Upper Thames Moths: Westcott, Bucks

Sunday 16 July 2023

Westcott, Bucks

Here we go again with another update from Westcott. Apart from a couple of really good nights (7th and 8th) the first half of July has been rather disappointing for moths. The days have often been nice enough but night-time temperatures have fallen rapidly or it has been very windy and this always has an effect on micros in particular. Very few of the smallest ones (Stigmella & Phyllonorycter species, etc) have come to light here so I expect there will need to be a concerted effort with leaf-mines if 700+ species is to be achieved in the garden again this year. Things are actually more or less on course for that to happen, with the list currently standing at more than 500 once dissections are taken into account, but the weather between now and the end of July doesn't look set to change much and from the beginning of August to the end of the year I rarely add more than 100 species.

Newcomers for the year-list over the past couple of weeks have included the following (others, including one or two of those listed below, have been retained for dissection):

(1st) Least Carpet

(2nd) Lunar Hornet Moth (daytime to LUN lure), Acrobasis repandana

(3rd) Herald

(4th) - nil -

(5th) Anacampsis sp., Gelechia sororculella

(6th) Borkhausenia fuscescens, Helcystogramma rufescens, Cydia fagiglandana, Agriphila tristella,

Dusky Sallow

(7th) Caloptilia cuculipennella, Prays ruficeps, Batia lunaris, Gelechia senticetella, Exoteleia dodecella, Anarsia innoxiella, Batrachedra praeangusta, Marasmarcha lunaedactyla, Apotomis turbidana, Spilonota ocellana, Zeiraphera isertana, Eucosma campoliliana, Eucosma conterminana, Pammene fasciana, Oncocera semirubella, Acrobasis advenella, Hypsopygia glaucinalis, Cataclysta lemnata/Small China-mark, Oak Hook-tip, Shaded Broad-bar, July Highflyer, Dark Umber, V-Pug, Bordered Beauty, Olive, Lesser Broad-bordered Yellow Underwing

(8th) Bucculatrix nigricomella, Oxypteryx atrella, Acleris holmiana, Gypsonoma dealbana, Dioryctria sylvestrella, Acrobasis suavella, Black Arches, Marbled Beauty

(9th) Plutella porrectella, Ruby Tiger, Double Dart

(10th) Cydia splendana, Pyrausta despicata, Slender Pug, Garden Tiger

(11th) Ypsolopha scabrella, Pyralis farinalis, Leopard Moth, Rosy Footman, Dark Spectacle

(12th) Athrips mouffetella, Acrobasis consociella, Mere Wainscot

(13th) Agriphila selasella, Brown-tail, Dingy Footman, Slender Brindle

(14th) Epiblema costipunctana

(15th) September Thorn, Shark

The stand-out moth for me over this period was Garden Tiger, such a splendid looking beast which was once so common but is fast becoming a rarity in our region. The visitor on the 10th was the first one seen here since 2019 and, as far as I'm aware, in subsequent years there have been only three other sightings in Bucks (two in 2020 from Newport Pagnell and Stoke Poges, none in 2021 and one in 2022 from Weedon).

Garden Tiger, Westcott 10th July

Migrants have been few and far between but another Delicate turned up on the 6th (the third this year). It was nice to get Pyrausta despicata on the 10th (only the fourth record for the garden and often associated with migration, although could just have wandered in from the Chilterns), while another Dark Sword-grass visited on the 14th.

Pyrausta despicata, Westcott 10th July

Dark Sword-grass, Westcott 14th July

Dark Arches is still going strong, with more than 1,500 individuals recorded in the garden by the end of the current period. As would be expected by now, the Common Rustic/Lesser Common Rustic and Uncertain/Rustic pairs are producing good numbers, as to a lesser extent are Heart & Dart and Large Yellow Underwing, while numbers of Scarce Footman and Common Footman are building fast. At the other end of the scale, Four-dotted Footman has had its best ever season here with a dozen recorded between 11th June and 6th July. I don't usually get more than one or two each year, the previous highest annual total being five in 2018.