A new Rose Chafer colony in Hull

The other day I heard a deep hum (sounding like that produced by a large bumblebee queen) and saw that it was came from a large green iridescent beetle flying around a flowering pyracantha. I waited for it to land excitedly, as I was pretty sure of what it was, and eventually the beetle landed on the flowers: as I expected it was a Rose Chafer, Cetonia aurata, my first one in Hull. I searched the bush and found at least four other individuals, feeding on the flowers. An hour later, as I returned from my walk I checked again and found a mating pair. Rose Chafers are a charismatic, jewel-like species. They are about 2 cm long, burnished metallic green and have variable wing markings, formed by whitish squiggles on the elythra. The species is not particularly widespread in the UK, and has an unusual patchy distribution, mainly in the south, with scattered coastal populations. It is often associated to urban environments such as gardens, parks and allotments.

A Hull population

I checked the NBN Gateway Atlas and iRecord for the species and was surprised to find that Hull appears to hold the only Yorkshire population of this species. There is one record from a private garden in Fulford, York in June 2019 and another from Bradford in June 2013. The 11 Hull records span the last 16 years (from 2020) all in a residential, leafy area of about two square km known as The Avenues. The records, all of adults, were submitted by 10 different observers, highlighting that it is a conspicuous species, with adults hard to miss. The records are from May to October, with a peak in July, which mirrors the adult flight period. The geographical tightness of the cluster suggests that this is a discrete established population. The origin of this population is intriguing, given the absence of nearby colonies, so an accidental introduction with compost or plant pots is a strong possibility.

Life cycle

The larvae take one year to complete their development in old wood, logs, stumps, compost piles, wood chips or leaf litter, decomposing these materials into rich mould. Occasionally they are found in pots including hanging baskets, where they are likely to be attracted to the compost, but they are not thought to feed on live roots or damage the plants. Larvae of some coastal populations feed on peat under coastal turf. They pupate around mid summer in a rounded, bumpy cocoon made of their faecal pellets. Adults are usually formed in August, but usually only emerge after overwintering in the following April or May. 

Behaviour and ecology

Rose Chafers fly in warm, sunny weather, and around the middle of the day, in search of flowers and mates, producing a deep bumblebee-like hum. They fly with their wing-cases closed and a modification of their elythra allows this. The adults feed on nectar and pollen on flowers with easily accessible pollen and nectar  including hogweed, guelder-rose hawthorn, but also artichokes, and cardoons. They tend to favouri individual plants at the peak of flowering where they can easily move across flowers, and on sunny aspects. Their hairy underside attracts pollen and they are pollinators of the plants they visit, as they move clumsily around an inflorescence and by flying between plants. Their name, however, comes from their penchant for eating petals ('chafing') of some rose cultivars. Populations might benefit from warming weather given the adults activity patterns and the current distribution.

Feeding adult.

The flying Rose Chafer about to land. Note the closed wing-cases.

Mating Rose Chafers. The female kept feeding through it.

Mating Rose Chafers.

More information

Fremlin, M. The Rose Chafer Cetonia aurata L.(Coleoptera: Scarabaeidae: Cetoniinae) in Essex: distribution and some aspects of its ecology. Essex Naturalist (New Series) 35, 167–178 (2018).

Maria Fremlin webpage on Rose Chafers.

Urban Essex Skippers

 I like insects that are a bit of a fieldwork challenge, and Essex Skippers are one of those. The Essex Skipper is a small butterfly with golden wings. As other skippers, they are fast flyers and like to perch on flower heads, well exposed, with plenty of darting chasing each other. They live in grasslands, and their larval foodplant, the common grass, Cock's-foot, whilst the adults like to nectar on thistles, ragwort and knapweeds. Emergence is usually in early July and the last ones are usually seen at the beginning of August, so a short flight period. 

Essex Skippers were one of the last species of butterfly listed in the UK. In 1890 F.W. Hawes published an article describing that he had collected the species in Essex, and that it was likely that it had been previously overlooked. He was right, and specimens were found in several collections that had been labelled as Small Skippers. The reason is that it is superficially very similar to the Small Skipper. The best way to tell them apart in the field is to get down at eye level with the butterfly when perched, and examine the underside of their antennae (if you have good eyesight!) or take a photo. Essex Skippers have ink black undersides of the antennae tip (top shot), while in the Small Skipper the underside of the antennae tips are orange-brown (photo below)

Small Skipper.

