On the Wildside with Ian Rotherham: Bring on the summertime hawkmoths

Each summer, especially when we have long, hot periods in June through to August, I get reader’s enquiries about big moths, particularly “big hawks”. Sometimes people see huge moths attracted to evening windows or outside lights, and on other occasions it is gigantic larvae, the caterpillars that draw attention. The third observation that I will return to later, are daytime flyers that look like Hummingbirds! However, in this case, Anita Shurey of High Green, Sheffield, found a huge caterpillar in the garden and wondered what on earth it was. Around about the size of a middle finger these creatures are so-named because the caterpillar has the form, appearance, and texture of “an elephant’s trunk” and hence the “Elephant Hawkmoth”. The markings are distinctive with “eye-markings” just behind the head to ward off predators, and the hooked tail deterring parasitic wasps. The nocturnal adults are striking individuals and will come to gardens to lay eggs on Fuchsia shrubs, often on patios and such places. Their favoured food-plants are stands of Rosebay Willowherb perhaps on a roadside, a woodland edge, or maybe so-called waste ground. Rosebay benefitted from the spread of Victorian steam railways and particularly where trackside vegetation caught fire due to flying sparks from the engines. This gave the plant two common names of “Fireweed” and “Railway Flower”. Other triggers for the spread of Elephant Hawkmoths associated with Rosebay were the World War Two bomb-sites from urban Blitz raids, and then the abundance of post-industrial derelict sites in towns and cities such as Sheffield, during the 1970s and 1980s. Good places to see the caterpillars today include stands of massed Rosebay Willowherb along walkways and cycleways on canal-side routes and former railway-lines.