This is the book, it is one of a series, Ebi-kun has his eye on the dinosaur one, I have my eye on the amphibians the ISBN is 4-09-217203-6 and it cost ¥2100, he used money that Baa-chan had given him to buy it. I don't read Japanese very well but I think this is meant for elementary school kids (6 years and up)
It is really well laid out and had great photos, not only of the bugs but their eggs, life cycle and habitat. On the butterfly pages there are pictures of the caterpillar so you can figure out what kind of butterfly or moth will be. (remember this guy)
The bugs that are similar are laid out side by side which makes identification easier. At the back of the book there are a couple of pages showing you how to catch various bugs and how to keep them so you can set up the right environment for them. We tend not to keep them but to send them to yochien, which I should add is encouraged, I don't know if that is a common thing here or, anywhere else for that matter.
The photos of the bugs are really clear and if the the bugs are small then they enlarge the picture but then next to it there is a grey silhouette so you can see the actual size. The information given tells you the name, what it eats, usual size (explanation on how to measure your bug at the front of the book), the area it is found in and the time of year you are likely to find it. A note about the language, Japanese uses 3 scripts, Hiragana which is the one children learn first, Katakana which is used for non Japanese words and Kanji which are derived from the Chinese characters. If you look above the kanji they have the word written in hiragana so even children (or people like me!) who can't read the kanji they can still read what it says. The great thing about this is that the subconscious picks up on the kanji, Ebi-kun knows quite a lot of kanji just from reading his books.
For the main bug types they have a 'parts of bug' page too, I really think these books are great value for money, there is so much information and the pictures and illustrations are great. I don't know if there is an English equivalent, if you know of one please let me know.