Diptilomiopus floridanus Craemer and Amrine sp. nov. (Figs 1–27, measurements and counts in Table 1)

Female (n = 90 for qualitative characteristics) (Figs 1–9, 15–22, 24–27). Idiosoma—Fusiform to somewhat elongate fusiform. Gnathosoma—Palp setae ep and v present; presence of palp setae d uncertain: the second author thought he could detect these setae, obscure and inserted on the medial surfaces of the palpi, and the first author could not detect them unambiguously among the other electron dense structures. Prodorsal shield—Similar to other Diptilomiopus spp., broadly oval and short, with a characteristic convex shape and posterior declivity; ornamentation on prodorsal shield consisting of ridges forming a cell-like pattern. Shield ornamentation includes parts of the median line, on the first and third quarter of the shield from the anterior shield margin; the cell-like pattern can be interpreted to be four rows of cells: 12 cells (six on each side of the median line) in anterior row (the sixth cell on either side is smaller and more obscure than the other cells), one cell in second row, visually in the center of pattern, and six cells in third row from anterior; two open cell-like areas formed by slight ridges present on basal declivity of shield could be vaguely determined in some specimens, forming the fourth, basal row. Area largely lateral to the shield and above the leg coxae (the second author regards this area as the lateral shield) with granules, sometimes forming vague circular patterns, and three incomplete annuli. Frontal lobe present, broader than long, apparently thin and flexible with anterior margin about straight; not overhanging basal parts of chelicerae entirely; usually inconspicuous in the slide-mounted specimens and difficult to detect. Tubercles of scapular setae (sc) present, small, rounded, anterior of posterior shield margin; setae sc absent. Opisthosoma—Evenly rounded; with middorsal longitudinal ridge on either side flanked by shallow furrow and subdorsal ridge, all declining post criad, absent from about annulus 40 posteriad. Dorsal annuli without microtubercles; except about six posteriormost dorsal annuli with tiny triangular, pointed microtubercles extending from posterior annulus margins. Microtubercles on ventral annuli relatively small, rounded, sometimes slightly pointed, close to posterior margins of annuli, becoming progressively more elongate ridges from about level of f (on posteriormost ca 10 ventral annuli). Setae h1 present, minute, largely shorter than one micron; setae d, e, f and h2 relatively long and finely tapered. Legs—Setal complement of Diptilomiopus, and legs II with ft' absent; all setae ft on legs I and II relatively long and strong, not tapering to very thin apical ends, rather ending relatively bluntly, and each with a very short sub-branch with very thin thread-like apical end at about basal third; solenidion ω straight or slightly curved, noticeably knobbed. Empodium (em) with rays at angle against each branch, especially at base of em; therefore, rays could not be accurately counted on slide-mounted specimens or most SEM images, particularly in dorsal view. Empodium in lateral view usually clearly 6-rayed, but could possibly sometimes be 5-rayed. Coxigenital region— Suboral plate with some granules and tubercles similar to those on the coxisternal plates; coxisternal plates I and II with rounded (granules) to elongate tubercles almost entirely covering coxisternal plates I, sparser and in small area anteriad to 2a on coxisternal plates II; coxisternal plates I separated from each other by a relatively weak, forked sternal apodeme for most of medial margin. Setae la and 2a “as usual” within Eriophyoidea (simple and tapering), relatively long, frequently convoluted, with well-developed setal tubercles; la anterior of imaginary line through tubercles of 2a. Setae 3a tapering and relatively short. Genitalia—Internal genitalia illustrated in Figs 9 and 21; external genital coverflap with slightly raised basal areas, vaguely in the shape of two contiguous, transverse ellipses, covered with granules and elongate tubercles that vary in shape and clarity between specimens, distally smooth.

Male (n = 26 for qualitative characteristics) (Figs 10,23). Morphology, including measurements and counts, similar to that of female, except for genitalia; most setal lengths similar to shorter corresponding setae in females (Table 2); opisthosoma with 59 dorsal and 71 ventral annuli. Genitalia with scattered microtubercles immediately posterior to eugenital setae, similar to many other eriophyoid species; eugenital setae unambiguously present, with well-developed setal tubercles.

Larva (n = 1 for qualitative characteristics) (Figs 11, 12). Only one, somewhat distorted and vague specimen was available for study. Prodorsal shield with striae or ridges forming mainly basal part of the cell-pattern of ridges found in the adult; tubercles of setae sc similar to those of adult; setae sc absent. Dorsal, irregular annuli or largely smooth area immediately posterior of prodorsal shield; remainder of dorsal annuli with tiny rounded microtubercles near posterior annulus margins, microtubercles posteriad progressively more pointed and progressively closer to posterior annulus margins, situated on posterior annulus margin beyond about level of setae f. Ventral annuli with tiny, pointed microtubercles generally further away from posterior annulus margins than dorsal microtubercles, largely present from first annulus beyond coxisternal plates, in a band corresponding in width with the mid-area between setae d and e; present on entire length of ventral annuli from e posteriad; elongate on ventral annuli beyond f Setal complements as in adult, including h1 present, however setae generally much shorter (Table 1). Legs: presence of short sub-branch, found on all setae ft in adult, not visible in specimen, possibly due to their orientation; em with fewer rays than adult, but impossible to count rays accurately. Coxisternal plates I and II with granules similar in shape and area covered than those in adult. Without external genitalia, but 3a present.

