Kota Ogawa

Kyushu University | Kyudai · Graduate School of Social and Cultural Studies

In a majority of ants, a newly mated queen independently founds a colony and claustrally raises her first brood without foraging outside the nest. During claustral independent colony foundation (ICF) in several ants, the esophagus of the founding queen expands and develops into a “thoracic crop,” which is then filled with a liquid substrate for lar...

In a majority of ants, a newly mated queen independently founds a colony and claustrally raises her first brood without foraging outside the nest. During claustral independent colony foundation (ICF) in several ants, the esophagus of the founding queen expands and develops into a thoracic crop, which is then filled with a liquid substrate for larva...

Background: Novel feeding adaptations often facilitate adaptive radiation and diversification. But the evolutionary origins of such feeding adaptations can be puzzling if they require concordant change in multiple component parts. Pelagic, heterorhabdid copepods (Calanoida) exhibit diverse feeding behaviors that range from simple particle feeding...

Background Aphids display “cyclic parthenogenesis,” in which parthenogenetically and sexually reproducing morphs seasonally alternate in the aphid annual life cycles. There are various characteristics that differ between asexual viviparous and sexual oviparous females. In oviparous females, swollen cuticular structures (~ 10 μm in diameter), called...

In termites, the soldier caste possesses morphological features suitable for colony defence, despite some exceptions. Soldiers are differentiated via two moultings through a presoldier stage with dramatic morphogenesis. While a number of morphological modifications are known to occur during the presoldier moult, growth and morphogenesis seem to con...

Polyphenism, in which multiple discrete phenotypes develop from a single genotype, is considered to have contributed to the evolutionary success of aphids. Of the various polyphenisms observed in the complex life cycle of aphids, the reproductive and wing polyphenisms seen in most aphid species are conspicuous. In reproductive polyphenism, the repr...

In many insect taxa, wing polymorphism is known to be a consequence of tradeoffs between flight and other life-history traits. The pea aphid Acyrthosiphon pisum exhibits various morphs with or without wings associated with their complex life cycle including wing polyphenism in viviparous females, genetic wing polymorphism in males, and a monomorphi...

Wing polymorphisms observed in many Insecta are important topics in developmental biology and ecology; these polymorphisms are a consequence of trade-offs between flight and other abilities. The pea aphid, Acyrthosiphon pisum, possesses 2 types of wing polymorphisms: One is a genetic wing polymorphism occurring in males, and the other is an environ...

Most aphids show reproductive polyphenism, i.e. they alternate their reproductive modes from parthenogenesis to sexual reproduction in response to short photoperiods. Although juvenile hormone (JH) has been considered a likely candidate for regulating the transition from asexual to sexual reproduction after photoperiod sensing, there are few studie...