the Carlisle area, in particular in my local Kingmoor Nature Reserve. However, although I saw plenty of adults in the autumn of last year - when I first developed a keen interest in shieldbugs - I didn't see any nymphs. This was partly due to the fact that this species overwinters in egg form, which means that the nymphs reach peak population level fairly early in the year, and there are relatively few of them left by the end of the summertime.
To give myself the best chance of catching as many of the nymphal stages as possible, I started checking out the broad-leaved low-lying vegetation on every outing from early May onwards. As the previous earliest record for a Spiked Shieldbug nymph in Cumbria was 20 June, this was probably a bit OTT, but as I did find several Blue Shieldbugs during these searches the time wasn't completely wasted!
I was beginning to lose hope, when on 21 June I stumbled across three clusters of nymphs just a few metres apart in Kingmoor North (two on different leaves of the same plant), containing about 40 or so individuals in all, spanning several stages of development; then two days later a further group of about 20 early-instars was found in Kingmoor Sidings. Unfortunately, I never located the Sidings group again, but thankfully the Kingmoor North specimens were seen on several further occasions, but the last time in cluster form on 27 June. Although fourth and final-instar nymphs were later found at High Stand Plantation, Glasson Moss, Drumburgh Moss and Sowerby Wood, early-instars were only found in Kingmoor.
The first sighting of a fourth-instar nymph was made on 21 June, when one was seen amongst one of the Kingmoor North clusters; the last sighting was on 25 August in High Stand Plantation. The first sighting of a final-instar nymph was on 7 July in Kingmoor North, and the last on 5 September on Glasson Moss. Adults were seen from 21 July to 24 October.
A number of length measurements of the earlier-instar nymphs were carried out, and although I accept that these may be of limited value, for the record the results were as follows:
First-instar: 1.7mm (25 Jun)
Second-instar: 2.8mm, 2.8mm (23/24 Jun)
Third-instar: 4.4mm, 4.7mm (23/24 Jun)
Fourth-instar: 6.0mm (25 Jun), 6.5mm (26 Jun), 6.0mm (23 Aug)
All Spiked Shieldbug photos taken this year and submitted to Flickr are included in my Spiked shieldbug (Year 2015) album, where more detailed information can be found. All of the shots included in the montage are taken from here. The contents of the montage are as follow:
Photo 1: Early-instar nymphs with a first-instar inset, Kingmoor North, 25 June
Photo 2: Second and third-instar nymphs, Kingmoor North, 23/24 June
Photo 3: Fourth-instar nymph, Kingmoor North, 23 August
Photo 4: Final-instar nymph with prey, Kingmoor North, 2 August
Photo 5: Adult teneral, Kingmoor North, 16 August
Photo 6: Adults with prey, Kingmoor North, 11 September
Photo 7: A mating pair, High Stand Plantation, 25 September