Baron Charles de Geer (the family is usually known as De Geer with a capitalized "De" and is pronounced "de yer");

Finspång Finspång () is a locality and the seat of Finspång Municipality, Östergötland County, Sweden with 12,440 inhabitants in 2010. Overview Finspång is a traditional industrial town. The first industries were established in 1580 when a Royal fact ...

in Risinge 30 January 1720 –

Stockholm Stockholm () is the Capital city, capital and List of urban areas in Sweden by population, largest city of Sweden as well as the List of urban areas in the Nordic countries, largest urban area in Scandinavia. Approximately 980,000 people liv ...

7 March 1778) was a Swedish industrialist and entomologist.

Life

De Geer, who came from a family with strong Dutch connections, grew up in

Utrecht Utrecht ( , , ) is the List of cities in the Netherlands by province, fourth-largest city and a List of municipalities of the Netherlands, municipality of the Netherlands, capital and most populous city of the Provinces of the Netherlands, pro ...

from the age of three. He returned to Sweden at the age of 19. He had inherited the entailed manor and important iron-works of Leufsta (Lövsta) in

Uppland Uppland () is a historical province or ' on the eastern coast of Sweden, just north of Stockholm, the capital. It borders Södermanland, Västmanland and Gästrikland. It is also bounded by lake Mälaren and the Baltic Sea. On the small uninhab ...

from his childless uncle and namesake and would substantially increased the wealth of the estate. Ever since he had received a present of some silk worms at the age of eight, he had an interest in

entomology Entomology () is the science, scientific study of insects, a branch of zoology. In the past the term "insect" was less specific, and historically the definition of entomology would also include the study of animals in other arthropod groups, such ...

and became a respected amateur entomologist at an early age. His major work was the ''Mémoires pour servir à l'histoire des insectes'' (eight volumes, 1752-1778). He was elected a member of the Royal Swedish Academy of Sciences already in 1739, at the age of nineteen, and a corresponding member of the French Academy of Sciences in 1748. He is buried with his spouse in

Uppsala Cathedral Uppsala Cathedral ( sv, Uppsala domkyrka) is a cathedral located between the University Hall of Uppsala University and the Fyris river in the centre of Uppsala, Sweden. A church of the Church of Sweden, the national church, in the Lutheran t ...

. His collections of insects were donated to the Academy of Sciences and now belong to the Swedish Museum of Natural History in Stockholm. He left a library at Leufsta which, among other things, included the papers of

Olaus Rudbeck Olaus Rudbeck (also known as Olof Rudbeck the Elder, to distinguish him from his son, and occasionally with the surname Latinized as ''Olaus Rudbeckius'') (13 September 1630 – 12 December 1702) was a Swedish scientist and writer, professor o ...

and an important collection of 18th-century

sheet music Sheet music is a handwritten or printed form of musical notation that uses List of musical symbols, musical symbols to indicate the pitches, rhythms, or chord (music), chords of a song or instrumental Musical composition, musical piece. Like ...

. The Leufsta library was acquired by

Uppsala University Library The Uppsala University Library ( sv, Uppsala universitetsbibliotek) at Uppsala University in Uppsala, Sweden, consists of 11 subject libraries, one of which is housed in the old main library building, Carolina Rediviva. The library holds books a ...

in 1986 after a donation by Katarina Crafoord (one of the daughters of Holger Crafoord, the founder of Gambro).

Achievements

De Geer was a great admirer of René Antoine Ferchault de Réaumur. Hence his modelling ''Mémoires pour servir à l'histoire des insectes'' on Réaumur's work of the same title. It, too, is in French, similarly in large

quarto Quarto (abbreviated Qto, 4to or 4º) is the format of a book or pamphlet produced from full sheets printed with eight pages of text, four to a side, then folded twice to produce four leaves. The leaves are then trimmed along the folds to produc ...

and with the same decorations. The ''Mémoires'' deal with 1,466

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, treating life histories, food and reproduction based on careful, patient investigation and analysis of existing literature. There are 238 copper plates. The descriptions are acutely observed. In nomenclature De Geer was less progressive; Volume 1 of the ''Mémoires'' (1752) was too early to employ the

binomial Binomial may refer to: In mathematics *Binomial (polynomial), a polynomial with two terms * Binomial coefficient, numbers appearing in the expansions of powers of binomials *Binomial QMF, a perfect-reconstruction orthogonal wavelet decomposition ...

system invented by his fellow Swede

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

. Volume 2 (1771) did not use it, but in volumes 3 (1773) to 7 (1778) the Linnean system was employed. However, for many species De Geer used two or more words for a specific name, such as ''Aphis betulae nigro punctata'',Used for a species in Volume 3, p. 45. these names were not binomial in the Linnean sense. He also proposed new names for many species which had previously been named and described by Linnaeus. It seems that using Linnean names was a concession to usage as in the 1760s and 1770s the Linnean system became increasingly employed, not because De Geer liked the new system. They had differences "not everyone sees things in the same light, and people have the weakness of frequently being too fond of their own opinions" (letter to Linnaeus 16 October 1772) and "if here and there I am still of a different opinion, I am now, as before, asking you not to take it amiss" (letter to Linnaeus 23 February 1774).

