|EUROPEAN AND MEDITERRANEAN PLANT PROTECTION ORGANIZATION
PPM, point 7.1
Draft Data Sheet – Extensive version
Name: Diocalandra frumenti (Fabricius, 1801) Syst. Elenth. 2:438
Synonyms: Calandra frumenti (Fabricius, 1801)
Sitophilus frumenti (Fabricius) Schoenherr, 1838:982
Diocalandra frumenti (Fabricius) Faust, 1894:354
Calandra bifasciata Boisduval, 1835: 445
Calandra montrouzieri Chevrolat, 1882: CXXVIII
Sitophilus subfasciatus Boheman, 1838: 971
Sitophilus stigmaticollis Gyllenhal, 1838: 972
Diocalandra frumenti var. stigmaticollis (Gyllenhal) Kolbe, 1910: 46
Sitophilus subsignatus Gyllenhal,1838: 973
Sphenophorus cruciger Motschulsky, 1858:69
Calandra punctigera Pascoe, 1885: 305
Callandra sechellarum Kolbe,1910:46
Taxonomic position: Insecta: Coleoptera: Curculionidae: Rhynchophoridae: Diocalandrini
Notes on taxonomy and nomenclature: The above taxonomic determination and the following notes follow a general scheme of classification used by E. C. Zimmerman in his 8 volume series of Australian weevils. Zimmerman (1993) raised the Rhyncophoridae to Family status within the super family Cuculionoidea and proposed a new tribe, the Diocalandrini to include the genus Diocalandra with Arecaceae as hosts but excludes the seed feeding genus Sitophilus. Diocalandra are small, slender weevils but the loss of sternite 9 in male specimens separates them from Sitophilus that they closely resemble. Morimoto (1978) has recognized and produced a key to 9 species of Diocalandra.
D. frumenti was originally described by Fabricius in 1801 as Calandra frumenti but since the adults vary greatly in size, colour and maculation (Zimmerman, 1993), the species has been redescribed many times (see above synonomy). Zimmerman (1993) indicated that this species closely resembles D. taitense (Guèrin-Mèneville) from the central and eastern Pacific islands with which it is often confused and he produced a key to separate the two species.
Common names: Palm weevil borer (English), four spotted coconut weevil (English), lesser coconut weevil (English), small weevil (Taiwan).
Bayer computer code: DIOCFR
Phytosanitary categorization :
D. frumenti has been collected from at least 17 genera of Arecaceae, with most of these being economically important palm species cultivated for food, oil, housing or landscape plants.
Major hosts include coconut (Cocos nucifera) and landscape palms such as Phoenix canariensis and its hybrids (Kahlshoven, 1981, Salomone Suárez et.al., 2000b).
Minor hosts include date palm (Phoenix dactylifera), oil palm (Elaeis guineensis), attap (Nypa fruticans) and a large number of other landscape palm species. The literature records include Archontophoenix alexandrea, Bismarkia sp., Caryota sp., Chrysalidocarpus lutescens, Dypsis lutescens, Dypsis lucubensis, Howea belmoreana, Mascarena verchaffeltii, Metroxylon sagu, Phoenix loureirii, Phoenix roebelenii, Ptychosperma macarthurii, Ravenea rivularis, Roystonea regia, Sabal palmeto, Washingtonia spp. and Wodyetia bifurcata (AVA, 2006; Lepesme, 1947; NGIA, 1998; Salomone & Caballero Ruano, 2008).
It is possible that the species has only recently adapted to the ornamental species in the genus Phoenix.
Howard et. al. (2001) who cited Lever (1979) as a reference, indicated that species in the Areca and Borassus genera in addition to Sorghum were also attacked by this weevil. Although D. frumenti has been raised under artificial conditions on sugar cane, the EPPO Expert Working Group for the Pest Risk Analysis of Diocalandra frumenti concluded that the pest is attracted to decaying tissues, but did not consider Poaceae as hosts, as there is only this record.
“CABI map 249” provides a distributional map of Diocalandra frumenti.
EPPO region: Spain (Canary Islands)
Africa: Madagascar, Mauritius, Seychelles, Somalia, Tanzania (including Zanzibar).
Asia: Bangladesh, India, Indonesia, Japan, Malaysia, Myanmar, Philippines, Singapore, Sri Lanka, Taiwan, Thailand.
Oceania: Australia (Northern Territory, Queensland, Western Australia), Guam, Palau, Papua New Guinea, Samoa, Solomon Islands.
South America: Ecuador.
Note: In Spain, the species was found in 1998 in the south of Gran Canaria, Canary Islands (González Núñez et al., 2002). In Japan, the species was discovered in 1977 on Okinawa, Ryukyu archipelago from palm trees introduced from Taiwan (Morimoto, 1985).
The life cycle was outlined by Hill (1983) to take 10-12 weeks, and included 4-9 days as eggs, a larval development of 8-10 weeks and a 9-10 day pupation period (in the wild). More recently, Liao & Chen (1997) reported a similar life cycle duration with individual stages for egg, larvae and pupae as 6-10; 35-40; and 10-16 days respectively. They indicated that adults survived 15-22 days. The life stage durations are similar to these found by González Núñez et al. (2002) in laboratory trials (25 ±1°C, 70%±10 HR) using sugar cane as a food source.
Adult D. frumenti weevils are attracted to sap exuding from wounded palm tissue (Kalshoven, 1981) or from flower bases (Lepesme, 1947) and lay eggs in various sites: inflorescences, the bases of petioles or peduncles, or in cracks near adventitious roots at the base of the stem.
In Taiwan, female D. frumenti drill holes with their mouthparts to lay eggs near the surface of an unopened leaf sheath on the palm Mascarena verchaffeltii (Liao & Chen, 1997), whereas González Núñez et al. (2002) reported that in experiments with sugarcane as the food source, D. frumenti laid eggs 1.0-2.5 mm deep, and that no sign of oviposition could be seen from the exterior of the cane.
The average fecundity was 0.13 egg per female per day during experiments on sugarcane (González Núñez et al. 2002). They considered this low fecundity to be balanced by the high longevity of the adults, although Liao & Chen (1997) reported that the adults survived only 15-20 days.
The larvae can bore galleries in any part of the palm: roots, petioles, inflorescences, fronds, leaf sheaths, fruits and to all heights of the trunk (González Núñez et al., 2002; Hill, 1983). They develop entirely within the palm tree. Gummy exudates are usually seen near the gallery entrance. Pupation takes place within the larval gallery but no cocoon is formed. González Núñez et al. (2002) found that on sugar cane, the pupation chamber is formed near the epidermis of the cane used as food, a circular hole of 1.5 mm of diameter being formed for exit of the pest. This hole is filled with debris, and the thin epidermis of the cane remains as a protection. Similarly, Liao & Chen (1997) indicated that the larvae move toward the edge of the leaf sheath to pupate. The adults remove the debris with their mouthparts to emerge.
Liao & Chen (1997) indicated that 10 or more larvae could develop in each leaf sheath and Salomone Suárez et al. (2000b) estimated that hundreds of individuals could be found in a single palm tree.
Picture: Eduardo Franquiz Alemán (2008) Galleries of D. frumenti in sugar cane. used as a food source.
Attack of Phoenix canariensis by D. frumenti
Picture by Francesco Salomone (2008)