1. Head of a dragonfly showing enormous compound eyes. (After Blaney 1976

2. Figure 4.1
Longitudinal section of a trichoid sensillum showing the arrangement of the three associated cells. (After Chapman 1991.)

3. Figure 4.2
Proprioceptors: (a) sensilla of a hair plate located at a joint, showing how the hairs are stimulated by contacting adjacent cuticle; (b) campaniform sensillum on the haltere of a fly. ((a) After Chapman 1982;
(b) after Snodgrass 1935; McIver 1985.)

4. Figure 4.3
Longitudinal section of a scolopidium, the basic unit of a chordotonal organ. (After Gray 1960.)

5. Box 4.1

6. Figure 4.4
Tympanal organs of a katydid, Decticus (Orthoptera: Tettigoniidae): (a) transverse section through the fore legs and prothorax to show the acoustic spiracles and tracheae; (b) transverse section through the base of the fore tibia; (c) longitudinal breakaway view of the fore tibia. (After Schwabe 1906; in Michelsen & Larsen 1985.)

7. Figure 4.5
The singing burrow of a mole cricket, Scapteriscus acletus (Orthoptera: Gryllotalpidae), in which the singing male sits with his head in the bulb and tegmina raised across the throat of the horn. (After Bennet-Clark 1989.)

8. Box 4.2

9. Box 4.3

10. Figure 4.6
The antennae of a male moth of Trictena atripalpis (Lepidoptera: Hepialidae): (a) anterior view of head showing tripectinate antennae of this species; (b) cross-section through the antenna showing the three branches; (c) enlargement of tip of outer branch of one pectination showing olfactory sensilla.

11. Figure 4.7
Location of pheromone-emitting female by male moth tacking upwind. The pheromone trail forms
a somewhat discontinuous plume because of turbulence, intermittent release, and other factors.
(After Haynes & Birch 1985.)

12. Figure 4.8
A pair of queen butterflies, Danaus gilippus (Lepidoptera: Nymphalidae: Danainae), showing aerial “hairpencilling” by the male. The male (above) has splayed hairpencils (at his abdominal apex) and is applying pheromone to the female (below). (After Brower et al )

13. Box 4.4

14. Figure 4.9
Longitudinal sections through simple eyes: (a) a simple stemma of a lepidopteran larva;
(b) a light-adapted median ocellus of a locust. ((a) After Snodgrass 1935; (b) after Wilson 1978.)

15. Figure 4.10
Details of the compound eye: (a) a cutaway view showing the arrangement of the ommatidia and the facets; (b) a single ommatidium with an enlargement of a transverse section. (After CSIRO 1970; Rossel 1989.)

16. Figure 4.11
The flash patterns of males of a number of Photinus firefly species (Coleoptera: Lampyridae), each of which generates a distinctive pattern of signals in order to elicit a response from their conspecific females. (After Lloyd 1966.)