MATERIALS AND METHODS

The following abbreviations are used: LZUY = Laboratoire de Zoologie, Université de Yaoundé I, Cameroon; MRAC = Musée Royal d’Afrique Centrale, Belgium; NHMB = Naturhistorisches Museum Basel, Switzerland.

The psyllids were captured in the Central Region of Cameroon; the following localities were inspected: Kala, 03°50’121”N, 11°21’004”E, 1122 m, Libellingoï, 03°54’236”N, 10°55’031”E, 396 m, Nkomilong, 03°49’954”N, 11°20’504”E, 1161 m, Ongot, 03°54’753”N, 11°23’070”E, 782 m and Oyack, 03°29’110”N, 11°30’050”E, 696 m.

Adult psylloids were captured with a sweep net of 0.5 mm mesh size and an aspirator. Nymphs were sampled directly from buds and leaves of the host plant. The specimens are preserved dry and slide-mounted or in 70% ethanol and are deposited in LZUY, MRAC and NHMB. Morphological terminology follows Malenovsky and Burckhardt (2009). The host plant was identified at the National Herbarium at Yaounde (Cameroon) and is deposited in LZUY. The morphology was illustrated using transmission (Leica microscope) and measurements were made from slide-mounted using Leica stereomicroscope. The following characters were measured for adults: BL, body length; BW, body width; HW, head width; AL, antenna length; F₁, length of first antennal flagellomere; WL, fore wing length; WW, fore wing width; wL, hind wing length; wW, hind wing width; MTL, metatibial length; MFL, metafemur length; MP, male proctiger length; PL, paramere length; DL, length of distal segment of aedeagus; FP, female proctiger length; SL, female subgenital plate length. Also the following characters were measured for the fifth instar nymph: BL, body length; BW, body width; AL, antenna length; FL, fore wing-pad length; ML, metatibial length.

Material examined: Kala: 23 iii 2007, 5 males, 6 females, 17 nymphs; 27 iv 2007, 4 males, 2 females, 3 nymphs; 27 vi 2007, 2 females; 20 vii 2007, 1 female, 1 nymph; 22 ix 2007, 1 male, 7 nymphs; 24 x 2007, 2 males, 2 females; 17 xi 2007, 5 males, 1 female; 27 xii 2007, 9 males, 6 females. Libellingoï: 7 vii 2007, 2 males, 3 females, 10 nymphs. Nkomilong: 19 ii 2007, 14 males, 11 females, 18 nymphs; 29 iii 2007, 8 males, 3 females; 30 iv 2007, 3 males, 1 female, 10 nymphs; 6 v 2007, 2 males; 29 vi 2007, 2 males, 3 females; 21 vii 2007, 1 male, 2 females; 22 viii 2007, 4 males, 4 females, 17 nymphs; 24 xi 2007, 1 male, 2 females. Ongot: 26 ix 2009, 3 males, 2 females, 20 nymphs. Oyack: 26 xii 2009, 2 females, 8 nymphs.

RESULTS AND DISCUSSION

Description
Fifth instar nymph
Coloration: Body uniformly pale yellow, compound eyes translucent with a reddish spot, anterior region of abdomen with five transverse brown bands and the posterior region with a large brown band.

Structure: Final instar nymph (Fig. 2a), elongate, not clearly divided into head, thorax and abdomen; the final instar nymphs length, 1.37 mm and wide, 0.48 mm; it is 2.9 times as long as wide. Antennae (Fig. 2b) slightly elongated with indistinctly segmented flagellum with three apically rhinarium. Antenna length, 0.20 mm. The head margin, thorax, anterior region of fore wing pads, wingpads and abdomen are covered by lanceolated setae. The hind leg (Fig. 2c) elongate, metatibia and metabasitarsus not clearly separated, tarsal arolium in a trapezoidal form, metatibia length, 0,19 mm. Abdomen dorsally weakly sclerotized, apex of abdomen broadly rounded, anus in ventral position; circumanal ring strongly sinuate, composed of a single row of pores.

