Neoseiulus benjamini (Schicha)

Lofego, Antonio C., Demite, Peterson R., Kishimoto, Raquel G. & De, Gilberto J., 2009, Phytoseiid mites on grasses in Brazil (Acari: Phytoseiidae), Zootaxa 2240, pp. 41-59 : 46-49

Neoseiulus benjamini (Schicha)

( Figures 1–7 )

Amblyseius benjamini Schicha, 1981: 203 ; Schicha, 1987: 119; Ueckermann & Loots, 1988: 142. Neoseiulus benjamini .— Beard, 2001: 131; Chant & McMurtry, 2003a: 27.

FEMALE (9 specimens measured). Dorsum. Dorsal shield reticulated, 358 (337–375) long and 155 (145– 167) wide; j1 18 (17–19), j3 18 (16–20), j4 12 (11–13), j5 12 (10–13), j6 13 (12–15), J2 14 (12–16), J5 11 (10–12), z2 14 (13–16), z4 15 (14–17), z5 11 (10–13), Z1 15 (13–17), Z4 22 (21–24), Z5 64 (57–70), s4 16 (15–18), S2 18 (17–22), S4 24 (22–29), S5 27 (25–30), r3 17 (15–19), R1 15 (13–18). All setae smooth, except J5 and Z5, serrate.

Ven t er. Sternal shield reticulated; distances between st1-st3 84 (79–86), st2-st2 56 (52–58). Genital shield striate, distance between st5-st5 60 (55–64). Ventri-anal shield roughly rectangular, reticulated, with pre-anal pores posteromesad to JV2, 120 (114–128) long, 91 (84–98) wide at level of ZV2 and 81 (75–85) wide at level of anus. JV5 34 (31–37).

Peritreme. Extending almost to level of j1.

Chelicera. Movable cheliceral digit 28 (26–29) long, with 1–2 teeth; fixed cheliceral digit 27 (26–29) long, with 6–10 teeth.

Spermatheca. Calyx disc-shaped, 5 (4–10) long; diameter near vesicle 10; atrium nodular.

Legs. Leg I, II, III, genu and tibia IV without macrosetae; St IV with macroseta sharp-tipped 27 (25–28) long. Chaetotaxy: genu II 2-2 /0-2/0-1; genu III 1-2 /1-2/0-1.

MALE (4 specimens measured). Dorsum. Dorsal shield reticulated, 276 (272–282) long and 136 (135– 137) wide; j1 16 (15–19), j3 18 (17–19), j4 11 (10–12), j5 10 (10–11), j6 12 (10–13), J2 12 (11–13), J5 10 (9– 10), z2 14 (12–15), z4 15 (14–16), z5 10 (10–11), Z1 14 (13–15), Z4 21, Z5 51 (47–57), s4 16 (15–16), S2 17 (16–17), S4 22 (21–22), S5 22 (21–23), r3 16 (15–17), R1 13 (12–14). All setae smooth, except J5 and Z5, serrate.

Ve n t e r. Ventri-anal shield 103 (97–114) long and 115 (105–125) wide at the anterior corners, fused to peritremal shield by anterior corners; JV5 23 (22–23).

Peritreme. Extending slightly anterior to the level of j3.

Spermatodactyl. L-shaped, shaft 15 (14–16).

Legs. Leg I, II, III, genu and tibia IV without macrosetae; St IV sharp-tipped, 24 (23–26) long.

Specimens examined: União Paulista (20°55' S, 49°55' W), August 2007, on B. brizantha (1 Ƥ). Sud Mennucci (20°39' S, 50°54' W), August 2008, on B. brizantha (1 Ƥ, 1 3). Santo Antônio do Aracanguá (20°55' S, 50°20' W), October 2007, on B. decumbens (1 Ƥ). Piracicaba (22°41'S, 47°37'W), February 2008, on M. minutiflora (1 Ƥ, 2 3); July 2008, on P. purpureum (1 Ƥ). São José do Rio Preto (20°47' S, 49°21' W), February 2008, on B. decumbens (1 Ƥ); August 2009 on B. decumbens (7Ƥ). Jales (20°13' S, 50°30' W), June 2008, on B. ruziziensis (1 Ƥ). Onda Verde (20°32' S, 49°14' W), July 2008, P. maximum (1 3). São José do Rio Preto (20°45' S, 49°19' W), July 2008, on B. brizantha (2 Ƥ).

Remarks: This species is previously known from Australia and South Africa. The measurements and shape of structures fit generally well the previous descriptions of N. benjamini ( Schicha 1981, 1987; Ueckermann & Loots 1988; Beard 2001). However, as indicated above, the Brazilian population examined in this study has a variable number of teeth on both cheliceral digits ( Fig. 7 ). This was confirmed from the examination of eight specimens collected from a same host ( B. decumbens ) in a same collecting site (São José do Rio Preto), seven of them collected on a same date. In some specimens, the variability was observed even between right and the left chelicerae.

Neoseiulus benjamini belong to paspalivorus species group, being more similar to N. mumai ( Denmark) , N. paspalivorus (De Leon) and Neoseiulus baraki . However, N. mumai and N. paspalivorus differ from N. benjamini by having the pre-anal pores longitudinally aligned with the bases of JV2; in addition, in N. mumai the ventri-anal shield is barrel-shaped and in N. paspalivorus seta Z4 and macroseta of tarsus IV are shorter (12 and 18 µm, respectively). Neoseiulus baraki differs from N. benjamini by having the reticulation of the dorsal shield, especially between setae of the j-J series, composed of less elongate cells, and ventri-anal shield less elongate. An examination of the holotype of N. baraki showed that seta ad1 of its femur IV is longer (18– 20µm) and thicker than seta ad2 (12–15µm) of the same segment; in the specimens collected in this study and identified as N. benjamini , both of these setae are slender and of the same length (12–15µm) ( Fig. 4 ). This species was originally described from a grass ( Pennisetum clandestinum Chiov. ). This is the first record of this species in the American continent.

Figures

FIGURE 7 Neoseiulus benjamini (Schicha). Female chelicerae (A – E variation in number of teeth).

FIGURES 1 – 6 Neoseiulus benjamini (Schicha). 1 – 4. Female: 1. dorsal shield; 2. ventral idiosoma; 3. spermatheca; 4. Leg IV. Male: 5. ventri-anal shield; 6. spermatodactyl.