ORNAMENTALSAND
TURF
ORNAMENTALS
The information and recommendations in this newsletter are applicable to North Carolina and may not apply in other areas.
The most common spider mite pest of conifers in North Carolina is the spruce spider mite, one of the cool weather mites. With the cool Spring we have had this year, the mites are still active in some places. Spruce spider mites do most of their damage in spring and fall. Also, spruce spider mites tend to feed on the older growth. However, these mites usually do not cause dieback. Spruce spider mites are relatively inactive in very cold weather and tend to die out in hot weather. Because the spruce spider mite tends to feed on older growth, thorough coverage is necessary to place the pesticide inside the plant where the mites are feeding. This mite is not particularly resistant to miticides. Kelthane is the old standby for spider mite control. If Kelthane is unavailable, then one of the horticultural oils or Cygon will do the job. The horticultural oils are effective for spider mites and they also control armored scale insects. Cygon is also effective and has the advantage of being systemic. Some additional information on cool weather mites is in Ornamentals and Turf Insect Note No. 77.
This is a good time of year to educate gardeners about the immature life stages of lady beetles. Lady beetle larvae are highly predaceous on aphids, mites and other tiny insects just like the brightly colored adults. Lady beetles are oval, almost hemispherical insects that are often shiny and have contrasting colors. Many species are red with black spots or black with red spots. A few species are gray with black spots or orange or brown. Most lady beetles are 1/4 inch or smaller and some are tiny.
The eggs of some lady beetles are yellow and less than 1/16 inch long. They are often laid on end in small masses. The eggs of others are scale-like and flat on the twigs of the plants. From the eggs hatch larvae, small insects that resemble tiny, short-snouted alligators with six legs. Some lady beetles have larvae covered with a fluffy white secretion which makes the insect look like a mealybug. The next stage is the pupa. Pupae are about the size of the adults, but the legs and antennae are closely pressed to the body. Also, the wing buds wrap around the body. The pupae are usually anchored to the substrate at the rear. Because lady beetle pupae do not resemble the adults (or anything else in the home gardener's experience) many gardeners assume that lady beetle pupae are pests sucking the life out of the plant. Consequently, these pupae are squashed or scraped off and destroyed. Each lady beetle larva eats many aphids and other pests, and each lady beetle lays many eggs which potentially hatch into many more larvae. Each pupa destroyed allows thousands of aphids to survive!
The wet, cool weather has resulted in a number of unsightly events
in turf. Small holes and mounds of soil are being reported in many
areas. These seem to be the result of a variety of organisms
ranging from earthworm castings, green June beetle grub tunnels and
mounds, mole cricket tunnels, and 13-year cicada nymph emergence
holes. Before taking any action, be sure to identify the cause of
the soil disruption and then determine if its truly a problem.
Web page last updated on May 18, 1998 by Stephen J. Toth, Jr..
