Jesus College Nature Trail

Biodiversity in Jesus College, Cambridge

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Walnut Pouch Gall /Aceria brachytarsus

We (Stewart Rosell and Rhona Watson) found this gall on the Walnut tree (Juglans regia c.1950) by North Court on 27th July 2021.  This seems to be the third recorded UK sighting of this gall.   A. brachytarsus is known from sightings in California and there have been occasional records of sightings from Iran and mainland Europe, but there were none from the UK until July 2021.

Sam Buckton made the first UK recorded sighting in Downing College on 2nd July 2021, and then he found it again in Cambridge University Botanic Gardens during their Bioblitz on 24th July.  He then passed on the details to us and we checked our large Walnut and we found it was there as well. The Downing College galls have been verified by several experts and Sam has looked at pictures of our galls and agreed that they are A. brachytarsus. 

On the 28th July I checked the Black walnut (Juglans nigra) c.1912 and I could not see any galls, although there were no low branches so I was unable to check properly, but the young (c1998) Walnut (Juglans regia) in the Orchard by the Fellows’ Garden also has A. brachytarsus.

Walnut has two other known Aceris galls; A. erinea and A. tristriata, and both were recorded on the North Court tree in 2021.

Aceris brachytarsus is sufficiently different from other Walnut galls for it to be identified easily, as it has a conical projection on the underside of the leaf, whereas A. erinea has large (1cm or more) ‘blisters’ on the leaf, and A. tristriata has a myriad of tiny (up to 2mm) round pustules all over the leaf.  (There is a third UK gall that may be found on Walnut, Microstroma juglandis, but it is visible as yellowish blotches and so it cannot be confused with A. brachytarsus). 

Aceria are gall mites; the mites themselves can only be seen using a high magnification, but their presence can be assumed due to the galls that are present on the leaves of trees.  The mites always produce similar galls and so it can be an easy way of increasing the species list of an area if you can identify the host plant and the gall itself.  

If any of you have Walnuts in your area then it might be worth checking to see what galls you have too.

Interesting fact:  This gall mite is new to the UK and so it is not on irecord (so if you are recording an example, record it under Aceria species and write in the Comments field). To get it added to irecord we have had to contact the Natural History Museum to ask for the gall mite to be added to the official UK Species Inventory – hopefully they will agree and it will be added soon.

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Six Fox Cubs and a Scarce Moth

We thought there were three or four fox cubs, but Jamie Andersen managed to get a photo and video on the evening of 22nd June which showed eight foxes.  It seems we have two adults and six cubs this year.  There have been more and more sightings over the past couple of weeks as the foxes are becoming a little more used to people.  I have been told that a good time to see them is 9.30pm on the rugby field.  The foxes are growing fast and are almost the same size as the adults now.

A ‘Nationally Scarce A’ moth has been found in College; the Horehound Long-horn/Nemophora fasciella.  This moth has metallic bronze and purple wings with long antennae, the males have a black head with white antennae and the females have a yellow head with black antennae.  I have seen several over the past two weeks, although most of them were seen between 21-23rd June.  (A female was seen on 21st June, five males were seen on 22nd June and two males on 23rd June.  I have since seen a male on 29th June and a female on 1st July).  They were seen on the scrub margin of the wood behind the cricket practice nets, either sitting in the sun at about eye height on the elm saplings, or on the tops of the nettles there.  It is a new moth for sight, and a rather beautiful one.  The food plant of the larvae is black horehound, and perhaps White dead nettle, and there is a little bit of both these in that area.  It is a BAP Priority species. The moth is considered Scarce and is usually only found in the SE of England.

This year I have also seen quite a few of the Yellow-barred longhorn moths.  I used to see them regularly dancing in the sunshine, but I haven’t seen them for a few years.  These moths have been spotted all along the woodland trail, in small numbers, but have been spotted regularly over the past few weeks. 

A third unusual moth that has been seen is the tiny Ectoedemia heringella/New Holm-oak pygmy.  This tiny moth (2-3mm) has been identified by its leaf mines that were abundant in the old Holm oak (Quercus ilex) c1780  in the Fellow’s Garden last year.  In fact, on looking carefully, just about every leaf on the old tree had several mines and by the end of the summer most of the leaves had turned brown from the mines, well before they were supposed to go brown in the autumn.  This week we have seen quite a few of the moths themselves.  We ran a moth trap on the night of Monday 28th-Tuesday 29th June and we counted up 100 of the moths in the trap (there was a little discussion as to the exact number).  This moth is impossible to determine the species without gen. det. (a dissection of the genitals).  Luckily Stewart Rosell kindly dissected one for us and confirmed the species.  So, technically we had 99 Ectoedemia species, and one Ectoedemia heringella in the trap that morning, but they were probably all Ectoedemia heringella.  This moth was first discovered in 2002 and it has since spread out from the southeast. The Marsh grass-veneer (Crambus uliginosellus), again with identification from Stewart, was also new to the College.

