Insect pests of ornamentals present in southeastern USA of potential quarantine interest
A book published by the North Carolina Cooperative Extension Service (Insect and related pests of flowers and foliage plants. Some important, common and potential pests in the southeastern United States) gives details on the biology, host plants, situation in southeastern US for many insect pests of ornamental plants. The EPPO Secretariat has tried to list below pests which could be of potential quarantine interest. This list (in alphabetical order) is a very preliminary one, whose purpose is mainly to stimulate further discussion.
- Callopistria floridensis (Lepidoptera: Noctuidae) - Florida fern caterpillar.
Geographical distribution: Canada, Colombia, Puerto Rico, USA (Florida, New York, New Jersey) and tropical America. One report of a finding (in 1988) in India (Bangalore, Karnataka) on ornamental ferns in a hotel.
Hosts: ornamental ferns and foliage plants (Adiantum, Asparagus sprengeri, Blechnum, Cyrtomium, Nephrolepis, Polypodium, Pteris).
Damage: Caterpillars are active feeders which can defoliate severely the plants. Larvae as they mature usually hide on the stems at the base of the plants or in the soil during the day. Pupation takes place in cocoon on the soil surface. Adults are nocturnal.
- Echinothrips americanus (Thysanoptera: Thripidae)
Geographical distribution: Bermuda, Canada (south), Mexico, USA (most of the eastern states). This thrips has been introduced into the Netherlands and France recently (see EPPO RS 95/093 and 98/143).
Hosts: many ornamental species. It can attack more than 40 plant genera from 20 families and Araceae and Balsaminaceae are particularly attractive to this insect. Among ornamental species it can be found on: Anthurium, Asparagus, Bambusa, Cordyline, Dendranthema, Desmodium, Dieffenbachia, Euphorbia, Ficus, Hibiscus, Impatiens, Passiflora, Philodendron, Spathiphyllum and Syngonium.
Damage: It feeds on leaf tissue and damage is very similar to that caused by mites, with light spots on the leaves. It can also feed on flower parts.
- Geshna cannalis (Lepidoptera: Pyralidae) - Lesser Canna leafroller.
Geographical distribution: USA (southeastern states), likely to occur in central America and tropical south America.
Hosts: Canna is apparently the only host.
Damage: Caterpillars fasten the edges of leaves before the leaves unroll or they can roll up one side of an open leaf. Within this shelter, the caterpillars feed on the upper surface of the leaves. Heavily infested leaves may never open and die. Infested plants usually do not bloom.
- Lygus lineolaris (Hemiptera: Miridae) - Tarnished plant bug.
Geographical distribution: Canada, Mexico, USA (widespread, prefers warm, humid to dry climates in the South, Southeast and Southwest) (see CABI map no. 38, 1954).
Hosts: polyphagous species (fruits, vegetables, ornamentals, field and forage crops, weeds). Glasshouse hosts include Aster, chrysanthemums, Dahlia, Impatiens and Tagetes.
Damage: By feeding, adults and nymphs cause yellowing, distortion of terminal growth and reduced plant growth. Flowers from damaged buds sometimes fail to develop on one side or the whole bud aborts.
- Microcephalothrips abdominalis (Thysanoptera: Thripidae) - Composite thrips.
Geographical distribution: tropics, and subtropics. Australia, India, Japan, Korea Republic, Peru, Taiwan, Thailand, USA.
Hosts: many ornamental species of family Asteraceae (e.g. Bidens formosa (cosmos), chrysanthemum, Helianthus, Pyrethrum, Tagetes, Zinnia). In Asia, its presence is reported on Orchidaceae, and also and tea and rice crops.
Damage: Heavy infestations cause damage to the corolla, stamens, and developing seeds of plants in the Asteraceae. Petals lose pigmentation, senesce early and drop prematurely.
- Phenacoccus gossypii (Hemiptera: Homoptera: Pseudococcidae) - Mexican mealybug.
Geographical distribution: Bahamas, Cuba, Mexico, Puerto Rico, USA (many southern states, Hawaii).
Hosts: many ornamental plants (e.g. Althea rosea, Aralia, chrysanthemum, Euphorbia pulcherrima, Gynura, Hedera helix, Ixia, Lantana). It attacks cotton, and is reported as a minor pest of lima beans (Phaseolus lunatus) in the warmer parts of USA.
Damage: Wilting and stunting of attacked plants. Plants are disfigured due to the presence of mealybugs.
- Platynota species (Lepidoptera: Tortricidae)
P. flavedana -variegated leafroller
Geographical distribution: Jamaica, USA (from Maine to Florida and west to Kansas and Texas).
