Synonyms and other taxonomic changes
Oecanthidae (full family)
Numbers
Arnett
(1) lists two genera:
Oecanthus (14 North American spp.) and
Neoxabea (1 species,
N. bipunctatus--
SINA lists one more in that genus). SINA also lists one more Oecanthus species - making a total of 17 species in the US. (With the recent discovery (May 2009) of Alexander's tree cricket, the U.S. total is now 18).
Thomas J. Walker published an annotated world checklist for Oecanthinae in 1966 with a total of 64 species: 47 Oecanthus, 6 Xabea and 11 Neoxabea.
Annotated Checklist of Oecanthinae (Orthoptera: Gryllidae) of the WorldIdentification
Medium-sized or small, delicate, and usually pale green. Other characteristics
(1) (2) (3) (4):
mouthparts directed forward
head long and narrow
hind
tibiae typically with small teeth between spines, at least in
Oecanthus (
Neoxabea lacks spines on tibiae)
tarsal claws with two lobes
forewings (
tegmina) of males often much wider than
abdomen
songs typically lower in pitch than other subfamilies of crickets (Gryllidae)
Genera can be differentiated as follows (
SINA):
Upper margins of hind tibiae armed with spines and teeth, first antennal segment lacks a
tubercle on distal border-->
Oecanthus
upper margins of hind tibiae unarmed, first antennal segment has prominent
tubercle on distal border-->
Neoxabea
ID for many species made by markings on the first two antennal segments -- the scape and the pedicel.
Example of antennal markings for Four-spotted Tree Cricket:
Example photos of different species of Tree Crickets:
Two-spotted
Snowy
Four-spotted
Davis'
Broad-winged
Western - pale
Western - brown
Riley's
Black-horned
Narrow-winged
Pine
Tamarack
Prairie
Fast-calling
Different-horned
Alexander's
No photos as of yet -
Brownsville (N. formosa)
Texas (unnamed O.)
Thin-lined (O. leptogrammus)
Species within the nigricornis group are often difficult to distinguish. The surest way to ID O. nigricornis, O. forbesi, O. argentinus, O. quadrapunctatus and O. celerinictus is by the number of pulses per second at a given temperature.
For example at 25.0 C - a tree cricket singing with:
42 pulses per second is O. quadrapunctatus
54 pulses per second is O. nigricornis
68 pulses per second is O. forbesi
Dr. Thomas J. Walker has several articles with graphs of pulses per second of these species.
Range
One or more species are found in each of the 48 continental U.S.
Habitat
Some found on trees, but others associated with shrubs or herbs.
Some examples: Post Oak, Red Maple, Birch, Apple, Crabapple, White Pine, Tamarack, Cedar, Grapevine, Raspberry, Red-twig Dogwood, Goldenrod, Thistle, Sunflower, Catmint, Soybean and Grasses.
Season
Nymphs emerge in warm weather (i.e. June in northern climates)
Singing males start calling in mid to late summer in northern climates.
Mating of adults in late summer / fall (i.e. Aug through Oct in northern climates)
Depending on the climate, two or three generations may occur in one season.
Food
Omnivores
Genus Oecanthus is predatory on other insects, especially those with soft bodies (Insects of Cedar Creek). One example: aphids.
Oecanthines also feed on leaf fibers, leaves, fruits.
Oecanthines raised indoors readily eat commercial cricket powder.
Life Cycle
Eggs are laid in stems of host plant. These eggs overwinter in northern climates and nymphs emerge in late spring to early summer.
Undergo a paurometabolous development (Gradual Metamorphosis). Nymphs resemble small adults and gradually develop external wing buds. They live in the same habitat as adults, typically taking the same food.
5 instar stages before reaching full adulthood (approximately 6 weeks).
The following photos are representatives of various life cycle stages. They include different individuals and different species:
Oviposited egg markings on stem
Egg
Nymph (less than 24 hours old)
Early instar
Middle instar
Advanced instar
Adult male
Adult female
Singing male
Mating pair
Ovipositing female
Remarks
A great source for 'everything you ever wanted to know about tree crickets' is an article written in May 1915 by Bentley B. Fulton in a Technical Bulletin for the New York Agricultural Experiment Station.
The Tree Crickets of New York: Life History and Bionomics
One predator of tree crickets is the Grass-carrying Wasp (Isodontia)
See Also
Carolina Ground Crickets and Say's Trigs have similiar sounding calls.
Print References
Capinera et al., pp. 205-209, plate 6
(2)
Borror and White (1970 ed.), pp. 84-85
(3)
Bland and Jacques, pp. 99-100, fig. 98
(4)
Internet References
http://oecanthinae Tree Crickets - information and photos
