Member list

Current members

Jo-Fan Wang
Territorial behavior, trait evolution.
Yi-Shou Yang
Reproductive Isolation of Psolodesmus mandarinus subspecies.
Yu-Hsun Hsu
Mating strategy, behavioural ecology, molecular ecology, population genetics, molecular phylogenetics, biostatistics.
Ying-Yuan Lo
Systematics, Behavior and Evolution of Lynx Spiders.
Lu-Yi Wang
Yu-Jen Yu
Variation and Adaptation of wings.
Wataru Kojima
Evolution of male sexual traits in Taiwanese scarab beetles.
Zhen-Yi Chen
Fighting behavior and reproductive strategy of stag beetles.
Teng-Yu Liu
Fighting behaviour and life history observation of a stag beetle Rhaetulus crenatus crenatus.
Leocris Batucan Jr.
New Species and DNA Barcoding of the Mayfly (Ephemeroptera) in Mt. Malindang, Mindanao, Philippines.
Princess Angelie S. Casas
Insect Diversity and Evolution
Chun-Yu Lin
Parasitoid Wasps of Damselflies

Past members

Hui-Yun Tseng
Aposematic coloration, island biogeography.
Yen-Ting Chen
Systematics and evolution of insects.
Yun-Chieh Cheng
Damselfly larval diet, molecular evolution.
Tai-Chia Chiang
The effect of aposematic colors of Pachyrhynchus weevils on avian predators.
Yong-Chao Su
Behavioral ecology, sociobiology, population genetics, and molecular phylogenetics.
I-Ting Hsiao
Variation of genitalia in Euphaea amphicyana.
Jyun-Huei Huang
The fighting behavior of a stag beetle, Rhaetulus crenatus.
Shi-Ting Wu
Membracis Phyllotropis.
Chiao-Wei Lin
The fighting behavior of a stag beetle, Rhaetulus crenatus.
Li-Wen Weng
Why do firefly larvae emit light?
Lan-Wei Yeh
Ecology and evolution of Taiwanese Carabus ground beetles.
Chung-Hsin Huang
Flucuating Asymmetry and Developmental Asymmetry of Cyclommatus mniszechi.
Wei-Liang Xiao
Variation of wing veins in Euphaea amphicyana.
Hung-Nien Chen
1. The effect of typhoon on survivalship of Matrona cyanoptera. 2. Modes of phenotypic variation in Euphaea amphicyana.
Chu-Yen Cheng
Phylogeography of a Philippine's treehopper, Leptocentrus reponens.
Che-Yu Kuan
Variation of mandibles in stag beetles.
Yat-Hung Lee
Speciation of Euphaea damselflies.
Ming-Yu Chen
Phylogeography and population history of the treehoppers, Centrochares horifficus from the Philippines Archipelago.
Shao-Chang Huang
Visual Communication of Matrona cyanoptera
Jen-Pan Huang
Population Genetics and Phylogeographic Analyses of Formosan Damselfly, Euphaea Formosa (Insecta: Odonata: Euphaeidae) from Taiwan
Wei-Yun Chen
Molecular and Phylogenetic Characterization of Endosymbiotic Bacteria of the Froghopper, Okiscarta uchidae (Insecta: Hemiptera: Cercopidae)

Visiting scholars and students

Jillian del Sol
Behavioral Ecology; Mating System Ecology; Weapon Ecology and Evolution; Evolutionary Biology
Ian Dela Cruz
New Species and DNA Barcoding of the Stonefly (Plecoptera) in Mt. Malindang, Mindanao, Philippines.
Shinya Komata
Ecology & Evolution of Wing Polymorphism in a Mimetic Swallowtail Butterfly, Papilio memnon.
Vanitha Williams
Predatory potential of waterbug, Diplonychus rusticus and dragonfly, Diplacodes trivialis on mosquito larvae.
Marina Vilenica
Dragonfly composition (Insecta, Odonata) in wetland area of Turopolje region, Croatia
Klaas-Douwe 'KD' B. Dijkstra
History, diversity and identification of dragonflies and damselflies (Odonata).
Erin McCullough
" Diversification of weapon form: aerodynamic costs of beetle horns.
Ashley E. King
Intrasexual combat and intersexual antagonistic co-evolution in horned beetles.

Lu-Yi Wang

Lu-Yi Wang

Title

Master Student 2015-

Species: Pachyrhynchus

Pachyrhynchus

Project

Defense Mechanism of Pachyrhynchus weevils.

Abstrct

E-mail:lu1200120012011@gmail.com

Project Description

Aposematic species often have a repellent secondary defense along with conspicuous coloration. As now we know that the colorful patterns on Pachyrhynchus weevils serve as warning signals against the predation of lizards (Tseng et al., 2014), we wonder what defense mechanisms have been evolved in these species. We will examine three hypotheses: 1) Morphological defense: Pachyrhynchus are too hard to be eaten. 2) Behavioral defense: The hooks at the end of the tarsus of Pachyrhynchus may play a role in defense. 3) Chemical defense: There are chemicals in Pachyrhynchus that are repellent or toxic to predators. Among these three possible mechanisms, we consider morphological defense to be the primary method that Pachyrhynchus uses to deter predators. Behavioral defense might be a supplementary strategy. Since there is no specialized secretory gland found in Pachyrhynchus weevils, the chemical defense hypothesis was excluded. This research project aim to provide empirical evidences to support that it is the physical hardness that plays the important role as main secondary defense, and this is the message that Pachyrhynchus weevils deliver with their aposematic coloration.

Too Hard to Swallow: A Novel Defense Mechanism in an Aposematic Beetle

Aposematic species often have a repellent secondary defense associated with conspicuous coloration. The colorful patterns of Pachyrhynchus weevils have been found to serve as warning signals against the predation of lizards. This study focused on the defense mechanisms of Pachyrhynchus weevils in Taiwan. Here, we tested three hypotheses: (1) The morphological defense: Pachyrhynchus are too hard to beeaten. (2) The behavioral defense: The claws at the end of the tarsus of Pachyrhynchus in couple with behavior may play a role in defense. (3) The chemical defense: There are chemicals in Pachyrhynchus that are repellent or toxic to attacking predators. We first compared the hardness of Pachyrhynchus with other sympatric prey of the lizard. Next, we performed manipulative experiments to test the importance of the hardness and claws in defense. Finally, we utilized GC-MS to analyze the chemical profile of Pachyrhynchus and compared these compounds with chemicals that other insects use as deterrents. Among these three possible defenses, we found that Pachyrhynchus use the hardness of exoskeleton as primary defense to deter predators. The grasping with tarsal claws is not an effective defense mechanism for lizards. Since there is no specialized secretory gland nor chemicals found in Pachyrhynchus weevils, the chemical defense hypothesis was excluded. Our findings provided the first empirical evidence to support that the physical hardness is the main secondary defense, underlying their aposematic coloration.

Pachyrhynchus sarcitis

Comparison of hardness and insect prey and bite force of lizard.

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