Captured Insect Tourists Help Avert Herbivory
Insectivorous plants are apparently not the only type of plant that benefits from insect passers-by. Insects ensnared in sticky or hook-like hairs on leaf and stem surfaces may feed and help build populations of predatory insects that protect the host plant from herbivorous insects. Most studies of beneficial insect populations don’t consider insect carrion as a food source for beneficial predators, but it may represent a significant contribution to the food web. Perhaps it is no accident that plants catch insects for this purpose. A simple field study using native annual tarweed (Madia elegans) was conducted at a nature reserve site near UC Davis. Dead fruit flies were placed on 41 test plants each week, with no flies placed on an equal number of control plants. Predatory insects were counted regularly on each plant. A dramatic increase in the numbers of predatory insects was found on the plants with the insect carrion. Consequently, there were fewer caterpillar pests to feed on the floral buds, and the tarweed was able to produce more seeds.
Nature 492, 314–315
Subsurface Water Retention Technology
The process of food crop production on sandy soil farmlands in arid and semi-arid regions of the country is expected to benefit from a new water-saving technology developed at Michigan State University. Contoured engineered films are placed at various depths below a plant’s root zone to retain soil water, but allow excess water to drain and roots to grow. Initial tests with prototype films showed very encouraging improvement in crop biomass and produce yield. It is believed the technology will use irrigation water and fertilizer more efficiently, while minimizing groundwater contamination.
Michigan State University Today, January 2013
Plants used in ancient times for their colorful dyes are now being tapped for those same chemicals to be used in another way. Purpurin, from the madder plant, (Rubia tinctorum), binds well to lithium and can be made into an effective cathode for lithium-ion batteries. The chemistry is simple, the cathode can be made at room temperature, and the source of the purpurin could come from agricultural waste. The ultimate goal is to devise greener batteries with plant-based anodes as well, and an electrolyte that doesn’t degrade the molecules.
Scientific Reports 2, Article number: 960, September 2012
Warmer Spring Temperatures, Earlier Flowering
If it seems that some of your favorite plants and fruit trees are flowering and producing fruit earlier, it just may be so. Plants come into flower by more than one genetic pathway. Approaching and passing a critical day length is a factor in some plants. Experiencing a critical level of warmth in the environment is perhaps one of the most important. Plants may use combinations of cues to bring them into flower. For those plants that use temperature as the primary cue, there will be an evolutionary advantage when the climate warms because they would be able to out-compete the plants waiting for day length cues to reproduce. Scientists in the UK have found a genetic transcription factor that directly activates the gene for flowering as a result of temperature increase alone. Problems will potentially arise as the climate warms, for both plants and flower-dependent insect species, if flowering occurs out of sync with the life cycles of specific pollinators.
Nature (Letters) 484, 242–245