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From a Cold, Wet Spring to a Warm, Dry Summer

In Cambridge we have had a cold, dry April followed by a very wet May.  As a result insects has been thin on the ground, and plants seem to be flowering later this year.  Moths, for example, have not been coming into traps and there have been several ‘blanks’ in the Botanic Gardens trap that is set out once a week.  We think this could well be a result of the cold nights and the poor weather.  The numbers in the moth trap only began to rise in the week of 7th June when the temperature began to heat up. 

In Jesus College, we have had birds nesting and fledging, but this year, for the first time the nestbox on the side of the Pavilion has been empty (apart from a spider that can occasionally be seen on the nestcam).   

We have had a family of Wrens (Troglodytes troglodytes) that fledged on 14th May, and the Moorhens (Gallinula chloropus) have fledged 6 chicks after one unsuccessful try (3 eggs were on the nest but they disappeared in mid-April…we suspect that a fox was the culprit).  Blackbirds have nested in the bike shed behind Lower Park Street and in the secret passage from the College out to Park Street; there has also been a family of Jays in the Master’s Garden.  Great tits have nested in the plinth outside Library Court V and a Blue tit has nested in the Judas tree in Library Court.   I saw my first Blackcap (Sylvia atricapilla) in College, a male,  on 14th April; two days later I saw a female and on May 3rd I saw a female carrying nesting material.  This year we have had several Starling (Sturnus vulgaris) nests in College.  Last year we seemed to have one lonely Starling calling from the large Ash tree behind the cricket practice nets; this year we have had at least three nests, and probably four.  This morning I counted 11 Starlings on the grass on Chapel Court.   There have been Starlings in New Square before, but this is the first time that I am aware of that they have bred in Jesus College itself. 

The Foxes (Vulpes vulpes) seem to be using their original den near the glade in the woods and I have had several reports of cubs this year, and it looks like we might have four.  Not many photographs yet, but I hope they will become more habituated to cameras as the cubs become older.  A Muntjac deer (Muntiacus reevesi) has been seen occasionally in College, and once overnight in Park Street; the gardeners think it may be living nearby and occasionally visiting the College.  I sighted a large Water vole (Arvocola amphibious) on 2nd June in the ditch; it is good to note that they are still there and have not been scared away by the route of the new mains electric cable that goes under the ditch.

I have also found a few new insects in College this Spring.  Among the most interesting are the ‘Zombie ladybirds’.  I have found several 7-spot ladybirds (Coccinella septempunctata) with little cocoons under their legs.  This cocoon contains the larvae of a small wasp called Dinocampus coccinelae.  It lays its eggs in ladybirds, they hatch, eat part of the ladybird, although you can occasionally see the ladybird moving its legs, but the cocoon is attached to something ,  and then they seem to use the body of the ladybird as a shelter whilst the wasp develops.  After about a week the wasp hatches and the ladybird occasionally survives.  I saw my first one this year and, now that I know about them, I have seen five of them in College.  I have seen them on the top of grasses and umbelllifers – so a good time to find them is on a cold day or morning, when normally the ladybirds would be tucked down in a shelter, and glance at all the ladybirds that are out and about.   As usual, 7-spots were the first ladybirds to emerge this year in College, closely followed by the 14-spot (Propylea quattuodecimpunctata) (of which there were many more than usual).  Harlequins are just beginning to emerge now, at the beginning of June. 

Another notable find is the Elm zigzag sawfly (Aproceros leucopoda).  I found a strange zigzag pattern on an elm leaf where something had been eating it away.  A  close examination showed a tiny caterpillar.  This turned out to be the appropriately named Elm zigzag sawfly.  They also have beautiful silken lattice cocoons.  Two of them were found on an Elm sapling in the glade.  Last year I found some Solomon’s seal larvae eating away at the Solomon’s seal plants outside the roost.  This year, I was able to identify several black Solomon’s seal sawflies (Phymatocera aterrima) flying around.  I didn’t see any eggs, but the caterpillars appeared on 8th June.

