Herself’s Houston Garden

One of the most fascinating things about plant and insect evolution is the defenses they mount to protect themselves from prey. Often plants or insects become toxic to the critters that eat them. Sometimes they grow to look like closely related toxic plants.

Milkweed has taken a different approach. It grows faster to better feed the caterpillars. This is great news for us monarch lovers. Monarchs have evolved to resist the toxins in milkweed. Tracing milkweed back it appears milkweed has given up on growing better hairs and more toxic latex and decided to concentrate on faster growth and repair.

The adage that your enemies know your weaknesses best is especially true in the case of plants and predators that have co-evolved: As the predators evolve new strategies for attack, plants counter with their own unique defenses.

Milkweed is the latest example of this response, according to Cornell research suggesting that plant may be shifting away from elaborate defenses against specialized caterpillars toward a more energy-efficient approach. Genetic analysis reveals an evolutionary trend for milkweed plants away from resisting predators to putting more effort into repairing themselves faster than caterpillars — particularly the monarch butterfly caterpillar — can eat them. . . . [ read more Milkweed's evolutionary approach to caterpillars: Counter appetite with fast repair]

So far down here in Houston, aphids have only been a problem with the tea roses and not very often there.  When I find them I spray with orange oil ( you can find it with the organic pesticides at any nursery ).  A couple of days of treating with oil generally takes care of even the worst aphid problem for me.

Mercer recommends just giving them a good blast of water with your garden hose in the afternoon.  This removes them from the plant and they rapidly dry out in our afternoon heat.

Aphids are amazingly tiny and damage your plant by sucking all the fluid out of the plant.  Aphids are rapid multipliers.  They are all born female and pregnant. Aphids come in green, white, black and yellow. But green is by far the most common color.

You will often find ants on plants with aphids. The ants come for the sap the aphids leave on the plant stems and eat the aphids. The ants don’t hurt the plant.  Some ants will also treat the aphids like cattle, keeping them alive, moving them to healthier plants, and generally watching out for them so they may get more of the sticky sap.

Aphid damage often shows in malformed flower blooms or curled leaves and wilting of new stems and young plants.

Plants are being intentionally radiated in a effort to speed up evolution to develop better varieties to feed a hungry planet.

The 80-year old technique of induced mutation uses radiation to alter genetic material in crop plants to boost output and disease resistance.

Selective mutation can also help crops adapt to changing climates and conditions.

Some 3,000 mutant varieties from 170 plant species spread over 60 countries — including cereals, pulses, oil, root and tuber crops — are currently cataloged in a seed database jointly run by the IAEA and the UN’s Food and Agriculture Organization (FAO).

Unlike bio-engineered genetic modification, induced mutation does not splice foreign genes into the plant, but rather reorganises its existing genetic material, the head of plant breeding and genetics at the IAEA, Pierre Lagoda, told journalists.

“Spontaneous mutations are the motor of evolution,” he said. [ read more Mutant plants can boost yields, resistance: IAEA conference.]