David Saunders appears to have stopped work on this memoir in around 2009, judging to references to published work in the last part.

Nevertheless, he continued to be involved in photoperiodism, often sought out for advice or for reviews. David continued to publish articles in the scientific literature.

Jean and David made a forminable team with Jean supporting David's work in many ways, until she passed away at the end of 2017. David buried himself in writing a major review for Annual Reviews, and subsequently remained on top of the literature and maintained contacts with colleagues around the world.

At the time David passed away in 2023, he was addressing referee comments on what would be his final and posthumous publication. He was a giant in the field to the very end.

David's list of publications can be found at Research Gate.

Here are two obituaries of David Saunders.

Obituary - David S. Saunders: man of insects and photoperiodism (Journal of Comparative Physiology A)
Helfrich-Förster, C. David S. Saunders: man of insects and photoperiodism (1935–2023). J Comp Physiol A (2023). https://doi.org/10.1007/s00359-023-01665-3 This is an open access article, and a pdf version may be downloaded here.

Obituary - Professor David Stanley Saunders (Antenna)
Here's a pdf of a proof copy of the obituary published in Antenna, the journal of the Royal Entomological Society, which is not open access.