This year has also been a good year for Crucifer shieldbugs (Eurydema oleracea).  I have only seen them a handful of times before, but this year they were around in their tens.  All three colours were represented, but the red and white versions were more numerous than the orange type.  There is a good spot for all shieldbugs just outside the NW corner of the hard tennis court.  There have been hundreds of Hairy shieldbugs (Dolycoris baccarum) and quite a few Common green shieldbugs (Palomena prasina)  there this year.  Three new shieldbugs for College have been seen: the Bishop’s mitre sheildbug (Aelia acuminate) , the Tortoise shieldbug (Eurygaster testudinaria) and the tiny Bordered shieldbug (Legnotus limbosus).

Not many butterflies have been seen so far, although I did find a communal web of Small tortoisehell caterpillars (Aglais urticae); unfortunately they were just under the Starling nest behind the cricket practice nets.  They disappeared when they were quite small.  A week later there was another communal web of Peacock caterpillars (Aglais io) in the same place.  These caterpillars survived and many cocoons were formed between folded up nettle leaves – I am still waiting for butterflies to emerge. 

The cricket field has been dug up this spring, in preparation for a ground source heat pump installation which will be used to provide all the fossil-free heating and cooling for the new kitchen.  Holes have been excavated by archaeologists, (their findings are awaited), and examined in detail by the foxes I heard,  and there will eventually be 49 bore holes in this area.  Once completed, the outfield will be reseeded and it should be ready to play for the 2022 season. North Court Meadow is flowering well with the majority of the flowers being Austrian chamomile.  The blue Cornflowers and red Poppies followed suit.  The second week of June has seen pink Corncockle and yellow Marigold begin to appear.  Our meadow is similar to the one in King’s College (where we got out seed from), but it is a little sparser.  Our flowers seemed to flower a few days ahead of the one in King’s.  Hopefully we shall get a few more perennial seeds in the mix next year so that the meadow can really begin to develop.  The flowers have been a magnet for Bumblebees (mainly Buff-tails (Bombus terrestris)  with some Vestal cuckoo bees and one or two Red-tails (Bombus lapidarius).  There is a small colony of Buff-tailed bumblebees that are nesting next to the wall at the back of the graduate allotment.  There have also been a few Honeybees (Apis mellifera) (the colony in the tree round the trail seems to be quite large) and one or two other insects like 7-spot ladybirds, Thick-thighed beetles (Odedmera nobilis) and I even found a Varied carpet beetle (Anthrenus verbasci).

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Gardens and Grounds

Wisteria, First Court

As the first lockdown began, we decided to split the gardening team into two separate shifts. our aim was to maintain our high standard of work by putting in extra effort with less time available. This has resulted not only in our usual upkeep of the grounds but also in a planting project throughout the woodland walk.

In phase one we planted around 300 trees and shrubs there. We plan, in phase two, to plant more trees in the winter of 2021. This came about after a request from students keen to raise funds and help with planting. Thee additional trees and plants will improve the walk in general and also be beneficial in terms of biodiversity.

Another improvement, this time in environmental sustainability, was the introduction of five new bespoke compost bays. We will produce a large amount of our own compost from College and garden waste, as well as from spent hops from the brewery and coffee grounds from the Roost Café. Coffee grounds in particular are an excellent contributor to top-quality compost and will greatly benefit the various gardens in Jesus.

With spring arriving, the wisteria in First Court (arguably the most photographed part of the College) is starting to bud and by early May it will be in its full glory. The Chapel Court wisteria is also coming along nicely and continues the theme throughout the grounds towards Library Court.

The lawns have fared less well, with extensive damage from cockchafer grubs, but we’re working hard to remedy this in the coming months. poor weather early in the year has made them easier to maintain and the longer we can keep activity off the grass the better.

We are very pleased with our new wildflower area outside north Court (seeded from King’s College wildflower meadow), sown back in October 2020. it has germinated quickly and will provide a fantastic display this summer. plans are now in place this autumn to sow a good proportion of Library Court with the same seeds, which become a vital food source for bees and pollinators, and provide a year-round habitat for local wildlife.

Paul Stearn, Head Gardener

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Early 2021

We launched an iRecord ‘activity’ on 12th February in College. People are encouraged to add any wildlife sightings to iRecord under hte Jesus college Cambridge Wildlife Recording Scheme.

