Morphological variations in the pre‐imaginal development of the ponerine antDiacamma ceylonense

Abstract

 Abstract Baratte, S., Cobb, M., Deutsch, J. and Peeters, C. 2005. Morphological variations in the pre-imaginal development of the ponerine ant Diacamma ceylonense . -Acta Zoologica (Stockholm) 86 : 25-31In the present paper, the larval development of the queenless ponerine ant Diacamma ceylonense is studied. Four instars were identified on the basis of cuticular processes -tubercles and spinules -which show discontinuous variation during growth and provide precise and reliable external morphological criteria for instar discrimination. In the first three instars, the larva possesses a striking proboscis, which disappears between the third and fourth instars. Larval weight increased around 50-fold in the 21 days of larval life between eclosion and pupation (mean weight for first instar = 0.37 mg; for fourth instar = 20 mg). In addition, the morphology of the gemmae, structures resembling vestigial wings in workers, is described in nymphae.

Juvenile hormone induces queen development in late-stage larvae of the ant Harpegnathos saltator

“…All larvae were checked daily for signs that they had molted into a new instar. Unlike other ant species (Baratte et al, 2005;Petralia and Vinson, 1979), the larval instars of H. saltator cannot be easily distinguished by differences in hair morphology or other conspicuous morphological features. However, at the beginning of each instar the larvae of H. saltator appear to have a higher density of tubercles covering their body (Fig.…”

Testing homology with morphology, development and gene expression: sex‐specific thoracic appendages of the ant Diacamma

“…They were regularly provided with water and fed with Tenebrio larvae, crickets, and honey diluted in water. Larval development of D. ceylonense proceeds through four instars distinguishable by their conspicuous processes on the cuticle (Baratte et al 2005). Prepupae and pupae were obtained by opening cocoons of different ages.…”

Estimating the rate of gamergate turnover in the queenless ant Diacamma cyaneiventre using a maximum likelihood model

“…In the closely related D. ceylonense, it takes 65 days from eggs to adult emergence (Baratte et al, 2005) and about 19 days before the future gamergate starts to lay eggs (CuvillierHot et al, 2002). Using these values for D. cyaneiventre, we can estimate that the confl ict over male production lasts a minimal value of 19 days (if a cocoon ecloses just after the gamergate death) and a maximal value of 84 days (if only eggs were present just after the gamergate death).…”

“…Just after a gamergate change, the next callow to emerge becomes the new gamergate; the remaining brood can never become gamergate in this colony because it emerged too late. Once the new gamergate starts laying eggs, the brood will be gradually replaced by nieces of the present workers in approximately 65 days (developmental time from egg to emergence, Baratte et al, 2005). Before the replacement of all the brood, the workers have a last opportunity to produce a descendant colony headed by a full-sister, by leaving the nest with some brood among which the fi rst worker to emerge (their fullsister) will be the gamergate of the new colony.…”

“…A few workers, a future gamergate (either a cocoon or an already emerged worker that retained its gemmae), and some young brood laid by the new gamergate of the mother colony (sister of the workers and mother of the brood), left this colony and established a new one. Such scenario is possible because the developmental time from egg to emergence (65 days, Baratte et al, 2005) is longer than the time to sexual maturity and mating (19 days, Cuvillier-Hot et al, 2002). Hence, the only fi ssion event genetically analysed so far in a queenless ant probably occurred just after a gamergate replacement.…”