Rapid flower closure of Drosera tokaiensis deters caterpillar herbivory.

Certain plants exhibit rapid movement in response to mechanical stimulation; however, the ecological functions of this behaviour are largely unknown. Here, we show that the rapid flower closure of Drosera tokaiensis (Droseraceae) in response to mechanical stimulation functions as a physical defence against a specialist herbivore Buckleria paludum (Pterophoridae) caterpillar. Following feeding damage on fruits, flowers, flower stalks and buds by B. paludum, D. tokaiensis closed its flowers nine times faster than during natural circadian closure. The extent of damage to ovules was significantly reduced when the flowers were able to close compared with the condition in which closure was physically inhibited by the application of a resin. Nonetheless, flower closure had no effect on the feeding damage to stamens and styles and promoted further damage to petals. Given that feeding on petals, stamens and styles had no significant effect on the number of mature seeds, rapid flower closure leading to the protection of ovules had an overall positive effect on the reproductive success of D. tokaiensis. Our study showed rapid plant movement as a novel case of induced physical defence against herbivory.

Convergence, Consilience, and the Evolution of Temperate Deciduous Forests.

The deciduous habit of northern temperate trees and shrubs provides one of the most obvious examples of convergent evolution, but how did it evolve? Hypotheses based on the fossil record posit that deciduousness evolved first in response to drought or darkness and preadapted certain lineages as cold climates spread. An alternative is that evergreens first established in freezing environments and later evolved the deciduous habit. We monitored phenological patterns of 20 species of Viburnum spanning tropical, lucidophyllous (subtropical montane and warm temperate), and cool temperate Asian forests. In lucidophyllous forests, all viburnums were evergreen plants that exhibited coordinated leaf flushes with the onset of the rainy season but varied greatly in the timing of leaf senescence. In contrast, deciduous species exhibited tight coordination of both flushing and senescence, and we found a perfect correlation between the deciduous habit and prolonged annual freezing. In contrast to previous stepwise hypotheses, a consilience of independent lines of evidence supports a lockstep model in which deciduousness evolved in situ, in parallel, and concurrent with a gradual cooling climate. A pervasive selective force combined with the elevated evolutionary accessibility of a particular response may explain the massive convergence of adaptive strategies that characterizes the world's biomes.

The effects of season, geography, and urbanization on the diversity of edible insects at food markets in Laos.

Laos, a mountainous and landlocked country located in Southeast Asia, has the highest percentage of people using insects as food in the world. Lao people obtain edible insects through harvesting in the natural environment and purchasing at food markets. There has been no comprehensive survey about sales of insects at food markets in the wider areas, and our understanding of sales of insects in Laos is limited. Our study aims to identify environmental factors affecting the sales and the diversity of edible insects sold at food markets in Laos. We visited 37 and 55 markets, during the dry and rainy seasons respectively, in northern Laos to record species of sold insects. We then analyzed the correlations between insect sales and three potential factors (seasons, provinces, and urbanization indices around the markets). There was no significant difference in the percentage of markets selling insects between in the dry and rainy seasons; 40-50% of the markets sold insects in both seasons. The composition of sold insects differed between in the dry and rainy seasons, which reflects the seasonality and life history of each insect species. There tended to be more groups of insects for sale in the Vientiane capital than in the other provinces in both seasons. This trend may reflect that it is more difficult to obtain edible insects through wild harvesting in highly urbanized Vientiane capital than in the other provinces, and the commercial demand for insects is increasing. This possibility is directly supported by the positive correlation between the urbanization index and the insect sales in the rainy season. Laos has recently undergone rapid urbanization, particularly in the Vientiane capital, and we predict that commercial demand for edible insects will be much higher in the Vientiane capital and the urbanized cities in the future.