Highlighting a selection of insects with freshwater larvae

by Ann Sylph on

National Insect Week is 18 to 24 June and London Rivers Week is 23 June to 1 July overlap (or form a confluence?) this year so I am taking the opportunity to feature a selection of insects with freshwater larvae. 

ZSL’s Volunteer Citizen Scientists monitor riverflies on a monthly basis using their abundance as a healthcheck for London’s rivers, find out more about this project and how to volunteer.  

Mayfly larvae are part of the riverfly monitoring programme, this illustration is an adult featured in The natural history of British insects, explaining them in their several states... together with the history of such minute insects as require investigation by the microscope... by E. Donovan,  London :  Rivington, 1793-1813 in 16 volumes.

Two adult mayflys, one on a plant and the other in flight
Common mayfly in Donovan Plate CXXVIII Volume 4

Edward Donovan (1768 – 1837) was a prolific author, artist and  illustrator.  He  produced several multi-volume illustrated books about British animals, including volumes on fish, molluscs, birds, mammals as well as insects. His books helped to popularise natural history in the late eighteenth and early nineteenth centuries.

Dragonfly and damselfly larvae are aquatic and so are frequently found when pond dipping. These dragonfly illustrations also feature in Donovan’s books on British insects.

Larval stage of dragonfly, wingless and on a reed
Larva of Libellula depressa in Donovan Plate XLIV Volume 2


Illustration of an adult dragonfly in flight
Adult dragonfly, Libellula depressa in Donovan Plate XXIV Volume 1]

Cased caddis and caseless caddis fly larvae are two types of fly larvae used in  riverfly monitoring. These amazing images are woodcuts featured in Gessner published in 1560. The caddis larvae are usually around 2cm long, the case is made from whatever materials are in the environment, so they can be made from small stones, sand grains or plant material. It is astonishing that these were depicted in such detail in 1560.

Woodcut illustration of cased and caseless caddis fly larvae
Woodcut illustrations of cased and caseless caddis fly larvae in Gessner 1560

Finally, I am finishing with an image of an adult caddis fly with a stunning illustration from British entomology, … by John Curtis, published in 1862. These volumes contain some of my favourite illustrations of British insects, as well as being very detailed, they are highly decorative. Each insect is accompanied by a wildflower, in this case large flowered willowherb. Curtis admitted that `Neglected as Trichoptera has been, it is difficult if not dangerous at present to enter far upon the subject of species...the elegant one figured has been selected from its appearing to be a nondescript;...the specimens figured and described were taken by myself in the Regent's Park, in the summer of 1822'. This confirms how amazing it was that Gessner featured caddis larvae in his book of 1560!

In flight adult caddis fly with large flowered willowherb
Leptocerus ochraceus in Curtis British Entomology Vol. IV Plate 410

If you would like to see some fish images from Donovan’s book on British fishes and find out about our oldest books on fish, then have a look at one of my previous blogs from last year.  

I must admit, I have a personal interest in riverfly monitoring as I am a member of the Citizen Crane team, monitoring the River Crane near my home one Saturday every month. 

If you are a teacher, you can book KS2 Educational Sessions - Pond Investigate! at ZSL Whipsnade Zoo - where students can discover some of these fascinating animals for themselves. 


Books featured

British entomology being illustrations and descriptions of the genera of insects found in Great Britain and Ireland..., by John Curtis. London :  Reeve, 1862 in 8 volumes.

The natural history of British insects, explaining them in their several states... together with the history of such minute insects as require investigation by the microscope... by E. Donovan,  London :  Rivington, 1793-1813 in 16 volumes.

Nomenclator aquatilium animantium. Icones animalium aquatilium in mari & dulcibus aquis degentium ... / per Conradum Gesner. Tiguri :  Froschover, 1560 [ZSL Library’s copy is bound with Icones animalium quadrupedum viviparorum et oviparorum, quae in Historiae animalium Conradi Gesneri libro I et II describuntur ... Editio secunda,…]


Further reading

The careering naturalists : creating career paths in natural history, 1790-1830 by Susannah Gibson, Archives of Natural History 2017, Vol. 42 Part 2, pp. 195-214. The career of Edward Donovan (1768-1837)

Celebrating Konrad Gessner's 500th birthday, by Emma Milnes, March 1st 2016 

John Curtis (Entomologist) Biography from the Proceedings of the Linnean Society, 1862. 


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