Cornegenapsylla sinica Yang and Li 1982

Cornegenapsylla sinica Yang and Li, 1982

(Figures 5B,C,F; 7E – H)

Cornegenapsylla sinica Yang and Li, 1982: 124; Burckhardt and Ouvrard (2012): 17.

Neophacopteron euphoriae Yang, 1984: 165; Li (2011): 1223.

Phacopteron sinicum (Yang and Li), Li (2011): 1223.

Material examined

3 ♂, 2 ♀, 2nd – 5th instars, Singapore Botanic Gardens, Singapore, 2 January 1997, ex Dimocarpus longan, J. Martin leg. (BMNH); 4 ♂, 1 ♀, 2nd – 4th instars, Bangkok, Thailand, 1961, ex Dimocarpus longan, A. Manjikul leg. (BMNH); 1 ♂, 3 ♀, Johor, Malaysia, 13 April 1970, ex Nephelium malaiense, Dept. Agric. leg. (BMNH).

Comments

With the synonymization of Neophacopteron euphoriae and Cornegenapsylla sinica by Li (2011), it is confirmed that there is a single species on longan that is widely distributed in South East Asia. Burckhardt and Ouvrard (2012) mistakenly mention the combination Cornegenapsylla euphoriae (Yang, 1984) when reinstating Cornegenapsylla as a valid genus. Cornegenapsylla sinica remains unusual within the Phacopteronidae for the long genal processes and the male terminalia covered with stout lanceolate setae, as well as a characteristic near vertical feeding posture (Yang et al. 2009). Without an explanation, but probably based on the relatively well-developed genae in the type species of Phacopteron Buckton, 1896, Li (2011) placed C. sinica in Phacopteron, which was subsequently reversed by Burckhardt and Ouvrard (2012). The type species of Phacopteron, Phacopteron lentiginosum Buckton, 1896 is a widespread species from Pakistan to South East Asia. The inclusion of the only other species in Phacopteron, Phacopteron gabrieli Navasero and Calilung, 2000, from the Philippines is considered doubtful. Phacopteron lentiginosum produces a completely enclosed round gall on the leaves of Garuga spp. (Burseraceae) (Hodkinson 1986; Li 2011), which dehisces after adult eclosion inside the gall (Raman 1987). A similar biology with emergence of the adult from a sac-like gall is illustrated here for Pauropsylla udei (Singapore specimens) on Ficus variegata (Figure 3E).

The 1st – 5th instar immatures of C. sinica were described and illustrated by Yang (1984). The 5th instar body margin is bordered with bluntly pointed setae situated on cuticular tubercles and the dorsum of 5th instars has sparsely distributed minute clubshaped setae (Figure 7E). Here we provide illustrations of 2nd, 3rd and 5th instars (Singapore specimens, Figure 7E, F, H), and a 3rd instar immature (Thailand specimens) showing the production of waxy filaments from the large pointed dorsal setae (Figure 7G). In contrast to C. allophyli sp. nov., the antenna of 5th instar immatures of C. sinica is 6- to 7-segmented, bearing only two rhinaria on the apical segments, and the anus is situated ventrally, surrounded by a small transverse circumanal ring composed of a single row of cells.

Host plant

Dimocarpus longan (Sapindaceae).

Distribution

China: Fujian, Hainan, Guangdong, Guangxi, Hong Kong (Yang and Li 1982; Martin and Lau 2011; Li 2011; and BMNH data); Malaysia (Hodkinson 1986); Taiwan (Yang 1984; Yang et al. 2009); Thailand (Hodkinson 1986), and Singapore (new record, BMNH data).

Biology

The immatures produce deep pit galls on young leaves (Yang 1984). Cornegenapsylla sinica is a pest of longan, an important fruit crop in South East Asia. It causes economic damage by direct effects of feeding, and possibly as well by the transmission of a 'filamentous virus ‘ (a suspected phytoplasma, cf. Nguyen et al. 2012) that is the agent of longan witches ’ broom disease (Chen et al. 1992, 2001; Xu et al. 2001; Yen et al. 2005).