In 1824 Curtis began his monumental masterwork, British Entomology: Being Illustrations and Descriptions of the Genera of Insects Found in Great Britain and Ireland, still widely considered as the finest nineteenth century work on the subject.

By the end of 1856 Curtis was totally blind, living at 18 Belitha-villas (now: Belitha Villas), Islington, London and receiving a civil list pension initially of £100 a year but later increased to £150.

It is related that his notice, as a child, having been attracted by the large hairy caterpillar of Arctia Caia, which, to his great astonishment and delight, was transformed, whilst under his care, into a beautiful moth, entomology at once became his ruling passion.

About this time, also, he became acquainted with an older and well-informed youth, Richard Walker, afterwards B.D, F.L.S., and Fellow of Magdalen, and the author of ‘Flora Oxoniensis’, in company with whom numerous excursions were made in the marshy districts surrounds his native place.

On his recovery he was sent to school at Norwich, where he was again fortunate in making the acquaintance of a youth named Henry Browne, whose mother possessed a collection of British Lepidoptera, the inspection of which still further increased the zeal of Curtis in his old pursuits.

When sixteen years of age, being obliged to choose a profession, he entered the office of a lawyer, although when there, dry legal technicalities were but little to his taste, and his desk probably contained more of natural history than of law.

Here, with a well-stored library, a well-named collection of insects, and congenial associates, the two friends spent their time most happily; and an entomological society was formed, in which the names of the Revs.

The latter two contained twenty-five plates, filled with details of the external and internal anatomy of insects, twenty of which were etched by Curtis and five by Henry Denny, the dissections having been for the most part made by Mr. Kirby.

Mr. Curtis, at this time, frequently made sketches from nature; and about 1816 he cultivated, more especially, a taste he had long entertained for the drawing of churches, fonts, and monuments, the views being coloured on the spot.

The battle of life now began in earnest; and having thus lost the advice and assistance of the first zoologists whom England has ever produced, Mr. Curtis (by the evidence of Mr. MacLeay and other friends) turned his attention to botanical drawing and engraving, which led to engagements with Dr. Sims, and introduced him to the Horticultural Society (of which his friend Dr. Lindley was Secretary), the Linnaean Society, &c. In 1822 he was elected a Fellow of this Society; and on 1 January 1824 appeared the first number of ‘British Entomology,’ “being Illustrations and Description of the genera of Insects found in Great Britain and Ireland, containing coloured figures from nature of the most rare and beautiful species, and in manty instances of the plants upon which they are found.” This great work extended to sixteen annual volumes, containing no less than 770 plates, occupied by what the unanimous consent of entomologists has pronounced to be the most exquisite figures of the kind ever produced.

This limited scope was proposed, partly, because it was known that the late J. Francis Stephens had long been engaged in preparing for publication a work on the species of British insects, the first number of which appeared on 1 May 1827.

In 1825, Mr. Curtis, in company with his friend Mr. Dale of Glanville’s Wooton, a most assiduous collector of British insects, made an entomological tour in Perthshire and the western isles of Scotland, returning by way of Edinburgh.

In this tour they were successful in collecting many very rare insects, together with thirty species not previously known as British, as well as numerous drawings of wild flowers for the illustration of Mr. Curtis’s great work.

In 1831 Mr. Curtis was elected Corresponding Member of the Royal Georgofili Society of Florence, and in the same year he published a “Description of the Insects brought home by Commander James Clark Ross in his Second Voyage,” forming part of the Appendix of Natural History.

In 1833, on the occasion of his reading a paper “On the Structure of Insects” before the Ashmolean Society of Oxford, he was elected an Honorary Member of that body; and in 1836 he received the same title from the Academy of Natural Sciences of Philadelphia.

On the completion of his ‘British Entomology,’ on 1 December 1839, Mr. Curtis sought for relaxation from the incessant application monthly required during the long space of sixteen years; but in 1841, his friend Dr. Lindley having commenced the ‘Gardeners’ Chronicle,’ Curtis undertook the entomological editorship, engaging to write articles on the insects injurious to gardeners and farmers, in a popular style, accompanied by figures on wood; and this task he continued to perform with unabating industry till 1847, when it was taken up by Mr. Westwood.

In the autumn and winter of 1850 he visited Nice, Genoa, Turin, and the North of Italy, returning by the Tyrol and Switzerland; and in the latter part of 1851, he visited Pau, the various cities along the Mediterranean, Venice, Florence, Lombardy, Switzerland, and France, continuing, nevertheless, to furnish communications on entomological subjects to various publications, and, amongst these, one to the ‘Linnaean Transactions,’ in 1852, “On the Economy of a New Species of Saw-fly (Selandria Robinsoni), the lavae of which feed upon Convallaria multiflora” and a “Notice regarding a Weevil of the vine and its Parasite (Rhynchites Betuleti)” in the ‘Proceedings’ for 1853; “On the genus Myrmica and other indigenous Ants,” in the ‘Linnaean Transactions,’ 1854, &c. The publication of so national a work as the ‘British Entomology,’ together with the great practical utility of his numerous memoires on economic entomology, fully justified the grant of an annuity of £100 which was conferred some years since upon Mr. Curtis, and subsequently augmented by an additional £50 on the occurrence of a sad event which took place shortly after the first grant of the pension, namely, the total loss of sight, induced, it is supposed, by the overstraining of the eyes in the execution of his numerous and laborious works.

Yours most faithfully, John Curtis"To Alexander Henry Haliday, Esq., M.A., &c, of Belfast, whose extensive knowledge and munificent contributions, have so greatly enriched this work and whose kindness and friendship in its progress have been an uninterrupted source of gratification, to the author, this volume" (British Entomology VII Homoptera.

I assure you one of the greatest pleasures in the progress of my great undertaking has been the associating my name with those whom I esteem and who like myself fare devote to the study of our branch of Natural History I may have only two more opportunities of thus gratifying myself and I shall be truly happy if they afford me the same unmixed pleasures as the present one does...John Curtis' insect collection is divided between the National Museum of Ireland – Natural History (via Trinity College Dublin, 7,656 specimens purchased by Thomas Coulter)[citation needed] and Museums Victoria[1] in Melbourne, Australia, which purchased the John Curtis Collection of British and Foreign Insects—comprising 38,031 specimens—for £567 in 1862.