Adult
Coloration: Overall body yellow. Pronotum, mesopraescutum, mesoscutum and mesoscutellum entirely dark brown. Antenna brown, segment 8 dark-brown apically, segments 9-10 entirely dark-brown. Compound eyes dark-brown and ocelli tranparent. Metatibia and metabasitarsus with several clear strong setae and metabasitarsus with two black spurs. Fore wing membrane clear, transparent with a large dark-brown which cover the most part of the fore wing cells. The dark-browning area along all the veins except the C+Sc, An, half of R, middle of M₃₊₄ and Cu₁ veins. A small dark-brown spot on An vein. Hind wing clear, transparent.

Structure: Head (Fig. 1a), in dorsal view, slightly wider than mesonotum, subglobular; vertex convex and frontal margin sharply defined and deeply incised by median suture. Lateral ocelli placed posteriorly on vertex. Vertex wider than higher and lack lanceolate setae. Genae distinctly not swollen but flat. Antenna long, slender, segments cylindrical, only segments 2 and 9 are widening to apex (Fig. 1b); Antennal flagellum 1.2 times longer than head width, first flagellomere, 0.09 times longer than antenna and it’s lacks rhinarium. Flagellomeres 2, 3, 5, 6, 7 with single rhinarium apically; flagellomere 4 with two rhinaria apically. Rhinarium of flagellomere 7 larger than the other ones and bear cuticular spines. Terminal setae subequal. Fore wing moderately elongate, outer anterior margin less evenly curved, apex rounded; spinules present in apical part of r₂, m₂, m₁ and cu₁ cells; cu₁ cell more wider than higher; fore wing 2.5 times longer than wide and 1.03-1.2 times longer than Hind wing. Costal break of C+Sc absent (Fig. 1c). Hind wing (Fig. 1d) with grouped costal setae: 1 before costal break and 3 after costal break; hamelus absent (1+3+0). Hind wing 3.2-3.5 times longer than wide. Hind legs (Fig. 1e and f), long and robust; metacoxa long with a short acute pointed meracanthus; the internal margin of metafemur relatively incurved on the middle part and bearing lanceolate setae; metatibia bearing along site 12-15 spaced slender, unsclerotized spurs and lanceolate setae, metatibia lacks apical sclerotized spurs; metabasitarsus bearing two black sclerotized spurs and the external face bearing two slender unsclerotized spurs; metatibia 0.77-0.79 times longer than head wide. Male terminalia as in Fig. 1g; proctiger relatively short, cylindrical (Fig. 1h); subgenital plate, in profile slightly longer than high; paramere (Fig. 1i), relatively long, in profile incurved on external margin, proximal region slightly narrow, on subapical part paramere bearing three slender unsclerotized spurs, paramere, 0.2 times longer than head wide; apical segment of aedeagus shorter than proximal segment, with narrow head weakly, gradually widening from base to apex, dorsal margin straight, sclerotized end tube of ductus ejaculatorius less longer (Fig. 1k), apical segment of aedeagus, 0.17 times longer than head wide.

Fig. 1(a-k):	Psedophaceopteron burchardti sp.n., (a) Head, (b) Antenna, (c) Fore wing, (d) Hind wing, (e) Hind legs, (f) Hind legs apical extremity, (g) Female terminalia, (h) male terminalia, (I) Proctiger, (j) Paramere and (k) Apical segment of aedeagus, Scale Bars: α: 0.04 mm, β: 0.08 mm, γ: 0.016 mm

Female terminalia as in Fig. 1g; proctiger relatively long and bearing four setae, dorsal margin straight, apical process long, circumanal ring with two rows of pores, but pores of outer row on dorsal margin are wider than the inner pores row; the outer row of the inner margin of circumanal pores are narrowed than the inner row; circumanal is very narrowed on his middle part; subgenital plate, in profile, relatively long, dorsal margin weakly concave, ventral margin more or less straight, apex divided on two lobes, external lobe narrow and internal lobe wide; dorsal valvulae are long; female proctiger is 0.4 times longer than head wide and female subgenital plate 0.3 times longer than wide head.

