Euseius ennsi, Ueckermann & de Moraes & Childers, 2020

Ueckermann, Edward A., de Moraes, Gilberto J. & Childers, Carl C., 2020, A new Euseius species on citrus and wild lime, Zanthoxylum fagara (Rutaceae), in Florida and an updated key to Euseius species from the state, Acarologia 60 (4), pp. 863-871 : 864-869

Euseius ennsi sp. n. ( Figs. 1–4 )

Zoobank: 7C513FDB-9D08-4D6A-967F-6157DF355BD7

Type material — Holotype female, 3 paratype females and 2 paratype males, on Citrus aurantium L., 5620 SW 3rd Place , Margate , 26.22660°N, 80.20377°W, 18 June 2012 ; 3 paratype females on C. reticulata x C. paradise, 2817 NE 20 Court , Fort Lauderdale , 26.15238°N, 80.11113°W, 18 June 2012 ; one paratype female on Citrus sinensis (L.), 2756 18th Street

NE, Fort Lauderdale, 26.14980°N, 80.11139°W, 18 June 2012 ; one female on wild lime, Zanthoxylum fagara (L.) Sarg., Secret Woods Park, Fort Lauderdale, 26.08839°N, 80.18028°W,

25 January 2012 ; one paratype female on C. sinensis, 600 SW 9th Street, Cape Coral, 26.63397°N, 81.9869°W ; 17 June 2013 ; one paratype female and one paratype male, on

Citrus tangelo J.W. Ingram & H.E. Moore, 401 SE 1st Terr, Pompano Beach, 26.22495°N, 80.12369°W, 18 June 2018 ; one paratype female, on Citrus limon (L.) Burm. Fil., 617 NW 13th

Terr, Cape Coral, 26.67776°N, 81.98931°W, 12 June 2013 ; 2 paratype females, on C. tangelo, 11773 85th Avenue N, Seminole, 27.85024°N, 82.80457°W, 19 June 2013 ; one paratype female,

on Citrus paradise Macfad, 1288 Olympic Circle, Green Acres, 26.65660°N, 80.15261°W, 20

June 2012; ; one paratype female on C. sinensis, 14642 168 Avenue, Indiantown, 27.02817°N, 80.48491°W, 15 June 2012 ; one paratype female on Citrus limon, 507 Warwick Drive, Venice, 27.06157°N, 82.36867°W, 17 June 2013 ; one paratype female on Citrus limon, 27595 Tarpon Way, Bonita Springs, 26.33568°N, 81.82864°W, 11 June 2013.

Female (n = 8)

Dorsum — Shield strongly reticulated. Length of shield (305­329) [310], width (214­233) [217]. Setae j1 (28­33) [30], j3 (32­41) [31], j4 (9­14) [11], j5 (9­12) [11], j6 (8­12) [10], J2 (10­12) [12], J5 (4­6) [5], z2 (17­25) [19], z4 (23­34) [25], z5 (8­11) [10], Z1 (9­13) [13], Z4 (9­13) [13], Z5 (61­73) [64], s4 (36­52) [36], S2 (13­24) [17], S4 (17­26) [21], S5 (20­30) [24], r3 (12­17) [15], R 1 (9­13) [11]. All dorsal setae smooth except for Z5, which are slightly serrate. Dorsal shield with 5 pairs of solenostomes gd (2, gd4, gd6, gd8, gd9) and 11 pairs of poroids. Sigilla present on prodorsum. Peritreme reaching to or just beyond setae z2 (130­153) [153] long ( Fig. 1 ).

Venter — All ventral shields smooth. Distances between St 1­ St 3 (58­65) [56], St 2­ St 2 (65­72) [67], St 5­ St 5 (64­72) [68]. Sternal shield with3 pairs of setae and 2 pairs of pores. Posterior margin of sternal shield lobed. Two pairs of metapodal shields present, primary shield (16­21) [20] long and secondary shield (9­120 [9] long. Ventrianal shield (95­105) [98] long, width at level of setae ZV 2 (46­56) [49], width at level of anal opening (66­74) [69]. With 3

pairs of preanal setae almost transversely aligned and 2 pores. Setae JV 5 smooth, (34­42) [37]

( Fig. 2A ).

Chelicera — The position of the chelicerae renders an illustration impossible. Fixed digit (20­26) [24], with apparently 4 small teeth and a pilus dentilis; movable digit (20­25) [24], with only one tooth.

Spermatheca — Calyx tubular with atrium bifid, (25­32) [27] long ( Fig. 2B ).

Legs — Macrosetae acute distally: Sge II (20­26) [24], Sge III (20­32) [28], St IV (66­76) [68], Sti IV (37­44) [38], Sge IV (47­55) [49]. Genu I 2­2/1­2/1­2, genu II 2­2/0­2/0­1, genu III 1­2/1­2/1­0, genu IV 1­2/1­2/1­0 ( Fig. 2C ).

Male (n = 2)

Dorsum — Similar to that of female, except for setae r3 and R 1 which are on the dorsal shield ( Fig 3 ). Length of shield 248­261, width 178­182. Setae j1 20­23, j3 28­32, j4 7­11, j5 8­10, j6 8­10, J2 10­11, J5 5­7, z2 19­22, z4 25, z5 7­10, Z1 9­10, Z4 11­12, Z5 52­53, s4 34­35, S2 15­16, S4 19­22, S5 17­26, r3 14­16, R 1 9­10. All dorsal setae smooth except for setae Z5 which are slightly serrate. Peritreme reaching level of setae z4.

