Australian Insect Sucks the Life Out of Plants

There’s another new pest in town, in fact it is all over Southern California now. It is responsible for defacing a species of shrub that has been one of the toughest and most problem free in our area-Myoporum laetum. This Australian native has glossy green leaves that are sort of sticky to the touch and small white flowers that are followed by tiny purple fruits. It normally takes drought and either full sun to partial shade and provides a handsome backdrop or hedge to 30 feet or so in height. Because it is tolerant of wind and salt spray, it is a good candidate for ocean-side gardens. These days, though, many of the leaves are shriveled and covered with brown specks. The culprit is a thrips (that’s the singular of its common name, believe it or not) that is also native to Australia or possibly New Zealand and has somehow made it across miles of oceans to land on our shores.

Thrips insects feed by sucking up plant juices after rasping a wound in the leaves, stems, flowers, or fruits. This new species, Klambothrips myopori, is tiny like many thripses are and only two- to two-and-a-half millimeters long, so it is easy to miss the insect itself. The damage it inflicts, however, can be extensive enough on stressed plants to lead to total defoliation, even death of the myoporum. It also lays its eggs inside the leaves, causing them to develop galls, or small bumps.

Treatment options are similar to those for other sucking insects; use least-toxic oils to smother them or soap sprays and prune out affected branches and dispose of them carefully. Since the insects complete their life cycle in as few as 10 days, it is important to apply any treatment while the adults are present and active. There is hope for a biological control, but it won’t be available any time soon. Water and feed stressed plants to ensure good health to fight off any attacks. The best defense is a vigorous plant that can tolerate and recover from some damage.

May Tips

•The deadline to nominate a property (yours or someone else’s) for the 2008 Santa Barbara Beautiful Awards is Friday, May 9. There are nine categories and nomination forms and information is available at sbbeautiful.org.

•The Cactus and Succulent Society is hosting its annual show and sale on Saturday, May 10, at MacKenzie Park. Lots of interesting plants to see and buy from 10 a.m.-3 p.m.

•Plant warm-season vegetables and summer annuals such as amaranth, petunia, sunflower, and zinnia.

•Watch for sucking insects and blast them with the hose. Control ants that may be “herding” them.