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Autumn Beetles

I found my fifth Bronze leaf beetle (Chrysolina banksia) in the woods on Monday 9th November.  These beetles are new to me this year, but it seems as if we now have a small colony in College.  I have found four of them on, or by, the large Green alkanet (Pentaglottis sempervirens) patch just to the west of the Cricket Pavilion, in a 10 foot patch by the path.  The other beetle was seen about 20 metres away to the east, still on the north side of the trail.

These are large beetles, with a body length of  8-12mm. They have a bronze, metallic sheen to their bodies and they have orange legs.  The first was seen on the 25th September and the last on the 9th November. 

This is a local species in the UK, usually in coastal areas of the south, and its favourite plants seem to be Ribwort plantain and Black horehound.  They have not been recorded much around Cambridge; they were spotted once in Cottenham, in 2019, but there have been no sightings more recent than that according to the NBN atlas.

They can be seen all the year round, although they tend to take shelter near the host plants in poor weather.  The ones that I saw could have been new generation adults: they appear in May/June and feed for a few weeks before aestivating during the summer.  They reappear in September and lay their eggs soon after.  The eggs are laid in small batches on the undersides of the host leaves – I have searched the Green alkanet and Black horehound nearby but have not found any eggs. 

I have been able to get a three new small wasps identified; unusually two of them had tricoloured legs, so identification was possible. There are thousands of small wasps in the UK and so identification can be difficult.  They were Rhopalum coarctatum (a small stem-nesting solitary wasp) and Schizopyga frigida (a parasitoid of, usually immature, spiders).  Other notable insects this season have been the ladybirds.  The first 16-spot ladybird (Tytthapis sedecimpunctata) was seen on the tarpaulin over the cricket practice nets on 6th October. I also found a Kidney-spot ladybird (Chilocorus renipustulatus), which is not uncommon in Jesus College, but this one had a moss-like fungus growing out of the beetle’s wing-case.  The fungus turned out to be a Hesperomyces species; a fungus that is usually only found on Harlequin ladybirds.  This is a sexually transmitted disease that does not kill the host.

This year has been a good year for fungi in College (or more exactly, as a fungi expert said to me, it has been a normal year after quite a few bad years).  I have seen much the same sort of fungi as in other years, luckily they often appear in the same place and so I am slowly learning a few more names each year.  The Shaggy parasols (Chlorophyllum rhacodes) by the Leylandii tree in the Orchard have been especially spectacular this year.  New fungi this year have been the tiny Small staghorn (Caolocera cornea); the Sheathed woodtuft (Kuehneromyces mutabilis) ; the popcorn looking Crepidotus (probably C. variabilis or C. cesatii); and the mushroom known as the Prince (Agaricus augustus).  I also think we have the Crystal brain fungus (Exidia nucleate) on some of the wood piles.

The Badger (Meles meles) has not been spotted again in College, but we have found another latrine – this time on top of the (squashed down) soil mound that covered the fox den by the cricket practice nets.  There have also been quite a few ‘snuffle holes’ around the trail, especially in the northeast corner of the trail.  A badger has also widened an old fox hole near the Glade.  There are two entrances that are used regularly.  Both foxes and badgers will move around and don’t always use the same sleeping place at night.  They may just bed down in a handy place.  We think we have a small Badger that visits occasionally rather than a full-time sett in the College as we are finding new snuffle holes every week.  Our dog Fox (Vulpes vulpes) has been seen occasionally around College, but usually in the early mornings (between 6-8am) and at night.  We don’t think that we have any foxes living on site any more. Izaak van Dongen  did send in a wonderful video for our facebook site of a Fox at dusk chasing a Heron from the field behind North Court one evening.  The male Fox was seen on the old hockey pitch on the night of 15/16th December by Ian Gilchrist, one of our porters, and it was calling loudly.

We have a  Grey squirrel that has a partly red coat.  Their fur can be variable in colour but this one is more obviously red compared to our other squirrels.  It may be making a nest in the new owl box in the NE corner of the trail.


The large mixed flocks of tits have been flying around the woods and gardens; they usually consist of mainly blue tits, but I have also seen Great tits, Coal tits and Long-tailed tits; although the Long-tails have often been seen in a flock on their own.  In December the tits seem to be pairing up and the Robins are beginning to sing to claim their territory.  A female Green woodpecker (Picus viridis) has been seen quite often in Library Court, either on the lawn early in the mornings searching for ants, or up in the Sycamore outside the library.

