In many other kinds of insects, and other organisms as well, sperm competition is an important selective force, and males are often favored to ensure that no other male copulates with his mate Parker, Monogyny refers simply to the possession by a colony of a single queen, as opposed to polygyny , which is the possession of multiple queens. Formica colonies transplanted into Hypoclinea territories were forced to emigrate, just as in the laboratory. One of the commonest triggering stimuli is rain, especially in species that occur in dry habitats such as deserts, grassland, and forest clearings. Please update your browser to view this site properly.
The key feature of the Formica polyctena annual cycle can be seen to be the relative environmental independence of the reproductive crop, which is reared from egg to adult at a time of year when little or no food is being gathered from outside the nest. The ability of a single mature colony to disseminate fertile queens in many directions over long distances is one of the reasons the fire ant is so difficult to eradicate Markin et al. The queens of Odontomachus haematodus are capable of rearing their first brood at least partially with their own oral secretions, but, in one experiment performed by Haskins and Haskins b , the larvae still failed to reach maturity. In general, first instar larvae are fed by regurgitation, trophic eggs, or both. Species such as leafcutters of the genus Atta , Myrmecocystus honey ants, Camponotus carpenter ants, and members of the Formica rufa group invest huge amounts of energy and time in the construction of nests. However, in later studies one of the authors Delage-Darchen, demonstrated that materials from the postpharyngeal lumen serve as nutrients and are fed to the larvae.
Fern - Sexual reproduction | registramos.info
Most data on the course of colony growth in social insects generally suggest curves that are roughly sigmoidal hence "logistic" in form Brian, b, As many as half a dozen of these balls would keep forming on every little bush and this went on throughout the morning. As a result, there should be an optimum number of nanitic workers, determined by the balance between the advantages of a larger initial worker force and the disadvantages of a smaller body size see Figure For a few worker generations, the average number of which varies among species, no new reproductive forms are reared. At the opposite extreme, mound-builders and a few other forms with deep, secure nests often remain at the same site for many years. In all but the most timid species, some of the workers--typically older individuals and members of the soldier major caste--run excitedly over the nest surface and surrounding terrain. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind.
Early experimental investigations on the two glands in Formica polyctena were contradictory. Soon afterward the first females alighted. Applying the standard argument from natural selection theory, this circumstance favors the evolution of premating isolating mechanisms. The general activity at the Pogonomyrmex rugosus mating site lasted about two hours, ending completely by hours as darkness approached. Another intrinsic isolating mechanism is differentiation in the preferred mating site within the major habitat. Filament Part of the stamen that supports the anther. A well-established principle of evolutionary biology is that when different species are faced with similar challenges in the environment, they often evolve very different mechanisms, even when they are closely related genetically at the outset.
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