Wildlife Review 2024: Wasps, Ants & Sawflies

Wasps 

In line with other insect groups 2024 was a poor year. The lack of solitary wasps on umbellifers was particularly noticeable with fewer social wasp nests adding to a disappointing year. Only 59 species were recorded compared with 71 last year.

The Warren is an important site for solitary wasps which several nationally scarce species that rely on bare areas of sand. Control of encroaching thick grassland ands scrub is important to maintain optimum habitat for these insects. Areas of open bramble are however also beneficial, providing essential nectar and bare sand.

Ichneumonidae (Darwin wasps)

A large family of parasitic wasps, but only a few are identifiable in the field. Found this year were the regularly reported Yellow-tipped Darwin Wasp Ichneumon stramentor from 13th April, White-striped Darwin Wasp I. sarcitorius on 2nd June, Black Slip Wasp Pimpla rufipes from 24th June and Diphyus quadripunctorius on 15th August. A Hedgerow Darwin Wasp Heteropelma amictum was a new species for site on 8th August.

Cynipidae (Gall wasps)

The actual wasps are rarely observed. However their galls are easy to find on host plants from late summer. The female inserts a chemical along with her eggs, this creates a plant mass for larvae to feed.

This year species included Ram's-horn Gall Wasp Andricus aries, Marble Gall Wasp A. kollari, Knopper Gall Wasp A. quercuscalicis, Cola-nut Gall Wasp A. lignicola, Silk-button Gall Wasp Neuroterus numismalis and a pasty gall wasp Pseudoneuroterus saliens on oaks and Sputnik Pea Gall Wasp Diplolepsis nervosa and Bedeguar Gall Wasp D. rosae on roses.

Oak Marble Gall Wasp Andricus kollari - Kevin Rylands

Gasteruptiidae (Gasteruptiids)

Only one of this small, but distinctive, parasitoid family was identified; a javelin wasp Gasteruption jaculator. Frequently found on umbellifers, the first this year was on 23rd July.

Gasteruption jaculator - Alan Keatley

Braconidae (Braconids)

These are tiny parasitic wasps that usually attack insect larvae, with some often used in agriculture as a biological pest control. The family Braconidae is huge in number and are frequently seen on site. However, in-field identification is near impossible and all species on the Warren audit are from historically taken specimens. An Alysiinae wasp found on 22nd October was one of several possible species, all of which would have been new for site. A parasite of fly larvae in carrion, it couldn't be identified by photographs alone.

Alysiinae sp 22nd October - Alan Keatley

Bethylidae (Bethylids)

Just one record, a Large-headed Bethylid Bethylus cephalotes on 1st July. A parasitoid of moth larvae. 

Dryinidae (Dryinids)

Strange looking parasitic wasps. An ant lookalike, the females are small and wingless, it is a larval parasitoid of leafhopper larvae. Rarely observed and probably under-recorded with few national records. Two Gonatopes clavipes were found this year on bare sand on 24th June and 16th July, the first since the only other record in August 1978. Careful searching amongst Marram may reveal more.

Gonatopes clavipes 16th July - Alan Keatley

Chrysididae (Cuckoo wasps)

Colourful parasitic wasps, mostly on crabronid digger wasps. The larvae feeding on the host eggs and larvae. Usually found in the vicinity of host nests. Species noted this year include Linnaeus's Cuckoo Wasp Chrysis ignita on 25th May, Glowing Cuckoo Wasp Hedychridium ardens on 6th June, a new species Narrow-bodied Cuckoo Wasp C. angustula on 25th June, Dull Cuckoo Wasp H. roseum on 18th July and another new species, one rapidly expanding its range, Noble Cuckoo Wasp H. nobile on 7th August.

Dull Cuckoo Wasp Hedychridium roseum 18th July - Alan Keatley

Pompilidae (Spider-hunting wasps)

Quick running ground hunters, many hunt specific spider families, dragging the paralysed prey back to the nest hole. Leaden Spider Wasp Pompilus cinereus, the site's commonest spider wasp was the first species of the year with records from 25th May. It can be found throughout the summer on bare sand. The second species to emerge was Bristle-tailed Anoplius A. infuscatus on 30th May.

The nationally scarce Potter Spider Wasp Auplopus carbonarius, a woodland species was discovered new to the Warren on 6th June, with Spot-headed Spider Wasp Agenioideus cinctellus, a hunter of jumping spiders, another good find on 11th June. Red-legged Spider-wasp Episyron rufipes, a large and common species, was often found on umbellifers from 12th June.

Agenioideus cinctellus 12th June - Alan Keatley

Vespidae (Social, potter and mason wasps)

A poor year. Fewer Common Wasp Vespula vulgaris nests and very few were seen in the early part of the year. Numbers increased in late summer and autumn with emerging males and workers. Some still on the wing in late November. The nationally scarce Median Wasp Dolichovespula media was a good find on 23rd April. A Tree Wasp D. sylvestris nest discovered in the Education Area on 22nd August to late November.

Median Wasp Dolichovespula media 23rd April - Alan Keatley

This year spring flying Mason wasps were non-existent. The first was Three-banded Mason Wasp Ancistrocerus trifasciatus on 19th June, followed by Willow Mason Wasp Symmorphus bifasciatus on 9th July. The nationally scarce Little Mason Wasp Microdynerus exilis was noted on 16th July. Usually seen in the spring, Early Mason Wasp A. nigricornis wasn't recorded until the late date of 1st October.

