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Montana Field Guide

Montana Field Guides

Fork-tailed Bush Katydid - Scudderia furcata

Native Species

Global Rank: G5
State Rank: SNR

Agency Status


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General Description
The following comes from Rehn and Hebard (1914), Hebard (1928), Blatchley (1920), Helfer (1971), Vickery and Kevan (1985), Elliott and Hershberger (2007), Himmelman (2009), and Scott (2010). This species is relatively small for the genus. It is slender in body form with a general body color that is a dark leafy-green, sometimes suffused with brown. The head, pronotum (thorax), and ventral surface is greenish-yellow, fading to a dull-clay-yellow. The base of the antennae are green and the apical three-fourths a dusky hue. The disk (top) of the pronotum is short with parallel lateral lobes with broadly rounded edges. Occasionally specimens may possess a pale-yellow stripe at the dorsal lateral angles of the pronotum. The hind tibia and femur (and female ovipositors) are greenish, but more often purplish-brown or reddish. The front and hind wings are subequal in width, and about 4.5 times as long as wide, and reticulated (veined). Nymphs are generally highly colored with strongly marked antennal segments.

Calling Song description
Songs have been verbally described as: (1) “Their sounds are soft, slow lisps delivered a few seconds apart in groups of three or four. Females respond with ticks, and males then reply with ticks” (Bland, 2003). (2) “A single sharp tsip that may be given singly, or else in a series of two or three, with a few seconds silence between each call” (Elliott and Hershberger 2007). (3) “A wet, isolated tzip, sometimes given in sequence, often irregular, with several seconds in between” (Himmelman 2009). (4) “Males stridulate in trees and bushes, often high off the ground, by day and night…song consists of rather soft lisps produced rather slowly, a few seconds apart, in a series of three or four (a “lisp”, defined as a “pulse”). Intervals between songs is erratic, from 1 to 30 minutes…Males also produce ‘ticks’ in the presence of responsive females…” Calling rates are also governed by ambient temperatures.

Overwinters in the egg stage. Nymphs occur from mid-July through the summer, and adults from late July, becoming abundant in August through October, depending upon temperatures and frosts (Vickery and Kevan 1985, Bland 2003, and Scott 2010).

Diagnostic Characteristics
The following come from Rehn and Hebard (1914), Hebard (1928), Blatchley (1920), Helfer (1971), Vickery and Kevan (1985), Elliott and Hershberger (2007), Himmelman (2009), and Scott (2010). The body length to end of forewings is 14-20 mm for males, and 18-22 mm for females. Pronotum length of males and females is 4.6-5 mm. The tegmina (wings) are 6-6.2 mm wide and 26-32 mm long. The hind femur is 19-20 mm. The female ovipositor is 6-7 mm long by 1.8-2.2 mm wide and curved upward.

The three Montana species, referred to as “Bush Katydids,” are rarely, if ever, confused with other katydid genera. However, within their own genus, it can be difficult to identify the species. The best “fool-proof” character for these species’ identity rests with the shape of the males’ genitalia at the tip of the abdomen, specifically the dorsal view of the apical U-shaped or forked notch of the supra-anal plate (see illustration).

Species Range
Montana Range Range Descriptions


Range Comments
The Forked-tailed Katydid is the most widely distributed and abundant species of the genus, ranging across all 48 conterminous U.S. from the east coast to the west coast, and occurring in southern British Columbia, Quebec, Ontario and Nova Scotia southward. In Montana, the species has been reported for 6 counties, but most likely occurs (and is common) over much of the state (Rehn and Hebard 1914, Blatchley 1920, Vickery and Kevan 1985, Capinera et al. 2004, Elliott and Hershberger 2007, Himmelman 2009, and Scott 2010).

Observations in Montana Natural Heritage Program Database
Number of Observations: 4

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

This species lives high in trees and bushes surrounding wetlands, woodlands, thickets, fencerows and in landscaped urban and suburban areas. It rarely descends to the ground but is “sometimes flushed amid tall grasses and forage crops”* (Vickery and Kevan 1985, Bland 2003, *Scott personal field notes 2018).

Food Habits
This species consumes leaves, flower petals, stamens and fruits. They rarely cause significant damage to ornamentals or crops. However, in orchards, it is sometimes considered a pest species requiring control measures due to fruit damage (Hadrick 2000).

Reproductive Characteristics
Pair formation and mating occur, on average, 20 days (ranging from 14 to 40 days) after reaching the adult stage. Detailed studies and observations are currently wanting in the literature regarding courtship, nuptial gifts, etc. The Forked-tailed Katydid produces one generation per year at northern latitudes, two at southern. During mating, the male passes a spermatophore to the accepting female, the functioning of which is probably like that which occurs with other species of katydids and crickets. Egg deposition by the female is rather unique. Since this species does not dwell on the ground, the female inserts her curved, knife-like ovipositor between the two epidermal layers of a leaf’s edge, splitting the layers. The eggs are very thin and wafer-like, between 4.5 mm long and 1.8 mm wide, light gray (that darken with age),and are smooth and glistening. Eggs are mostly laid on leaves around the outer perimeter of a tree or bush. One to five eggs are laid in a single row per leaf and a female can lay an average of 175 eggs. A single tree or bush can also host the eggs of several different females. When the eggs hatch, the nymphs pass through 6 instars to adult stage (Vickery and Kevan 1985, Hadrick 2000).

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Citation for data on this website:
Fork-tailed Bush Katydid — Scudderia furcata.  Montana Field Guide.  .  Retrieved on , from