Acropyga

Abstract: The mealybug tribe Xenococcini (Hemiptera: Pseudococcidae) comprises three genera, Eumyrmococcus Silvestri, Neochavesia Williams & Granara de Willink and Xenococcus Silvestri, trophobiotically associated with ants of the genus Acropyga Roger (Hymenoptera: Formicidae). Alate Acropyga queens vertically transmit trophobionts by carrying them along on the nuptial flight, a unique behaviour termed trophophoresy. Xenococcine mealybugs have never been collected without ant associates, and putatively only associate with Acropyga. Xenococcine mealybugs are characterized by the absence of dorsal ostioles, presence of distally cup-shaped circuli and a female pupal instar rather than a third feeding instar. The phylogeny of this tribe is derived for the first time using morphological data from adult females (53 characters) through Bayesian inference and maximum parsimony methods. Monophyly of the clade is strongly supported and a discussion of their taxonomy is included. The Neotropical genus Neochavesia was recovered as monophyletic. Eumyrmococcus, as previously defined, was recovered as paraphyletic, and thus two species are transferred to Xenococcus: Xenococcus kinomurai (Williams & Terayama) comb.n. and Xenococcus neoguineensis (Williams) comb.n. Two species groups are recognized within Eumyrmococcus: the Eumyrmococcus scorpioides species group, restricted to the eastern Mediterranean and Afrotropics, and the Eumyrmococcus smithii species group, restricted to the Orient and Indo-Australasia. Six new species are described: Eumyrmococcus adornocapillussp.n. from Australia; Eumyrmococcus sarnatisp.n. from Fiji; Eumyrmococcus ordinotersussp.n. and Xenococcus baryglobosussp.n. from the Solomon Islands; Neochavesia cephalonodussp.n. from French Guiana; and Neochavesia linealumasp.n. from Guyana. The systematics and biology of the xenococcine mealybugs is discussed in the context of obligate ant symbiosis.

Abstract: The mealybug-tending ant A. epedana is an obligate coccidiphile with trophophoretic queens. Trophophoresy is defined as the behavior of a foundress queen transporting a trophobiont on her mating flight for the establishment of a new mealybug \"herd\" in her new colony. Both the male and queen of A. epedana are described here for the first time. Observations on a laboratory colony of A. epedana suggest that the ants obtain most, if not all, of their energy requirements from the mealybugs they tend. When offered a variety a food items ranging from dead insects to sugary substances (e.g. honey, sugar water), the ants refused them and even acted aggressively towards the dead prey items. Observations of a laboratory colony also revealed a peculiar body jerking behavior suggestive of a form of vibrational communication, though its exact function remains to be

Abstract: Recent studies by Bunzli (1935) have demonstrated the importance of ants of the genus Acropyga (subgenus Rhizomyrma ) to the cultivation of coffee in Surinam. The ants ( Rhizomyrma paramaribensis Borgmeier and R. rutgersi Bunzli) tend coccids on the roots of the Liberian coffee trees and these coccids transmit an infectious phloemnecrosis. This phloemnecrosis in epidemic years caused a loss of 20–40 per cent of the coffee production in many fields in Surinam (Stahel, in Bunzli, p. 559). Earlier studies by GOldi (1892), Pickel (1927) and Costa Lima (1928) showed that coccids ( Rhizoecus coffeae Laing) tended by other species of this subgenus caused severe injury to coffee trees in northeast Brazil. According to Donisthorpe (1936) a species of Rhizomyrma has recently been taken associated with a coccid at the roots of coffee in Colombia.