Christine A Johnson

American Museum of Natural History · Division of Invertebrate Zoology

Average global sea surface temperatures have been consistently higher during the past thirty years than any other time since reliable temperature recordings in 1880. Marine life is sufficiently adaptable to survive in a range of temperatures, but extended periods of temperature extremes can have a profound effect on the biology and behavior of aqua...

Species of the ant genus Polyergus are social parasites that steal brood from colonies of their hosts in the closely related genus Formica. Upon emergence as adults in a mixed population, host Formica workers carry out all the normal worker functions within the Polyergus colony, including foraging, feeding, grooming, and rearing brood of the parasi...

Areas of endemism are essential first hypotheses in investigating historical biogeography, but there is a surprising paucity of such hypotheses for the Nearctic region. Miridae, the plant bugs, are an excellent taxon to study in this context, because this group combines high species diversity, often small distribution ranges, a history of modern ta...

Phytophagous insects attack all of the nearly 20,000 species in the North American flora. Some of the insects are known generalists, while others tend to be more specific, associating with only one species or only closely related host plants. This aspect of phytophagous insect natural history has historically been of great interest to plant bug spe...

In monogyne (single queen) ant colonies, worker aggression against intruders, including newly-mated sister queens (gynes) seeking readoption, prevents the development of multi-queen colonies. Some ant species, however, produce multiple queen colonies (polygyny) via the adoption of new gynes in response to ecological, genetic and social parameters....

Johnson, C. A., Sundström, L. & Billen, J. 2005: Development of alary muscles in single-and mul-tiple-queen populations of the wood ant Formica truncorum. — Ann. Zool. Fennici 42: 225–234. Formica truncorum is an ant species that maintains populations dominated by either single-queen (monogyne) or multiple-queen (polygyne) colonies. New queens (gyn...

Approximately 150 ant species are facultatively or obligately queenless whereby mated workers assume the role of the queen. In many of these species a reproductive dominance hierarchy is established by way of aggressive interactions. Top-ranking workers, which are typically the most fecund, acquire a characteristic cuticular hydrocarbon profile. We...

Species of the genus Acropyga are rarely encountered subterranean ants that rely on mealybugs or aphids to provide their nutritional needs. Female Acropyga (Formicinae) alates of pantropical and Mediterranean species carry mealybugs with their mandibles while swarming and probably inoculate their new nests with these mealybugs. The natural history...

Laryngodus Herrich-Schaeffer, 1850, is redescribed, including, for the first time, nymphal morphology. Three species are recognised based on qualitative morphology, a principle components analysis of morphometric data, and the study of sequence data from the mitochondrial genes COI and 16S. They are: L. australiae Herrich-Schaeffer from the south-w...

Social insects that have secondarily lost the worker caste are the ultimate social parasite; they allocate their energy to sexual production and, thus, rely completely on the host for survival. Most inquiline species are rare, and little is known about their life histories except that they are completed within the host colony. Here we report intrac...

Competition is an important evolutionary force behind population regulation and community structures. The degree of competition symmetry (competition hierarchies) between species determines coexistence, exclusion, or niche differentiation. Intraspecific competition, however, is an important component in dictating levels of symmetry/asymmetry betwee...

Conflicts over reproductive division of labour are common in social insects. These conflicts are often resolved via antagonistic actions that are mediated by chemical cues. Dominant egg layers and their eggs can be recognized by a specific yet similar cuticular hydrocarbon profile. In the facultatively queenless ant Gnamptogenys striatula, a worker...

Fluctuating selection is a major theme in the evolutionary and ecological literature, yet attempts to measure how differential selection across time or space affects long-term change in life history traits or behaviors are still rare. Social evolution among the insects has been broadly studied with respect to how key parameters such as queen number...

In ca. 150 species of queenless ants, a specialized queen caste is rare or absent, and mated workers take over the role of the queen in some or all of the colonies. Previously, it has been shown that reproduction in queenless ants is regulated by a combination of dominance behavior and chemical fertility signaling. It is unknown, however, whether c...

Slave-making ants are specialized social parasites that steal the young from colonies of their host species to augment their slave supply. The degree of parasite-host specialization has been shown to shape the trajectory along which parasites and hosts coevolve and is a prime contributor to the geographic mosaic of coevolution. However, virtually n...

Social parasites exploit the behaviours of other social species. Infiltration of host systems involves a variety of mechanisms depending on the conditions within the host society and the needs of the social parasite. For many species of socially parasitic ants, colony establishment entails the usurpation of colonies of other species. This frequentl...

Social parasites exploit the behaviours of other social species. Infiltration of host systems involves a variety of mechanisms depending on the conditions with-in the host society and the needs of the social parasite. For many species of socially parasitic ants, colony establish-ment entails the usurpation of colonies of other species. This frequen...

Over 15 years ago, Bruce Charlton (1987) suggested in his article ‘Think Negative’ that many disciplines would benefit if negative results were given public airing. He argued that science needs reports of negative results for the simple reason that similar investigations, which are often costly and time-consuming, are frequently duplicated and produ...

Gnamptogenys menadensis is an arboreal nester that forages opportunistically almost exclusively on vegetation, sometimes recruiting others to participate in prey retrieval. The three-dimensional characteristics of vegetation suggest that functions describing recruitment decision thresholds or the pattern of recruitment in arboreal species may diffe...

A new colony of the slave-making ant Polyergus breviceps is initiated when a newly mated gyne invades a host nest and kills the resident queen. This process seems to result in chemical camouflage of the invading gyne and allows her to usurp the position of colony reproductive. Young, recently mated Formica gynes, however, are not attacked. To deter...

Queens of the slave-maker ant, Polyergus breviceps, take over nests of their Formica host species by fatally attacking the resident queen. As workers only begin grooming the P. breviceps queen once she has ceased her attack, we investigated whether a change in parasite queen chemistry may account for the change in worker behavior. Cuticular hydroca...

Queens of the slave-making ant, Polyergus breviceps, take over nests of adult Formica workers when establishing new colonies. Although nave to slave-maker brood, the usurped Formica rear Polyergus offspring and nests containing both host and parasite species forms. Host worker acceptance of parasite brood has been attributed to the similarity of br...

"A dissertation submitted to the Graduate Faculty in Psychology ... " Thesis (Ph. D.) -- City University of New York, 2000. Includes bibliographical references (leaves 184-217).