Kestrel, female

We have had a female Kestrel (Falco tinnunculus) living in College this autumn.  She has been regularly seen, either in the woods or sitting on the edge of the cricket practice nets.  She can be hard to spot when she is in the trees, as she seems to fly away when anyone approaches, but occasionally she lets people get closer.  Hopefully she will stay around over the winter and nest next year; this may happen if she manages to find enough food (consisting of small mammals).   We occasionally saw a dark buzzard for a few weeks in the woods but it has not been seen since October.  

We seem to be getting a larger and larger flock of Black-headed gulls (Chroicocephalus ridibundus) appearing on the sports field each year, usually on the football field.  I don’t check the numbers regularly, but I did see 54 of them on 7th October, and there was also one Common gull (Larus canus) amongst the flock.  A common pheasant (Phasianus colchicus)  (either a female or immature) was seen around College in early December.  The short tail on the bird seems to suggest that it was an immature bird.

I have found a few more plant galls this autumn; Dasineura urtica on Nettle, and Dasineura fraxini on Ash. Aceria cephalonea on Sycamore, the Oak marble gall Andricus kollari, on Oak and Aceria ilicus on Holm oak; (Aceria ilicus type 2).  Experts say that there seem to be two types of gall called Aceria ilicus, the pimple type on the upper side of the leaf that was mentioned in the last blog, and the felt gall that I subsequently found on a different Holm oak in the woods.

Unfortunately the old Bird Cherry in Garden Court fell down on 24th October.  The dead tree had been carved into a sculpture by a local artist, Richard Bray, in June 2015 and it was called the Bird Cherry Spire.  Richard did comment at the time that the tree stump was in a worse condition than anyone has expected and there were quite a few beetle larvae (Cockchafers) found in the trunk when it was being sawn into shape.  The Spire had been leaning for a while and  it eventually fell over this autumn.  We have had lots of fungi growing on and around the stump, particularly Common inkcaps (Coprinopsis atramentaria) and Turkey tails (Trametes versicolor) at the base for the past couple of years and the Slime mould Enteridium lycoperdon on the trunk in 2018.  When the soil under the tree was investigated we found lots of Lesser stag beetle larvae (Dorcus parallelipipedus) – they are known to live in decaying wood. NB The larvae can be difficult to differentiate between Lesser stag and Stag beetles but I have never seen a Stag beetle on site, and I have seen two adult Lesser stag beetles next to the sculpture this year, so I think that they were probably Lesser stag beetles.   Although I am sad to lose the sculpture, the gardeners have planted a new Bird cherry sapling (Prunus padus) in the same place and it will be good to get a beautiful tree in the path.  I have fond memories of arriving in College and walking under a canopy of spring blossom from the old Bird cherry tree.

Our gardeners were lucky enough to receive bales of hay cut from the flower meadow in King’s College this autumn.  After drying out the bales, the flower seed was collected and a lawn in North Court was sown on October 26th.  Although this project was planned mainly so as to improve biodiversity in College, the chosen lawn had not been in a good condition and it is also one that had a lot of Chafer grubs under the grass, so that the flowers will help prevent this area from looking unsightly due to the Crows digging up the lawn for beetle larvae.   

It is wonderful that Jesus has its first wild flower meadow (although the area round the wildlife pond is also sown with native flowers) and it is exciting to start a project that has been in the planning stage for a few years.  The donation from King’s College has meant that we could plant the meadow this year rather than having to follow our original plan of sowing next year.  This first year seed mix will be mainly annuals, as the hay was a cut from the first year on King’s meadow, and so hopefully the gardeners will also be able to add some perennials to our lawn mix next year.  Lawns are mainly monocultures, so having a mix of native wild flowers will help with biodiversity in our College (see the report from King’s College  

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July, August and September

The female Speckled wood butterfly is playing dead, the male is moving around her, trying to lift her upright and fanning his wings. This is probably to waft phoromones over the female. Evnetually I got too close trying to video and they both flew away.

My last blog was written in July.  The College has changed from mid-summer into autumn since then.

There have been several new sightings of species in College, but there have been no confirmed sightings of the fox cubs since they left College in the spring.  We have occasionally seen the dog fox but, despite a new fox hole in the woods near the glade, he has not been seen regularly since the spring.  Foxes do tend to move around quite a bit, so hopefully we will see them both back in College again soon.

Badger latrine, by trail close to Lower Park Street gates.

