A short discussion of some scales affecting shade trees and hardy shrubs

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UNITED STATES DEPARTMANT OF AGRICUL
AGRICULTURAL RESEARCH ADMINISTRATIO

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BURIAU OF ENTOMOLOGY AND PLANT QUARANTINGE 5 Dey ag Annitt
Forest Insect Investigations See
Forest Entomology Brief 70 | : Beltsvill e, Maryland

CuriiadNovember zy AUSIEXO)
- & SHORT DIS CUSSION OF SOME SCALES AFFECTING SHADE TREES AND HARDY SHRUBS

Euonyms_scale.-- The euonymus scale (Unaspis euonymi (Comst.)) is a
persistent and serious vest of euonymus. It also attacks celastrus and
vrobably vachistima and pachysandra. It is difficult to control, sometimes
requiring several years! work to secure the results desired. The evuonymus
scale is a problem sufficient to maxe it questionable whether the planting
of euonymus as an ornamental, especially in neighborhoods where the plant is

already fairly abundant, is desirable.

The methods suggested for its control are cutting and burning the dead
and heavily infested portions of piants that can be spared without seriously
injuring the appearance of the plant, and then spraying the remainder of the
plant in the early spring just before new growth commences, using a dormant
strength oil emulsion or miscible oil. It would also be a very good plan to
Wateh the Diait during the growing pneriod for the anpearance of the crawlers.
Or youn2 seaiscs. Traere are likely to be several generations of these. One
May OG2ur around the micale of Mey, anobher from the mic Le To “bhe lativer
pace of junc, and possibly another group of icrawlers late in the summer. When
the crawlers are Paget and abundant, the infested portions of the plants
should be given a thorough aapileabaee of the following spray:

Nilcotime /Suilkragew(40 mercemb\!. sc) eae 6. l-t/4) Feasvoonpulls
SONU) jah LENSES CG oo Qh se oun meigh om nchl Cal I ion wagon LC) 2xONDUsIOKSIOh MmellOILes) oxoyoralit WIL}
WEITERE CHa i 6 oo | GUNG Bo mG conto s CiLLCw Sim ciins opmo Ni cotaind sabe rexcalsioyal

Dissolve the soad flakss. in warm water before adaing the nicotine sulfate.
liteme there ts a sheavy autestation of the sealie, better control can be had
by adding 4 level tablespoonfuls of s white-oil umilsion (83% of oil) (as
Volek or Verdol) to the formulation. The white-oil emulsion has the consis-
tency of mayonnaise and must be gracually thinnec with water before it is
adged to the other ingredients inthe fornula.

Pane; eed te yscallles——) Te pine mecdlie ox mime Neat seale (Phenacaspis

pinifoliae (Fitch) is frevuently found on ornamental pines and on spruce. It
is a white scale, shaped like an oyster shell, that adheres very closely to
the neeclss. Control consists of spraying the infested plants and parts of
plants early in the spring just before new growth starts. using one of the
Winter oil emulsions or miscible oils. As in the case of the evonymus scale,
this scale insect can be combatted very weil by spraying for the “crawlers”

with the summer spray materials suggested above, if a careful watch is kept
for the appearance of the young scales. These are usually found during the
middle of May, the middle of June, mid-August and Mid-September. —

Juniper scale.-- Juniper, or cedar, and arbervitae are very frequently
attacked by a small scale insect technically known as Diaspis carueli Targ.
ana commonly called the juniper scalc. The control of this insect will require
the same ssray materials and methods suggested for combating the pine leaf
scale and euonymus scale. It is not certain that this species hés as many
generations as those treated above, but one group of crawlers will usually be
FOuNnG dunIne the: Lirst halt of june.