Wednesday, October 30, 2013

Milkweed and the Tale of the Mummy

Oleander aphids on milkweed

The leaves on the milkweed plant (Asclepias syriaca) in the meadow are shriveling to yellow and crinkly brown. Yet upon closer inspection there is still some life along the plant’s folds and stems. A milkweed bug (Oncopeltus fasciatus) avoids my gaze and moves to the underside of a leaf and along the stem there are clusters of Oleander aphids (Aphis nerii) being farmed by tiny red ants. The aphids have an orange color, because just like the larvae of the milkweed beetle and monarch butterfly caterpillar, they acquire glycosides from the milkweed sap, which renders them toxic to predators. The ants protect the colonies of aphids because they feed off the honeydew, which is secreted by the tiny black tubes, or cornicles, on the aphid’s rear ends. With the first frost the aphids, ants and beetle will be gone and the milkweed plant will wither and retreat into the ground. Even if I had discovered these aphids during the growing season I would have left them well alone as a wasp parasitizes large numbers of them. Female wasps (Lysiphlebus testaceipes) lay their eggs in aphid nymphs. As the parasitoid wasp develops and consumes the insides of the nymph the aphid’s body turns color. The wasps finally emerge leaving behind brown papery mummies. Infestations of aphids on plants that are more ornamental are dealt with a soapy spray. But in this wildlife habitat garden I let nature take its course and leave the parasitoid wasps to do their thing.

Saturday, October 5, 2013

Berries for Wildlife's Winter Table

Goldenrod flowers are fading to brown from gold, but berries are now ripening and readying for wildlife’s winter table. I searched around my garden to see what is on offer. The young Winterberry holly (Ilex verticillata) plants have large clusters of shiny red berries. They will persist well into winter and cheer the winter landscape while providing sustenance for the northern mocking bird, the American robin and the brown thrasher.

The flowering dogwood tree (Cornus florida) in my garden is not in the best of health, but it hangs in there and produces brilliant red berries, which will feed the northern flicker, the yellow-bellied sapsucker and the eastern towhee. 

Pokeweed (Phytolacca americana) is a robust weed that people love to hate, but I let it grow in the wilder parts of my garden. In the Fall it comes into its own when it sports clusters of juicy, purple berries on magenta pink stems. The berries provide sustenance for migrating birds. This plant has been used for dye, ink for the pen that signed the Declaration of Independence and a spring vegetable, which is high in vitamins A and C. In southern states young shoots are canned and sold as “Poke Sallet”. All other parts of the plant, including the berries, are poisonous.

Red chokeberry (Aronia arbutifolia) produces tiny little red apples (it belongs in the apple family). This is a very tart fruit, which will persist on the shrub and provide winter interest in the garden before becoming palatable enough for a late winter feast for birds.

False Solomon’s Seal (Maianthemum racemosa) looks a little bedraggled this year because we have had little rainfall lately. This plant grows in the shady wilder parts of my garden and usually at this time of the year it has golden yellow leaves and plump red berries, which are relished by birds.

Tea viburnum (Viburnum setigerum) is a plant I uncovered at the edge of my garden in the tangled wood. It will be interesting to see what will eat the berries of this non-native plant. Right now I am enjoying this shrub’s ornamental properties and I am assuming insect pollinators were responsible for these gorgeous red clusters.