Fig. 5

Details of the ultimate leg tip and podomeres in female and male Haplophilus subterraneus as depicted from SEM. a Tip of tarsus 2 of a female’s ultimate leg, which is encircled by trichoid sensilla (note the characteristic socket). Encompassed by that circle, 1–2 sensory cones with round socket are present, located close to a depression on a larger cuticular field (asterisk). Frequently, smaller pores of solitary flexo-canal glands are present. b Tip of tarsus 2 in a male ultimate leg. Likewise, one or two sensory cones framed by a larger cuticular field and flanked by a fissured area of the cuticle are present (asterisk; obscured by secretion or dirt). Several shafts of trichoid sensilla are broken off. c Apical view on the female tarsus 2 tip with terminal invagination (asterisk), two sensory cones, and mostly trichoid sensilla (which are hard to distinguish at this magnification and viewing angle). d Sensilla microtrichodea at the transition of tibia and femur in a female ultimate leg. e Detail view of two sensilla microtrichodea at the transition of tibia and femur. Note the deflection of the lower sensillum and the restricting socket in the upper sensillum. Abbreviations: fceg solitary flexo-canal gland, gd stalked duct of epidermal gland, sc sensory cone, st sensillum trichodeum