Phloem-feeder
Guides
Toumeyella liriodendri
tuliptree scale
Toumeyella liriodendri, the tuliptree scale, is a soft scale insect (Coccidae) native to North America and specialized on Liriodendron tulipifera (tuliptree or yellow-poplar). This univoltine species overwinters as second-instar nymphs on twigs, matures to adults in spring, and produces eggs that hatch into crawlers in early summer. First-instar nymphs feed on leaf undersides before migrating back to twigs in autumn. Males are unknown; reproduction is presumed parthenogenetic. Heavy infestations cause branch dieback, reduced growth, and honeydew production that supports sooty mold growth. The species has been the subject of recent genomic research, with a 536Mb genome assembly revealing it as an early-diverging soft scale with 17 chromosomes.
Toumeyella parvicornis
pine tortoise scale
Toumeyella parvicornis is a soft scale insect in the family Coccidae, commonly known as the pine tortoise scale. Native to North America, it has become a serious invasive pest in Mediterranean Europe, particularly damaging stone pine (Pinus pinea) forests in Italy and France since its detection in 2015. Mature females are distinctive for their glossy reddish-brown, dome-shaped bodies resembling tiny tortoises, measuring 4–5 mm long. The species has a wide host range among pine species and reproduces parthenogenetically—males have never been recorded. Heavy infestations cause tree weakening, defoliation, and potential death through phloem feeding, with secondary impacts including sooty mold growth on honeydew excretions and altered fire behavior in affected forests.
Tramini
Tramini is a tribe of aphids within the family Aphididae, subfamily Lachninae. Members are medium to large aphids characterized by robust bodies, long antennae, and siphunculi that are either absent or reduced to small pores. The tribe includes conifer-feeding aphids, with many species associated with pine (Pinus) hosts.
Trialeurodes
greenhouse whitefly, whitefly
Trialeurodes is a large genus of whiteflies in the family Aleyrodidae, containing economically significant agricultural pests. The genus includes species such as the greenhouse whitefly (T. vaporariorum) and the bandedwinged whitefly (T. abutiloneus), which infest hundreds of host plant species including vegetables, cotton, and ornamental plants. Members are tiny phloem-feeding insects, typically measuring 1–3 mm, with distinctive waxy wings and piercing-sucking mouthparts. Several species are subjects of intensive biological control research using parasitoid wasps.
Trialeurodes abutiloneus
bandedwinged whitefly, banded-wing whitefly
Trialeurodes abutiloneus is a small whitefly species in the family Aleyrodidae, first described by Haldeman in 1850. Adults measure approximately 1 mm in length and are distinguished by transverse zig-zag bands on the forewings. The species is a phloem-feeding plant pest and a known vector for Abutilon yellows virus and Sweet potato chlorotic stunt virus. It is primarily associated with malvaceous crops including cotton and hibiscus, as well as sweet potato and soybean.
Trialeurodes vaporariorum
Greenhouse Whitefly, Glasshouse Whitefly
Trialeurodes vaporariorum is a globally distributed pest of protected horticulture, frequently found in greenhouses and polytunnels. Adults are 1–2 mm with yellowish bodies and four wax-coated wings held parallel to the leaf surface. The species has a broad host range exceeding 300 plant species across multiple crop families. It causes economic damage through direct phloem feeding, honeydew excretion, and associated sooty mold growth. Population dynamics show seasonal peaks in late autumn, with densities reaching 5–7 adults plus nymphs per leaf in greenhouse broccoli systems.
Trioza
psyllids, jumping plant-lice
Trioza is the type genus of psyllids in the family Triozidae, comprising sap-sucking insects with worldwide distribution. Species in this genus exhibit diverse host associations, ranging from agricultural crops to native trees. Several species are economically significant: Trioza erytreae transmits citrus greening disease (Huanglongbing), T. apicalis is a major pest of carrot in northern Europe, and T. brevigenae is an invasive pest of ornamental Ficus in California. The genus is characterized by distinct morphological features and complex life cycles involving seasonal migration between summer hosts and overwintering sites.
Trioza magnoliae
Red Bay Psyllid
Trioza magnoliae, commonly known as the Red Bay Psyllid, is a gall-forming psyllid native to eastern North America. This species induces characteristic galls on the leaves of native Persea bay trees, particularly red bay (Persea borbonia) and related species. The insect has a wide distribution across the eastern and central United States. While primarily an ecological curiosity due to its gall-forming habit, it has gained attention in relation to the decline of red bay populations caused by the invasive laurel wilt disease, as the psyllid's host trees face significant mortality.
Tuberculatus pallidus
pale oak aphid
Tuberculatus pallidus is a species of aphid in the family Aphididae, described by Davidson in 1919. It belongs to the genus Tuberculatus, which comprises aphids primarily associated with oak trees (Quercus spp.). The species name "pallidus" refers to its pale coloration. Like other members of its genus, it is likely a specialist feeder on oak foliage, though specific biological details remain poorly documented in accessible literature.
Tuberolachnus
giant willow aphid, giant bark aphid
Tuberolachnus is a genus of aphids in the family Aphididae, established by Mordvilko in 1909. The genus contains three described species, with Tuberolachnus salignus (the giant willow aphid) being the most well-known and widely studied. Members of this genus are among the largest aphids in the world, with body lengths reaching up to 5.8 mm. They are notable for their obligate parthenogenetic reproduction, extremely low genetic diversity, and status as invasive pests in multiple regions including New Zealand, India, and Patagonia.
