Objectives
• To learn how to recognize key characteristics of Dendrolimus (lappet moths) and Lymantria (gypsy moths)
• To learn how to recognize similar, native, look-alike species and distinguish them from the potential invaders
Introduction
• Defoliation = the removal of all or part of the foliage of a plant
• Herbivore = an animal which eats only plants
• Insect defoliators damage plants by eating leaves or needles
Photo: tent and defoliation on aspen © William M. Ciesla, Forest Health Management International, Bugwood.org
Introduction
Classification based on
• Insect order
• Pattern
• Feeding structure
• Time of year
• Host specificity
Photos: katydid feeding on leaves (top) © Herbert Pase III, Bugwood.org and skeletonizing on European linden (bottom) © Steven Katovich, USDA-FS, Bugwood.org
Defoliation clue: insect order
Most common insect orders which defoliate plants
• Lepidoptera—moths, butterflies
• Hymenoptera—sawflies, wasps
• Coleoptera—beetles
• Orthoptera—katydids, grasshoppers, etc.
• Diptera—flies Photos: pine sawfly (top) © USDA-FS Region 8 - Southern Archive, Bugwood.org and
(bottom) viburnum leaf beetle adults © D.D. O’Brien, Cornell University, Bugwood.org
Defoliation clue: pattern
Defoliation by pattern
• Complete leaf eaten
• Individual holes
• Mining
• Skeletonizing
Photo: complete defoliation on pine caused by spiny caterpillar © William M. Ciesla, Forest Health Management International, Bugwood.org
Defoliation clue: pattern
Complete defoliation Individual holes
Skeletonizing Mining damage
Photos: clockwise from top left © H. Ovidiu, University of Oradea; P. Weston, Cornell University; M. Zubrik, FRI – Slovakia; J. Solomon, US-FS. All images Bugwood.org.
Defoliation clue: feeding structures
Feeding structures
• Tents
• Rolled leaves
• Casebearers
• Free feeders
Photos: eastern tent caterpillars (top) © David Cappaert, Michigan State Univ., Bugwood.org and orangestriped oakworms © Ryan St. Laurent, Cornell University
Defoliation clue: feeding structure
Tents Rolled leaves
Free feeders Casebearers
Photos: clockwise from top left © P. Sloderbeck, Kansas State University; DPIW, Tasmania Archive; W. Upham, KSU; B. McNee, WI-DNR. All images Bugwood.org
Defoliation clue: time of year
Insects cause damage at specific times of the year
• Spring defoliators
• Spring/summer
• Summer
Photo: fall webworm nests © Dawn Dailey O’Brien, Cornell University
Asian defoliators (AD) vs native defoliators
• Native defoliators and the established European gypsy moth (Lymantria dispar) frequently defoliate broadleaved trees
• The AD belonging to the genus Lymantria may defoliate broadleaved or coniferous trees
• The ADs in the genus Dendrolimus are conifer feeders
• Total defoliation of conifers is uncommon to rare in the Eastern US―and should alert you that it could likely be an AD introduction
AD vs native defoliators
Native defoliating lappet moths (Lasiocampidae)
– Same family as Dendrolimus
– Forest tent caterpillar is common on oaks
– Eastern tent caterpillar is common on black cherry
Photos: forest tent caterpillar (top) © Franclemont larval slide collection, CUIC and eastern tent caterpillar (bottom) D. D. O’Brien, Cornell University
AD vs native defoliators
• Native defoliators feed primarily on broadleaved trees
• Conifer defoliation is uncommon in the Eastern US
– Pine sawflies (order: Hymenoptera)
• In parts of the western US native Lepidoptera conifer defoliators include the pine silkmoths & Douglas fir tussock moth
AD vs native defoliators
• Defoliation of conifers in the Eastern US should be an instant red flag – Dendrolimus sibiricus, D. punctatus, and D. pini
are obligate conifer feeders
– Gypsy moths native to Asia (Lymantria spp.) will also feed on conifers
• In the event of defoliation of coniferous trees, any Lepidoptera larvae should be collected and identified
Conifer defoliation facts
• Coniferous trees are less tolerant of defoliation than deciduous trees.
• Defoliation makes trees more vulnerable to secondary organisms.
• Late season defoliation is less stressful than early season defoliation.
Recognizing AD larvae
• The larvae of the three Dendrolimus spp. are all similar to each other, but very recognizable when compared to native conifer feeders
• Most AD Lymantria spp. larvae are very similar to each other and cannot always be readily differentiated from the already established European gypsy moth
Larvae: Dendrolimus
Pine-tree lappet moth (Dendrolimus pini)
Masson pine caterpillar (Dendrolimus punctatus)
Photos: © William M. Ciesla, Forest Health Management International, Bugwood.org
Larvae: European gypsy moth (Lymantria dispar dispar)
Photos: © Franclemont larval slide collection, CUIC, Cornell University
Lymantria look-alike: Panthea furcilla (Noctuidae: Pantheinae)
Photos: © Franclemont larval slide collection, CUIC, Cornell University
Dendrolimus larval look-alike: Tolype sp. (Lasiocampidae)
Tolype velleda
Tolype laricis
Photos: © David Cappaert, Michigan State University, Bugwood.org and Connecticut Agricultural Experiment Station Archive, Connecticut Agricultural Experiment Station, Bugwood.org
Dendrolimus larval look-alike: Artace sp. (Lasiocampidae)
Dot-lined white Artace cribrarius larva Artace colaria female
Photos: Artace cribrarius larva, courtesy of Sean McCann, Bugguide.com and Artace colaria female © CUIC, Cornell University
Dendrolimus larval look-alike: American lappet moth
(Phyllodesma americana: Lasiocampidae)
Photo courtesy of Andrée Reno Sanborn of Barton, Vermont
Dendrolimus larval look-alike: Gloveria (Lasiocampidae)
Gloveria gargamelle larvae
Photos: Gloveria gargamelle courtesy of Valerie Bugh
Dendrolimus larval look-alike: Olceclostera angelica (Apatelodidae)
Photo courtesy of Colin Gillette
Siberian silk moth (Dendrolimus sibiricus)
Males and females are similar but females are larger, with broader wings.
