The 11 families of the superfamily Curculionoidea mostly look like weevils, with a rostrum (or snout). The bark-beetles (Curculionidae: Scolytinae) and the pinhole-borers (Platypodidae) look quite different but their cylindrical body-form is adapted to tunnelling in wood; I have given them a webpage of their own here.
With about 628 British and Irish species, Curculionoidea is one of the biggest groups of beetles. For a good few years, I had pretty much ‘no idea’ about the Curculionoidea but Mike Morris is the man who’s changed that. To identify British and Irish weevils, you need to get hold of the five RES Handbooks that Mike has produced.
Morris, M.G. (1990). Orthocerous weevils. Coleoptera: Curculionoidea (Nemonychidae, Anthribidae, Urodontidae, Attelabidae and Apionidae). Handbooks for the identification of British insects, vol. 5, part 16. London: Royal Entomological Society. Nearly out of print – only damaged stock available.
- my copy is extensively annotated, especially the Apionidae keys, which form the major part of the handbook.
- Four species have been added to the British list since the keys were published:
- Helianthemapion aciculare (on Common Rock-rose) (Fowles and Morris, 1994)
- Ixapion variegatum (on Mistletoe) (Foster et al., 2001)
- Rhopalapion longirostre (on Hollyhocks) (Jones, 2006)
- Pseudoperapion brevirostre (on Perforate St-John’s-wort) (Hodge, 2011).
- See also: Morris, M.G. (1993). ‘British orthocerous weevils’: corrections and new information (Coleoptera, Curculionoidea). Entomologist’s monthly magazine, 129, 23 – 29.
Morris, M.G. (1997). Broad-nosed weevils. Coleoptera: Curculionidae (Entiminae). Handbooks for the identification of British insects, vol. 5, part 17a. London: Royal Entomological Society. Available to purchase here.
- There is a mistake in the Key to Tribes (p. 9): Barynotus (Brachyderini) has been omitted from the key and cannot be keyed out.
- I have found Sitona particularly difficult to identify using this handbook, which is a shame as they are one of the most frequently encountered genera of broad-nosed weevils. Kevan (1959) is a very useful additional key to Sitona.
- The following species have been added to the British list since the keys were published:
- Pachyrhinus lethierrhyi (on Chamaecyparis, Cupressus, Thuja, Juniperus, etc.) (Plant et al., 2006)
- Pachyrhinus mustela (on Pinus nigra) (Denton, 2005)
- Brachyderes incanus (on Pinus nigra) (Denton, 2005)
- Brachyderes lusitanicus (exhibited by Max Barclay at the BENHS Annual Exhibition in 2006)
- Otiorhynchus armadillo (Barclay, 2003)
- Otiorhynchus salicicola (Barclay, 2003)
- Otiorhynchus cribricollis (Harrison, 2008)
- Otiorhynchus uncinatus (Heal, 2013)
- Charagmus gressorius (Cunningham, 2012)
- There has been an important update to the Trachyphloeini (affecting genera Trachyphloeus and Cathormiocerus) (Morris, 2011).
Morris, M.G. (2002). True weevils (part I). Coleoptera: Curculionidae (subfamilies Raymondionyminae to Smicronychinae). Handbooks for the identification of British insects, vol. 5, part 17b. London: Royal Entomological Society. Available to purchase here.
- Hyperinae were accidentally omitted from the key to subfamilies. See Morris (2003) for a corrected key.
- Cotaster uncipes was added by Hammond (2008) from woodland leaf litter
- Allopentarthrum elumbe was added to the British list by Turner (2011) as Pentarthrum elumbe from the Humid Tropics Biome of the Eden Project.
- Conarthrus praeustus was added by Allen and Turner (2012) from the Eden Project.
Morris, M.G. (2008). True weevils (part II) (Coleoptera: Curculionidae, Ceutorhynchinae). Handbooks for the identification of British insects, vol. 5, part 17c. St Albans: Royal Entomological Society. Available to purchase here.
- Page 56, the conservation status of Glocianus moelleri is RDBK (revised from RDB3), not RDB3 as stated.
- Page 81, key to genera of Phytobiini, couplet 1. Rhinoncus are not always “without a tooth on each side of the middle” of the pronotum.
Morris, M.G. (2012). True weevils (part III) (Coleoptera: Curculioninae, Baridinae, Orobitidinae) . Handbooks for the identification of British insects. St Albans: Royal Entomological Society. Available to purchase here.
- Morris (2013) gives “errors, corrections and amplifications” to accompany True Weevils III and is essential reading, especially for anyone attempting to use the key to groups of all Curculionoidea. Here’s a brief summary:
- Page 2, couplet 4 has failed to take into account two species (Stenopelmus rufinasus and Rhinocyllus conicus) with atypically short and broad rostra that belong to the Phanerognatha but will key out erroneously as Entiminae.
- Page 6, couplet 26 relies on deciding whether the fore-tibia is with or without a mucro. But Morris (2013) warns that the difficulties of distinguishing between a mucro and an uncus make this an unsatisfactory couplet. Actually, the situation is worse than that and trying to progress beyond couplet 26 may be a waste of time for many specimens. Firstly as Andrew Duff has pointed out, the two branches of couplet 26 merge again at couplet 30, and while this isn’t necessarily erroneous, I can’t see any other sensible explanation. I don’t trust the key past couplet 26 and it may actually be impossible to key out any of the species between couplets 35 and the end (couplet 40) without contradicting your choices at couplet 27 (metathoracic epimera visible from above) and couplet 34 (metathoracic epimera not visible from above), as pointed out by Simon Horsnall.
