Johann Wilhelm Meigen (3 May 1764 – 11 July 1845) was a German entomologist famous for his pioneering work on Diptera.

This was already heavily indebted by the Seven Years' War, then bad crops and rash speculations forced the sale of the farm and the family moved back to Solingen.

Another family friend a Reformed Church organist and teacher called Berger, gave him lessons from his 10th year on in piano, orthography, and calligraphy.

Meigen's first attempts to identify his collection which was mainly of Diptera were made with a two-volume work by Philipp Ludwig Statius Muller a German translation of Linnaeus's Natursystem published in the Netherlands by Houttyn.

This conclusion had already occurred to both Moses Harris in England and Louis Jurine in Geneva but at the time Meigen was unaware of this.

Sensing an important step forward he secured the works of Fabricius and from that time concentrated on Diptera.

He soon found that wing venation alone was not enough to classify the Diptera correctly and he began to make drawings of the antennae viewed under a 20-power wooden-framed microscope purchased at the fair in Aachen, This and also a lens of about 6-power, and his own very sharp eyesight and visual memory led him to the next important conclusion, that the Diptera could only be classified using character combinations; what is now known as an eclectic system.

A Swiss, Count von Meuron, who was in the Dutch service and whose brother was governor of Trincomalee on Ceylon heard of their wishes and obtained for them the offer of positions as surgeons on an East Indiaman, with an additional stipend.

In 1801 Meigen met the French naturalist Count Lacépède who had come to Stolberg to visit the brass works.

Illiger had captured a new and unknown Dipteron and showed a pen drawing of it to Meigen, asking him how it should be classified.

In 1815, Meigen received a letter from State Attorney (Justizrat) Christian Rudolph Wilhelm Wiedemann asking if there was any prospect that his work begun in 1804 could be continued.

The first volumes of Die Fliegen were published by Meigen himself, but the costs were high, in spite of a considerable list of subscriptions.

He took on the determination of at least 50,000 specimens from Germany, France, the Pyrenees, the Alps and northern Italy and worked on it for a year and a half.

Eventually, through the intervention of the inspector of water supply, he got a well paid contract for some map-drawing lasting a couple of years.

He was able, however to make a trip to the Siebengebirge chiefly for botany and Meigen made some drawings of plants for Prof. Johann Georg Christian Lehmann a Hamburg botanist.

In 1821, Meigen made the acquaintance of Professor Heinrich Moritz Gaede of Liège, whose name he gave to Trypeta gaedii and the tachinid genus Gaedia.

On 30 July they were back in Kiel, where everything in the collections of Fabricius and Westermann was carefully examined and compared and the unknown species drawn and described.

Also in Hamburg, Meigen met the entomologist Sommer from Altona and the botanist Johann Georg Christian Lehmann.

The trip to Denmark and Sweden lasted altogether 12 weeks, the result of which was a series of colored drawings of more than 400 species of insects, together with their descriptions and a large number of notes and corrections.

Soon after 1822, the French school closed down completely and Meigen took the unpaid position of organist for his parish but he wrote a choral book, for which the church board paid him well.

In 1825, Meigen made a translation of François Fénelon ‘s Telemachus, and in the same year he was enabled to attend a meeting of naturalists in Berlin.

The following year, 1827, a Handbuch für Schmetterlingsliebhaber (Handbook for Butterfly Collectors) appeared under his name, and he also started a much larger work on Lepidoptera.

The last volume of this work, also containing numerous drawings made largely from nature by Meigen himself, appeared in 1842.

Macquart told Meigen that he would like to buy them, quoting a price of 1800 francs on behalf of the Jardin des Plantes in Paris.

He paid an additional 1200 francs for Meigen's collection of Diptera, which also went to Paris.In the 1970s the colour paintings were published as plates by Morge (selection shown immediately below).

His books and fruit and plant collections were bought by the Verein für natürliche Wissenschaften und Gewerbe (Society for natural sciences and industry) in Aachen.

Aside from his beautifully executed drawings Meigen's great achievement was to employ combinations of morphological characters to work out his scientific classification.

Thus he had come to the same conclusion as Pierre André Latreille, Moses Harris and Louis Jurine though independently and an eclectic methodology was firmly established.

The Diptera are divided into 88 genera, each with a short diagnosis in French and the number of European species which Meigen recognised as belonging to each genus.

In 1908 Hendel reintroduced Meigen's 1800 names and republished Nouvelle Classification des Mouches A Deux Ailes which had priority.