Showing papers by "Fuminori Ito published in 2016"
Journal Article•
TL;DR: The defensive function of petiole spines in queens and workers of the formicine ant Polyrhachis lamellidens was investigated using the ant predating tree frog Hyla japonica, indicating that the spines of workers provide an effective defense against the tree frogs.
Abstract: The defensive function of petiole spines in queens and workers of the formicine ant Polyrhachis lamellidens was investigated using the ant predating tree frog Hyla japonica. Ant workers have hook-like large spines on their petiole while the queen petiole has only small slightly curved spines. Intact workers of P. lamellidens are unpalatable while workers without spines and intact queens are palatable, indicating that the spines of workers provide an effective defense against the tree frogs. Caste differences of spine morphology therefore affect the defense potential of the ants.
16 citations
TL;DR: Ants show a remarkable diversity in the morphological specialization of the worker's reproductive apparatus, that allows to distinguish four types, type 1: workers that have ovaries and a functional spermatheca, and that reproduce like queens, type 2: workers have ovary and a vestigial spermatic disc, and type 4: workers lost both Ovaries and sperMatheca.
Abstract: Reproductive division of labor is one of the crucial features in social insects, however, the developmental mechanisms leading to modifications in the reproductive apparatus of workers are still not very clear. Ants show a remarkable diversity in the morphological specialization of the worker's reproductive apparatus, that allows to distinguish four types, type 1: workers that have ovaries and a functional spermatheca, and that reproduce like queens, type 2: workers have ovaries and a vestigial spermatheca, type 3: workers have ovaries but no spermatheca, and type 4: workers lost both ovaries and spermatheca. We investigated morphogenesis of the worker spermatheca in 28 ant species by histological examination. In workers of type 1, the morphogenesis of the spermatheca is very similar to that in ant queens. In type 2, the spermathecal disc also differentiates, however, the development is interrupted and remains vestigial. In types 3 and 4, the absence of the spermatheca in the adult phase is caused by a degeneration after initial formation of the spermathecal disc or by a complete lack of the spermathecal discs. The timing of these interruption and degeneration events varies among species. The species exhibiting an earlier interrupting point of spermatheca formation in workers have a larger queen-worker dimorphism, that seems to be independent from ant phylogeny.
16 citations
TL;DR: Four solitary queens of the invasive ant Anoplolepis gracilipes under stones in East Java, Indonesia produced nanitic workers by claustral colony foundation, the first report of independent colony foundation by queens in this species.
Abstract: We collected four solitary queens of the invasive ant Anoplolepis gracilipes under stones in East Java, Indonesia. They produced nanitic workers by claustral colony foundation. This is the first report of independent colony foundation by queens in this species. The discovery may give an important insight into discussion on the origin of this invasive ant.
12 citations
TL;DR: The mandibular gland in workers of the formicine ant Myrmoteras iriodum differs from other ants both in its general morphology and ultrastructural organization, and should be studied using gland extracts and behavioural observations.
6 citations
DOI•
31 Dec 2016
TL;DR: The present paper is the first description of the queen caste of Yunodorylus and the queens were interestingly subdichthadiiform, which has an important implication in the further understanding of the evolution of the “Army Ant Adaptive Syndrome” in the subfamily Dorylinae.
Abstract: Yunodorylus comprises four named species and has so far been known exclusively from the Indo-Chinese and IndoMalayan subregions. Recently, two queen-right colonies of Yunodorylus eguchii Borowiec, 2009 were found in a lowland evergreen forest in Lo Go Xa Mat National Park, southwestern Vietnam. The present paper is the fi rst description of the queen caste of Yunodorylus. The queens were interestingly subdichthadiiform. This discovery has an important implication in our further understanding of the evolution of the “Army Ant Adaptive Syndrome” in the subfamily Dorylinae.
4 citations
Journal Article•
TL;DR: Observations in the laboratory indicated that mating occurred inside the nest and that males could mate with more than one worker.
Abstract: I report the colony composition and nesting biology of Platythyrea sp. (parallela-group) in the Bogor Botanic Gardens, West Java. This species, which always nests in trees, reproduces through both dealated queens and mated workers. Among 13 collected colonies, dealated queens reproduced in only one colony, which also contained six mated workers, of which three had active ovaries. In the queenless colonies, the percentage of mated workers among the worker population was high, while there were many non reproductive mated workers. Observations in the laboratory indicated that mating occurred inside the nest and that males could mate with more than one worker.
3 citations