- See Morris (2013) for other errors of figure numbering, etc.
- Not mentioned in Morris (2013): p. 39, couplet 5, the fore femur of Anthonomus rufus is shown in fig. 76 not fig. 75. But then based on the illustrations, any difference in the size of teeth on fore femora between rufus, pedicularius and conspersus is tiny – there must be some mistake. The figures on p. 37 show fore-legs of: 75 bituberculatus; 76 rufus; 77 pedicularius; 78 conspersus; 79 piri.
- One additional species has already been discovered: Bradybatus fallax. Roger Booth found one resting on his car roof in Merton Park, Surrey on 13 August 2011. It is associated with Sycamore and other Acer species. I found one by beating trees, including sycamore, in Middlesex on 9 May 2013. It can be identified using Die Rüsselkäfer Baden-Württembergs (see below).
I really appreciate all the effort that Mike has put in to these Handbooks and he deserves nothing but praise. But I will give the advice that I wish I’d been given when I first started trying to use the keys:
- Have a dictionary handy and be prepared to expand your vocabulary. The keys use some precise technical terms which I had not previously encountered, e.g. “gibbous”.
- Beware of the numbering. The keys do not consistently follow the standard nested cascade structure but are often tangled.
- In most beetle keys, the best character will be given first, and other characters will be given in descending order of usefulness until enough characters have been given to ensure an accurate decision. However, most of the weevil couplets contain several characters: you don’t necessarily need to evaluate all of them, and the best characters are not always the first.
It is in the nature of weevils that many of the identification characters are comparative. Even though Mike’s gone to a great deal of effort in his keys to give measurements and plenty of illustrations, it’s still a lot easier to identify weevils when you’ve got a reasonably comprehensive reference collection to work with. So if you are just starting out on weevils, I would say that the following book is essential if only for the photographs – leafing through the 82 plates is like looking through a museum collection. Currently available from amazon for £41.57 – good value for a 944-page hardback book with loads of colour photos.
Rheinheimer, J. and Hassler, M. (2010). Die Rüsselkäfer Baden-Württembergs. Heidelberg: verlag regionalkultur. [In German]
Of course, the other important thing to say about weevils is that they feed on plants or plant materials (wood, seeds). To really get to know the weevils, you’ve got to get at least a basic grasp of botanical identification. But weevils are well worth the effort – a really rewarding group if not slightly addictive. Fear no weevil!
Allen, A.J. and Turner, C.R. (2012). Conarthrus praeustus (Boheman in Schönherr, 1838) (Curculionidae: Cossoninae) in Britain. The Coleopterist, 21, 21 – 23.
Barclay, M.V.L. (2003). Otiorhynchus (s. str.) armadillo (Rossi, 1792) and Otiorhynchus (s. str.) salicicola Heyden, 1908 (Curculionidae: Entiminae: Otiorhynchini) – two European vine weevils established in Britain. The Coleopterist, 12, 41 – 56.
Cunningham, A. (2012). Charagmus gressorius (Fabricius, 1792) (Curculionidae) in Devon – new to Britain. The Coleopterist, 21, 77 – 78.
Denton, J. (2005). Brachyderes incanus (Linnaeus) and Pachyrhinus mustela (Herbst) (Curculionidae) in Surrey – new to Britain. The Coleopterist, 14, 1 – 5.
Fowles, A.P. and Morris, M.G. (1994). Apion (Helianthemapion) aciculare Germar (Col., Apionidae), a weevil new to Britain. Entomologist’s monthly magazine, 130, 177 – 181.
Foster, A.P., Morris, M.G. and Whitehead, P.F. (2001). Ixapion variegatum (Wencker, 1864) (Col., Apionidae) new to the British Isles, with observations on its European and conservation status. Entomologist’s monthly magazine, 137, 95 – 105.
Hammond, P.M. (2008). Cotaster uncipes (Boheman, 1838) (Curculionidae) apparently established in Britain. The Coleopterist, 17, 43 – 46.
Harrison, T. (2008). Otiorhynchus cribricollis Gyllenhal (Curculionidae) new to Britain. The Coleopterist, 17, 141 – 143.
Heal, N.F. (2013). Otiorhynchus uncinatus Germar (Curculionidae) new to Britain, from Kent. The Coleopterist, 22, 67.
Hodge, P.J. (2011). Pseudoperapion brevirostre (Herbst, 1797) (Apionidae) new to the British Isles. The Coleopterist, 20, 111 – 115.
Jones, R.A. (2006). Rhopalapion longirostre (Olivier, 1807) (Apionidae) finally discovered in Britain. The Coleopterist, 15, 93 – 97.
Kevan, D.K. (1959). The British species of the genus Sitona Gemar (Col., Curculionidae). Entomologist’s monthly magazine, 95, 251 – 261.
Morris, M.G. (2003). The identification of Hyperinae (Curculionidae). The Coleopterist, 12, 85 – 87.
Morris, M.G. (2011). Taxonomic and nomenclatural changes in the British Trachyphloeini (Curculionidae, Entiminae). The Coleopterist, 20, 77 – 81.
Morris, M.G. (2013). ‘True Weevils (Part III)’: errors, corrections and amplifications. The Coleopterist, 22, 65 – 66.
Plant, C.W., Morris, M.G. and Heal, N.F. (2006). Pachyrhinus lethierryi (Desbrochers, 1875) (Curculionidae) new to Britain and evidently established in south-east England. The Coleopterist, 15, 59 – 65.
Turner, C.R. (2011). Pentarthrum elumbe (Boheman) (Curculionidae, Cossoninae) in Britain. The Coleopterist, 20, 20 – 22.