S. Mahunka szerk.: Folia Entomologica Hungarica 52. (Budapest, 1992)

infestation. The two attacked plants developed short, abnormal shoots that shriveled up four months after the first frass tendrils appeared. The first adults appeared two weeks after the protrusion of the frass tendrils. On the two canes, 25 and 32 holes were counted, respectively. From the 11th July to the 16th November, 137 adult females emerged from the former, while 162 from the latter plant. The beetles came out of the tunnels in reverse and this process lasted for hours. They wandered about on the canes and on the ground surface and, presumably owing to the adverse conditions of the laboratory, died in a day or two. The infested canes were cut into pieces and the galleries could be studied. The gallery system is horizontal. All the tunnels are 1 mm in diameter. The entrance tunnel goes right in the hard, 1-1.5 cm wide ring of the secondary transport tissue then irregularly ramifies in the spongy cylinder of the primary transport tissue (Fig. 3). In some cases the tunnel bifurcates at the meeting of the two types of tissue and proceeds along the meeting sur­face. The bulk of the tunnels is found in the central part where a few vertical tunnels of 1-2 cm in length were also observed. The beetles As for most species of Xyleborus, the males of Xyleborus affinis are 'dwarfed, flight­less, eyes reduced, rare' (Beaver and Maddison 1990). They never leave the gallery system. The detailed description of females (Figs 4-5) and keys for identification have been provided by Bright (1968), Wood (1982) and Beaver and Maddison (1990). In his identification key to Hungarian Scolytidae, Endrődi (1959) mentions 7 species of Xyleborus to occur in the Carpathian Basin. Of them, Xyleborus dispar (Fabricius, 1792) and X. cryptographus (Ratzeburg, 1837) clearly differ from affinis in having the pronotum as long as broad (elongate in affinis). X. eurygraphus (Ratzeburg, 1837) is 3.5­4 mm in length and has the anterior margin of pronotum nearly straight (arcuate in af­finis which is always under 3 mm). X. monographus (Fabricius, 1792) has in the apical declivity of elytra 2 or 3 conspicuously large teeth near the suture (small denticles in the intervals in affinis). The characters distinguishing X. dryographus (Ratzeburg, 1837), pfeili (Ratzeburg, 1837) and saxeseni (Ratzeburg, 1837) are summarized in Table 1. Life history Xyleborus affinis is one of the most dangerous pests of different tree species in the tropical and subtropical countries. It is known to occur in 22 states of the U.S.A, in Cent­ral and South America, from Hawaii to Malaya and in tropical Africa (Schedl 1963, Wood 1982). Unintentional introductions have been recorded from Belgium in 1950, Is­rael in 1952, Switzerland in 1955 and Germany in 1956 (Schedl 1963). As far as the host plants are concerned, about 300 species are listed by Schedl (1963), Wood (1982) and others. From economical point of wiew, the most important examples are Albizzia, Ced­rela, Celtis, Citrus aurantium, Citrus grandis, Cocos nucifera, Codiaeum, Coffea ara­bica, Eucalyptus, Ficus, Hevea brasiliensis, Mang if er a indica, Pinus, Pterocarpus, Qjuercus, Saccharum officinarum, Theobroma cacao (Schedl 1963), Betula, Carya, Cas­tanea, Diospyros, Liquidambar, Mimosa, Robinia (Bright 1968), Cornus, Fagus, Fraxi­nus, Prunus, Taxodium distichum, Ulmus (Schneider 1987), Citrus limon (Beaver and Maddison 1990). Severe infestation on imported canes of Dracaena fragrans 'Massan­geana" was reported from Florida (Hamlcn and Woodruff 1975).

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