Works

*''Tal om nyttan, som Insecterne och deras skärskådande, tilskynda oss, ...'' Stockholm 1744–47. *''Mémoires pour servir à l'histoire des insectes.'' Grefing & Hesselberg, Stockholm 1752–78. *''Tal, om insecternas alstring.'' Stockholm 1754. *''Abhandlungen zur Geschichte der Insecten.'' Müller & Raspe, Leipzig, Nürnberg 1776-83 p.m. *''Genera et species insectorum''. Crusium, Leipzig 1783 p.m.

Common insects described by De Geer

*''Camponotus pennsylvanicus'', the black carpenter ant (Hymenoptera: Formicidae) *''Dermestes maculatus'', a

skin beetle Dermestidae are a family of Coleoptera that are commonly referred to as skin beetles. Other common names include larder beetle, hide or leather beetles, carpet beetles, and khapra beetles. There are over 1,100 species described. Dermestids have ...

, Coleoptera 1774 *''Xestobium rufovillosum'', the

death watch beetle The deathwatch beetle (''Xestobium rufovillosum'') is a species of woodboring beetle that sometimes infests the structural timbers of old buildings. The adult beetle is brown and measures on average long. Eggs are laid in dark crevices in old w ...

, Coleoptera 1774 *''Meconema thalassinum'', oak bush-cricket, Orthoptera 177
Picture
*''Gasterophilus intestinalis'', horse

botfly Botflies, also known as warble flies, heel flies, and gadflies, are a family of flies known as the Oestridae. Their larvae are internal parasites of mammals, some species growing in the host's flesh and others within the gut. '' Dermatobia hom ...

, Diptera 1776 *''Episyrphus balteatus'', a

hoverfly Hover flies, also called flower flies or syrphid flies, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, whil ...

, Diptera 1776 *''Triatoma rubrofasciata'',

Triatominae The members of the Triatominae , a subfamily of the Reduviidae, are also known as conenose bugs, kissing bugs (so-called from their habit of feeding from around the mouths of people), or vampire bugs. Other local names for them used in The Amer ...

Hemiptera Hemiptera (; ) is an order (biology), order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, Reduviidae, assassin bugs, Cimex, bed bugs, and shield bugs. ...

1773 *''Erythrodiplax unimaculata'', a dragonfly,

Odonata Odonata is an order of flying insects that includes the dragonflies and damselflies. Members of the group first appeared during the Triassic, though members of their total group, Odonatoptera, first appeared in Late Carboniferous. The two com ...

1773 *''Anasa tristis'', squash bug,

*''Hepialus'' (''Korscheltellus'') ''fusconebulosa'',

map-winged swift The map-winged swift (''Pharmacis fusconebulosa'') is a moth belonging to the family Hepialidae and has a patchy distribution throughout Eurasia. The species was first described by Charles De Geer in 1778. It was previously placed in the genus ' ...

moth,

Lepidoptera Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...

1778 *''Microctenochira quadrata '', Cassidinae, Coleoptera 1775

References and further research

*Anfält, Tomas (1991): Consumer of enlightenment. Charles De Geer - savant and book collector in eighteenth-century Sweden. ''The Book Collector 1991, part 2'', 197-210. *Duncan, James (1804-1861): ''Introduction to entomology''. Lizars, Edinburgh 1840. *Pont, A.C. (1996): Some reflections on the history of systematic Dipterology. ''Dipterists Digest'', Series 2, 2: 49–70. *Ekland, Karl Johan & Hamberg, Erik (ed.) (2018) ''En liten bok om Lövstabruk'' n Swedish, English, German and French Uppsala. *Degeer's insect collection, without the original labels and not in the original cabinet may be found at the Swedish Museum of Natural History.

External links

*Charles de Geer
Mémoires pour servir à l'histoire des insectes
', digital facsimile at the Gallica website.
Gaedike, R.; Groll, E. K. & Taeger, A. 2012: Bibliography of the entomological literature from the beginning until 1863: online database - version 1.0 - Senckenberg Deutsches Entomologisches Institut.

References

{{DEFAULTSORT:De Geer, Charles 1720 births 1778 deaths 18th-century Swedish businesspeople 18th-century Swedish zoologists Swedish entomologists Hymenopterists Swedish arachnologists Members of the French Academy of Sciences Members of the Royal Swedish Academy of Sciences People from Finspång Municipality Geer, Charles de Utrecht University alumni Swedish people of Belgian descent

Charles Charles is a masculine given name predominantly found in English language, English and French language, French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic, Proto-Germanic name (in runic alphabet) or ''*k ...