Table Of Content© Entomologica Fennica. 9 December 2002
Book review gether. Protuberances are often directed in the way
that ensures an optimal function. In the oviposi-
Attachment devices of insect cuticle tor valvulae, comb-like structures angled pos-
teriorly prevent eggs from moving in the wrong
Gorb, S. 2001: Attachment Devices of Insect Cuti- direction, on the body surface, angled outgrowths
cle. Kluwer Academic Publishers, Dordrecht/Bos- provide an ability for directional motion within a
ton/London. 305 pages. ISBN 0-7923-7153-4. substratum with high viscosity (dung, mud, or liv-
ing tissues).
How does a fly manage to walk on the ceiling or The head-arresting system in dragonflies and
on a glass-window surface? These are questions damselflies is described in detail in a chapter with
that Dr. Stanislav Gorb deals with in his book explanations of the skeleton-muscle organization
“Attachment Devices of Insect Cuticle”. and functional significance of the arrester.
The structure of the book is logical and sys- Frictional surfaces adapted to affix parts of the
tematic, starting with the basal physics of attach- body, such as tarsi or antenna, and the design of
ment (friction, adhesion, surface texture, and liq- the insect unguitractor apparatus on the pretarsus
uid films), followed by various aspects of interac- is the theme of another chapter. Here are also de-
tions between bodies in contact, and ending with scribed the self-folding armored membranes in
ecological implications of changing surface tex- Diptera. These are found in six families and exist
tures and constructions. in joints between basal segments of legs, and in
In the first chapters, Gorb recollects our basic transitional areas between segments. The author
knowledge of the insect cuticle: its design and found at least six types of microstructures of these
mechanical properties, and continues by classify- membranes and the construction makes the mem-
ing cuticular protuberances like acanthae and brane possible to fold in only certain ways. Lock-
microtrichia. He gives examples of their univer- ing devices are also found e.g. in syrphid flies that
sal functions: in body coloration pattern, oxygen position the legs in certain ways during flight.
retention, thermoregulation, aerodynamic-active Wing-locking devices are dealt with in a spe-
surfaces, sound generation, defence, grooming and cial chapter. Such microstructures, microtrichia
food grinding. fields, are described from hind wings, elytrae, tho-
After that, attention is directed to the princi- rax, and abdomen in Coleoptera; tegmina and
ples of cuticular attachment in Arthropoda, which metanotum in Dermaptera; thorax and alulae in
the author divides into the eight fundamental Diptera; scutellum in Hymenoptera; and fore-
classes: hooks, locks/snaps, clamps, spacers, suck- wings of Heteroptera.
ers, expansion anchors, adhesive secretions and Attachment pads, the devices used by the in-
friction. They are exemplified with scanning elec- sect for walking on smooth surfaces, are either
tron micrographs and line drawings. hairy or smooth. Dr. Gorb gives an overview of
He then discusses the frictional systems that the external tarsal morphology from all orders and
are found in Arthropoda. Frictional systems are describes the surface characteristics of the cuticle
parasite-host or predator-prey associations, attach- protuberances. We learn that flies use four differ-
ments during copulation or attachment to the sub- ent movements of the foot to detach it during
stratum. In the latter part, comparisions with ver- walking, namely shifting, twisting, rotation and
tebrates are drawn, exemplified by the ability of pulling. High-speed recordings show these find-
lizards to hang on the ceiling or to climb on verti- ings. Did you know that flies have three feet in
cal glass surfaces. Interlocking of body parts, e.g. contact with the surface when they walk on verti-
coiling of the proboscis in Lepidoptera, is ex- cal or horizontal surfaces, while they have four
plained by high friction between processes that while walking upside down on the ceiling? Dif-
act like pressing the hairs of two stiff brushes to- ferent types of setae on the pulvilli have evolved,
246 ENTOMOL. FENNICA Vol. 13
depending of the size of the animal. The heavier insects also in this matter, which for instance has
the insect, the larger the setal tip. caused the plants to evolve “dusty” surfaces to
The dependence of secretion in frictional sys- prevent insects from walking on them. Different
tems is also of great interest. Spirally oriented pore examples of plant surface waxes are shown, pat-
canals seem to assist in the distribution of these terns that apparently function in the mechanical
substances onto the substratum. Dr. Gorb shows interaction between plants and insects.
that flies can make footprints on glass surfaces. The last chapter is titled “Nature’s design as a
The secretions seem to make the setae act as suck- basis for biomimetics”. Parallels between natural
ers on smooth surfaces. surface systems and man-made inventions of fas-
After discussing the sensory organs that reg- teners are discussed, for instance Velcro fasten-
ister the position of the different body parts, the ers of different types and car tires.
evolution of the frictional systems is clarified, Despite its minor inconsistencies, the book
especially that of the odonate head arrester, the gives a good overview of where we stand today
ovipositor coverage, and the wing-locking de- in the questions of arthropod attachments. After
vices. Using a cladogram, the author also tries to reading this book, you will understand much more
fit the evolution of pad structures into hexapod of the flies’ problems of walking on the ceiling. It
phylogeny. is not just to do it; you must also know exactly
Ecological implications are also discussed, and how to lift your feet and how to detach them.
comparisons made with host-plant surfaces. There
certainly has been coevolution between plants and Lennart Ågren
