By Matthew Cobb
Like Jerry, I study what many scientists call ‘The Fly’ – Drosophila melanogaster. Unlike many of our colleagues, however, we both know that other flies are available, and that in some ways D. melanogaster has been turned into a piece of laboratory equipment , for we have virtually no idea about what it actually gets up to in the wild. Both Jerry and I have studied other species, though only (I think) closely related species of Drosophila. Heavens, we’ve even gone hunting for them in Africa (guided, and in Jerry’s case alongside, the sadly departed Daniel Lachaise). (In 2006 Jerry and I published a memorial article to Daniel, which is sadly behind a paywall).
However, any feeling that I had the slightest idea about the variety to be found within my chosen study group – Diptera – has been blown away by reading Stephen A. Marshall’s stupendous new book, Flies: The Natural History and Diversity of Diptera, which appeared at the end of last year. I bought myself a copy for Xmas, and unless you are a thorough dipterophobe, I urge you to order a copy NOW! Both the pictures and the text will enlighten and amaze you. As E. O Wilson rightly says: “Stephen A. Marshall has delivered one of the most beautiful and useful accounts of insect life ever written.”
Steve even makes me feel not so bad about my Drosophila-centred knowledge – “The genus Drosophila, with some 1,500 species, is larger and more diverse than most families of living things.”
Steve is based at the University of Guelph in Ontario and is both a skilled entomologist and a great photographer. I’ve scanned a few of the pictures, with Steve’s permission (apologies to all for any crappy scanning and cropping). Most of the hundreds of images show flies in their natural surroundings, a very few are of skewered museum specimens and there are loads of pictures of the larval stages.
There is a great section on the various flies that live in and around streams around the world – many of them nasty bitey things that make those beautiful areas relatively inhospitable (I’m looking at you, Highlands of Scotland). I always wondered what all those biting flies did when there aren’t people about, and answered myself by saying ‘well they must bite other mammals’. That’s no doubt true, but Flies shows us that they also bite other flies:
Here’s a biting midge taking a meal from a crane fly:
Here Forcipomyia biting midges suck the blood from the wing veins of a lacewing.
- (c) Stephen Marshall
Flies is divided into three parts – Life Histories, Habits and Habitats; Diversity (the bulk of the book) and Identifying and Studying (including some keys that look user-friendly, but will be difficult, because taxonomy is).
One of things that soon becomes clear is that apart from biting and eating crap, many flies are cunning kleptoparasites – they steal predator’s food. Here are a couple of dramatic photos.
First, “Adults of milichiid genus Desmometopa are often specialized kleptoparasites, swiftly attracted to Honey Bees captured by other arthropods such as robber flies or spiders, like the Cuban lynx spider shown here.”
These Olcella flies (can you see both of them?) are getting a quick meal from some hapless ant that is being snarfed by a spider (that’s my caption, not Steve’s):
The Diversity sections is divided into three main chapters, corresponding to the current classification of the order (this has changed a number of times!) – the Lower Diptera (includes mosquitoes, crane flies and lots and lots of midges), the Lower Brachycera and Empidoidea (the former includes Horse flies and Bee flies, the later are the “Dance flies”), with the final, and biggest, chapter, devoted to the Higher Brachycera or what I still call the Cyclorrapha, which includes almost half of identified fly species, including Drosophila melanogaster.
Each of these chapters consists of a brief explanation of the classification – invaluable for an ignoramus like me – followed by page after page of fantastic photos, each with an informative caption.
Here are some of my favourites. First, members of the Rachicerus genus looks like they have multi-segmented comb-like antennae. Why? Their larvae live under the bark of trees where they eat other larvae:
A male Lindneromyia – found in soft fungi throughout the world (NO IT HAS NOT BEEN PHOTOSHOPPED). The eyes of the female are small and separated. Presumably either the male has to track the female for mating, or he is subject to some specific natural selection pressure that means he needs what looks like 360 degree vision.
Bromophila caffra from Africa. This species, like others in its genus, “has the startling habit of ejecting yellow fluid from its mouth”. Note it does not have any ocelli – the three tiny extra eye-patches on the top of the head that are used for detecting polarised light. Even Lindneromyia has them.
And finally, can you guess what is weird about this Ormia fly? (Answer below the photo)
It’s nocturnal. Very few flies fly in the dark. These parasitise crickets, using specially-enlarged structure to detect the vibrations produced by their prey. Look at those long legs!
This is just a fraction of the wonders that await you inside the pages of this marvellous book!
Stephen A Marshall (2012) Flies: The Natural History and Diversity of Diptera. Firefly Books. ISBN-13: 978-1770851009