The main sighting this summer has been a Badger (Meles meles).  It has been seen twice; once at 2.58am on 23rd July by our porter, Ian Gilchrist, and there was another sighting of the badger on 29th July with Jake Moscrop.  The badger was seen (thank goodness for CCTV!) leaving the College by going under the Lower Park Street gates and it was seen for the second time in the same area.  The nearest badger setts are in St John’s and Churchill and so perhaps it was a young male foraging.  They do travel  far to forage, 2k is a good distance for this.  There have been no sightings since then, but there have been lots of snuffle holes around that side of College and on 11th September I found a badger latrine – a hole where a badger had recently defecated.  They tend to do this on the edges of their territory, so I think we can say that Jesus College now has a badger on site.  Foxes and badgers can coexist, even though badgers are more dominant.

My favourite sighting this summer was of a butterfly, the White-letter hairstreak (Satyrium w-album).  It was sitting on the grass between North Court and Maintenance, and when it eventually flew off (I got too close with my camera) it flew towards the Buckthorn trees outside North Court.  I didn’t get very good views, but they were good enough to identify the large white ‘W’ on the outside of the hindwing.  I have never actually seen this species before and so it was a lifetime tick for me as well as being new for the College.  Other Lepidoptera sightings have been more reports of the Box-tree moth (Cydalima perspectalis).  I haven’t had the moth trap out since lockdown, but I have seen this moth several times on the roof of the Library Cloisters.  All three colour shades have been seen, the white, striped and dark forms of this moth.  I have looked at the box in College but have not seen signs of any caterpillars (yet).

One new beetle for the site was the tiny beetle seen on the Dogwood in Library Court.  This turned out to be the Bruchidius siliquastri; a recent (2014) introduction of the species to Britain.  There were about 30 of them seen on the one Dogwood plant, about 40 feet from a Judas tree on the other side of the court.  This beetle lives in the pods of Judas trees.  I also found several  Viburnam beetles (Pyrrhalta viburni) on the Birthwort plants in the Fellows’ Garden.  I wonder if this beetle is responsible for the small holes that have appeared in the Birthwort (Aristolochia clematitis) leaves this year.

The Willow emerald damselflies (Chalcolestes viridis) have been seen around the pond and Jesus Ditch and I have seen several pairs mating on the vegetation overhanging the pond.

The young Tawny owls (Strix aluco) have been seen a few times this summer, and I have also seen what is probably an adult on a couple of occasions (the young begin to look very like the adults towards the autumn and so it can become difficult to tell them apart).   Other bird news is that our Stock doves (Columba oenas) fledged at least two chicks this year.  We don’t know if the Sparrowhawks (Accipiter nisus) have nested in the College grounds this year, but we have seen them flying over College several times and we have also seen several signs of them feeding here too.

The corvids are digging up our lawns again for chafer grubs.  The Crows (Corvus corone) were seen digging up the lawns in Chapel Court on September 4th, and the Jackdaws (Corvus monedula) were seen digging in Second Court on 14th September.

I have started searching for Oak galls this year; it is apparently a good year for them.  Plant galls are ‘abnormal growths induced by the presence of another organism living in or on the host plant and causing its cells to enlarge and/or multiply to provide both food and shelter for the gall-causer’ (Britain’s Plant Galls; a photographic guide by Michael Chinery, 2011).  The presence of these galls on our oaks indicates the presence of specific gall-causing invertebrates and so we can add a few more species to our species list.  The most common gall seen on most of our oaks is the Knopper gall and this is induced by the gall wasp Andricus quercucalicis.  The Common Spangle gall is caused by the gall wasp Neuroterus quercusbaccarum; the Ram’s-horn gall is caused by the gall wasp Andricus aries and Cola nuts by Andricus lignicolus.   Our Walnut tree by North Court is infected by the gall mites Aceria erinea and Aceria tristriati.  There are Cecidophyopsis psilaspis and Taxomyia taxi on several of our Yews.  I have made a new Page for Plant Galls under the species lists and hope to add to this list in spring.

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The Golden Hoverfly (Callicera spinolae)

Golden hoverfly

I was lucky last week when I caught sight of a rare hoverfly in College.  I took some photos, did a little research and it turned out to be the Golden hoverfly, nationally ‘Rare’, JNCC ‘vulnerable’  and a UKPAB species. It is also rare in Western Europe, with East Anglia being its European stronghold.   The Hoverfly Recording Scheme only receives records of about two sightings per year of this species; one recent set of sightings, I am told , is usually from along the edge of The Lodge in Sandy, although I believe they spend a long time searching for that record every year.  The NBN Atlas  has 54 records in total, going back as far as 1924.  The Buglife website says that it has only been seen in four locations in the past 10 years.  This hover is known from East Anglia, but the only other record from this hectad was in 1991 from Wandlebury. 