Ancistrocerus trifasciatus 16th July - Alan Keatley

Sphecidae (Sand wasps)

Easily recognised, the only Sand wasp species found on site is Red-banded Sand Wasp Ammophila sabulicola, it is also the only invertebrate on the SSSI citation. Usually found searching for moth larvae on bare sand, the first was on 25th May with the last record on 23rd September.

Red-banded Sand Wasp Ammophila sabulicola 23rd September - Alan Keatley

Crabronidae (digger wasps)

The largest solitary wasp family with the majority found during the summer months. The first of the year were a Small Shieldbug Stalker Dryudella pinguis and the appropriately named Common Spiny-digger Oxybelus uniglumis both on 2nd June. Usually found nectaring on umbellifers, Intermediate Shield Wasp Crabro peltarius and Large Shield Wasp C. cribrarius were noted from 5th June, along with the tiny Minute Digger Wasp Diodontus minutus, a small colonial nester on bare sand.

Intermediate Shield Wasp Crabro peltarius - Alan Keatley

The first of the Crossocerus wasps was a Wesmael's Digger Wasp C. wesmaeli on 6th June with a Four-spotted Digger Wasp C. quadrimaculatus on 12th June. Two further species,  Trilobed Boxhead Wasp C. podagricus on 24th June and Hairy-backed Boxhead Wasp C. megacephalus on 23rd July.

Crossocerus quadrimaculatus 24th June - Alan Keatley

The nationally scarce Three-spotted Digger Wasp Nysson trimaculatus was noted on 8th June, with the grasshopper hunting Common Tachysphex T. pompiliformis on the search from 11th June. The wood-nesting Horned Black Wasp Passaloecus corniger was recorded from 17th June and White-lipped Digger Wasp Lindenius albilabris from 19th June.

Three-spotted Digger Wasp Nysson trimaculatus 8th June - Alan Keatley

The first Sand-tailed Digger Wasp Cerceris arenaria aka the Weevil-wolf, and a host of Noble Cuckoo Wasp was noted on 27th June with the Honey Bee hunting Bee-wolf Philanthus triangulum flying from 29th June. Mournful Wasp Pemphredon lugubris, another wood nesting species, occurred from 16th July, with the Shieldbug Stalker Astata boops from 18th July. A White-spotted Digger Wasp Harpactus tumidus was noted on 31st July.

Shieldbug Stalker Astata boops 9th September - Alan Keatley

The first Four-banded Hopper Wasp Gorytes quadrifasciatus was noted on 18th July, Two-banded Hopper Wolf Lestiphorus bicinctus from 26th July with the nationally rare Broad-banded Hopper Wasp G. laticinctus a good find on 28th August. Field Digger Wasp Mellinus arvensis aka Fly Wolf were active from August 8th, with the distinctively shaped Slender Wood-Borer Trypoxylon attenuatum on 17th September one of the last additions to the year's wasps. 

 Two-banded Hopper Wolf Lestiphorus bicinctus 29th August - Alan Keatley 

Ants

Apart from the ubiquitous Small Black Ant Lasius niger, the only other ant species identified this year was in fact new for site with a Woodland Red Ant Myrmica ruginodis on 13th March. 

Woodland Red Ant Myrmica ruginodis with Bibio johannis 13th March - Alan Keatley

Sawflies 

Sawfly larvae feed on vegetation and are usually plant host specific and some adults mimic other hymenoptera. Although many species require specimens for identification, a good number can be identified at various life stages. Twenty-four species were identified this year compared with thirty in 2023. Two new species were identified, taking the Warren total to 67. 

Argidae (fuse-horned sawflies).

It was a particularly poor year, with just one species recorded. The Common Bramble Sawfly Arge cyanocrocea was found in good numbers around its host plant from 9th May.

Tenthredinidae (common sawflies)

Mostly colourful species with a good many mimics of other hymenoptera. Spring species included two common Nettle sawflies Aglaostigma aucupariae and A. fulvipes and a pine-feeding sawfly Neodiprion sertifer. 

Aglaostigma fulvipes - Alan Keatley

A rose sawfly Pristiphora biscalis found on 27th April was the first new species of the year. Other spring records included Macrophya alboannulata (Elder), Blennocampa phyllocolpa, the rose-leaf rolling sawfly, Tenthredo livida (willows) and Turnip Sawfly Athalia rosae.

Turnip Sawfly Athalia rosae - Alan Keatley

Into summer most sawflies were to be found on trees as adults, larvae or galls. Noted this year were willow gall sawfly Euura bridgmanii, a Sycamore sawfly Heterarthrus flora, the Alder sawflies Eriocampa ovata, Fenusa dohrnii and Hemichroa crocea.

Eriocampa ovata - Alan Keatley

Species recorded on Birch included Fenusa pumila, Fenusella nana and Hemichroa australis, Profenusa pygmaea on Oak and Pear Slug Sawfly Caliroa cerasi on Hawthorn.

Pear Slug Sawfly Caliroa cerasi - Alan Keatley

Associated with the grasslands were Tenthredo arculata (White Clover) and T. amoena (St.John's wort), a new species found on 24th August, Athalia bicolor (buttercups), A. scutellariae (Skullcap) and Dolerus aericeps (horsetails).

Tenthredo amoena - Kevin Rylands

Athalia bicolor - Alan Keatley