Anatomical organization of the tracheal system ofVarroa jacobsoni (Acari: Varroidae)

The respiratory system of the femaleVarroa jacobsoni (Oudemans): its adaptations to a range of environmental conditions

“…1 C, 1 E, 1 F, 1G,2B,2C,2E-2H,3A-3D ), as described in some littoral Uropodina (Pugh et al, 1987b). The 'floor' and 'walls' of both the peritrematic groove and stigmatic atrium are lined with broad-basedl distally parabolic micropapillae ( ='villi' of Richard et al, 1990), which are longest proximal to the inner stigmatic orifice within the stigmatic atrium (Figs. 2E-2H,3B; Table 1 ).…”

“…Although the mode of respiration has not been described, it has been assumed that the peritreme forms a plastron (Strube and Fletchmann, 1985;Liu, 1986;Ramirez and Otis, 1986;Ramirez, 1987;Richard et al, 1990). However, the peritrematic slit is too narrow to support a gas gill (Table 1, Appendix 1 ), and the entry of water into the peritrematic groove and stigmatic atrium to form an intraperitrematic plastron as observed in some Mesostigmata is unlikely (Hinton, 1971;Krantz, 1974;Pugh et al, 1987a).…”

“…2G,2H,3B). The tracheal trunks are lined with spiral taenidia, typical of other Gamasina (Witalifiski, 1979;Pugh et al, 1987a,b) but are bilaterally cross-linked (Richard et al, 1990), a feature previously recorded only in the Halarachnidae (Newell, 1947). Contrary to the interpretation of Liu ( 1986 ), no direct muscles are associated with the respiratory system of V. jacobsoni, or any other mesostigmatic mite (Woodring and Galbraith, 1976;Witalifiski, 1979;Pugh et al, 1987a,b).…”

“…2G,2H,3B ). The deeper-lying tracheal atrium, overlooked by Richard et al (1990) APmax --r cos• + x//2/4-r 2 sin2~ (after Crisp, 1964) Where: 7 = surface tension of water = 72 dynes cm -~ (Hinton, 1971 ); ~ = contact angle = 110 ~ ( Hinton, 1971 ); r= radius of supporting elements (lips of groove/stigma); l= separation of supporting elements.…”

“…Suggestions include "respiratory regulation" (Oudemans, 1904;Langhe et al, 1976), "adaptations" to temperature, humidity, pressure and/or carbon dioxide concentration (Langhe and Natzkii, 1977;Shabanov et al, 1978;Sadov, 1980;De Jong et al, 1982;Liu, 1986;Ramirez, 1987 ), a buoyancy organ (Strube and Fletchmann, 1985 ), a snorkel (Ramirez, 1987 ), a respiratory plastron (Strube and Fletchmann 1985;Liu, 1986;Ramirez and Otis, 1986;Ramirez, 1987;Richard et al, 1990) or concerned with "hydraulic balance" (Fletchmann, in Ramirez, 1987 ).…”