Venter — Sternogenital shield smooth, 123­134 long and 84­87 wide at level between setae st2 and st3 with 5 pairs of setae and 2 pairs of poroids. Ventrianal shield reticulate­striate, 104­105 long, width at level of anterior margin 143­149, with 3 pairs of transversely aligned preanal setae and 2 pores. Setae JV 5 smooth, 22­23 ( Fig. 4A ).

Chelicera — Spermatodactyl L­shaped and 26­27 long ( Fig. 4B ). Fixed digit, with 2 teeth and a pilus dentilis; movable digit with only one tooth.

Legs — Macrosetae acute distally: Sge II 21, Sge III 22­23, St IV 53­54, Sti IV 29­31, Sge IV 36­38. Genu I 2­2/1­2/1­2, genu II 2­2/0­2/0­1, genu III 1­2/1­2/1­0, genu IV A 1­2/1­2/1­0.

Etymology

This species is named after the late Dr Wilbur R. Enns in recognition of his roles as teacher and advisor in the Department of Entomology, University Missouri­Columbia.

Remarks

This species closely resembles Euseius quetzali McMurtry et al., 1985 , a species described from Guatemala and also reported from Mexico and California (Demite et al., 2019). Congdon

& McMurtry (1986) compared the morphology of populations from California and Guatemala identified as E. quetzali . They were very similar, except for the larger ratios j 1/ j 3 and z 4/ z 2,

and shorter peritreme in the Californian population; these characteristics of the Californian population are comparable with those of the specimens collected in this study. Results of crossing experiments conducted by Congdon & McMurtry (1986) led them to conclude that the

Californian population belonged to the same species as populations they collected in Mexico and Guatemala. In the first part of that study, no offspring were obtained when crossing

Californian E. quetzali and Mexican Euseius hibisci (Chant) , indicating that they belonged to different species. However, the results obtained when crossing Californian populations of those species were not considerably different from the results obtained when crossing Californian and Guatemalan populations of E. quetzali . In both cases, females were never produced in the crossings. In the first case, males and females were produced only by E. hibisci females, while in the second case, males and females were produced by females from both areas. Hence, we consider that their decision about the identity of the species was based on the lack of sufficient evidence that they belonged to different species rather on the availability of evidence showing that they belonged to the same species. Phytoseiids are known to reproduce mainly by a process designated as pseudoarrhenotoky ( Hoy, 2011), in which offspring are only produced after mating and fertilization of the eggs.

According to our examination of paratypes of E. quetzali , from data provided in the original description of the species ( McMurtry et al., 1985) and in the redescription by Congdon &

McMurtry (1986), this new species differs from E. quetzali by the ornamentation of the dorsal shield (smooth in the central area of the podonotal region of the dorsal shield E. in quetzali ), and by the much shorter j 4– j 6, J 2, z 5, Z 1 and Z 4, which appear to be the shortest dorsal shield setae of the new species but also shorter than that of E. quetzali . In our examination of the paratype females, the peritreme extends only up to z 2, instead of up to j 3 as shown in the illustration of the original description.

Euseius ennsi n. sp. is also similar to E. obispoensis Aponte & McMurtry, 1997 especially for the strong reticulation of the dorsal shield. The latter differs for: having r 3 always and R 1

occasionally on dorsal shield; most dorsal shield setae as long as to up to 20% longer except z 4

and s 4, about 20% shorter; and ventrianal shield strongly reticulate in preanal region and light reticulation in anal region. The new species also resembles E. citri van der Merwe & Ryke,

1964 and E. citrifolius Denmark & Muma, 1970 ; however, E. citri has calyx of spermatheca slightly bulged near atrium and flaring near vesicle, whereas E. citrifolius has dorsal shield only lightly reticulate and macroseta of basitarsus IV distinctly bent. As the latter species, E. relictus

Chaudhri, Akbar & Rasool differs from the new species by having macroseta of basitarsus IV

(as well as macrosetae of genu and tibia IV) distally bent. Euseius vulgaris Liang & Ke, 1983

differs from the new species for having peritreme longer (reaching midway between insertions of j 3 and z 2, and ventrianal shield almost twice as wide at anus level than at level of Zv 2.

This new species is also very closely related to E. vivax (Chant & Baker) and E. fructicolus

(Gonzalez & Schuster) but differs from both in that the dorsal shield is completely reticulated and not smooth as in E. fructicolus and lightly reticulated as in E. vivax . They also differ from the new species in the shape of the tubelike calyx of the spermatheca, which is almost straight in the former two but bent or coiled in the new species. The macrosetae on leg IV of

E. fructicolus are blunt distally but acute in the new species. Setae Z5 are serrated in the new species but smooth in both E. vivax and E. fructicolus . In the new species setae Z5 is about six times as long as j6 and J2 but about five times or less in E. vivax and E. fructicolus , respectively

( Lopes et al., 2015).

Figures

Figure 1 Euseius ennsin. sp., female. Dorsal view.

Figure 2 Euseius ennsin. sp., female. A – Ventral shields; B – Spermatheca; C – Leg IV.

Figure 3 Euseius ennsin. sp., male. Dorsal view.

Figure 4 Euseius ennsin. sp., male. A – Ventrianal shield; B – Spermatodactyl.