Tuesday, 28 April 2015

Northants and Peterborough Diptera Group April Meeting

The first field meeting of the year is always the last Sunday in April. Following the pattern of the past few years, a warm and very promising spell of weather had broken into decidedly cold and breezy conditions with the vegetation left wet after overnight rain. Not the most auspicious start to the season. We met at the roadside next to Mantle's Heath and walked over to High Wood and Meadow, Wildlife Trust reserve. The flush at the entrance to the reserve has recently had some maintenance work done on it and it looked very promising for later in the year. With the cold conditions, nothing was flying so it was a matter of sweeping the vegetation to see what turned up. The most productive area was the lower damp meadow where a mixture of rushes and grass tussocks provided some shelter for insects. The first craneflies of the season were just emerging and I found one male Tipula vittata close to the small stream at the bottom of the meadow. Several very small blackish craneflies turned out to be Ormosia lineata. These were identified from the male genitalia after dissection. Although the species is fairly widespread, it is not often recorded as it has an early flight season of April and May.

One member of the St Mark's fly family Bibionidae was caught - Bibio johannis.

Four species of hoverfly were found by me in the meadow: Melanostoma mellinum, Platycheirus clypeatus, Eupeodes latifasciatus and Eristalis pertinax. Hopefully other members of the group may have found some more. 

Damp meadows can be very good for dung flies, Scathophagidae, but I only found one species, a male Scathophaga inquinata.

With the meadow being rather unproductive I tried the wood as I thought the shelter might provide better conditions. The wood looks splendid at this time of the year with its carpets of bluebells and canopy of cherry blossom. However it did not yield much in the way of diptera. In fact I only took a single fly. This was the common Spring hairy-eyed cranefly, family Pediciidae, Tricyphona immaculata.

So, it was not a very productive start to the season but it was a very pleasant walk in a superb location.

Sunday, 19 April 2015

April 2015

Since my last post I have received an earlier record of a hoverfly in Northants. On 2nd January 2015, Tim Newton found a hoverfly on his window which he correctly identified as Scaeva silenitica. We do not get many records of this species so it was a realyy remarkable find.

The warm weather in April has been bringing out the hoverflies, although I have not seen many species yet. There are loads of Eristalis pertinax about and there have been some Epistrophe eligans. The first record of this latter species came from Stuart Baker on 16th April at Southfield Farm Marsh. Graham Warnes found Melangyna quadrimaculata, another species with few records. Yesterday at Pitsford Reserve I found Helophilus hybridus and Melangyna cincta as well as a few very common species.

Earlier this week Bob Bullock sent me a photo of a blowfly he had seen at Pitsford in the Walgrave arm.  This is Cynomya mortuorum, a spectacular species with its metallic blue body and bright yellow face and jowls. We get few records of it although it is very distinctive. If you come across any recently dead animals it is worth looking round for this species. Bob said that there was a dead shrew nearby. Here is Bob's photo.
(C) Bob Bullock 2015