Tuberolachnus salignus
Giant Willow Aphid
Tuberolachnus salignus, the giant willow aphid, is one of the largest aphid species in the world, reaching up to 5.8 mm in body length. It is an obligate parthenogenetic species, reproducing without males and producing genetically identical female offspring. Native to Asia, it has become cosmopolitan, spreading to all continents except Antarctica. The species feeds primarily on willow phloem sap and is considered an invasive pest in regions including New Zealand, where it impacts willow-based industries and apiculture through copious honeydew production.
Typhlocyba quercus
orange-spotted leafhopper
Typhlocyba quercus is a leafhopper species in the family Cicadellidae, commonly known as the orange-spotted leafhopper. It is a phloem-feeding insect primarily associated with oak trees (Quercus species), where it completes its entire life cycle. The species overwinters as eggs deposited in oak twigs, with nymphal development occurring in spring and adults present from mid-summer through fall. Multiple generations occur annually.
Unaspis citri
Citrus Snow Scale, Orange Chionaspi, Orange Snow Scale, White Louse Scale, White Snow Scale
Unaspis citri is an armored scale insect (Hemiptera: Diaspididae) that infests citrus crops worldwide. The species forms dense colonies on bark, fruit, and leaves, causing direct damage through sap feeding and indirect harm by promoting sooty mold growth. It is economically significant in citrus-producing regions, particularly Florida, where management requires integrated approaches combining monitoring, biological control, and targeted chemical applications.
Unaspis euonymi
Euonymus Scale
Unaspis euonymi is a diaspidid scale insect native to East Asia and now widespread as an invasive pest. It infests Euonymus species and several other ornamental plants, causing significant damage in urban and suburban landscapes. The species exhibits pronounced sexual dimorphism in both morphology and feeding behavior. It has been extensively studied as a target for classical biological control using introduced and native natural enemies.
Uroleucon cirsii
Large Thistle Aphid
Uroleucon cirsii, commonly known as the large thistle aphid, is a species of aphid in the family Aphididae. It is a phloem-feeding insect that specializes on thistles and related plants in the Asteraceae family. Like other members of the genus Uroleucon, it exhibits parthenogenetic reproduction during the growing season, forming colonies of females that reproduce without males. The species is known from Europe, with confirmed records in Belgium, Denmark, and Norway.
Uroleucon erigeronense
Large fleabane daisy aphid
Uroleucon erigeronense is a species of aphid in the family Aphididae, first described by Thomas in 1878. It feeds primarily on plants in the Asteraceae family, with a particular association with Erigeron (fleabane) species. The species exhibits flexible reproductive strategies: holocyclic in northern climates, producing sexual forms in autumn, and anholocyclic in warmer regions. It shows seasonal host-shifting behavior, moving between overwintering perennial hosts and blooming annuals. Native to North America, it has been introduced to Europe, Australia, and Korea.
Uroleucon nigrotuberculatum
red goldenrod aphid
Uroleucon nigrotuberculatum, commonly known as the red goldenrod aphid, is a North American aphid species introduced to Japan. In its native range, it is a specialist feeder on Solidago (goldenrod) species. Following introduction to Japan, this aphid has demonstrated remarkable dietary flexibility, expanding its host range to include multiple exotic plant species beyond its native specialization. The species exhibits complex ecological interactions, including semiochemical-mediated relationships with gall-forming flies and serves as prey for various native parasitoids and predators in its introduced range.
Uroleucon obscuricaudatum
Dusky-tailed Sunflower Aphid
Uroleucon obscuricaudatum is a North American aphid species in the family Aphididae, commonly known as the Dusky-tailed Sunflower Aphid. It is a specialist feeder on Heliopsis helianthoides (oxeye sunflower) and related Asteraceae plants. The species exhibits typical aphid life history traits including parthenogenetic reproduction during the growing season. Like other Uroleucon species, it produces honeydew and serves as prey for diverse natural enemies including lady beetles, flower flies, lacewings, and spiders.
Uroleucon verbesinae
Bicolored Frostweed Aphid
Uroleucon verbesinae is a North American aphid species in the family Aphididae. It belongs to the large genus Uroleucon, whose members typically feed on plants in the Asteraceae family. The species reproduces parthenogenetically during spring and summer, producing all-female colonies. Like other Uroleucon aphids, it exhibits synchronized defensive behaviors when disturbed.
Vestistilus patruelis
Vestistilus patruelis is a species of treehopper in the family Membracidae, first described by Carl Stål in 1864. The species belongs to the tribe Ceresini within the subfamily Smiliinae, a group characterized by often elaborate pronotal modifications. Treehoppers in this family are known for their diverse and frequently ornate pronotal structures that extend over the body. As a member of the Membracidae, V. patruelis is presumed to be a phloem-feeding insect utilizing plant vascular tissues.
Xylastodoris luteolus
Royal Palm Bug
Xylastodoris luteolus is a thaumastocorid true bug that feeds exclusively on royal palms (Roystonea regia). Adults are golden-yellow, darkening with age; nymphs are pale yellow to orange. The species completes development from egg to adult in approximately 30 days at 80°F, passing through five nymphal instars. Its feeding causes distinctive yellow spots on leaflets that expand into brown necrotic areas, resulting in premature leaf death. No natural enemies have been documented.
Zonocyba pomaria
White Apple Leafhopper
Zonocyba pomaria is a leafhopper species in the family Cicadellidae, commonly known as the White Apple Leafhopper. It was originally described as Typhlocyba pomaria by McAtee in 1926 and later transferred to the genus Zonocyba. The species is recorded from western and central North America. As a member of the subfamily Typhlocybinae, it belongs to a group of leafhoppers often associated with woody plants.