''Acronicta americana'', the American dagger moth, is a
moth
Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...
of the family
Noctuidae
The Noctuidae, commonly known as owlet moths, cutworms or armyworms, are a family (biology), family of moths. Taxonomically, they are considered the most controversial family in the superfamily Noctuoidea because many of the clades are constantly ...
. It was originally
described by
Thaddeus William Harris
Thaddeus William Harris (November 12, 1795 – January 16, 1856) was an American entomologist and librarian. His focus on insect life cycles and interactions with plants was influential in broadening American entomological studies beyond a narrow ...
in 1841 and is native to North America.
Description
The American dagger moth has a
wingspan
The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the opposite wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingsp ...
of It usually has a sharp, double postmedian line, with white in between the two lines.
There is a black dash on the anal area of the forewing. The hindwing is gray with a faint, darker gray median line in the male.
The female is similar, except the hindwing is completely dark.
Subspecies
* ''Acronicta americana americana''
* ''Acronicta americana obscura''
* ''Acronicta americana eldora''
Distribution
The American dagger moth is found in North America east of the
Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...
.
Flight period
The American dagger moth can be seen from April to September throughout its range.
Caterpillar
Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths).
As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder ...
s can be seen from July to October. It has one brood in the north and two to three broods in the south.
Habitat

The American dagger moth is found in deciduous woodlands and forests.
Life cycle
The young caterpillar is densely covered with yellow
seta
In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms.
Animal setae
Protostomes
Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae, ...
e. The older caterpillar's setae are either pale yellow or white. All
instar
An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to ...
s have thin, black setae on the first and third abdominal segments. On the eighth abdominal segment, there is one tuft of black setae. The caterpillar will reach a length of .
While there are numerous reports of the larval hairs of this species sometimes causing skin irritation in humans, there is no evidence that they possess any form of venom.
Host plants
* ''
Acer'' – maple species
* ''
Acer negundo
''Acer negundo'', also known as the box elder, boxelder maple, Manitoba maple or ash-leaved maple, is a species of maple native to North America from Canada to Honduras. It is a fast-growing, short-lived tree with opposite, ash-like compound l ...
'' – box elder
* ''
Aesculus hippocastanum
''Aesculus hippocastanum'', the horse chestnut, is a species of flowering plant in the maple, Sapindus, soapberry and lychee family Sapindaceae. It is a large, deciduous, synoecious (hermaphroditic-flowered) tree. It is also called horse-chestnu ...
'' – horse chestnut
* ''
Alnus
Alders are trees of the genus ''Alnus'' in the birch family Betulaceae. The genus includes about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species ext ...
'' – alder species
* ''
Betula
A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech- oak family Fagaceae. The genus ''Betula'' contains 3 ...
'' – birch species
* ''
Carpinus caroliniana
''Carpinus caroliniana'', the American hornbeam, is a small hardwood understory tree in the genus ''Carpinus''. American hornbeam is also known as blue-beech, ironwood, musclewood and muscle beech. It is native to eastern North America, from Mi ...
'' – American hornbeam
* ''
Carya
Hickory is a common name for trees composing the genus ''Carya'', which includes 19 species accepted by ''Plants of the World Online''.
Seven species are native to southeast Asia in China, Indochina, and northeastern India (Assam), and twelve ...
'' – hickory species
* ''
Castanea
The chestnuts are the deciduous trees and shrubs in the genus ''Castanea'', in the beech family Fagaceae. The name also refers to the edible nuts they produce. They are native to temperate regions of the Northern Hemisphere.
Description
C ...
'' – chestnut species
* ''
Cercis
''Cercis'' is a genus of about 10 species in the subfamily Cercidoideae of the pea family (biology), family Fabaceae. It contains small deciduous trees or large shrubs commonly known as redbuds in the USA. They are characterised by simple, rou ...
'' – redbud species
* ''
Corylus
Hazels are plants of the genus ''Corylus'' of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family, Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, ...
'' – hazel species
* ''
Fraxinus
''Fraxinus'' (), commonly called ash, is a genus of plants in the olive and lilac family, Oleaceae, and comprises 45–65 species of usually medium-to-large trees, most of which are deciduous trees, although some Subtropics, subtropical specie ...
'' – ash species
* ''
Juglans
Walnut trees are any species of tree in the plant genus ''Juglans'', the type genus of the family (biology), family Juglandaceae, the seeds of which are referred to as walnuts. All species are deciduous trees, tall, with pinnate leaves , with ...
'' – walnut species
* ''
Platanus
''Platanus'' ( ) is a genus consisting of a small number of tree species native to the Northern Hemisphere. They are the sole living members of the family Platanaceae.
All mature members of ''Platanus'' are tall, reaching in height. The type ...
'' – sycamore species
* ''
Populus
''Populus'' is a genus of 25–30 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar (), aspen, and cottonwood.
The we ...
'' – poplar species
* ''
Quercus
An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...
'' – oak species
* ''
Salix
Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions.
Most species are known ...
'' – willow species
* ''
Tilia
''Tilia'' is a genus of about 30 species of trees or bushes, native throughout most of the temperateness, temperate Northern Hemisphere. The tree is known as linden for the European species, and basswood for North American species. In Great Bri ...
'' – basswood species
* ''
Ulmus
Elms are deciduous and semi-deciduous trees comprising the genus ''Ulmus'' in the family Ulmaceae. They are distributed over most of the Northern Hemisphere, inhabiting the temperate and tropical- montane regions of North America and Eurasia, ...
'' – elm species
References
{{Taxonbar, from=Q2040387
Acronicta
Moths described in 1841
Moths of North America