Hypocryphalus scabricollis (Eichhoff)

Faccoli, Massimo, Campo, Giuseppe, Perrotta, Giancarlo & Rassati, Davide, 2016, Two newly introduced tropical bark and ambrosia beetles (Coleoptera: Curculionidae, Scolytinae) damaging figs (Ficus carica) in southern Italy, Zootaxa 4138 (1), pp. 189-194 : 189-191

Hypocryphalus scabricollis (Eichhoff)

(= Cryphalus scabricollis Eichhoff )

Description. An accurate description of H. scabricollis is reported by Mifsud & Knížek (2009). H. scabricollis is a small species (1.5–1.9 mm in length) which could be confused with two other bark beetle species— Hypoborus ficus Erichson and Hypothenemus leprieuri (Perris) —commonly infesting figs in the Mediterranean regions (Pfeffer 1995). H. ficus is usually smaller (1.0– 1.3 mm in length) than H. scabricollis , with pronotum covered by long, recumbent, white scale-like setae; on the elytra the same setae are recumbent along the striae but erect along the interstriae. The elytral surface of H. scabricollis , instead, is covered with rather dense but microscopic scalelike setae and erect sparse hairs ( Fig. 1 A and 1B). Moreover, H. ficus has entire eyes which are instead emarginated in H. scabricollis ( Fig. 1 B). Lastly, the anterior margin of the pronotum of H. scabricollis is armed by 5–6 conspicuous and protruding teeth of which the two central are bigger than the others; in H. ficus , instead, no teeth occur along the anterior margin of the pronotum.

H. scabricollis could be also confused with H. leprieuri , which is similar in size, with females about 1.4–1.6 mm long and males slightly smaller. The two species, however, can be distinguished from each other through the antennae. H. leprieuri shows sub-oval antennal club with straight sutures, of which the first is partly septate, and a funicle that is 5-segmented in females and 4-segmented in males; H. scabricollis shows antennal club rounded with remarkably procurved sutures which are not septate ( Fig. 1 B), and the funicle is 4-segmented in both sexes. Lastly, H. leprieuri has not been found in Sicily; it is recorded only in Cyprus, Algeria, Sardinia, and Tuscan Islands (Pfeffer 1995; Faccoli and Cecchi 2003).

Distribution. Hypocryphalus scabricollis is an Asian thermophilous species that was first described from the Myanmar ( Burma), in the Indian sub-continent ( Wood & Bright 1992). The species is also found in Bangladesh, Burma, China (Hainan Island, Yunnan), India (Andaman Islands, Assam, Bengal, Bihar, Madhya Pradesh, Maharashtra, Punjab, Tamil Nadu, Uttar Pradesh), Philippine Islands (Luzon), Sri Lanka, and Vietnam ( Wood & Bright 1992).

In Europe, H. scabricollis was recorded for the first time in 1991 in Malta ( Mifsud & Knížek 2009) where it has become a common and widely distributed species ( Mifsud et al. 2012). This is the first record of H. scabricollis to Italy.

Host plants. In the native range, H. scabricollis has been reported as developing under the bark of many tropical trees, including Afzelia bijuga , Albizzia stipulata , Bassia latifolia , Bombax malabaricum , Buchanania lanzan , Canarium euphyllum , Excoecaria agallocha , Garuga pinnata , Mesua ferrea , Odina wodier , and Ficus spp. ( Wood & Bright 1992). In Malta, it was initially recorded from Ficus retusa ( Mifsud & Knížek 2009) , but recently it has been mainly found on F. carica ( Mifsud et al. 2012) . In Sicily H. scabricollis has been found on both wild and cultivated varieties of the common fig, F. carica .

Taxonomic notes. Specimens of H. scabricollis collected in Sicily were carefully compared to those collected in Malta revealing that Sicilian and Maltese specimens are identical (Knížek, pers. comm.). Nevertheless, Mifsud & Knížek (2009) suggested that the specimens of H. scabricollis collected in Malta—and hence in Sicily—actually belong to the species Cryphalus dilutus Eichhoff , an Indian species reported as synonymous of C. scabricollis by Wood (1989), although some morphological differences in the pronotum exist ( Mifsud & Knížek 2009). More detailed morphological and molecular studies on H. scabricollis and its synonymous ( C. dilutus , C. discretus Eichhoff and C. brevisetosus Schedl ) are hence needed.

Figures

FIGURE 1. Hypocryphalus scabricollis: A) dorsal view; B) lateral view.