Fedrizziidae Trägårdh 1937

Seeman, Owen D., 2007, Revision of the Fedrizziidae (Acari: Mesostigmata: Fedrizzioidea), Zootaxa 1480, pp. 1-55 : 5-8

Fedrizziidae Trägårdh 1937

Type genus. Fedrizzia Canestrini

Diagnosis. Sternogynial shield enlarged, the only genital shield visible externally ( Figs 2 b, 3). Latigynial shields internal and strap-like, closely approximating the ventral shield, the lateral sides of the genital opening, and posteriorly connected to a tiny, internal mesogynial shield. Mesogynial shield associated with an internal porose plate. Ventrianal shield present, partially or wholly separate from ‘ventral’ shields (fused exopodal, marginal, metapodal and ventral shield). Seta h3 of male 5–10 long, positioned closer to midline of gnathosoma than h2 ( Fig. 4 ). Corniculi large, broad, semi-membranous flaps that approximate the internal malae ( Figs 1 , 4 ). Marginal dorsal setae small, <15 long, excepting the anterior pair of dorsal setae. Dorsal shield with an anterior hyaline process, sometimes extending posterior of coxa II. Associated with the Passalidae ; other host records accidental. Known distribution: Australia, Indonesia, Malaysia, Thailand, Papua New Guinea, and Philippines.

Remarks. The Fedrizziidae and Klinckowstroemiidae have extremely similar morphologies and host associations, and differ only in the formation of the female genital shields ( Fig. 2 ) and their biogeographical distribution. Here, I have retained the interpretation of the marginal, internal genital elements in Fedrizziidae representing highly reduced latigynial and mesogynial shields. The latigynial shields are strap-like and lay beneath the edge the sternogynial shield, and meet posteriorly at a small, ovular mesogynial shield. The junction of these shields is associated with an internal porose plate, especially obvious in Neofedrizzia , and also present in the Klinckowstroemiidae . However, unlike the Klinckowstroemiidae , the Fedrizziidae have up to three processes that lie mostly behind the sternogynial shield, extending up to 100 µm posteriorly. I regard these processes as the modified apodemes and condyles of the genital shields of Klinckowstroemiidae , especially the sternogynial apodeme ( Rosario & Hunter 1987).

Kethley (1977) defined the Klinckowstroemiidae + Fedrizziidae by five setal absences: al1 and pl1 on genu I, av1 and pl1 on genu II and pl1 on tibia IV. However, my analysis of leg setation shows these setae are present in Klinckowstroemiidae and Fedrizziidae ( Figs 5–8 ). Kethley (1977) did not have immature life stages for these families, so his absences may represent different interpretations of leg chaetotaxy.

The number of setae on each leg segment is uniform across the family: Cx I–IV 2-2 -2-1; Tr I–IV 6-5 -5-5; Fe I–IV 12-10-7-8; Ge I–IV 11-11-9-9; Ti I–IV 13-10-9-9; Ta I–IV 33 (approx.)-19-19-22. Kethley (1977) implied that the chaetotaxy of fedrizziid and klinckowstroemiid mites is identical, but in comparison to Rosario and Hunter (1987) there are several differences: the trochanters are 6-4-4-4, i.e., one less seta on Tr II–IV; the femora are 10-9-7-8, i.e., two less setae on femur I and one less seta on femur II; and the tibiae are 11-10- 9-9, i.e., two less setae on tibia I. Furthermore, Rosario and Hunter (1987) report 17 setae on tarsi II–III (lacking the small terminal setae ad1 and pd1) and 18 setae on tarsus IV (lacking ad1 and pd1, but also av4 and pv4 on the intercalary sclerite). I have examined specimens of Klinckowstroemiella from Ecuador and Klinckowstroemia from Mexico and found all of these differences to be incorrect: leg chaetotaxy of Klinckowstroemiidae is the same as the Fedrizziidae .

The modified legs of adult fedrizziid mites make the assignment of leg setae difficult, but the legs of immature life stages are unspecialised and leg chaetotaxy of the deutonymph is considerably simpler ( Figs 9– 12 ). I have applied the deutonymphal setal names for N. camini to that of the adult ( Figs 5–8 ), thus making the assumption that the chaetotaxy of N. camini deutonymphs is applicable to all fedrizziid and klinckowstroemiid mites. I believe this is a reasonable assumption because of the uniformity of leg chaetotaxy across the Fedrizziidae and Klinckowstroemiidae . The chaetotaxy of the Fedrizzioidea is also comparable to that of M. vazquezus : fedrizzioids have two additional setae on femur I, pl2 and av3; seta al3 instead of al2 (this represents a different interpretation of which al seta is on the basifemur) on femur II; lack seta al2 on genu II; lack seta pv1 on genu III; and lack setae pv1 and pl1, but has seta pd3 on genu IV.

Within the Fedrizziidae , the form of leg setae is moderately useful in Fedrizzia and less so (but still worthwhile) in Neofedrizzia . However, I have generally avoided using these characters in diagnoses because setae intermediate between slender and spine-like are difficult to interpret.

Figures

FIGURE 1. Chelicerae of a female Fedrizzia oudemansi. A palmate corniculus is to the bottom-right of chelicerae, and the corniculus is overlaid by the pilose seta av 1 of the palp trochanter. Scale bar = 10.

FIGURE 2. Genital shields of female (A) Klinckowstroemiidae, Klinckowstroemia sp. (Mexico, ex Heliscus tropicus) (B) Fedrizziidae, Neofedrizzia vidua (QM S 74209). Sg = sternogynial shield; Lg = latigynial shield; Mg = mesogynial shield. Scale bar = 50 µm.

FIGURE 4. Gnathosomal region of male (A) Fedrizzia abradoalves sp. nov. and (B) Neofedrizzia vidua. Abbreviations: h 1 – 3 = hypostomal setae 1 – 3; av 1 = first anteroventral seta of palp trochanter. Arrow points to hypostomal tubercle. Scale bar = 10.

FIGURES 5 – 8. Leg chaetotaxy of adult Neofedrizzia helenae sp. nov. 5, leg I; 6, leg II; 7, leg III, 8, leg IV. Scale bar = 50.

FIGURES 9 – 12. Leg chaetotaxy of the deutonymph of Neofedrizzia camini sp. nov. 9, leg I; 10, leg II; 11, leg III, 12, leg