Species Diversity and Distribution Patterns of the Ants of Amazonian Ecuador

Ants are among the most diverse, abundant and ecologically significant organisms on earth. Although their species richness appears to be greatest in the New World tropics, global patterns of ant diversity and distribution are not well understood. We comprehensively surveyed ant diversity in a lowland primary rainforest in Western Amazonia, Ecuador using canopy fogging, pitfall traps, baits, hand collecting, mini-Winkler devices and subterranean probes to sample ants. A total of 489 ant species comprising 64 genera in nine subfamilies were identified from samples collected in only 0.16 square kilometers. The most species-rich genera were Camponotus, Pheidole, Pseudomyrmex, Pachycondyla, Brachymyrmex, and Crematogaster. Camponotus and Pseudomyrmex were most diverse in the canopy, while Pheidole was most diverse on the ground. The three most abundant ground-dwelling ant genera were Pheidole, Solenopsis and Pyramica. Crematogaster carinata was the most abundant ant species in the canopy; Wasmannia auropunctata was most abundant on the ground, and the army ant Labidus coecus was the most abundant subterranean species. Ant species composition among strata was significantly different: 80% of species were found in only one stratum, 17% in two strata, and 3% in all three strata. Elevation and the number of logs and twigs available as nest sites were significant predictors of ground-dwelling ant species richness. Canopy species richness was not correlated with any ecological variable measured. Subterranean species richness was negatively correlated with depth in the soil. When ant species were categorized using a functional group matrix based on diet, nest-site preference and foraging ecology, the greatest diversity was found in Omnivorous Canopy Nesters. Our study indicates ant species richness is exceptionally high at Tiputini. We project 647–736 ant species in this global hotspot of biodiversity. Considering the relatively small area surveyed, this region of western Amazonia appears to support the most diverse ant fauna yet recorded

Population Structure and Social Organization in the Primitive Ant Amblyopone Pallipes (Hymenoptera: Formicidae)

Volume: 89Start Page: 65End Page: 8

Age-related changes in biogenic amines in individual brains of the ant Pheidole dentata

The behavioral development of minor workers of the ant Pheidole dentata involves a progression of tasks beginning with brood care and culminating in foraging as individuals age. To understand the role of brain neurochemistry in age-related division of labor, we measured the levels of serotonin, dopamine and octopamine in individual brains of minor workers of different age. Serotonin and dopamine levels were significantly correlated with worker age: both increased as minor workers matured, and serotonin rose significantly in the oldest ants. In addition, the serotonin:dopamine ratio was significantly higher in the oldest workers. Octopamine levels did not change with age, although the ratios of octopamine:serotonin and octopamine:dopamine were significantly higher in the youngest workers. These age-associated changes in biogenic amine levels suggest an involvement of neuromodulators in minor worker behavioral ontogeny and temporal polyethism in P. dentat

Origins of Aminergic Regulation of Behavior in Complex Insect Social Systems

Neuromodulators are conserved across insect taxa, but how biogenic amines and their receptors in ancestral solitary forms have been co-opted to control behaviors in derived socially complex species is largely unknown. Here we explore patterns associated with the functions of octopamine (OA), serotonin (5-HT) and dopamine (DA) in solitary ancestral insects and their derived functions in eusocial ants, bees, wasps and termites. Synthesizing current findings that reveal potential ancestral roles of monoamines in insects, we identify physiological processes and conserved behaviors under aminergic control, consider how biogenic amines may have evolved to modulate complex social behavior, and present focal research areas that warrant further study

Biogenic amines and collective organization in a superorganism : neuromodulation of social behavior in ants

The ecological dominance of ants has to a great extent been achieved through their collective action and complex social organization. Ants provide diverse model systems to examine the neural underpinnings of individual behavior and group action that contribute to their evolutionary success. Core elements of ant colony structure such as reproductive and ergonomic division of labor, task specialization, and social integration are beginning to be understood in terms of cellular neuroanatomy and neurochemistry. In this review we discuss the neuroethology of colony organization by focusing on the role of biogenic amines in the control of social behavior in ants. We examine the role of neuromodulation in significant sociobiological characteristics of ants, including reproductive hierarchies, colony foundation, social food flow, nestmate recognition, territoriality, and size- and age-related sensory perception and task performance as well as the involvement of monoamines in collective intelligence, the ultimate key to the global dominance of these remarkable superorganisms. We conclude by suggesting future directions for the analysis of the aminergic regulation of behavior and social complexity in ants.17 page(s

Territoriality, Nest Dispersion, and Community Structure in Ants

Volume: 88Start Page: 265End Page: 31

Biogenic Amines and Collective Organization in a Superorganism: Neuromodulation of Social Behavior in Ants

The ecological dominance of ants has to a great extent been achieved through their collective action and complex social organization. Ants provide diverse model systems to examine the neural underpinnings of individual behavior and group action that contribute to their evolutionary success. Core elements of ant colony structure such as reproductive and ergonomic division of labor, task specialization, and social integration are beginning to be understood in terms of cellular neuroanatomy and neurochemistry. In this review we discuss the neuroethology of colony organization by focusing on the role of biogenic amines in the control of social behavior in ants. We examine the role of neuromodulation in significant sociobiological characteristics of ants, including reproductive hierarchies, colony foundation, social food flow, nestmate recognition, territoriality, and size- and age-related sensory perception and task performance as well as the involvement of monoamines in collective intelligence, the ultimate key to the global dominance of these remarkable superorganisms. We conclude by suggesting future directions for the analysis of the aminergic regulation of behavior and social complexity in ants.17 page(s