Valid Names Results

Rhizoecus amorphophalli Betrem, 1940 (Rhizoecidae: Rhizoecus)

Nomenclatural History

• Rhizoecus amorphophalli Betrem 1940: 267. Type data: INDONESIA: Java, Buitenzorg (now Bogor), on Amorphophallus variabilis. Lectotype, female, by subsequent designation (Hamble1979b,64). Type depository: Bogar: Agricultural Experiment Station, India; accepted valid name
• Ripersiella amorphophalli (Betrem, 1940); Hambleton 1946: 61. change of combination
• Rhizoecus amorphophalli; Hambleton 1946: 61. subsequent use Notes: Author's name mis-spelled "Betram".
• Rhizoecus advenus Beardsley 1966: 468. Type data: HAWAII: Honolulu, on Cordyline terminalis. Holotype, female, Type depository: Honolulu: Bernice P. Bishop Museum, Department of Entomology Collection, Hawaii, USA; junior synonym (discovered by Hamble1979b, 63). Illustr.
• Rhizoecus advenoides Takagi & Kawai 1971: 374. Type data: JAPAN: Tokyo, Tatikawa (Tachikawa), on Artemisia lavendulaefolia. Syntypes, female, Type depository: Sapporo: Entomological Institute, Faculty of Agriculture, Hokkaido University, Japan; junior synonym (discovered by JansenWe2015, 18). Illustr.
• Rhizoecus amorphophali Betrem, 1940; Meurgey 2011. misspelling of species epithet
• Rhizoecus amoprhophalli Betrem, 1940; Sreerag, et al. 2016: 149. misspelling of species epithet
• Rhizoecus amorphalli Betrem, 1940; Kaydan, et al. 2017: 315. misspelling of species epithet

Common Names

Ecological Associates

Hosts:

Families: 8 | Genera: 11

Associates:

Families: 2 | Genera: 2

Geographic Distribution

Keys

• KaydanKoKo2019: pp.3-4 ( Adult (F) ) [Neotropical Rhizoecus species]
• KaydanKoWi2017: pp.314-315 ( Adult (F) ) [Rhizoecus from Southern Asia]
• Tanaka2016: pp.119, 121 ( Adult (F) ) [Identification key to Japanese Rhizoecidae species] Key as: Rhizoecus advenoides
• JansenWe2015: pp.12, 16 ( Adult (F) ) [Subterranean mealybugs of The Netherlands]
• DanzigGa2015: pp.437-438 ( Adult (F) ) [species of Rhizoecus] Key as: ?Rhizoecus advenoides
• KozarKo2007: pp.132-137 ( Adult (F) ) [world] Key as: Rhizoecus advenoides
• KozarKo2007: pp.132-137 ( Adult (F) ) [world]
• Willia2004a: pp.748-750 ( Adult (F) ) [Rhizoecus species of southern Asia]
• Jansen2003: pp.300 ( Adult (F) ) [Netherlands]
• Tang1992: pp.54 ( Adult (F) ) [China] Key as: Rhizoecus advenoides
• Tang1992: pp.54 ( Adult (F) ) [China]
• Willia1985d: pp.234 ( Adult (F) ) [India]
• Beards1966: pp.468 ( Adult (F) ) [Federated States of Micronesia]
• Beards1966b: pp.151 ( Adult (F) ) [Hawaiian islands]
• Hamble1946: pp.60 ( Adult (F) ) [World]

Remarks

• Systematics: Takagi & Kawai (1971) summarised the differences between Rh. advenoides and Rh. advenus Beardsley, which were synonymised by Hambleton (1979). Important discriminating characters of Rh. advenoides and Rh.amorphophalli Betrem (1940) are the labium, which is as long as wide, and the tubular ducts, which should miss a pale circular area around its orifice. Rhizoecus amorphophalli on the other hand should have a labium which is longer than wide and the tubular ducts possess a pale circular area around the orifice. These characters actually represent variability within populations of both species. Besides, the number of circuli in both species is variable and may be 1 or 2 and the circulus has a reticulated distal plate (Williams 1985). The number of tritubular pores on the dorsal abdominal segments is between 2 and 7, the shape of the claw digitules is variable and the third antennal segment is not constant within populations of both species. Jansen and Westenberg concluded that Rh. advenoides Kawai & Takagi is a junior synonym of Rh. amorphophalli, which represents a rather variable taxon. Danzig & Gavrilov-Zimin thought that Rh. advenoides Kawai & Takagi was more likely a synonym of Rh. inconspicuus, but hesitated to formally synonymize the two since they did not have access to type material.
• Structure: Prepupae and pupae of are without any covering. Adult males of Rhizoecidae are either wingless, brachypterous or alate (Williams & Hodgson, 2013).
• Biology: Occurring on the roots of its host plants. Mealybugs are seen in clusters on the stem, petiole and leaf, particularly on the lower side. This pest thrives in hot and humid conditions. mealybugs enter soil cracks and holes formed after pseudostem drying and infest the corms.
• Economic Importance: When the temperature is more than 30°C its infestation is severe, and increases with rising temperature and humidity. During storage, when temperature and humidity are high, it can infest an entire batch of corms of the host plant. During storage, when temperature and humidity are high, it can infest an entire batch of corms. Severely infested corms shrivel which adversely affects their quality and marketability. Infestation also affects the corms’ ability to sprout which then affects subsequent production and productivity. An aqueous salt solution was found to be very effective in controlling the mealybug and retaining the quality of the corms, with subsequent benefits to corm sprouting and vigour of the following crop. Only a weak dilution (1000 ppm, about 1 teaspoon of salt in 10 litres of water) is required and treating the corms is easy. Common salt is both cheap and widely available. Unless the protective mealy substance on the body of the mealy bug is dissolved, no insecticide can penetrate into and kill the pest. In order to facilitate this a detailed study on the structure and chemistry of mealy substance secreted by R. amorphophalli was undertaken by Sreerag, et al. (2016).
• General Remarks: Description and illustration of adult female by Beardsley (1966), Hambleton (1979b), Williams (1985d), Williams (2004a) and by Kozár & Konczné Benedicty (2007). See Hambleton (1977b) and Williams & Granara de Willink (1992) for information on type material. Description and illustration of adult female junior synonym, Rh. advenoides by Takagi & Kawai (1971) and by Kozár & Konczné Benedicty (2007).

Illustrations

Citations