Diaphorina albomaculata, Capener, 1970

Aléné, Désirée Chantal, Latar Vernyuy, Nina, Djiéto-Lordon, Champlain & Burckhardt, Daniel, 2021, Diaphorina pfanderae Aléné and Burckhardt sp. nov. (Hemiptera: Psylloidea: Psyllidae) and its association with ants on Ozoroa pulcherrima (Anacardiaceae), Journal of Natural History 55 (27 - 28), pp. 1649-1662 : 1658-1659

Key to the species of the Diaphorina albomaculata group

Adults

1. Fore wing predominantly light with dark pattern consisting of dots that are partly confluent; cell r1 with large light area................................................................................................... 2

– Fore wing predominantly dark with a few light areas; cell r1 entirely dark, at most with a few small light dots................................................................................................................................... 4

2. Paramere with forward directed hook apically. Ventral margin of female subgenital plate evenly weakly convex. On Vernonia amygdalina (Asteraceae) ............................................. ............................................................................................................................ D. enderleini Klimaszewski

– Paramere lacking apical hook. Ventral margin of female subgenital plate with strong basal swelling. On other hosts.............................................................................................................................................. 3

3. Fore wing relatively narrow,> 2.3 times as long as wide. Paramere digitiform. Basal swelling on female subgenital plate forming large hump. On Searsia undulata spp. ( Anacardiaceae )...................................................................................................... D. natalensis (Pettey)

– Fore wing relatively wide, <2.2 times as long as wide. Paramere lamellar. Basal swelling on female subgenital plate forming flat bump. On Solanum incanum (Solanaceae) ............. .............................................................................................................................................. D. solani Capener

4. Cell m2 of fore wing with, at most, a few small light spots. Paramere with small apical forward-directed hook. Ventral margin of female subgenital plate with large hump. On Searsia leptodictya (Anacardiaceae) ........................................................................................ D. tenebrosa Capener

– Cell m2 of fore wing with a large light area.Paramere subacute or narrowly rounded apically. Ventral margin of female subgenital plate weakly curved or angular, lacking large hump. On Ozoroa spp. (Anacardiaceae) ..................................................................................................................................... 5

5. Fore wing relatively wide, <2.2 times as long as wide; lacking light spots along wing margin in cells r1, r2 and m1. Paramere subacute apically. Ventral margin of female subgenital plate weakly curved. On O. insignis subsp. reticulata , O. paniculosa ....................... ............................................................................................................................. D. albomaculata Capener

– Fore wing relatively narrow,> 2.3 times as long as wide; bearing light spots along wing margin in cells r1, r2 and m1. Paramere narrowly rounded apically. Ventral margin of female subgenital plate angular. On O. pulcherrima .................................................... D. pfanderae sp. nov.

Last-instar immatures

(Immatures of D. natalensis are unknown)

1. Caudal plate with several long robust setae on either side of medial indentation .... 2

– Caudal plate with several lanceolate setae on either side of medial indentation ................... 4

2. Circumanal ring completely reduced. On Vernonia amygdalina (Asteraceae) ...................... ....................................................................................................................... D. enderleini Klimaszewski

– Circumanal ring developed, consisting of a few pores. On Anacardiaceae .................... 3

3. Wing pads and caudal plate with inconspicuous microscopic marginal lanceolate setae. On Ozoroa pulcherrima .............................................................................. D. pfanderae sp. nov.

– Wing pads and caudal plate with conspicuous macroscopic, evenly spaced marginal lanceolate setae. On Searsia leptodictya ............................................ D. tenebrosa Capener

4. General body colour brown. Caudal plate with 7–10 lanceolate setae on either side of medial indentation. On Ozoroa insignis subsp. reticulata , O. paniculosa (Anacardiaceae) .............................................................................................................................. D. albomaculata Capener

– General body colour pale cream. Caudal plate with 4–5 lanceolate setae on either side of medial indentation. On Solanum incanum (Solanaceae) ........ D. solani Capener

Biology

Adults and immatures of D. pfanderae were observed feeding on young plants of O. pulcherrima , especially on the underside of leaves, along the petiole and the midrib, and even on fruit-bearing stalks. Eggs were laid on the leaf-blade near the central vein ( Figure 5 (b)). The different stages were always associated with the three ant species Camponotus congolensis Emery, 1899 , Camponotus flavomarginatus Mayr, 1862 and Crematogaster sp. ( Hymenoptera : Formicidae ). Of these, C. congolensis was the most abundant, with 391 individuals, followed by Crematogaster sp. (288 individuals) and C. flavomarginatus (220 individuals).

The infestation of leaves by the psyllids did not significantly differ between the three age classes of leaves (Χ2 = 1.78; p = 0.41) ( Table 1 ), and the relative numbers of psyllids on young and very young leaves were approximately the same (37.24% and 38.86%, respectively). Camponotus congolensis was predominantly found associated with colonies of immature psyllids on the very young leaves (47.57%), while C. flavomarginatus was most abundant on young leaves (41.82%). Crematogaster sp. , in contrast, was evenly distributed among the three age classes of leaves ( Table 1 ). These ants would often, but not always, build shelters around the colonies of D. pfanderae .

The Spearman’s test performed between ant species and the psyllid showed that the number of individuals of D. pfanderae was positively and significantly correlated with that of C. congolensis (R = 0.49, P <0.001) and Crematogaster sp. (R = 0.50, P <0.001).

Figures

Figure 5. Diaphorina pfanderae Aléné and Burckhardt sp. nov., egg and immatures. (a) Habitus of fifth instar, left side; (b) egg clusters and immatures; (c) caudal plate; (d) colony covered in honeydew; (e) circumanal ring.