Comparative reproductive biology of the social parasite Acromyrmex ameliae de Souza, Soares & Della Lucia and of its host Acromyrmex subterraneus subterraneus Forel (Hymenoptera: Formicidae)

Abstract

-Social parasites exhibit several characteristics that allow them to exploit their host species efficiently. The smaller size of parasite species is a trait commonly found in ants. In this work, we investigated several aspects of the reproductive biology of Acromyrmex ameliae De Souza, Soares & Della Lucia, a recently discovered parasite of Acromyrmex subterraneus subterraneus Forel. Sexuals of A. ameliae are substantially smaller than those from host species. Parasite queens laid significantly less worker eggs than host queens and inhibit sexual production of the host. The sex ratio of parasite species is highly female biased. Interestingly, we have observed parasite coupling on the laboratory, inside the nests and in the ground, opening the possibility to use controlled mating to study genetic approaches of parasitism in the ants.

Relaxed selection underlies genome erosion in socially parasitic ant species

“…Life as an inquiline social parasite universally requires new and highly specific adaptations to host finding, intrusion into mature host colonies, and manipulation of the hosts’ brood care behavior to favor the non-related inquiline brood. Some of these adaptations have been studied in A. insinuator 77 – 79 , A. ameliae 80 , and a number of recent reviews have also underlined the consistency of convergent adaptations across ant inquiline social parasites 28 , 31 , 81 . The fact that we did not detect clear genomic signatures of adaptive change shared across the three independently evolved social parasite species may well be because convergent evolution does not necessarily rely on the same set of genes, particularly in lineages heavily affected by drift, or because changes were concentrated in regulatory, non-coding regions.…”

Morphology of the Ovary and Spermatheca of the Leafcutter Ant Acromyrmex rugosus Queens (Hymenoptera: Formicidae)

“…The number of ovarioles found in A. rugosus was different from that found in Acromyrmex subterraneus subterraneus (Forel) (Hymenoptera: Formicidae), with 28 ovarioles per ovary (Antunes et al 2002); Acromyrmex ameliae De Souza, Soares & Della Lucia (Hymenoptera: Formicidae) with 13 to 15 ovarioles per ovary (Soares et al 2010); Acromyrmex octospinosus Reich (Hymenoptera: Formicidae) and Acromyrmex echinatior (Forel) (Hymenoptera: Formicidae), with 5 to 6 ovarioles per ovary (Dijkstra et al 2005); and queens of the genus Atta with more than 300 ovarioles per ovary (Tschinkel 1987). The number of ovarioles per ovary in ants vary from 2 to 1,300 (Hölldobler & Wilson 1990), and may be related to the queen's reproductive capacity (Antunes et al 2002).…”

The Diet of Upland Sandpipers (Bartramia Longicauda) in Managed Farmland in Their Neotropical Non-Breeding Grounds

“…Temporal variation in occurrence was analyzed using a Canonical Correspondence Analysis comparing frequencies of occurrence between years. Estimation of maximum prey size was done using insects collected in the field and values reported in the literature (Schatz & Wcislo 1999, Arnett 2000, Arnett et al 2002, Henry 2009, Bentancourt & Scatoni 2010, Soares et al 2010, Aisenberg et al 2011. ).…”