Origin of "minibeasts"?

What is the origin of the term minibeasts?

Growing up in the UK I never heard the term, but recently I have heard it prolifically used in preschool education and children's television programmes.

Minibeast or "Minibeasts" is a term for a variety of arthropods and other invertebrates, including spiders, ants, butterflies, bees, wasps, flies, woodlice 1, and many others. The United Kingdom-based Young People's Charitable Trust defines them as "small animals" in a factsheet written for young readers [2]. There is a "Minibeast Zooseum" in Michigan dedicated to invertebrates[3].Minibeasts, as indicated by their name, are generally 'mini' or small.

The study of minibeasts is common as part of the primary school curriculum. Studying minibeasts is a very effective way to observe many biological concepts first hand, which is not possible with many larger animals. Life cycles, food chains, and bodily structure and function are just some of the basic elements of biological science which can be easily explained using minibeasts. "Bugs Alive!" at Melbourne Museum features a huge number of live minibeasts with detailed information about them, while services such as "Minibeast Wildlife" [4] and "Travelbugs" [5] take live minibeast to schools and provide educational resources.

Source: Wiki

The term has become very popular since 1980 as shown on Ngram, apparently with the educational trend developed in those years.