The Golden hoverfly is a large yellow fly, with long antennae, and it is one of the three Longhorn hoverfly species in the UK. If you get a good view you should be able to see the distinctive white ends to the antennae.  Parts of the abdomen can look brassy or a metallic green and there are large yellow stripes across the abdomen.  It is usually seen in September or October in old woodland, as the larvae breed in wet rot holes in deciduous tree trunks.  They take two years to reach the pupa stage and then they emerge; adults are most commonly seen feeding on pollen and nectar from ivy flowers.

I was walking round the woods one lunchtime and I decided to look at the fallen ivy tree by the Glade.  The tree has been an old trunk covered in ivy for a long while, but it eventually fell down in Storm Ciara in February this year.  I checked and the tree was originally an English oak (Quercus robur), but I am not sure when it lost its branches and became a pillar of ivy in the middle of the woods.  Luckily our gardeners left it in situ and it has continued to be a wonderful wildlife habitat this year.  I often see Blackbirds and Wrens amongst the ivy; and there is a new fox hole that was dug during the shutdown (sometime between March and September this year) under the tip of the tree. I think I even saw a Bank vole last week disappearing underneath the ivy too.  Now that the ivy has come into flower the plant is covered in all types of flies, bees and wasps.

I was on the hunt for the Ivy bee (Colletes hederae) in College.  I had had my first sighting in College the previous day amongst a garden border and I decided to check on flowering ivy to see if I could get a better photo.  I spent quite a long time with my camera trying to take pictures of this smart looking little mining bee and I became aware of a large hoverfly flying around too.  Never staying long enough for me to get a good look at it, it was a burst of yellow, flitting rapidly from ivy flower to flower.  My first thought was that it looked like the hornet mimic hoverfly, Volucella inannis, but that this identification was not quite right.  It was a very large hover, larger than the honey bees and Common wasps which were flying around, but I was not aware of anything that it could be that was so large, apart from the volucella hoverflies.  I managed to get a few quick record shots of the hover, but I was aware that I didn’t get a perfect photograph.  It spent quite a while on the other side of the fallen tree from me , whichever side of the tree I was standing on.  Eventually I had to move on and get back to work after my lunch hour.

I put some pictures on the wonderful UK Hoverflies facebook group entitled ‘Am I a hoverfly?’ and I quickly got quite a few answers!   The moderators of this website add the records to the national Hoverfly Recording Scheme and so ‘our’ hoverfly, female, will become part of the national and international record.

It was a lucky sighting, and the College gardeners’ policy of leaving dead wood (wherever safe to do so) has has a wonderful result.  I am not sure if the hoverfly was bred in our wood, but it is possible that it was.

I have been back to look for this hoverfly, but I have not seen it again.  It was probably a once-in-a-lifetime sighting.

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How do you move a bee colony?


Tim with the new bee colony

Noticed some strange boxes on the scaffolding in Second Court? You might be surprised to learn it’s the removals van for a colony of bees! Architect and apiarist Tim Wylie told us how it’s done.

A bee colony took up residence in Second Court in 2018 but putting up scaffolding to repair the stonework on the tower meant that the colony needed to be moved to a new location.

The colony had been using an overflow pipe to get into the building to their nest in the roof cavity. By coincidence, College librarian Rhona Watson was told about the swarm arriving. She wrote in the Wildlife blog: ‘A bee swarm came towards College on the weekend of the 19/20th May and headed across the playing fields towards Second Court.  The queen and her bees found a hole in the walls of M Staircase facing into the court.  You can still see some honey bees flying in and out of the hole if you look up towards the top of the building.

Having provided a home for the colony for two years, we wanted to make sure that our Jesuan bees were transferred safely to a new home. Just like moving your own home, moving a bee colony is costly and time-consuming! A colony will not move once it has set up its home; if the nest is destroyed the bees will not find a new home. Instead, we called in Tim Wylie, an architect and apiarist.

Mesh tube insterted into entrance of colony.

Tim placed a second colony of bees in a small hive next to the hole in the brickwork (the entrance to the old nest). A mesh tube was inserted into the hole so that bees can exit the old hive. The clever part is that when the bees returned, they were looking for a hole in the wall and didn’t know to go through the mesh tube to get in. They therefore joined the new hive. Hopefully the bees from the two colonies wouldn’t fight because Tim had chosen a new colony with lots of young bees but few forager bees.

