Suzuki Noriyuki, PhD

I am an evolutionary ecologist who uses insects as a model system. My specific focus is to understand cause and consequence of the evolution of host range since it is closely associated with species coexistence as well as phenotypic diversification. My main approaches are fieldwork and laboratory experiment, but I also adopt molecular techniques, mathematical models, and meta-analysis.


2007 BS Kyoto University, Japan
2009 MS Kyoto University, Japan
2009-2012 JSPS Research Fellow (DC1) at Tohoku University
2012 PhD Kyoto University, Japan
2012-2015 JSPS Research Fellow at Tohoku University
2013-2014 Part-time lecture at Miyagi Womens’ University
2014-2016 Assistant Professor at Rissho University
2016-2017 JSPS Fellow for Research Abroad at University of California, Berkeley
2018-present Associate Professor at Kochi University, Japan


Suzuki Noriyuki, Junki Sugo, Masaaki Ohata & Naoya Osawa (2019) Habitat generalization of a predatory ladybird, Harmonia yedoensis (Coleoptera: Coccinellidae), in an allopatric area with respect to its sibling species Harmonia axyridis. Entomological Science, 22,389–392.

Yuma Takahashi & Suzuki Noriyuki (2019) Colour polymorphism influences species’ range and extinction risk. Biology Letters 15, 20190228. *Equally contributed

Andersen JC, Oboyski P, Davies N, Charlat S, Ewing C, Meyer C, Krehenwinkel H, Lim JY, Noriyuki S, Ramage T, Gillespie RG & Roderick GK (2019) Categorization of species as native or nonnative using DNA sequence signatures without a complete reference library. Ecological Applications, 29: e01914.

Atsushi Honma, Norikuni Kumano & Suzuki Noriyuki* (2018) Killing two bugs with one stone: a perspective for targeting multiple pest species by incorporating reproductive interference into sterile insect technique. Pest Management Science, 75, 571–577. *Correspondence author

Yuma Takahashi, Ryoya Tanaka, Daisuke Yamamoto, Suzuki Noriyuki and Masakado Kawata (2018) Balanced genetic diversity improves population fitness. Proceedings of the Royal Society B: Biological Sciences, 285, 20172045.

Henrik Krehenwinkel, Marisa Fong, Susan Kennedy, Edward Greg Huang, Suzuki Noriyuki, Luis Cayetano & Rosemary Gillespie (2018) The effect of DNA degradation bias in passive sampling devices on metabarcoding studies of arthropod communities and their associated microbiota. PLOS ONE, 3, e0189188.

Suzuki Noriyuki, Yukari Suzuki-Ohno & Koh-Ichi Takakura (accepted) Variation of clutch size and trophic egg proportion in a ladybird with and without male-killing bacterial infection. Evolutionary Ecology.

Naoya Osawa, Narihiro Kagami, Suzuki Noriyuki & Nobuko Tuno (2015) Size-related non-random mating in a natural population of the ladybird beetle Harmonia axyridis (Coleoptera: Coccinellidae). Acta Societatis Zoologicae Bohemicae79, 113–119 (Free PDF).

Suzuki Noriyuki (2015) Host selection in insects: reproductive interference shapes behavior of ovipositing females. Population Ecology57, 293–305.

Suzuki Noriyuki & Naoya Osawa (2015) Geographic variation of color polymorphism in two sibling ladybird species, Harmonia yedoensis and H. axyridis (Coleoptera: Coccinellidae). Entomological Science, 18, 502–508.

Suzuki Noriyuki, Yuichi Kameda & Naoya Osawa (2014) Prevalence of male-killer in a sympatric population of two sibling ladybird species, Harmonia yedoensis and Harmonia axyridis (Coleoptera: Coccinellidae). European Journal of Entomology, 111, 307-311.

Suzuki Noriyuki, Naoya Osawa & Takayoshi Nishida (2012) Asymmetric reproductive interference between specialist and generalist predatory ladybirds. Journal of Animal Ecology, 81, 1077–1085.

Suzuki Noriyuki & Naoya Osawa (2012) Intrinsic prey suitability in specialist and generalist Harmonia ladybirds: a test of the trade-off hypothesis for food specialization. Entomologia Experimentalis et Applicata, 144, 279–285.