Wingspan
• male: 40–60 mm
• female: 60–80 mm
Key features
• three dark, notched stripes on the wings
• white spot usually present near center of forewing
© Kent Loeffler, Plant Pathology and Plant-Microbe Biology, Cornell University
Siberian silk moth (Dendrolimus sibiricus)
♀
Photo: Pest and Diseases Image Library, Bugwood.org
Males and females are similar but females are larger, with broader wings. Wingspan • male: 40–60 mm • female: 60–80 mm Key features • three dark, notched
stripes on the wings • white spot usually
present near center of forewing
Pine-tree lappet moth (Dendrolimus pini)
Males and females are similar but females are larger, with broader wings. Wingspan • male: 50–70 mm • female: 70–90 mm Key features • prominent brown bands
located at the base of the forewing
• white spot usually present near center of forewing
Masson pine caterpillar (Dendrolimus punctatus)
Males and females are similar but females are larger, with broader wings. Wingspan • male: 50–80 mm • female: larger Key features • wings mostly uniform brown • line nearest edge of wing
unconnected • line discontinuous rather
than mostly continuous as in D. sibiricus and D. pini
Large look-alike, Southwestern lappet moths (Lasiocampidae)
Gloveria arizonensis Gloveria medusa Gloveria gargamelle
Large native non-Lasiocampidae pine feeders
Pine devil (Citheronia sepulcralis) Northern pine sphinx (Lapara bombycoides)
Pandora pine moth (Coloradia pandora)
Lymantria (the similar species)
• L. dispar asiatica
• L. dispar japonica
• L. umbrosa
• L. albescens
• L. postalba
The key feature to recognize: arc and dot
dot
arc
Lymantria (the unique, easily identifiable species)
• L. mathura — Rosy gypsy moth
• L. monacha* — Nun moth
• L. xylina
Rosy gypsy moth (Lymantria mathura)
Wingspan
• male FW length: 21–24 mm
• female ~38 mm
Key features
• males yellow hindwings
• females whitish with pink
– immediately recognizable from other AD Lymantria spp.
– no native look-alike species
Lymantria xylina
Wingspan
• male FW length: 25–28 mm
• female: ~35 mm
Key features
• off-white coloration
• single transverse, wavy band on forewing
– No native look-alike species
Nun moth (Lymantria monacha)
Wingspan • male FW length: 18–20
mm • female: 27–29 mm Key features • white forewings with ziz-
zagging lines • arc/dot not as
pronounced • heavy maculation • hindwings are greyish
Nun moth look-alikes
Furcula scolopendrina
Lichnoptera decora
Black zigzag moth (Panthea acronyctoides)
Native tussock moths (Erebidae: Lymantriinae)
Orgyia spp. Key diagnostic features
• white patch in lower corner of forewings, about a quarter of the way from edge (in most species)
• dorsal abdominal tufts of scales
• females are wingless
Dasychira spp. Key diagnostic features
• Dorsal abdominal tufts of scales
Native tussock moths: Orgyia
Orgyia spp.
Key diagnostic feature
• patch of white scales on the bottom edge of the forewing
Lymantria dispar dispar
Key diagnostic feature
• no white patch
• arc dot feature
Native tussock moths: Orgyia
Orgyia leucostigma
Orgyia definita
Orgyia pseudotsugata
Orgyia falcata Orgyia antiqua
Native tussock moths: Dasychira
Dasychira spp. Key diagnostic features • dorsal tufts of scales • stockier than Orgyia spp. • females are winged
Lymantria dispar dispar Key diagnostic features • no dorsal tufts • arc dot feature
Native tussock moths: Dasychira
Dasychira tephra Dasychira obliquata
Dasychira vagans Dasychira plagiata
Dasychira grisefacta
Supporting materials
Visit www.FirstDetector.org for materials to supplement this presentation including posters, diagnostic photo guides and promotional materials.
Authors
Ryan St. Laurent ‘16, Department of Entomology, Cornell University
Rachel McCarthy, NPDN Training and Education Coordinator, Department of Plant Pathology and Plant-Microbe Biology, Cornell University
References
• https://caps.ceris.purdue.edu/survey/asian-defoliator/reference/2013 • Ferguson D.C. (1978) Noctuoidea, Lymantriidae. In: Hodges RW et al. (Eds) The
moths of North America, fascicle 22.2. Wedge Entomological Research Foundation, Washington, DC.
• Franclemont, J.G. (1973). The Moths of America North of Mexico. 20.1. Mimallonoidea and Bombycoidea, Apatelodidae, Bombycidae, Lasiocampidae. London, E.W. Classey & R.B.D.
• Pogue, M. G. and P. W. Schaefer. (2007) A review of selected species of Lymantria Hübner [1819] including three new species (Lepidoptera: Noctuidae: Lymantriinae) from subtropical and temperate regions of Asia, some potentially invasive to North America. Forest Health Technology Enterprise TeamTechnology Transfer. FHTET-2006-07.
• Wagner, D. L. (2005) Caterpillars of Eastern North America: A Guide to Identification and Natural History. Princeton University Press.
• Wagner, D. L., D. F. Schweitzer, J. B. Sullivan, and R. C. Reardon. (2011) Owlet Caterpillars of Eastern North America (Lepidoptera: Noctuidae). Princeton University Press.