title: Extreme convergence in egg-laying strategy across insect orders.
abstract: The eggs of stick and leaf insects (Phasmatodea) bear strong resemblance to plant seeds and are commonly dispersed by females dropping them to the litter. Here we report a novel egg-deposition mode for Phasmatodea performed by an undescribed Vietnamese species of the enigmatic subfamily Korinninae that produces a complex egg case (ootheca), containing numerous eggs in a highly ordered arrangement. This novel egg-deposition mode is most reminiscent of egg cases produced by members of unrelated insect orders, e.g. by praying mantises (Mantodea) and tortoise beetles (Coleoptera: Cassidinae). Ootheca production constitutes a striking convergence and major transition in reproductive strategy among stick insects, viz. a shift from dispersal of individual eggs to elaborate egg concentration. Adaptive advantages of ootheca formation on arboreal substrate are likely related to protection against parasitoids and desiccation and to allocation of specific host plants. Our phylogenetic analysis of nuclear (28S, H3) and mitochondrial (COI, COII) genes recovered Korinninae as a subordinate taxon among the species-rich Necrosciinae with Asceles as sister taxon, thus suggesting that placement of single eggs on leaves by host plant specialists might be the evolutionary precursor of ootheca formation within stick insects.
authors.affiliation: Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Georg-August-University Göttingen, Berliner Str. 28, 37073 Göttingen, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Goldberg
authors.affiliation: Royal Belgian Institute of Natural Sciences, Vautier Street 29, 1000 Brussels, Belgium.
authors.forename: Joachim
authors.initials: J
authors.lastname: Bresseel
authors.affiliation: Royal Belgian Institute of Natural Sciences, Vautier Street 29, 1000 Brussels, Belgium.
authors.forename: Jerome
authors.initials: J
authors.lastname: Constant
authors.affiliation: Schädrütihalde 47c, 6006 Lucerne, Switzerland.
authors.forename: Bruno
authors.initials: B
authors.lastname: Kneubühler
authors.affiliation: Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Georg-August-University Göttingen, Berliner Str. 28, 37073 Göttingen, Germany.
authors.forename: Fanny
authors.initials: F
authors.lastname: Leubner
authors.affiliation: Zoological Institute and Museum, Ernst-Moritz-Arndt-University, Johann-Sebastian-Bach-Str. 11/12, 17489 Greifswald, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Michalik
authors.affiliation: Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Georg-August-University Göttingen, Berliner Str. 28, 37073 Göttingen, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Bradler
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000145:classification / Q000254:growth & development; D005260:Female; D006657:Histones / Q000235:genetics; D007313:Insecta / Q000145:classification / Q000254:growth & development / Q000502:physiology*; D020050:Mantodea / Q000145:classification / Q000254:growth & development; D008928:Mitochondria / Q000235:genetics; D010063:Ovum / Q000254:growth & development / Q000378:metabolism; D010802:Phylogeny; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D014057:Tomography, X-Ray Computed
chemical_list: D006657:Histones; D012339:RNA, Ribosomal, 28S