BUTTERFLY World's demise was a great loss to our cultural and natural landscape but there's still hope as Hertfordshire’s butterfly populations as their shifts, movements and place in our changing countryside and towns are revealed in a new book devoted to our lovely local Lepidoptera.

Butterflies of Hertfordshire and Middlesex by Andrew Wood, Hertfordshire’s official butterfly recorder, provides a comprehensive guide to every species currently found in the two counties – and considers the reasons why some are increasing, while others have declined or disappeared altogether.

Climate and landscape changes, together with lessons drawn from the hits and misses of conservation measures, feature in the 272-page book, which is lavishly illustrated with photographs taken in the area and population maps that illustrate trends over almost 40 years. More than 4,800 local enthusiasts contributed to the latest survey, which covers changes up to 2015.

• Among the success stories is an account of Hertfordshire’s ‘flagship’ butterfly, the Purple Emperor (whose trademark sheen is only revealed in males when their wings catch the light.) From just one record, near Hitchin, in the 1980s the species is being reported from a growing number of locations, including Whippendell Woods in Watford. Careful study by conservationists has provided greater understanding of its habits and needs – including better woodland management to retain the shrubby willows where females lay their eggs.

• The book also describes how one of Britain’s rarer butterflies, the Chalkhill Blue, has been restored to relative abundance on Therfield Heath near Royston after a worrying decline a decade ago. It also explains how its relative, the Small Blue, which was thought to have disappeared from Hertfordshire, has established thriving colonies outside St Albans at the site of the now-closed Butterfly World venture – and on the edge of Letchworth.

• On the negative side, it tells the sad story of the attractively-patterned Wall Brown butterfly. Once common across our area, it disappeared in just 20 years and not been seen in the wild since 2005. Theories for its loss across swathes of southern England include the use in agriculture of neonicotinoid pesticides, nitrogen pollution and negative effects of global warming on its breeding cycle.

In addition to reporting the status, history, ecology and conservation needs of resident and migrant species, the book also provides a detailed guide to more than 50 places that are among the best to see butterflies locally, including rarer species.

The ‘hot spots’ described include:

Aldbury Nowers near Tring, which has more species recorded than any other site in our county. The rare Green Hairstreak, Dingy and Grizzled Skippers, Dark Green Fritillary and Small and Chalkhill Blues are all found here.

Bricket Wood Common between St Albans and Watford: a good place to find spectacular woodland butterflies such as the Purple Emperor, White Admiral and Silver-washed Fritillary.

Heartwood Forest north of St Albans where the White-letter and Purple Hairstreak butterflies have been found, as well as grassland species.

Andrew Wood, whose home is in Bengeo, says: “The history of butterflies in our area during the past 30 years is, in many ways, a microcosm of the issues and challenges facing those of us who enjoy wildlife and want to understand how best to protect the variety of our different species. Meeting their varying needs is often a complex task and we know from the past 30 years how limited knowledge can lead to poor decisions. But by helping more people to appreciate our butterflies and look out for them, we can increase the chances that future success stories in conservation outnumber our failures.”

* Butterflies of Hertfordshire and Middlesex by Andrew Wood is published by Hertfordshire Natural History Society (in association with Butterfly Conservation Hertfordshire and Middlesex Branch). The full price is £34, but it is available on a pre-publication offer until the end of January of just £19.99 including p&p. Details at www.hnhs.org or from HNHS Secretary, 250 Sandridge Road, St Albans AL1 4AL.

There will also be a book launch event at 11.30am on Friday, December 9 at RSPB Rye Meads Visitor Centre, Hoddesdon.