Nymph (n = 7 for qualitative characteristics) (Figs 13,14). Prodorsal shield with striae or ridges forming mainly central part of the cell-pattern of ridges found in the adult; tubercles of setae sc similar to those of adult; setae sc absent. Dorsal annuli just behind posterior margin of prodorsal shield regular. Dorsal annuli smooth (without microtubercles), with pointed microtubercles on the rear margins of the posterior-most annuli, largely beyond f (similar to adult). Ventral annuli with microtubercles similar in shape, size and area covered as adult, but clearly pointed, and possibly slightly further anterior to posterior annulus margins, progressively more elongate, with elongate ridges on about 7 posterior-most annuli. Setal complements as in adult, however setae generally shorter than in adult and longer than in larva (Table 2); coxisternal plates I and II with granules similar in shape and area covered as adult; presence of short sub-branch on setae ft uncertain, em possibly 4- or 5-rayed (difficult to count). Without external genitalia, ventral annuli interrupted where external genitalia would be present in adult, 3a present.

Host plants and relation to hosts. Type specimens were collected from Citrus aurantiifolia (Christm.) Swingle ‘Key’ (Key lime), C. x aurantium L. (sour orange), C. x latifolia (Yu. Tanaka) Yu. Tanaka (lime or Tahiti lime), C. limon (L.) Burmann ‘Eureka’ and ‘Meyer’ (Eureka and Meyer lemon), C. reticulata Blanco x C. x paradisi Macfad. (tangelo), C. sinensis (L.) Osbeck (orange or sweet orange) (Rutaceae). A complete list of all Rutaceae ”. whereon D. floridanus was collected is reported by Childers et al. (2017). The exact niche of D. floridanus was not determined, because plant material (largely leaves and twigs) were directly washed in alcohol. However, it probably lives exposed on the leaf surfaces, similar to D. assamica.

Type material. All specimens were collected in Florida, USA by Carl C. Childers. Holotype. female (the holotype female can be distinguished by being the specimen imaged in Fig. 15 and depicted in Figs 2 and 8); together on one slide with 18 paratypes of D. floridanus sp. nov. (12 females, 4 males and 2 immatures), West Palm Beach, 240 Wenonah Place, 21-V-2012, from Key lime (FSCA). Paratypes. 2 females, 1 male and 1 immature on two slides, Naples, 1147 Palmatta Ridge Road, 10-VI-2013, from Eureka lemon (FSCA and NCA); 5 females on one slide, Boca Raton, 7801 Cloverfield Circle, 19-VI-2012, from lime (variety unknown) (NCA); 2 females and 3 males on one slide, Palm City, 4042 St. Lucie Lane, 14-VI-2014, from Key lime (FSCA); 10 females and 4 males on two slides, Palm City, 602 Pine Tree Lane, 14-VI-2014, from Meyer lemon (FSCA); 5 females on one slide, West Palm Beach, 240 Wenonah Place, 21-VI-2012, from Key lime (FSCA); 11 females, 4 males and 1 immature on four slides, Pine Island, 7648 Helen Rd., Bokeelia, FL, 12-VI-2013, from Meyer lemon (FSCA and NCA); 2 males and 2 immatures on one slide, Hollywood, 1910 Bahama Drive, 2-VI-2011, from lime (variety unknown) (FSCA); 6 females, 1 male and 2 immatures on two slides, Ft. Pierce, 6902 Sebastian Road, 12-VI-2012, from sour orange and tangelo (FSCA and NCA); 18 females and 1 male on three slides, Hollywood, John Williams Park, 23-VIII-2011, from sour orange (FSCA and NCA); 3 females on one slide, Ft. Lauderdale, 2725 NE 27^th Court, 18-VI-2012, from sweet orange (variety unknown) (FSCA); 15 females and 6 males on one slide, Green Acres, 1288 Olympic Circle, 20-VI-2012, from Key lime (FSCA).

Note. Diptilomiopus floridanus sp. nov. usually occurred mixed, on the same slides, with largely P. oleivora, single specimens of other mite families (not Eriophyoidea), and on two paratype slides, Aceria sp. cf. A. sheldoni.

Etymology. The species name floridanus is derived from “Florida”, the USA state where it was found the first time, and grammatically the species name is an adjective, singular, masculine and nominative.

Differential diagnosis. Diptilomiopus floridanus sp. nov. is morphologically similar to D. assamica, D. combreti and D. euscaphiae, and occurs on broadly the same hosts (Citrus spp.) as D. assamica. These four species differ largely in the ornamentation of the prodorsal shield and female genital coverflap, and presence of a small sub-branch on tarsal setae ft (Table 2). Some characters differentiating Diptilomiopus spp., including these four species, might be ambiguous due to wrong morphological observations, or lack of adequate description of intraspecific variation, or due to inadequate slide preparation. For example, setae hl has been described as being absent in D. assamica by Keifer (1959), but was found to be present in Australian specimens of the same species (Knihinicki & Boczek 2002), and differences were also found between the measurements of structures of the Australian (Knihinicki & Boczek 2002) and Indian specimens (Keifer 1959) of this species, providing that the Australian specimens were indeed D. assamica. The ornamentation of the female genital coverflap is one of the major characteristics differentiating the four species. The coverflap of D. assamica might have had ornamentation which was, as in the new species, very vague and unclear in slide-mounted specimens and might have been missed, but in this case, apart from Keifer (1959) describing the coverflap as smooth, this was corroborated in his differentiation of D. assamica from Diptilomiopus knorri Keifer (Keifer 1974).