ORNAMENTALSAND
TURF
ORNAMENTALS
The information and recommendations in this newsletter are applicable to North Carolina and may not apply in other areas.
Green June beetles and Japanese beetles are still pestering rose
growers and other horticulturists. Soon we should see bluewinged
wasps (Scolia dubia) and other beetle grub parasites flying over
the turf. Cicadas are singing "full blast"; cicada killer wasps
and cowkillers are also out now. Keep an eye out for spider mites.
The remnants of Hurricane Danny knocked spider mite populations
down, but they may rebound if the weather becomes dry.
Euthyrhynchus floridanus is a stink bug that feeds on other plant
pests. It is one of the more attractive stink bugs with three
orange spots on a dark, metallic blue background. These insects
overwinter as adults probably in some dry, sheltered location.
Eggs are laid the following spring. The eggs take 19 to 33 days
later. Nymphs of Euthyrhynchus floridanus take a long time to
develop through five stages (40 to 67 days). New females wait 5 or
6 days before mating and the eggs are laid 23 to 67 days later.
Total developmental time for this species is much longer than for
plant-feeding stink bugs. Immature Euthyrhynchus floridanus are
highly aggregated and even attack larger prey in concert.
Apparently aggregation behavior allows them to successfully attack
prey too large to be subdued by a single nymph. Sometimes the
adults aggregate with nymphs, although when times get hard these
bugs sometimes feed on smaller individuals. When the bugs jab
their prey with their proboscis, they inject a toxin that slowly
immobilizes the prey. Euthyrhynchus floridanus bugs have an
unusual wagging behavior in which the bug rocks its body from
side to side while it grips the substrate firmly with its feet.
This is thought to be a defensive behavior. Many of these
predaceous stink bugs feed on plant tissue when insect prey is not
available. Plant feeding is not reported for Euthyrhynchus
floridanus, but if such feeding does occur the plant damage must be
slight and is certainly outweighed by their beneficial role in
controlling plant-feeding pests.
Jadera haematoloma does not have an official common name, but
golden-rain-tree bug would be appropriate. It feeds on rose of
Sharon, Chinaberry and other plants, but especially on the seeds of
golden-rain-trees, even those that fall to the ground. Jadera
haematoloma bugs sometimes become extraordinarily abundant. This
bug is in the same family as boxelder bugs (scentless plant bugs),
and its biology is similar. These bugs seek out sheltered spots to
overwinter. During the winter they will probably crawl out on
sunny days and retreat during dark, cloudy and extremely cold
weather. Once the weather stays cold, there is not much point in
spraying insecticide to control these bugs on the outside of homes
(vacuum up the ones that wander indoors). When the bugs are cool,
their metabolism is so slow that enzymes in their blood can
detoxify pesticides before the pesticides can kill the insect. In
cool weather, many of them will hide in some dry, overwintering
habitat so that spraying insecticide on a single day may completely
miss much of the population.
Fleahoppers are small plant bugs which feed on various garden
plants. Females tend to be oval with short wings or more slender
with longer wings. Males are even more slender. Fleahoppers cause
pale spots on the upper leaf surface, and they deposit fly specks
of excrement on the lower surface. Heavily-infested leaves drop
from plants prematurely. Garden fleahoppers overwinter as eggs
laid from August through September. Nymphs emerge in early spring
and feed on undersides of leaves. Nymphs feed and develop from 11
to 35 days before maturing into adults. Adult fleahoppers live 1
to 3 months. Each female lays about 100 eggs that are inserted
into the stems or leaves. There are at least five generations per
year in North Carolina. Typically, garden fleahopper infestations
are sporadic so that one application of a pesticide may bring
months or years of relief. Mavrik, malathion, Sevin or Orthene
should give adequate control of fleahoppers. There is additional
information on the biology of garden fleahoppers in AG-136, Insect
and Related Pests of Flowers and Foliage Plant.
Most of the Leptoglossus bugs are plant feeders and are somewhat
common but not particularly damaging (the most damaging member of
this family is the squash bug in the genus Anasa). The leaffooted
bug, Leptoglossus phyllopus, feeds on sunflower seed heads (killing
the seeds), tomatoes, potatoes and other vegetables, pecans, and
fruit crops such as peaches. They are called leaffooted bugs
because the hind tibia is expanded into a leaf-like structure in
the adults. Young nymphs have more ordinary-shaped hind legs, but
with each molt the tibia becomes wider. Except for the squash bug,
the leaffooted bugs are sensitive to pesticides such as Sevin,
Orthene, malathion, Talstar, Tempo 2, Mavrik, Dylox, pyrethrin, and
resmethrin. There is some additional information on these insects
in AG-295, Insect and Related Pests of Vegetables, a North
Carolina Cooperative Extension Service publication that should be
available in every county Extension Center.
Web page last updated on August 11, 1997 by Stephen J. Toth, Jr..
