Orchidophilus Buchanan

Centrinus auctt. (non Schönherr, 1825). Murray (1869; species description). Baris auctt. [= Baridius, unjust. emend.] (non Germar, 1817). Waterhouse (1874; species description), Blackburn (1900; species description).

Acythopeus auctt. (non Pascoe, 1874). Pascoe (1887; species description), Lea (1906; discussion of generic assignment), Barber (1917; species description), Schlechter (1927; synopsis), Swezey (1934; note on undescribed species); Heller (1940; discussion of Acythopeus).

Apotomorhinus auctt. (non Schönherr, 1844). Kolbe (1906; species description).

Orchidophilus Buchanan, 1935: 45. Morimoto (1994; synopsis, key to species), Morimoto & Yoshihara (1996; key to Oriental genera), Anderson (2002; key to North American weevil genera).

Type species: Orchidophilus peregrinator Buchanan, 1935, by original designation.

Distribution. Native to Indonesia, Malaysia, the Philippines, Singapore, possibly Taiwan, Thailand and parts of Australia; adventive in American Samoa, Australia, Brazil, Canada, the Cook Islands, Germany, Great Britain, Hawaii, Japan, the Netherlands, the Netherlands Antilles, New Caledonia, Papua New Guinea, South Africa, South Korea, Sweden and the United States (Fig. 1).

Biology. The life history of O. aterrimus was studied by Mau (1983) in Hawaii and by Hirao et al. (2001) in the Philippines. Eggs were found to be deposited singly in holes made in stems, leaves, pseudobulbs and flowers. Mau (1983) determined the average time needed for development at 24 ºC as 11 days for eggs, 117 for larvae and 16 for pupae, followed by a pause of several weeks before emergence of the adults. Hirao et al. (2001) observed a faster development at 28–35 ºC, with an average of 7 days for eggs, 75 for larvae and 10 for pupae. The number of larval instars was generally five. Pupation took place inside the gallery in a cocoon made of fibres and frass. Females maintained a constant level of fecundity for approximately 40 weeks. Adult weevils were extremely long lived in the Hawaiian laboratory. Half of the males and females lived for 34 and 37 weeks, respectively; single specimens lived up to 12 months. Adults were predominantly diurnal. Feeding occurred on all epigeous parts of the host, with a preference for young growth. The larva was described by May (1994) and Pakaluk (1994). Information on pest management is given by Hara & Mau (1988), Hansen et al. (1991), Hata & Hara (1991, 1992) and Hara & Hata (1994).

Recognition. Orchidophilus differs from the similar Acythopeus complex by the following characters: (1) apical portion of pygidium abruptly bent ventrad and delimited by transverse carina; (2) antennal club notably compact, with distal three segments comprising merely one-third or less of its entire length; (3) fifth tarsomere at most two times longer than third tarsomere; (4) tarsal claws short, approximately as long as fifth tarsomere is wide; (5) integument matt; and (6) association with orchids. Morimoto & Yoshihara (1996) provide a key that distinguishes Orchidophilus from other Oriental Baridinae.