Ornamentals Susceptible to Pests

The first line of defense against insect and mite pests of ornamental landscape plants is to select adapted plants that are not known to develop perpetual pest problems. Plant ornamental plants in suitable locations and care for them properly to avoid plant stress conditions.

The list below contains frequently encountered insect and mite pest problems on ornamental plants in the Texas landscapes. Plants NOT known to suffer from arthropod attacks are NOT listed.

Note: Pest complexes on ornamental plants change continually. Native (Florida wax scale) and exotics (chilli thrips and pink hibiscus mealybug) pests can suddenly become major pests periodically or interminably.

This list has been modified and printed with permission from the author from:

Whitcomb, C. E. 1983. Know It and Grow It, Lacebark Publications, Stillwater, Oklahoma, 739 pp.

Deciduous Trees (trees that lose their leaves)

Acer negundo L.  Boxelder – boxelder bug, aphids, borers
Albizia julibrissin Durazz.  Silktree or mimosa – mimosa webworm
Betula nigra L.  River birch – mites in hot, dry locations
Betula pendula Roth  European birch – borers, spider mites and aphids on new growth
Carya illinoensis (Wangh.) Koch.  Pecan – tent caterpillars, pecan weevils, pecan nut, hickory shuckworm, aphids, walnut caterpillars
Carya spp.  Hickories – tent caterpillars
Catalpa bignonoides Walt.  Southern catalpa – caterpillars (Catalpa sphynx)
Celtis occidentalis L.  Hackberry – nipple gall
Ceris canadensis L.  Eastern redbud – leaf rollers, leaf miners, borers on old trees
Chionanthus virginicus L.  Fringtree or Old Man’s Beard – occasionally mites in full sun locations
Cornus florida L.  Flowering dogwood – borers attack old trees
Crataegus spp.  Hawthorn – hawthorn lace bug
Diospyros virginiana L.  Common persimmon – tent caterpillars
Euonymus bungeanea Maxim.  Winterberry euonymous – none serious (rarely euonymous scale on deciduous eunoymous)
Fraxinus americana L.  White ash – borers on stressed trees
Frazinus excelsior L.  European ash – borers on weakened trees
F. pennsylvanica March  Green ash – borers on old or weakened trees
F. quadrangulata Michx.  Blue ash – borers on stressed trees
Gleditsia tracanthos L.  Honeylocust – mimosa webworm, spider mites, borers on old or weakened trees
Juglans nigra L.  Black walnut – tent caterpillars
Koelreuteria paniculata Laxm.  Panicled golden raintree – boxelder bugs
Liquidambar styraciflua L.  Sweetgum – tent caterpillars, occasionally aphids and spider mites
Morus alba L.  White mulberry – borers on old trees or stressed trees
Platanus occidentalis L.  Sycamore or American planetree – sycamore lacebug and sycamore leaf beetle
Populus alba L.  White poplar – leaf hoppers occasionally
P. deltoides Marsh.  Eastern cottonwood – sycamore leaf beetle, borers on old or weakened trees
P. nigra L. ‘Italica’  Lombardy poplar – thrips
Prunus armeniaca L.  Apricot – borers, on older stressed plants
P. cerasifera Errh.  Purpleleaf plum – peach twig borer, occasionally mites under hot, dry locations
P. persica (L.) Batsch  Common peach – aphids, mites, borers, tent caterpillars and others
P. serotina Ehrh.  Black cherry – Eastern tent caterpillar, fall webworms and others
P. serrulata Lindl.  Japanese flowering cherry – borers, mites
Pyrus communis L.  Common pear – Aphids and mites, occasionally
Quercus macrocarpa Michx.  Burr oak (white oak group) – aphids and spider mites, occasionally
Q. nigra L.  Water oak (red oak group) – scale insects, various chewing insects
Robinia pseudoacacia L.  Black locust – locust borer, leaf miners
Salix babylonica L.  Weeping willow – thrips, aphids, occasionally borers on old trees
Sassafras albidum (Nutt.) Nees  Sassafras – leaf-eating insects
Sophora japonica L.  Japanese pagoda tree – spider mites occasionally
Sorbus aucuparia L.  European mountain ash – borers on trees under stress or in poor sites, occasionally spider mites or aphids
Syringa reticulata (Blume) Hara.  Japanese tree lilac – Lilac borer on stressed trees, occasionally scale and mites
Taxodium distichum (L.) A. Rich.  Bald cypress – occasionally galls
Tilia americana L.  Areican linden or basswood – occasionally borers on weakened tree growing on poor site
T. cordata Mill.  European littleleaf linden – defoliators
T. tomentosa Moench.  Silver linden – leaf eating caterpillars
Ulmus americana L.  American elm – elm leaf beetles, Dutch elm disease
U. crassifolia Nutt.  Cedar elm – elm leaf beetles
U. parvifolia Lacebark elm (true Chinese elm) – rarely damaged by elm leaf beetle, Dutch elm disease resistant
U. pumila L.  Siberian elm – elm leaf beetle
Zelkova serrata (Thunb.) Makino.  Japanese zelkova – elm leaf beetle