Fig. 2(a-c):	Final instar nymph of Psedophaceopteron burchardti sp.n., (a) Final instar nymph, (b) Antenna and (c) Hind leg. Scale Bars: α: 0.04 mm, β: 0.08 mm, γ: 0.016 mm

Comment: Pseudophacopteron burckhardti sp.n. differs from the nine described species from Cameroon (Malenovsky et al., 2007). Nymphs are closed to P. morion and P. electum with the antenna structure, P. cumiculus with the circumanal ring structure. Adults are closed to P. eastopi with male and female terminalia.

Fifth instar nymph antenna of P. burckhardti lacking distinct segments as P. morion and P. electum but the latter two previously described species have two rhinaria; P. burckhardti have three rhinaria. Also outer surface basally with 7 sharp cuticular teeth compared to 8-12 sharp cuticular teeth of P. morion. Others Pseudophacopteron spp., previously described have distinct antennal segments. Tarsal arolium of P. burckhardti longer than wide, rectangular, different in shape with P. cuniculus, triangular and the others Pseudophacopteron spp. which are commonly broad. Circumanal ring large and sinuate, widely extending on the dorsal and ventral surface of caudal plate. Circumanal large and sinuate is different from P. morion which is small and oval, P. cuniculus which strongly sinuate or P. electum which is wide, fore and hind margin close together. Abdomen dorsally on each side with seven sclerites but the number of sclerites is six with P. cuniculus and five with P. morion and others species described from Cameroon.

The disposition of the spots on the fore wing is very different of those of species described by Malenovsky et al. (2007) and fore wing without the costal break. The structures of the male terminalia especially the paramere and female terminalia are different from the structures of the nine species but P. burckhardti is getting closer with Peudophacopteron eastopi on the structure of the smallest size of adult (fore wing length, P. eastopi: 0.90-1.26, P. burckhardti: 1,18-1,48 mm; head width, P. eastopi: 0.35-0.41 mm, P. burckhardti: 0.48-0.73 mm). In P. burckhardti, antenna long, slender, segments cylindrical, only segments 2 and 9 are widening to apex, rhinarium of flagellomere 7 larger than the other ones and bear cuticular spines but in P. eastopi, antenna long, slender, segments cylindrical, weakly widening to apex, the last rhinarium with a wreath of cuticular spines; antenna length (P. eastopi: 0.46-0.57 mm, P. burckhardti: 0.48-0.75 mm). In P. burckhardti, male proctiger cylindrical but in P. eastopi, male proctiger slightly narrowing to apex (P. burckhardti: 0.15-0.20 mm, P. eastopi: 0.11-0.13 mm). In P. burckhardti, apical segment of aedeagus with narrow head weakly, gradually widening from base to apex, sclerotized end tube of ductus ejaculatorius less longer but in P. eastopi, apical segment of aedeagus with a slightly hooked head, broad and rounded at apex, sclerotized end tube of ductus ejaculatorius relatively long. In P. burckhardti, subgenital plate, in profile slightly longer than high but in P. eastopi, subgenital plate, in profile as long as high; subgenital plate length (P eastopi: 0.18-0.21 mm, P. burckhardti: 0.15-0.35 mm).

CONCLUSION

P. burckhardti is different of the nine species described by Malenovsky et al. (2007) in Cameroon, according to the original description as follows. For the fifth instar nymph, the posterior region of fore wing pads is covered by the simple lanceolate setae; tarsal arolium with a trapezoidal form, circumanal ring less large and strongly sinuate, composed of a single row of pores. For adult, the fore wing maculation occupy the ½ of r₁ and r₂ cells; 2/3 of m₂, m₁ and cu₁ cells; 1/3 of cu₂ cell; Hind wing with grouped costal setae: 1 before costal break and 3 after costal break; hamelus absent (1+3+0); paramere is relatively long, in profile incurved on external margin, proximal region slightly narrow, on subapical part paramere bearing three slender unsclerotized spurs; female proctiger with a narrowing circumanal, subgenital plate, in profile, relatively long, dorsal margin weakly concave, ventral margin more or less straight, apex divided on two lobes, external lobe narrow and internal lobe wide. Pseudophacopteron burckhardti is a newly described psyllids species from Cameroon. The new species does not induce galls on its host; the sucking activities of nymphs distort leaves which become necrotic in part. Z. gilletii is a commercial timber used in traditional medicine. P. burckhardti could be consider as a pest of this plant in Cameroon.