Suzuki Noriyuki, Kazutaka Kawatsu & Naoya Osawa (2012) Factors affecting maternal trophic egg provisioning in non-eusocial animals. Population Ecology, 54, 455–465.

Atsushi Honma, Shigeki Kishi, *Suzuki Noriyuki & Daisuke Kyougoku (2012) Behavioral mechanisms of reproductive interference. Japanese Journal of Ecology, 62, 267-274 [in Japanese]. *Corresponding author

Suzuki Noriyuki, Naoya Osawa & Takayoshi Nishida (2012) Host specialization caused by reproductive interference. Japanese Journal of Ecology, 62, 267-274 [in Japanese].

Suzuki Noriyuki, Naoya Osawa & Takayoshi Nishida (2011) Prey capture performance in hatchlings of two sibling Harmonia ladybird species in relation to maternal investment through sibling cannibalism. Ecological Entomology 36, 282-289.

Suzuki Noriyuki, Koji Akiyama & Takayoshi Nishida (2011) Life-history traits related to diapause in univoltine and bivoltine populations of Ypthima multistriata (Lepidoptera: Satyridae) inhabiting similar latitudes. Entomological Science 14, 254-261.

Suzuki Noriyuki , Takashi Matsumoto & Takayoshi Nishida (2010) Phylogenetic analysis of Ypthima multistriata (Lepidoptera: Satyridae) showing non-clinal geographic variation in voltinism. Annals of the Entomological Society of America 103, 716–722.

Suzuki Noriyuki, Shigeki Kishi & Takayoshi Nishida (2010) Seasonal variation of egg size and shape in Ypthima multistriata (Lepidoptera: Satyridae) in relation to maternal body size as a morphological constraint. Annals of the Entomological Society of America 103, 580–584.

Suzuki Noriyuki, Masaya Yago & Jiro Uehara (2009) A congener-like larval form of Choaspes subcaudatus (Lepidoptera: Hesperiidae) from northern Laos, with a description of its immature stages and male genital morphology. Butterflies 51, 18–22.


Ecological specialization caused by reproductive interference

Closely related species often differ in the quality and breadth of resources exploited, but the actual mechanisms causing these differences are poorly understood. I focused on interspecific negative mating interaction, reproductive interference, which has been underestimated in the context of ecological generalization and specialization. My study system is the two sibling ladybird species that coexist in the same region in central Japan. Harmonia yedoensis is a specialist that preys only on pine aphids, which are highly elusive and nutritionally unsuitable for ladybird hatchlings (Noriyuki et al. 2011 Ecol Entomol; Noriyuki & Osawa 2012 Entomol Exp Appl), whereas H. axyridis is a generalist predator with a broad prey and habitat range. I showed that the generalist species is superior to the specialist species in terms of reproductive interference, suggesting that asymmetric reproductive interference from the dominant species may force the non-dominant species to become a specialist predator that exclusively utilizes less preferred prey in nature (Noriyuki et al. 2012 J Anim Ecol). This means that reproductive interference can cause an oviposition preference in insects that is not optimal for the survival and development of the offspring, as a result of maternal adaptive behavior that maximizes the mother’s own fitness (Noriyuki 2015 Pop Ecol).

Adaptation and constraint in trophic egg-laying

Mothers of some animals, such as true bugs and snails, produce non-developing eggs or egg-like structures for offspring nutrition. Several authors have suggested that such trophic egg-laying should evolve only when mothers cannot lay large egg size (morphological constraint hypothesis) and adaptive significance of trophic egg-laying was unclear. First, I showed that morphological constraint on egg size is weak at best in ladybirds that produce trophic eggs (Noriyuki et al. 2012 Pop Ecol). Next, I theoretically showed that trophic egg-laying is favored in heterogeneous environments when mothers cannot adjust egg size plastically. This means that trophic egg provisioning may be a flexible maternal adaptation to a heterogeneous environment rather than a response to a morphological constraint.



Faculty of Agriculture and Marine Science,
Kochi University, Japan
nsuzuki [at] kochi-u.ac.jp