Dr Phil Smith: Wildlife notes August 2020

Goat Moth (Dr Phil Smith)

 

On average, August is the wettest summer month, so it wasn’t surprising that we had rain on 14 days. Most of it was light but the second week was warm and humid, culminating in a thunderstorm on the 10th. The spring drought seemed a distant memory as late summer flowers like Grass-of-Parnassus proliferated in the damp conditions. Many of our dune-slacks didn’t dry up at all, my measuring point in the Devil’s Hole at Ravenmeols registering shallow water throughout.

Our concerns about the absence of Six-spot Burnet moths in July proved unduly pessimistic, their numbers rapidly increasing in early August, joining the second generation of Northern Dune Tiger Beetles. The latter seems to have done particularly well this year, Gems in the Dunes staff reporting hundreds in their usual bare sand habitat, mostly on the frontal dunes. A large area of flowering Apple Mint (the “mint patch”) at Ravenmeols attracted a wide range of insects, though the number of butterflies was down on last year. Even so, the glamorous Red Admiral, Peacock, Comma and Small Tortoiseshell, accompanied more mundane Gatekeepers. I was especially pleased to find two Small Heaths, a butterfly that is declining nationally but is still plentiful on the Sefton Coast. Amongst a wealth of bees and flies on the mint, the impressive Tachina fera attracted attention. This is a large bristly fly that parasitises various moth caterpillars. The female lays its eggs on leaves. When the eggs hatch, the young larva enters the body of a caterpillar and eats it from the inside.  This fly is widespread and common throughout much of the country, having a successful life-style shared by a great number of flies and wasps. These include a group of flies known as “beegrabbers” from their habit of jumping on bees and laying an egg on them. The larva develops inside the bee and eventually kills it. I found the widely distributed Four-banded Beegrabber on several occasions but the much rarer Dark-cheeked Beegrabber was a particular highlight, two being photographed on Ragwort at Ravenmeols on 18th. Two Common Lizards basking on a nearby log pile was a distraction from the insects.

A familiar garden-escape, Snowberry flowers are attractive to many insects in late summer. Visitors to a large clump at Falklands Way, Ainsdale, included the spectacular Lesser Hornet Hoverfly, Large Pied Hoverfly and Bumblebee Hoverfly. I was also pleased to see two Speckled Bush-crickets here at their only known Sefton colony. Photos of a solitary bee sent to the expert Ben Hargreaves were identified as a male Ivy Bee. It uses other flowers when Ivy is in short supply. I had another at Ravenmeols on 30th, this time on the first Ivy flowers, while Pete Kinsella reported many at Crosby.

A trip to Sands Lake at Ainsdale on 19th was rewarded with the amazing sight of a five-inch-long Goat Moth caterpillar heading across the boardwalk. They live for up to four years inside trees growing in wet places, feeding on the wood and emerging to pupate in the soil. A Red-listed species, the moth is becoming increasingly rare nationally, so it was a rare treat to see the caterpillar. It has massive jaws to deal with its tough diet but it only bit me once as I eased it into a better position for a photo.

A few days earlier, slack 50, just north of Sands Lake produced my only Ruddy Darter of the year so far. We seem to be losing this colourful dragonfly. It reached us from the south in 1989, becoming well established on the coast. However, the last few years have seen a marked decline here and elsewhere in the Northwest for reasons that are not clear. In contrast, the Migrant Hawker, another colonist from the south is doing well here. From mid-month, it was a familiar sight in sheltered, sunny spots, culminating in an impressive count of 29 at Ainsdale Sand Dunes National Nature Reserve on 24th.

One of my regular survey venues is the recently formed Green Beach just north of Ainsdale-on-Sea. The youngest section provided a flamboyant display of Sea Aster, which attracted a migrant Painted Lady butterfly. Progressing northwards, the vivid pink flowers of Lesser Centaury vied for my attention with masses of Grass-of-Parnassus, a Sefton Coast speciality. I was also delighted to find a new colony of Variegated Horsetail, a plant described as “vanishingly rare in lowland England.”

An August visit to Freshfield Dune Heath Nature Reserve for the flowering Heather is a must, though it was already past its best on 29th. Nevertheless, it was alive with insects, including an attractive Mason Wasp of the genus Ancistrocerus and a Four-banded Beegrabber. Short, grassy areas produced several Mottled Grasshoppers, while, two Buzzards constantly called overhead. Six House Martins flew south with a few Swallows, no doubt on their way to Africa for the winter.

The last day of August saw me at Falklands Way where a jewel-like Rosemary Beetle was new to me. Originally from southern Europe, it appeared in London in the late 1990s and rapidly spread north through England and Wales, even reaching Scotland.