Valid Names Results

Eumyrmococcus smithii Silvestri, 1926 (Xenococcidae: Eumyrmococcus)

Nomenclatural History

• Eumyrmococcus smithii Silvestri 1926: 273. Type data: CHINA: Macao, on roots of plants, attended by ant Acropyga (Rhizomyrma) sauteri Forel.. Lectotype, female, by subsequent designation (Willia1978DJ,63). Type depository: Portici: Dipartimento de Entomologia e Zoologia Agraria di Portici, Universita di Napoli Federico II, Italy; accepted valid name

Common Names

Ecological Associates

Hosts:

Families: 1 | Genera: 3

Associates:

Families: 1 | Genera: 1

Geographic Distribution

Keys

• Tanaka2016: pp.119, 121 ( Adult (F) ) [Identification key to Japanese Rhizoecidae species]
• LiTsWu2014: pp.371 ( Adult (F) ) [Mealybugs with legs on bamboo in China]
• Hodgso2012: pp.52 ( Adult (M) ) [Key to known adult males of Eumyrmococcus species]
• SchneiLa2011: pp.68-70 ( Adult (F) ) [Genera and species of the tribe Xenococcini]
• KozarKo2007: pp.572-573 ( Adult (F) ) [Species of Eumyrmococcus]
• Willia1998DJ: pp.9 ( Adult (F) ) [World]
• Willia1993DJ: pp.220 ( Adult (F) ) [World]

Remarks

• Biology: The ant Acropyga sauteri Forel has an obligate, mutualistic symbiosis with the mealybug, Eumyrmococcus smithii Silvestri, on Okinawa Island, southern Japan. The mealybugs live inside ant nests nearly all their lives, and the ants depend on them for food. Alate foundress queens carry mealybugs during their nuptial flights, using them to establish new colonies at new sites. However, important aspects of the symbiosis have not yet been elucidated. The present study characterizes the basic biology of the symbiosis and describes for the first time the morphologies of all growth stages of E. smithii. Our study suggests that E. smithii has only one nymphal stage, followed by a female pupal stage or male prepupal stage. Intensive sampling of ant nests across seasons showed that A. sauteri prefers nest sites 5-20 cm underground. Acropyga sauteri produced reproductive stages mainly in mid-March or early April, and numbers of both ant workers and mealybugs increased from spring to summer. Experimental determination of colony identity with a method using nestmate recognition by ants suggested that each ant colony rarely has a perimeter greater than 30 cm, that the ants are monogynous, and that different ant colonies are densely aggregated along the root system of a plant, adjacent to each other but not interflowing. Both symbiotic partners were vulnerable to attacks by several common subaerial ant species following physical disturbance to their nests.Occurring on the roots of the host plant and in the nests of ants. Winged female and worker ants carry the mealybugs in the mandibles when disturbed (Kishimoto-Yamada et al., 2005).
• General Remarks: Description and illustration of the adult female by Silvestri (1926), Williams D. J. (1970, 1978), Yang (1982), Tang (1992) and by Williams (1998).

Illustrations

Citations