Plant Health Problems

Diseases caused by Fungi:

Powdery mildew, Phyllactinia guttata.
White powdery appearance of leaves indicates the presence of this fungus which spreads in hot humid weather.

The severity of the disease may be reduced by improvement of air flow around the plant. This disease is usually not so severe that treatment is warranted. However, fungicide sprays can be applied as soon as symptoms are detected. Among the compounds registered for use in Connecticut are potassium bicarbonate, horticultural oil, and sulfur. Consult the label for dosage rates and safety precautions.

Insect Problems:

Aphids, Aphis fabae, A. spiraecola, Acyrthosiphon pisum.
The bean aphid, the spiraea aphid, and the pea aphid all infest bittersweet. Spraying with insecticidal soap, ultra-fine horticultural oil or malathion, which are among the compounds registered for control of this pest in Connecticut, will be effective. Imidacloprid applied as a systemic to be taken up by the roots will also provide season-long control. Consult the label for dosage rates and safety precautions.

Euonymus scale, Unaspis euonymi.
This pest of euonymus also infests bittersweet and pachysandra. The female shells are gray and pear-shaped, and the male shells are smaller, narrower, and whiter. There are probably two generations each season, and the winter is passed in a nearly mature condition; eggs are formed during May and hatch later in the month. All badly infested and injured branches may be cut and burned, if allowed. Among the compounds registered for control of this pest in Connecticut are horticultural oil, insecticidal soap and malathion. Spraying with ultrafine horticultural oil, either in mid-April for a dormant treatment or early June and again in mid-July, will control this scale while conserving the natural predators and parasites that might be present. Sprays of insecticidal soap and malathion applied in early June and again in mid-July will also control this scale. Consult the label for dosage rates and safety precautions.

Twomarked treehopper, Enchenopa binotata.
This grotesque little insect has a curious projection on the thorax that makes it resemble a bird in profile. When several individuals walk along the stem one behind another, one thinks of a flock of geese marching single file. The eggs are laid in white frothy masses on the twigs. Immatures and adults are present in July and August. The adults are dark brown with two narrow white spots on the ridge of the back.

Ordinarily, control measures are not needed, but the immatures may be managed with sprays of malathion, which is among the compounds registered for control of this pest in Connecticut. Imidacloprid applied as a systemic to be taken up by the roots will also provide season-long control. Consult the label for dosage rates and safety precautions.