Hosts: Polyphagous (e.g: apple, clover, cotton, citrus, Euphorbia pulcherrima, Hypericum, maple, peach, Rosa, sassafras, strawberry).
P. stultana - omnivorous leafroller
Geographical distribution: Mexico, USA (California, Maryland, Pennsylvania, Virginia).
Hosts: Polyphagous (e.g: capsicum, citrus, cotton, celery, grapes, lucerne, Rosa, stone fruits, tomatoes)
P. idaeusalis - tufted apple bud moth
Geographical distribution: Canada (British Columbia), USA (Michigan, North Carolina, Pennsylvania, Virginia).
Hosts: Polyphagous (e.g: Acer, apple, cherries, clover, Euphorbia pulcherrima, Solanum, Solidago, walnut, willow).
Damage: Feeding on the leaves. Leaves are rolled and tied by silk, as larvae construct their nests.
- Rhizoecus americanus (Hemiptera: Homoptera: Pseudococcidae) - Root ;mealybug.
Geographical distribution: Colombia, Costa Rica, Cuba, Ecuador, Honduras, Jamaica, Martinique, Mexico, Panama, Puerto Rico, Trinidad, USA (Florida), Virgin Islands (US). Found in Italy for the first time in 1992 on Saintpaulia (in glasshouses in Pieve san Paolo) and on Phoenix roebelenii (in the field in Catania).
Hosts: many ornamentals (e.g. Aralia, Asparagus, chrysanthemum, Dieffenbachia, Ficus, Gardenia, Hibiscus, Kentia, Lantana, Phoenix, Saintpaulia, Strelitzia, etc.) (see Ben-Dov for a more complete list)
Damage: All stages can be found on the roots of the plants and growing medium. As they attack roots, plant growth is reduced, foliage is deteriorated and plants may finally die. Considered as a serious pest in Florida nurseries (Ben-Dov, 1994)
- Stenoptilodes antirrhina (Lepidoptera: Pterophoridae) - Snapdragon plume moth.
Geographical distribution: USA (California, but they also have been found in glasshouses in southeastern states which have received cuttings from California).
Hosts: Antirrhinum is apparently the only host.
Damage: Larvae mine the leaves and feed externally on leaves, buds and flower parts.
- Stephanitis pyrioides (Hemiptera: Tingidae) - Azalea lace bug.
Geographical distribution: Japan, USA (from New York to Massachusetts southward to Florida and west to Texas).
Hosts: azalea (evergreen cultivars are preferred hosts, but also attacks deciduous cultivars), mountain laurel (Kalmia latifolia) and rhododendron.
Damage: caused by adults and nymphs by feeding on leaves. Reported to be the most serious pest of azalea since its introduction from Japan in the 1920s.
Note: Another species, the andromeda lace bug, Stephanitis takeyai, also occurs in USA (introduced from Japan). It is a pest of Pieris japonica (andromeda) and Rhododendron. This species has recently been found outdoors in a very limited outbreak in UK (see EPPO RS 98/061). A third species, Stephanitis rhododendri already occurs in Europe but has probably been introduced from North America. It causes damage locally on azalea and rhododendron.
- Trialeurodes abutilonea (Hemiptera: Homoptera: Aleyrodidae) - banded-winged whitefly.
Geographical distribution: Cuba, USA (Arizona, California, Colorado, District of Columbia, Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maryland, Mississippi, Missouri, New Mexico, New York, North Carolina, Pennsylvania, South Carolina, Texas, Utah, Virginia).
Hosts: originally described on Abutilon theophrasti but is now considered as a polyphagous species (e.g. Euphorbia pulcherrima, Geranium, Hibiscus, Petunia, many weeds). It is reported as an occasional economic pest of ornamentals. It also occurs on cotton and vegetable crops.
Damage: direct feeding damage and presence of honeydew and sooty mould which alter the appearance of the ornamentals. If not controlled, it can be a very damaging pest. It is reported as being able to transmit viruses (e.g. abutilon yellows ?closterovirus, diodia vein chlorosis ?closterovirus), but not as efficiently as Bemisia tabaci.
Insect and related pests of flowers and foliage plants. Some important, common and potential pests in the southeastern United States. edited by Baker, J.R. (1994) North Carolina Cooperative Extension Service, US, 106 pp.
Also available on INTERNET:
Ben-Dov, Y. (1994) A systematic catalogue of the mealybugs of the work (Insecta: Homoptera: Coccoidea: Pseudococcidae and Putoidae) with data on geographical distribution, host plants, biology and economic importance. Intercept Limited, Andover, UK, 686 pp.
Bin-Cheng Zhang (1994) Index of economically important Lepidoptera, CABI, Wallingford, UK, 599 pp.
CABPest CD and CABI maps.