Deciduous Shrubs and Vines

Berberis thunbergi Japanese barberry – occasionally aphids
Campsis radicans (L.) Seem. ex Bur.  Trumpet creeper – leaf-feeding insects
Caragana arborescens Lam. – spider mites on hot, dry sites
Chaenomele speciosa Nakai.  Flowering quince – San Jose scale, other scales, aphids on new foliage and mites in hot, dry locations
Cortaderia selloana Aschers. and Graebn.  Pampas grass – sugarcane borer
Cotoneaster spp.  Cotoneaster – mites, webworms
Euonymus alata Sieb.  Winged euonymus or burning bush – unlike evergreen euonymous,   rarely has euonymous scale
Hibiscus syriacus L.  Rose-of-Sharon or shrub althea – aphids occasionally on new growth, spider mites in hot dry locations, sweetpotato whitefly
Hydrangea quercifolia Bartr.  Oakleaf hydrangea – none serious, aphids occasionally on new growth
Lagerstroemia indica L.  Crapemyrtle – aphids frequently on soft new growth
Poncirus trifoliata Raf.  Trifoliate orange – mites, scales
Prunus glandulosa Thunb.  Flowering almond – stem borers and aphids, occasionally
Punica granatum L.  Pomegranate – mealybugs often found on the developing fruits
Rhus glabra L.  Smooth sumac – occasionally chewing insects damage foliage
Rosa spp. Rose – aphids on new growth and flowers, thrips damage flowers.
Syringa vulgaris L.  Common lilac – lilac scale can be serious in northeast, lilac borer on older clump but rarely kills plant

Broadleaf Evergreen Trees and Shrubs

Aucuba japonica Thunb.  Japanese aucuba or gold dust plant – occasionally scale but rarely serious
Buxus microphylla Sieb. and Zucc.  Japanese boxwood, littleleaf box – occasionally mites
B. sempervirens L.  English or common box – leaf miners, spider mites
Callistemon rigidus R.  Bottlebrush – mites in dry, hot locations
Camellia japonica L.  Japanese camellia – tea scale (white cottony scales on the underneath side      of the older leaves)
C. sasanqua Thunb.  Sasanqua camelia – tea scale
Elaeagnus pungens Thunb.  Thorny elaeagnus or silverberry – spider mites
Euonymus japonica Thunb.  Evergreen euonymous – euonymous scale
E. kiautschovica Loes.  Spreading euonymous – least susceptible of the evergreen euonymous          to euonymous scale, but this pest may still be serious
Gardenia jasminoides Ellis.  Gardinia, Crape jasmine – aphids, mites, whitefly, scales
Ilex altaclarensis (Loud.)  Dallim – spittle bugs
I. aquifolium L.  English holly – spittle bugs, occasionally
I. cornuta Lindl.  Chinese or horned holly – tea scale in cool shady areas with por drainage
I. crenata Thunb.  Japanese holly – scale, spider mites in light sandy soils
I. opaca Ait.  American holly – leafminer, scale insects, bud moth and mites in some locations, spittle bugs damage leaves emerging in mid- to late season
I. vomitoria Ait.  Yaupon holly – leafminer particularly on dwarf varieties, leaf phylloxera in some areas, rarely a problem with scale
Leucophyllum frutescens (Berland.) I.M. Johnst.  Texas sage – lantana lacebug, sweetpotato whitefly
Ligustrum japonicum Thunb.  Japanese or wax leaf ligustrum – may serve as a “carrier ” of whitefly and other landscape pests
Myrica cerifera L.  Southern wax myrtle – occasionally webworm
Nerium oleander L.  Oleander – Oleander caterpillar, a stinging caterpillar (asp) that will defoliate plants
Opuntia spp.  Prickly pear and Cholla cactus – cottony scale
Photinia serrulata Lindl.  Chinese photinia – fruit moth larvae
Pittosporum tobira Ait.  Japanese pittosporum or mock orange – mealybugs
Prunus caroliniana (Mill.) Ait.  Carolina cherry laurel – grasshoppers and other chewing insects occasionally
P. laurocerasus L.  Cherry laurel or English laurel – grasshoppers during mid- summer to early fall
Pyracantha coccinea Roem.  Pyracanthaor firethorn – lacebug, spider mites, occasionally scale in shady locations, leaf rollers in some areas
P. koidzumii Rehd.  Formosa pyracantha – lacebug, spider mites in dry locations, occasionally scale in shady locations, leaf rollers in some areas
Quercus virginiana Mill.  Live oak – gall-forming insects
Rhododendron indicum (L.) Sweet.  Southern or indica azalea – lacebugs, mites and scale in some locations
R. obtusum (Lindl.) Planch.  Kurume azalea – lacebugs and mites occasionally cause damage
V. suspensum Lindl.  Sandanqua viburnum – aphids common on new growth
Washingtonia filifera Washington palm – none serious (palm tortoise beetle)
Yussa aloifolia L.  Spanish bayonet – scale insects in humid, poorly drained sites
Y. filamentosa L.  Adam’s needle yucca – scale insects in humid, poorly drained sites
Y. gloriosa Mound lily yucca – scale insects in humid, poorly drained sites