The first time I saw this butterfly was at Spurn, in 2018, but in the last few years I have recorded it in several sites in Hull. Last week, I found it in my patch, at Sculcoates, on a meadow in a disused cemetery. As other species I've dealt with in the blog over the years, it is expanding its range northwards, possibly due to a combination of climate warming and habitat changes. It appears to be using motorway and trunk road embankments to disperse and it has been reported that hay transport could be another way this butterfly has colonised new sites, as the tiny eggs travel with the grass.

Essex Skipper, my first one at the patch. Sculcoates, 5th July 2025.

Ivy bees in Hull

 I have spent some time watching mature Ivies lately. It is Ivy peak flowering season, and the couple last days have been warm and sunny, bringing the insects out, the ivies humming with insect activity. Droneflies, Red Admirals, Comma, Wasps, honeybees are attracted to flowering bees. I was actually looking for Green Mesh Weavers, on an Ivy in an untarmaced tenfoot (alleys between houses) when I noticed two stripy bees rummaging around the leaf litter at the bottom of the ivy. I couldn't believe they were Ivy Bees, Colletes hederae! I have previously seen Ivy Bees in east Yorkshire, at North Ferriby and at Flamborough, but I thought we wouldn't get them in Hull due to our clay soils, as this bee needs loose soils for nesting. 

Two bees exploring the soil under the ivy, this is probably loose enough and sunny enough for a nest site?

A winner from climate change

Ivy Bees started colonising the UK from 2001, after expanding in northern Europe, and in the last couple of decades its distribution range has rapidly expanded northwards, with the first Scottish records coming in 2021. The mail pollen source for its larvae is Ivy, and the bee flight period coincides with the flowering season of ivy, from September to early November, with a single brood. They are solitary bees but they tend to nest together, sometimes forming large nesting aggregations in suitable habitat. Females will excavate a nest and line the walls with a cellophane-like substance, which explains another name of the bee, Cellophane Ivy Bee. Ivy pollen is brought to the nest and an egg is laid atop a mound of pollen, before the cell is sealed and another load of pollen is collected for the next egg.

One of the Ivy Bees near the ground after some exploring.

A female laden with pollen having a rest to clean its tongue.

A foraging female showing the banded abdomen. This bee is relatively large, the size of a honey bee, with orange hairs on the thorax, and contrasting broad buff bands in the abdomen, unlike its close relative the Sea Aster bee, which is smaller and has a white banded abdomen. Habitat, timing and foraging flowers can also help distinguish these bees.

The Green Meshweaver gets to Hull

 

Another post on a rapidly expanding species, this time a small spider, the Green Meshweaver, Nigma walckenaeri. All started on Saturday, during the YNU AGM in the University of Hull, where spider expert  Geoff Oxford, showed us a specimen he had just collected from the university grounds, a tiny green spider that is currently expanding its range across the UK and now colonising Yorkshire. We all admired the individual, which had been collected with its web on a leaf. 

The first Nigma walckenaeri record from Hull.

After returning from the meeting, I searched the garden ivy, and since I've been searching ivy and holly, which are favoured leaves to weave it's mesh. Nigma walckenaeri  chooses curled leaves, so it can take advantage of this to hide under its little web. As other regular character in this blog, Amaurobius, Nigma is a cribellate silk weaver. 

Today, I took a local walk and came across a magnificent mature ivy, south east facing. I started searching its leaves, wondering if I had the wrong search image in my mind. It didn't take long to find a Nigma.

Nigma walckenaeri  habitat.

There it was! A light-touch web of blueish threads with the green spider sitting, well camouflaged, underneath.

I moved part of the web aside to have a closer look (also top shot). This is a female, with her whole body green. Once I had seen one, I found another, and another, almost every ivy leaf had it's little Nigma in it. 

A male, with its brown cephalothorax.

This individual was busy weaving its web.

I even spotted a male (with reddish-brown opistosoma) on the edge of a female's web.

Until 1993 it was only found in London and the home counties, and it is associated to parks and gardens. Since then it has been steadily spreading north. I'll keep a look for it in the garden!