... flexion of the joint gives a variable stimulus to the sensilla, thereby allowing TIC 04 5/20/ 04 4 :47 PM Page 87 Mechanical stimuli 87 knob-like modified hind wing of Diptera), at the base of which there ... that controls the mode of reproduction (i.e either sexual or parthenogenetic) The setting of the biological clock (Box 4. 4) relies upon the ability to detect photoperiod 4. 4.2 Stemmata The only visual ... light), chemo- for taste and odor, geo- for gravity, hygro- for moisture, TIC 04 5/20/ 04 4 :47 PM Page 111 Further reading phono- for sound, photo- for light, rheo- for water current, and thermo- for...