Noar Hill, Revisited - July 2014

Around this time last year I visited the Hampshire and Isle of Wight Wildlife Trusts Noar Hill Nature Reserve in order to carry out a grasshopper survey. The visit was a success as we recorded the local Rufous Grasshopper, along with a variety of other species. The Trust is looking to set up a standardised monitoring programme for the species, so when I was asked to assist I jumped at the chance. We visited the site on 22nd July with the main purpose to survey for grasshoppers, and test the survey methodology that had been designed, but whilst I was there I took the opportunity to catch up with a few other species. 

As I have covered grasshoppers before I didn't take any photos, but during the survey we recorded Rufous, Common Green, Field, Stripe-winged and Meadow Grasshopper and Speckled, Dark and Roesel's Bush Crickets. Noar Hill is well know for its orchids too and there was plenty of evidence of them, but the only species in flower was the Pyramidal Orchid

Pyramidal Orchid Anacamptis pyramidalis

As would be expected at this time of year, butterflies were everywhere and making use of the abundance of nectar available. Meadow Brown, Ringlet, Gatekeeper and Red Admiral were the most numerous, the latter species making the most of the flowering Hemp Agrimony.

Red Admiral Vanessa atalanta

Silver-washed Fritillary and Marbled White seemed to be just hanging on, with some very tatty individuals present, whereas the Brimstone's and Green-veined White's were immaculate and clearly evidence of a recent emergence.

Brimstone Gonepteryx rhamni

Green-veined White Pieris napi

We also recorded Large and Small Skippers, but the only species of Blue recorded was Common Blue. This time last year their had been an abundance of Chalkhill Blues at the site, but we may have been a bit early this year.

Small Skipper Thymelicus sylvestris infected with the red mite Trombidium breei

Whilst photographing a Small Skipper and Common Blue I noticed that they were infected with a small red mite. I did a bit of research and it appears that this mite is Trombidium breei, which usually attaches itself to the legs or thorax of its host. Apparently there are no detectable negative impacts on the host butterfly, and the mites transfer from host to host via flower heads. For more information on butterfly parasites check out the following link enemies of butterflies.

Common Blue infected with Trombidium breei

Female Common Blue

Another species recorded was the Small Heath, but only in small numbers. In total we recorded 13 species of butterfly during our visit.

Small Heath Coenonympha pamphilus

Despite the orchids not being in flower there were plenty of other plant species on show, including bellflower, yellow-wort, Greater Knapweed and Harebell.

Greater Knapweed Centaurea scabiosa

Harebell Campanula rotundifolia

The Small Scabious flowers were proving very popular with the Six-spot Burnet moths, which were the most numerous moth species we recorded.

Six-spotted Burnet Zygaena filipendulae stephensi on Small Scabious

On the Lookout for Grasshoppers at Noar Hill - 15th August 2013

I had the opportunity to get out of the office yesterday in order to carry out an Orthoptera (Grasshopper and Cricket) survey at The Hampshire and Isle of Wight Wildlife Trusts Noar Hill Reserve. The main purpose of the visit was to check on the status of rufous grasshopper, a species that is known to be present, but had not been searched for recently. It is a species that is restricted to southern England on south-facing slopes of unimproved calcareous grassland, Noar Hill provides the ideal location for the species and has known to be present for many years.

Classic piece of chalk grassland at Noar Hill

The reserve was once the site of medieval chalk workings, but is now owned by the Wildlife Trust. In the spring and early summer it is carpeted with chalk downland flowers, including many species of orchid.

Harebell Campanula rotundifolia

I was hoping for a warm, still and sunny day, since these are the best conditions for Orthoptera surveys. Unfortunately it was quite windy and cloudy, so sunny periods were interspersed will long periods of shade, the temperature dropped considerably during these periods. Over 35 species of butterfly have been recorded at the site, and it wasn't long before we were seeing some of them. Chalkhill Blue was the first species recorded, keeping low in the vegetation but occasionally basking during a sunny interval. This species appears to have had a great year, as on the Wildlife Trusts Arreton Down reserve on the Isle of Wight, a few thousand individuals have been on the wing in recent days. A spectacular sight if you can get there to witness it!

Male Chalkhill Blue Lysandra coridon

Several common blue butterflies were also on the wing, although not as many as there were chalkhills, and the supporting cast included small heath, meadow brown, large and green-veined white and gatekeeper.

Male Common Blue Polyommatus icarus

Hemp-agrimony provided a rich source of nectar for more species, especially peacock, small tortoiseshell and a handful of clouded yellows that were scattered around the site. The latter proved incredibly difficult to photograph as they were easily disturbed, and were being blown around in the gusty conditions.

Peacock Inachis io

Underwing of Peacock Inachis io

Along the woodland edges silver-washed fritillary's, brimstone's and Comma's were also taking advantage of the rich nectar source provided by the hemp-agrimony.

Silver-washed Fritillary Argynnis paphia

Silver-washed Fritillary

Grasshoppers and crickets were proving difficult to locate since they were not really singing in the unfavourable conditions. Dark bush cricket was the first to be heard, and soon meadow, common green and field grasshopper had also been added. Roesel's bush cricket is one of those species which has expanded rapidly since being first recorded in the extreme south-east of the country. A handful of this species were recorded in the areas of taller vegetation, along with a few long-winged coneheads.

Sheltered sunny glade which proved to be a great location for
Rufous Grasshoppers

Eventually, after several hours of searching, a male rufous grasshopper was recorded in a sheltered glade in the east of the site. This species is one of the easier grasshopper species to identify due to the presence of a range of features, some of which are unique and are present on males, females and nymphs.

Male Rufous Grasshopper Gomphocerippus rufus

The grasshopper is generally brown in colour and usually has a reddish abdomen. The male has large club shaped antennae, similar to a butterfly, that are tipped white, these are diagnostic. They do also occur on females and nymphs but are not as pronounced, as can be seen in the pictures below.

Female Rufous Grasshopper

They also have pale palps, which are located by the mouth parts, and the call is like a clockwork toy unwinding. It is a late maturing species and with adults not usually found until late July, but they can survive until late November and even early December.

Rufous Grasshopper - Final instar nymph

Another species restricted to south-facing calcareous slopes in the south of England is stripe-winged grasshopper. It is quite a widespread species and can be quite common in some places. It has a very distinctive call that lasts about 10 to 20 seconds, it is very high pitched, starts with a hiss and then continues with a buzzing, metallic, pulsating sound.

Stripe-winged Grasshopper Stenobothrus lineatus

One distinctive feature is the enlarged central cells of the forewing, you may need a hand lens to see it, but it does tend to give the grasshopper the appearance of having a broad wing.

Enlarged central cells on wing of Stripe-winged Grasshopper

By the end of the visit eight species of Orthoptera had been recorded, including the target species and 13 species of butterfly. Not bad for a blustery afternoon in Hampshire.