The zoologist has made it his life's work to raise the profile of invertebrates - from flies and beetles to worms and snails - and educate people about how the entire planet, from humans to plants, rely on them for survival.
At first working for three national entomological societies, along with other organisations and committees, he brought insects to the forefront of conservation efforts in Britain and around the world.
Then, after becoming alarmed at the rate of decline of invertebrates, and the unwillingness of governments to address the problem, he set up the pioneering charity Buglife, dedicated to the preservation of the world's smallest creatures.
Today the organisation has 30 members of staff, offices around the country, and has played a significant role in helping preserve many endangered British invertebrate species.
Alan, 77, who has been involved in bug conservation for 55 years, said that he realised after the 1992 Rio Earth Summit that invertebrates "needed a spokesman".
He said: "I've been keen on insects since I was five, and got involved in nature conservation in my 20s.
"As I got more involved I realised that there were no organisations with invertebrates as a priority. It was clear at the Earth Summit that governments were dragging their feet on protecting invertebrates. They didn't come up with an action plan, so we got three NGOs together and came up with one ourselves."
Passionate about persuading people of the importance of bugs, Alan has authored and contributed to more than 100 publications on the subject and has won two prestigious Marsh Awards.
Seen as one of the world's leading experts on insects, he has also spent years getting his hands dirty studying and recording insect groups, and published world-renowned reference books to help people identify insects, including British hoverflies and British soldier flies.
He has also held numerous significant roles in the conservation sector including president of the British Entomological Society and vice-president of the Royal Entomological Society and the Natural History Society, and founding member of Invertebrate Link (Joint Committee for the Conservation of British Insects) and the National Trust's Nature Conservation Panel.
Alan, from Peterborough, Cambs, said: "Saving the small creatures around the world is so important for many different reasons. A quarter of the food we eat is insect-pollinated, and you also need pollinators to keep wild flowers thriving.
"Invertebrates in the soil eat decaying vegetation and recycle nutrients back into the soil to maintain soil fertility.
"And a large proportion of our birds, fish, and mammals like hedgehogs feed on invertebrates, so if they die out it has a devastating effect on many other plants and animals."
"There are up to 35,000 species of land and water invertebrates in Britain, and to support that number of species in a landscape you need to a great variety of specialized requirements.
"Sadly our landscape is becoming simplified and we are losing the habitats which allow invertebrates to thrive, like fallow fields. These days the most important land for invertebrates are brownfield sites, which the government now wants to build on, so we have a real crisis on our hands. Many brownfield sites have have more endangered species than national nature reserves."
The Buglife charity actively works to save Britain's rarest little animals, from bees and beetles to woodlice and dragonflies.
The only organisation in Europe devoted to the conservation of invertebrates, their projects include creating highways of flower-rich strips to allow bees and butterflies to move through the landscape, and creating wildlife areas in towns and cities so people can have more contact with insect life.
They also engage the local community in conserving endangered bugs, encouraging people to look out for certain species and create the right habitat to help them thrive again.