Invertebrate report for first half of 2013
On 13 February - only a week or so from snow in the garden which wasn't to be the last – there was sunshine as well as a bit of warmth in the sun. On a stem of rhododendron just inside the entrance to the City of London Cemetery was my first ladybird of the year – a Pine Ladybird Exochomus 4 pustulatus, and there were more enjoying the sunshine, plus torpid ones sheltering in the dried up flower-husks, where they probably overwinter. Crocuses and Winter Aconiteswere flowering, and just one flower of Lesser Celandine, and on the white flowers of Viburnum, three species of hoverfly were found. Most of these were Drone Fly Eristalis tenax, and there were lesser numbers of the Marmalade Hoverfly, Episyrphus balteatus. The third species was a single individual and probably Melicaeva auricollis. On an adjacent Mahonia, its yellow flowers were attracting mainly Honey Bees, Apis mellifera.
No butterflies were seen, whereas last year Red Admirals were seen on Wanstead Flats on 26th February; it has been reported that butterfly numbers were considerably down last year, and this will doubtless be reflected on numbers this year. On the heathers – many of which were flowering – quite a lot of insect activity was taking place, with the flowers large numbers of Honey Bees as well as the large and familiar Buff-tailed Bumble Bee, Bombus terrestris.
Disappointingly, by the next day the weather had again turned colder, and this trend was to continue well into April and even May, with a few days of relative warmth followed by mostly unseasonal cold. I'd intended to put out a moth trap early this year, but on the few occasions that I did the catch was nil until 10th April, when there 3 Common Quakers nestling in the egg-boxes the following morning. In the whole of April I had 6 species and 28 specimens of moth in the trap. However, the trap occasionally does contain other things, and one such on 11th April was a wasp of an Ophion species.
Pond Skaters were to be seen on my small garden pond from about this time, too, and Eristalis tenax hoverflies were quite frequently seen on the slightly warmer days. The 13th April was one such, and in the City of London Cemetery – around the heather beds – together with the bumblebees and a few spiders, was my first Bee-fly Bombylius major of the year. Bee-flies will not fly in temperatures less than 17ºC., and considering the extended winter and long drawn-out spring, I saw more and in more places than I've ever seen before. The last – though not in the Wanstead area – was on 6th June. There was a Comma butterfly in the garden on 15th April, and mining bees (Andrena species) were appearing on Wanstead Flats by the 29th as well as the common Buff-tailed bumblebee Bombus terrestris.and Red-tailed Bumblebee Bombus lapidarius. A Small Tortoiseshell butterfly was also spotted on Wanstead Flats.
By the 1st May, Tim Harris – who had been putting out a moth trap in Belgrave Road at the other end of Wanstead Flats to myself - had accumulated a total of only 16 moth species during this year, and I only 6. However one or two new species for the area were cropping up in early May, including the micro-moth Pyrausta despicata and a Red-green Carpet.
On the butterfly front, Holly Blue butterflies began to appear in my garden and elsewhere on 2nd May and on 3rd there were Orange Tips, Speckled Wood and Peacock in Wanstead Park, plus Green-veined Whites, Large Whites and Small Whites in Aldersbrook Exchange Lands.
My first damselfly of the year was – as usual – a Large Red, in my garden on the 6th May, after which I had a look at Wanstead Park. An invertebrates of particular interest was a Slender Ground-hopper Tetrix subulata at the east end of Heronry Pond. I have only ever seen one before, and that too was by Heronry Pond, although in 2009. Also in the pond was the larva of a Tipula species Cranefly. I'd been catching sight of a Great Diving Beetle in my garden pond for some time, but it had surfaced only briefly then dived and swam rapidly out of sight into the depths. On 7th May I managed to photograph it at the surface and identify it as a female Dytiscus marginalis.
On 7th May Tim had a Broom Tip Chesias rufata, which was a new species for the area. This was worthy of a bit of research, and Tim could find no reference to any records in our area since at least 1989 on the Essex Field Club database. Indeed, in Essex it only seems to have been recorded in a handful of squares since that time. Wanstead Flats does have plenty of broom, so we may have a population. Another new species in the Belgrave Road trap was a Yellow-barred Brindle moth on 20th May.
By the latter part of May a variety of hoverflies were now visiting my garden including Helophilus pendulus and particularly Eristalis tenax.
On 27th May Tim Harris discovered a Green Hairstreak colony on Wanstead Flats - the first report of these butterflies in our area save for a possible one I saw some years ago by the Grotto. It is a widespread species, but found in very localised communities due to habitat loss so it is quite something that we have a population here. Small Copper butterflies were also beginning to emerge.
More species of damselflies were beginning to emerge as the weather became warmer at the very end of May. Most that were seen on 31st May were in the teneral stage, which is just after they have emerged from the pupal stage and either or both Azure and Common Blue. There were also Large Red, some Blue-tailed and some Red-eyed damselflies. By the Heronry Pond, leaves of Flag Iris had numbers of the Long-jawed Orb-weaver Spiders Tetragnatha extensa on them, and an adult and a few very small Slender Ground-hoppers were seen in the same location as the adult seen on 6th May. This would seem to indicate that we have a healthy population.
Also on 31st May, the Soldier Beetle Cantharis rustica was seen in the Exchange Lands and Flea Beetles - Altica species - were appearing on the leaves of water-side plants in Wanstead Park. Large White butterflies were seen, and there were many Craneflies around in the grassland.
(See also Early Invertebrates 2012 for comparison with last year)
Paul Ferris