Arytinnis modica (Loginova) Percy Csiro, 2003

Percy Csiro, Diana M., 2003, Legume-feeding psyllids (Hemiptera, Psylloidea) of the Canary Islands and Madeira, Journal of Natural History 37, pp. 397-461 : 433

Arytinnis modica (Loginova) comb. n.

(figures 13A, B, 20B)

Arytainilla modica Loginova, 1976: 23 ; Hodkinson and Hollis, 1987: 42.

Adult

Colour. Mid-green to yellow-green or grey-green; forewing clear, veins uniform light or mid-brown.

Description. Loginova (1976).

Nymph

Colour. First to second instars orange or cream, some with black tergites, 4th–5th instars pale green or yellow.

Fifth instar structure. Antennal segments seven.

Fifth instar measurements. (Specimens 4) BL: 1.6–1.75; BW: 1–1.03; WL: 0.57–0.65; CPL: 0.47–0.55; CPW: 0.61–0.7; RW: 0.17–0.18; HW: 0.61–0.69; AL: 0.88–1.08.

Fifth instar chaetotaxy. Head setae simple; ocular seta simple, inconspicuous; primary and secondary post-ocular setae simple or narrowly capitate. Dorsal thoracic setae short simple. Forewing and hindwing pads each with one apical macroseta, distinctly or narrowly capitate, on the hindwing pad paired with smaller simple seta; proximal setae if present simple, sometimes indistinct from simple surface microsetae. Dorsal abdominal pre-caudal macrosetae absent or present on anterior tergites, short simple, caudal plate macrosetae absent (numerous small simple); sectasetae four pairs; marginal abdominal setae (other than sectasetae) three or four pairs (fourth sometimes reduced or simple), distinctly capitate; pleurite setae paired capitate and simple. Foreleg without capitate setae; middle leg capitate setae on tibia, two (one proximal, one larger distal); hind leg capitate setae on femur and tibia, on tibia two or three (one or two proximal, one larger distal).

Host plant. Teline stenopetala ssp. stenopetala and ssp. microphylla , Chamaecytisus proliferus .

Distribution. Canary Islands: La Palma and El Hierro.

Notes. This is the only species with bi-generic host preference in Arytinnis gen. n. It occurs on the two most westerly islands where it replaces the closely related A. dividens on the host plant Chamaecytisus proliferus . It occurs sympatrically with A. occidentalis on Teline stenopetala ssp. stenopetala and ssp. microphylla , and sympatrically with Arytaina devia on Chamaecytisus proliferus .

Biology. Clusters of eggs and small nymphs (1st–2nd instars) were found under floral bracts and petiolar bracts. Small nymphs were also observed on leaf buds and on fruit.

Comment. The colonization of host plants in two unrelated genera (i.e. from different host groups within the Genisteae ) appears to originate from a recent host switch in the progenitor of A. modica (possibly A. hupalupa on La Gomera) from Chamaecytisus to Teline , and the subsequent retention of preference to both hosts with the colonization of El Hierro and La Palma. This evolutionary scenario and the genetic variation in these host races are currently being investigated in a molecular anaylsis.

Material examined. Canary Islands, La Palma: 3 W, 2 X, 1 nymph, SE rd Santa Cruz to La Caldera, 28°43∞N, 17°46∞W, 930 m, ex Teline stenopetala , 15 July 1997 (DP 73). 5 W, 1 X, rd to La Cumbrecita, 28°39∞30◊N, 17°50∞45◊W, ca 900 m, ex Chamaecytisus proliferus , 16 May 1998 (DP 189). 13 W, 16 X, 4 nymphs, Los Tilos, Barranco del Agua, 28°47∞30◊N, 17°47∞45◊W, ca 500 m, ex Teline stenopetala , 17 May 1998 (DP 192). 49 W, 26 X, 9 nymphs, NW rd from Llano Negro to La Caldera, 28°48∞N, 17°55∞30◊W, ca 1050 m, ex Chamaecytisus proliferus , 19 May 1998 (DP 201). El Hierro: Holotype W (dry mounted) and 5 WX paratypes, Guarasoca, 26 March 1950, H. Lindberg (ZMH). 4 W, 2 X, between Mirador de la Peña and Mirador Jinama, 27°47∞30◊N, 17°58∞W, 900–960 m, ex Teline stenopetala , 12 July 1997 (DP 63). 6 nymphs, as for previous except, 27°48∞N, 17°58∞W, 860 m, ex Chamaecytisus proliferus (DP 64). 89 W, 56 X, 3 km W of San Andres, 27°45∞30◊N, 17°58∞30◊W, 1250 m, ex Chamaecytisus proliferus , 22 May 1998 (DP 210). 33 W, 28 X, 11 nymphs, El Golfo, rd to Frontera, 27°44∞N, 18°01∞30◊W, 1100 m, ex Teline stenopetala , 22 May 1998 (DP 212).