Groundcovers

Ajunga reptans L.  Carpetbugle, ajuga or bugleweed – spider mites in hot, dry locations
Aspidistra elatior Blume Cast iron plant – occasionally mites in dry locations or scale insects
Euonymus fortunei (Turcz.) Hand. – Mass.  Evergreen wintercreeper – euonymus scale
Hedera helix English ivy – spider mites
Iberis sempervirens L.  Evergreen candytuft – occasionally grasshoppers
Jumiperus conferta Parl.  Shore juniper – spider mites, particularly in hot, dry locations (west side of buildings)
J. horizontalis Moench.  Creeping juniper – spider mites
J. procumbens Miq.  Japanese garden juniper – spider mites in hot dry locations in late summer
Liriope muscari L.  Lily turf, monkey grass or liriope – occasionally grasshoppers
Pachysandra terminalis Sieb. and Zucc.  Pachysandra or Japanese spurge – occasionally scale

Coniferous Evergreen Trees and Shrubs

Cupressocyparis leylandi Dall. & Jacks.  Leyland cypress – bagworms, occasionally
Cupressus arizonica Lemm.  Arizona cypress – bagworms
C. sempervirens L.  Italian cypress – bagworms, mites in hot locations with poor air movement
Juniperus chinensis L.  Chinese juniper – bagworms, spider mites
J. davurica Parl. ‘Expansa parsoni’  Parsons juniper – spider mites in hot, dry locations
J. excelsa Bied.  Spiny greek juniper – bagworms
J. sabina L.  Savin juniper – bagworms, spider mites
J. scopulorum Sarg.  Rock mountain juniper – bagworms, spider mites
J. squamata Buch-Ham ‘Meyeri’ Rehd.  Meyer or Fishtail juniper – occasionally bagworms, spider mites, juniper scale
J. virginiana L.  Eastern redcedar – bagworms, spider mites
Libocedrus decurrentCalifornia insence cedar – bagworms occasionally
Picea abies (L.) Karst.  Norway spruce – mites, spruce budworm
Pinus cembroides Zucc.  ‘Edulus’ Pinyon pine – pine tip moth
P. densiflora Siebold. & Zucc.  Japanese red pine – scale insects, rarely
P. echinata Shortleaf pine – pine tip moth, bark beetles on stressed trees
P. elliotti Engelm.  Slash pine – pine tip moth
P. mugo Turra. ‘Mughus’  Mugo pine – pine tip moth
P. nigra Arnold.  Australian pine – resistant to pine tip moth
P. palustris Mill.  Longleaf pine – occasionally bark beetles on old or stressed trees
P. ponderosa Dougl.  Ponderosa or western yellow pine – some insect damage occasionally
P. resinosa Ait.  Red or Norway pine – pine tip moth on young trees
P. strobus L.  White pine – occasional pests
P. sylvestris L.  Scotch pine (Scots pine) – tip moth on young trees
P. taeda L.  Loblolly pine – pine tip moth
Pseudotsuga menziesi (Mirb.) Franco  Douglas fir – aphids, bark beetles, especially on stressed trees
Thuja occidentalis L.  Eastern arbovitae or white cedar – bagworms, spider mites
T. orientalis L.  Oriental or Chinese arbovitae – bagworms, spider mites