China is one of the most prolific countries for dinosaur material in the world, from skeletons to footprints and eggs. At present, China has documented more than 160 kinds of dinosaur, 35 genera and 39 ichnospecies of...China is one of the most prolific countries for dinosaur material in the world, from skeletons to footprints and eggs. At present, China has documented more than 160 kinds of dinosaur, 35 genera and 39 ichnospecies of dinosaur footprints, and 17 genera and 44 oospecies of dinosaur eggs. The dinosaur eggs in China are mainly distributed in Xinjiang, Inner Mongolia, Ningxia, Gansu, Henan, Hunan, Hubei, Jilin, Liaoning, Shandong, Zhejiang, Jiangxi and Guangdong （Fig. 1）, especially in Xixia of Henan, Nanxiong of Guangdong and Yunxian County of Hubei, which have the widest distribution, the best preservation and the most diversity.展开更多
The effects of competition on populations of the bean weevil Zabrotes sub- fasciatus were analyzed during 41 generations under different competition levels. Three competition environments were established by maintaini...The effects of competition on populations of the bean weevil Zabrotes sub- fasciatus were analyzed during 41 generations under different competition levels. Three competition environments were established by maintaining the number of couples （6） and varying the amount of available host seeds： HC, high （limited availability of host： 1.35 g）; IC, intermediate （intermediate availability of host： 6 g）; and LC, low competition （abun- dance of host： 36 g）. It was found that the distribution of the eggs laid on grains was different among treatments： in LC, for example, although females showed high fecundity （35.4 ± 5.6 eggs/female） the number of eggs laid on each grain was small （1.2 ± 0.4 eggs on each seed）, thus avoiding larval competition of their offspring; whereas in HC treatment, females showed low fecundity （27.04 ± 4.5 eggs/female） but laid many eggs on each grain （15.03 ± 4.3 eggs）. There were no changes in the ability to respond to different amounts of host via oviposition behavior （egg distribution） during 41 generations. How- ever, HC females had more offspring than LC females under HC conditions. This suggests that HC insects evolved toward higher fitness in crowded conditions. In addition, after inverting the competition level, insects behaved independently of the treatment conditions they experienced through generations, thus showing that oviposition behavior is flexible. Taken together, our results show that Z. subfasciatus presents a broad range of behavioral and physiological responses which allows for quick and reversible adjustments to sudden changes in the amount of resources.展开更多
文摘China is one of the most prolific countries for dinosaur material in the world, from skeletons to footprints and eggs. At present, China has documented more than 160 kinds of dinosaur, 35 genera and 39 ichnospecies of dinosaur footprints, and 17 genera and 44 oospecies of dinosaur eggs. The dinosaur eggs in China are mainly distributed in Xinjiang, Inner Mongolia, Ningxia, Gansu, Henan, Hunan, Hubei, Jilin, Liaoning, Shandong, Zhejiang, Jiangxi and Guangdong （Fig. 1）, especially in Xixia of Henan, Nanxiong of Guangdong and Yunxian County of Hubei, which have the widest distribution, the best preservation and the most diversity.
文摘The effects of competition on populations of the bean weevil Zabrotes sub- fasciatus were analyzed during 41 generations under different competition levels. Three competition environments were established by maintaining the number of couples （6） and varying the amount of available host seeds： HC, high （limited availability of host： 1.35 g）; IC, intermediate （intermediate availability of host： 6 g）; and LC, low competition （abun- dance of host： 36 g）. It was found that the distribution of the eggs laid on grains was different among treatments： in LC, for example, although females showed high fecundity （35.4 ± 5.6 eggs/female） the number of eggs laid on each grain was small （1.2 ± 0.4 eggs on each seed）, thus avoiding larval competition of their offspring; whereas in HC treatment, females showed low fecundity （27.04 ± 4.5 eggs/female） but laid many eggs on each grain （15.03 ± 4.3 eggs）. There were no changes in the ability to respond to different amounts of host via oviposition behavior （egg distribution） during 41 generations. How- ever, HC females had more offspring than LC females under HC conditions. This suggests that HC insects evolved toward higher fitness in crowded conditions. In addition, after inverting the competition level, insects behaved independently of the treatment conditions they experienced through generations, thus showing that oviposition behavior is flexible. Taken together, our results show that Z. subfasciatus presents a broad range of behavioral and physiological responses which allows for quick and reversible adjustments to sudden changes in the amount of resources.
