Typhlodromalus peregrinus (Muma)

Kreiter, S., Mailloux, J., Tixier, M. - S., Le Bellec, F., Douin, M., Guichou, S. & Etienne, J., 2013, New Phytoseiid Mites Of The French West Indies, With Description Of A New Species, And New Records (Acari: Mesostigmata), Acarologia 53 (3), pp. 285-303 : 294-295

Typhlodromalus peregrinus (Muma)

Typhlodromus peregrinus Muma, 1955: 270 ;

Typhlodromalus peregrinus Muma and Denmark, 1970: 88 ; Moraes et al., 1986: 132, 2004: 202; Zacarias and Moraes, 2001: 582;

Typhlodromus (Amblyseius) peregrinus Chant, 1959: 97 ;

Amblyseius peregrinus McMurtry, 1983: 255 . Moraes et al., 1991: 130;

Typhlodromus (Amblyseius) robineae Chant, 1959: 98 ;

Typhlodromus (Amblyseius) evansi Chant, 1959: 99 ;

Typhlodromus (Amblyseius) primulae Chant, 1959: 99 (synonymy, according to Muma, 1964)

This species is very common on citrus ( Muma, 1955, 1967; Peaea, 1992; Childers, 1994; Villanueva and Childers, 2004, 2005; Fadamiro et al., 2008, 2009) and solanaceous plants ( McMurtry, 1983; Fiaboe et al., 2007) in several countries and is very often reported as the most abundant species.

Typhlodromalus peregrinus can be found at the underside of mature citrus leaves, inside tree canopy, under empty scale armor, clump and dead scale insects whitefly exuvia, sooty mold and mine of Phyllocnistis citrella Stainton ( Muma, 1967; Childers, 1994; Villanueva and Childers, 2011). Muma (1969) reported that T. peregrinus was able to reproduce and develop on Panonychus citri (McGregor) but did perform better on eggs and crawlers of chaff scale, Parlatoria pergandii Comstock , and six-spotted spider mite, Eotetranychus sexmaculatus (Riley) . This phytoseiid was also reported to feed on Phyllocoptruta oleivora (Ashmead) , providing some degree of rust mite suppression on lime ( Peaea, 1992). Thus, T. peregrinus seems to be a generalist species with the ability to reproduce and develop on the two key pests on Guadeloupe and Martinique citrus, P. citri and P. oleivora and probably several occasional pests. Its optimal preys were evaluated as Aleyrodidae , Coccidae , and Tetranychidae by Muma (1971). Fouly et al. (1995) have studied the biology of T. peregrinus in the laboratory at 26°C. Each of the following organisms was evaluated as suitable diet: all stages of T. urticae ; immature stages of P. citri ; and pollens of Malephora crocea , Quercus virginiana , and Typha latifolia . The combination of T. urticae with pollen was also tested. Total developmental time ranged between 5.73 and 7 days for females and between 5.67 and 6.93 days for males. The percentage of females in the total population ranged between 53 and 61 %. A diet of T. urticae provided the shortest generation time (T), greatest female longevity, and mean total fecundity (F) which resulted in the highest net reproductive rate (Ro) value (25.31 expected females per female), intrinsic rate of increase (rm = 0.224), and finite rate of increase (λ = 1.25) per day for T. peregrinus . Diets of only P. citri or M. crocea resulted in close values of T = 8.67, 8.91; F = 47.11, 49.47; R 0 = 24.00, 26.65; rm = 0.210, 0.219; and λ = 1.23, 1.24, respectively. Quercus virginiana and T. latifolia were the less favorable food sources, with results of T = 8.78, 9.41; F = 30.38, 24.25; R 0 = 14.20, 12.04; rm = 0.193, 0.170, and λ = 1.21, 1.18, respectively.

The occurrence of high densities of this species on ground cover vegetation (weeds) is explained in Alabama citrus orchard ( Fadamiro et al., 2008, 2009) by the possibility that grasses may serve as overwintering sites and alternative food sources, which is probably the most important factors in French West Indies citrus orchards as there is no overwintering in citrus crop in this tropical area.

Typhlodromalus peregrinus was collected from 64 ground cover plants or vines in Florida citrus fields ( Childers and Denmark, 2011) with highest numbers found on the following plants: Bidens alba , Solanum americanum (which is one plant of the ground cover on which T. peregrinus was collected in Guadeloupe), Amaranthus spinosus , Gnaphalium pensylvanicum , Lantana camara and Chenopodium ambrosioides ). In Florida, the highest numbers of T. peregrinus in ground cover corresponded with peaks in thrips numbers, suggesting possible predation on one or more species of thrips occurring. Childers and Denmark (2011) suggest that this species should therefore be evaluated as a predator of thrips larvae and/or adults. Significant increases in numbers of T. peregrinus were also correlated with increased levels of several pollen species on citrus leaves ( Villanueva and Childers, 2004).

Thus, considering all these elements, it is possible that T. peregrinus may constitute a key species in citrus orchards in French West Indies.

Previous Records — Brazil, Colombia, Costa Rica, Ecuador, Guatemala, Guyana, Hawaii, Honduras, Mexico, Nicaragua, Puerto Rico, Suriname, USA (Florida, Alabama, Missouri), Venezuela ( Moraes et al., 2004b).