The old queen was still in the old nest, laying lots of eggs. As she had lost her forager bees, the remaining colony were using up the stored nectar/honey to feed the new grubs. When a tipping point was reached, the old queen and what was left of the workers left the nest. 

A smoker (middle of the picture) with the new colony (wooden box with blue binding), and the mesh tube (top left of photo, to the right of the down pipe).

After the old queen had left, the new colony were left in place for a few weeks so that they could be checked for the disease ‘European foulbrood’, a known problem in Cambridge. If all goes well, the combined colony will be taken in stages to its new home in St Neots.

This technique is called ‘trapping out’. It doesn’t always work, but it is currently going well, with the new colony swelling in numbers.

The Jesuan bees are Honey bees, Apis mellifera. Honey bees come in a variety of shades: the new hive is a dark native brood, the old colony is a ‘reasonably’ dark bee. Honey bees have to contend with many diseases, intensive farming practices, and garden and agricultural chemicals. Bee numbers are declining, as are most pollinators and other insects. We are proud that we have been able to look after our bee colony by making sure it has a safe new home. (The last six photographs are by Tim Wylie).


Shorter version originally published at: Jesus College Cambridge; News and Articles.

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Spring into Summer

We started lockdown in the spring and it is now full summer in Jesus.  I have really missed walking around the grounds every day and seeing the small changes that make up spring and then summer arriving.  I have been allowed to come into College occasionally and I walked round the grounds with my camera.  It has been interesting seeing the different canvases of the seasons; the swathes of few-flowered garlic were covering the woodlands when I left, then the next time I came in the daffodils that were just bursting into flower were showing yellow under the trees.  Then the tree canopy closed over and the Cow parsley ruled but, the next time I came in, Nettles had replaced the cow parsley.  Once, when I walked round the nature trail, every bird box had tweeting coming from it and I saw lots of tit species flying to and from the boxes. Now the tree canopy is dark and it is overshading the almost bare ground.  Most of the juvenile birds have stopped calling and the swifts are sweeping over the grounds, screaming loudly.

I have been lucky to spot wildlife this spring, and even luckier that people who have been locked in College have been sending me their sightings too.  

Fox and cub in Jesus Lane, sent in by William Fleming

I was sorry to miss the sight of our Fox cubs (Vulpes vulpes).   Four people sent me photos and information when they saw the vixen carrying at least four cubs, one by one, away from the den behind the cricket practice nets, into Second Court and Chapel Court, through the Master’s Garden and out under the gate and along Manor Street on 15th April.  We then heard that they had moved into Christ’s College  and there were five cubs.  (Thanks to Steve, Grahame, James and Will for the information). We haven’t seen them since in Jesus but we do see the dog fox quite often in the grounds.

Blue tits (Cyanistes caeruleus) nested in the College nest box again.  There were about 7-9 eggs, and 6 of them hatched, starting on 7th May.  Unfortunately a couple of them died, then a week later three more died.  One chick was left and fledged successfully on the afternoon of 29th May.

I was walking along the trail at 9.15 one morning (22nd June) and I don’t know what made me look up, (I usually look for movement when I am looking for wildlife, but on this occasion I did look up and there was a juvenile Tawny owl (Strix aluco) looking back at me.  It stayed still as I took lots of photographs.  It was out on a branch and only its eyes moved as I walked around the tree to try for a better shot.  As  I walked away, I saw a second bird hiding in the crook of the tree.  I later heard that someone else had seen four owlets and two parents in the same tree.  A student went the next day and also got some photos of an owlet on the same branch.  The tree was the Horse chestnut at the northeast corner of the trail, where the two paths meet, straight across the trail from the wooden bench.

Other notable spots have been a pair of Water voles (Arvicola amphibius) mating in Jesus Ditch (19th May); our Moorhens (Gallinula chloropus) nesting again in the Flag iris in the pond, with, I think, one egg fledging (thanks Ben and Lena) ; an Emperor dragonfly (Anax imperator) ovipositing in the pond on 24th June and some ‘new for site’ spots:

Astata boops ( a species of solitary wasp whose prey is shieldbug nymphs); Aritranis director, an ichneumon wasp; 2spot ladybird (Adalia bipunctata); Box tree moth (Cydalima perspectalis), an invasive species of moth that is devastating  Box plants across southern England;  Solomon’s seal sawfly larvae (Phymatocera aterrima); and Lesser stag beetle (Dorcus parallelipipedus).