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Colonies of Polistes (Polistella) nipponensisPérez orphaned in the pre-emergence stage (before the emergence of the first workers) were maintained by emerging workers and produced reproductives (males and gynes). The number of nest mate workers potentially available for the first emerging worker is suggested as the main factor determining whether emerging workers successfully maintain the orphan colony or they leave the natal nest. The fast development of the first workers may increase the fitness of the founding female even if she dies in the pre-emergence stage.

Nerve fibers of the human fasciculus gracilis were studied on 10 male cadavers aged 41-97 years using a discriminative staining method and a microscopic image-analyzing system. Our data show that the transverse areas of axons in the human fasciculus gracilis significantly decrease with age, while no significant correlation was observed between the number of fibers and age.

Ants often tend and protect the larvae of various myrmecophilous lycaenid species, which influences the fitness of butterflies by altering their growth and developmental time. Tending produces diverse effects depending on lycaenid sex and the lycaenid/ant species combination. Effects are widely variable, especially in facultatively myrmecophilous lycaenids such as Plebejus argyrognomon praeterinsularis, because they are associated with several ant species and can survive without any ant tending. We studied the effects of ant tending on the adult body mass and larval developmental time of P. argyrognomon praeterinsularis. Female larvae grew significantly heavier as adults when tended by Camponotus japonicus rather than by either Lasius japonicus or no ant species. Ant tending did not affect the body mass of adult males or the developmental time of either male or female larvae. Thus, tending by C. japonicus could increase the fitness of P. argyrognomon praeterinsularis by increasing the mass of females without prolonging the duration of vulnerable immature stages, because larger females generally lay more eggs. This means that even facultatively myrmecophilous lycaenids might gain fitness benefits from particular ant species, which could be important in the conservation and management of at-risk species of facultatively myrmecophilous lycaenids.