I was astonished when I read "Life on a Little Known Planet: A Biologist's View of Insects and Their World" [1]. The author was an entomologist who was one of the world's foremost experts on parasitic wasps.
He'd put out traps to catch flying insects at his home over the summer in, if I recall correctly, New England, and often find ones that he didn't recognize. He'd even find parasitic wasps he didn't recognize. Upon further checking he'd find that many of these were unknown to science.
I'd always thought that if you wanted to find insects unknown to science you'd have to go to isolated areas that had not been well explored.
There was a good illustration in the book of how little we know. There was some invasive insect that was causing a lot of damage to California orange crops [2]. The invasive insect was native to Florida. In Florida its population was kept under control by a species of parasitic wasps that laid their eggs in its larvae which became wasp food before they could mature and start attacking the orange crop.
A lot of money was spent to import those wasps into California and release them. This kind of biological pest control is attractive because parasites are often very specific about what species they will use as a host, which was the case with these wasps, so this should be safe as far as species other than the invasive one are concerned. The parasites aren't going to switch to some native host.
They were correct in that the parasites didn't go after anything else, so caused no harm. But they also didn't go after the invasive insect. They just didn't lay eggs and died off.
Eventually someone figured out why it hadn't worked. It turned out that what we had thought was a species of invasive insect turned out to be two very closely related species, call them A and B. The parasitic wasp species that laid eggs in their larvae also turnout out to be two species. One of the wasp species laid eggs in A larvae, and only A larvae, and the in B larvae, and only B larvae.
All the invaders in California were from A, and all the wasps they trapped in Florida and sent to California were from the species that lays eggs in B.
Evans is a treasure, and "little-known planet" is right. Too, as phylogenetics continues to overturn the classic understanding of taxonomic relationships, the family often seems to grow about as much more complex as less, of late. It is actually getting clearer, but there are also whole taxa whose existence can be inferred from genomic evidence but not demonstrated because no example has yet been found. By all impressions, it's a wildly exciting field of study in recent decades, if not one seeing the concomitant level of investment.
If you find the subject compels, the next place I'd point you would be Seirian Sumner's quite recent and frankly outstanding Endless Forms, which offers both a worthy successor to Evans' perspective on the hymenopterans, and a view of the astonishing breadth of the field's development since Evans' own day - and no shortage of remarkable anecdotes, either. (Hymenopterology has a habit of furnishing these, I find! Search "Polydnaviriformdae" some time...)
He'd put out traps to catch flying insects at his home over the summer in, if I recall correctly, New England, and often find ones that he didn't recognize. He'd even find parasitic wasps he didn't recognize. Upon further checking he'd find that many of these were unknown to science.
I'd always thought that if you wanted to find insects unknown to science you'd have to go to isolated areas that had not been well explored.
There was a good illustration in the book of how little we know. There was some invasive insect that was causing a lot of damage to California orange crops [2]. The invasive insect was native to Florida. In Florida its population was kept under control by a species of parasitic wasps that laid their eggs in its larvae which became wasp food before they could mature and start attacking the orange crop.
A lot of money was spent to import those wasps into California and release them. This kind of biological pest control is attractive because parasites are often very specific about what species they will use as a host, which was the case with these wasps, so this should be safe as far as species other than the invasive one are concerned. The parasites aren't going to switch to some native host.
They were correct in that the parasites didn't go after anything else, so caused no harm. But they also didn't go after the invasive insect. They just didn't lay eggs and died off.
Eventually someone figured out why it hadn't worked. It turned out that what we had thought was a species of invasive insect turned out to be two very closely related species, call them A and B. The parasitic wasp species that laid eggs in their larvae also turnout out to be two species. One of the wasp species laid eggs in A larvae, and only A larvae, and the in B larvae, and only B larvae.
All the invaders in California were from A, and all the wasps they trapped in Florida and sent to California were from the species that lays eggs in B.
[1] https://www.amazon.com/Life-Little-Known-Planet-Biologists/d...
[2] I read the book a long time ago. I may be misremembering the specific crop, and the specific types of insects involved.