Specimens examined — Guadeloupe, Basse- Terre, Vieux-Habitants, Station Le Bouchu du CIRAD, 16°03’N, 61°45’W, alt. 21 m, 9 ♀ and 7 ♂ extracted froom a mixture of various herbaceous plants collected in an experimental citrus crop ( Achyranthhes aspera , Centrosema sp., Chamaescye hypericifolia , Chloris inflata , Croton lobatus , Echinochloa colona , Ipomea hederifolia , Macroptilium lathyroides , Merremia umbellata , Neonotonia wightii , Rhynchosia minima , Solanum americanum , Tridax procumbens , Urena lobata , Vernonia cinerea ), Mailloux coll., April to December 2008.

Remarks — this is the first record of this species in the West Indies. The measurements and description of the specimens collected fit very well those given by Moraes and Mesa (1988).

The average measurements of the nine adult females presently found are: dorsal shield strongy reticulated on the whole dorsum, 344 (329 – 350) long and 219 (184 – 285) wide, with 5 solenostomes (gd1, 2, 6, 8 and 9), 10 pairs of poroids, 17 pairs of dorsal setae and 2 pairs of sub-lateral setae: j1 25 (22 – 29), j3 37 (34 – 42), j4 15 (11 – 20), j5 17 (14 – 20), j6 20 (16 – 27), J2 20 (17 – 23), J5 8 (6 – 11), z2 21 (20 – 25), z4 33 (28 – 41), z5 17 (11 – 20), Z1 32 (29 – 35), Z4 48 (47 – 51), Z5 59 (57 – 61), s4 45 (38 – 50), S2 31 (28 – 34), S4 25 (20 – 30), S5 13 (10 – 19), r3 18 (12 – 22), R1 17 (13 – 20). All setae smooth, except Z4 and Z5 which are moderately serrated. Peritreme extending to the level of j1. Ventral shields smooth. Sternal shield large, with 3 pairs of setae and 2 pairs of pores; 1 pair (st4) out of the sternal shield, on a small metasternal shield; posterior margin with a convex lobe overlapping the genital shield. Distances between st1-st3 66 (63 – 71), st2-st2 63 (60 – 65), st5- st5 76 (73 – 78). Two pairs of metapodal shields 16 (14 – 18) long, 4 (3 – 6) wide for the largest, 5 – 8 long and very thin for the smallest one. Ventrianal shield with 3 pairs of pre-anal setae, JV1, JV2 and ZV2 and one pair of elliptical pre-anal pores. Membrane surrounding ventrianal shield with 4 pairs of setae ZV1, ZV3, JV4 and JV5 and 4 pairs of round to oblong poroids; ventrianal shield 93 (88 – 103) long, 64 (60 – 68) wide at level of anterior corners and 61 (57 – 74) wide at level of anus. JV5 42 (37 – 45) long and smooth. All legs with smooth macrosetae: SgeI 17 (13 – 23), SgeII 20 (18 – 25), SgeIII 30 (28 – 30), Sti- III 20 (15 – 25), SgeIV 42 (34 – 44), StiIV 3 (18 – 25), StIV 62 (58 – 65). All macrosetae are whip-like with a small bulbous tip. Chaetotactic formula of genu II: 2-2/0, 2/0-1; genu III: 1-2/1, 2/0-1. Length of legs I: 342 (278 – 369), II: 253 (226 – 282), III: 251 (214 – 286), IV: 341 (275 – 388). Chelicerae with fixed digit 32 (30 – 36) with 7 teeth and movable digit 30 (28 – 32) with 3-4 teeth. Calyx of spermatheca fundibular ( Denmark et al. 1999) with the cervix elongate, 5 (3 – 7) wide and 16 (9 – 22) long, with a big atrium at the basis.

The average measurements of the seven adult males presently found are: dorsal shield like in the female, 256 (243 – 275) long and 143 (134 – 149) wide. Setae j1 19 (18 – 20), j3 29 (25 – 30), j4 11 (7 – 13), j5 12 (8 – 16), j6 14 (12 – 16), J2 11 (7 – 16), J5 7 (5 – 8), z2 16 (13 – 17), z4 27 (25 – 29), z5 11 (10 – 12), Z1 18 (16 – 22), Z4 34 (31 – 37), Z5 39 (34 – 42), s4 35 (33 – 36), S2 17 (16 – 18), S4 14 (12 – 16), S5 9 (7 – 12), r3 17 (15 – 19), Rl 13 (12 – 16). Peritreme extending to the level of j1. All venter shields smooth. Sternogenital shield with 5 pairs of setae and 2 pairs of pores. Distances between st1- st3 58 (56 – 59), st2-st2 54 (50 – 56), st5-st5 37 (32 – 40). Ventrianal shield not fused with peritremal shields with 3 pairs of pre-anal setae, JV1, JV2 and ZV2, one pair of elliptical preanal solenostomes and 2 pairs of poroids. Membrane surrounding ventrianal shield with one pair of setae JV 5 in level with anal opening, and no visible pair of oblong poroids; ventrianal shield 93 (85 – 100) long, 132 (127 – 146) wide at level of anterior corners and 59 (54 – 65) at level of anus. Macrosetae on all legs: SgeI 15 (13 – 18), SgeII 16 (15 – 20), SgeIII 22 (20 – 25), StiIII 15, SgeIV 31 (27 – 36), StiIV 17 (15 – 21), StIV 46 (40 – 51). Chaetotactic formula of genu II and genu III are identical to the female. Length of leg I: 250 (228 – 276), II: 202 (182 – 228), III: 218 (193 – 253), IV: 304 (275 – 326). Spermatodactyl of cheliecerae with a large toe terminating the foot, shaft 19 (18 – 20) long.