Great grig

Appearance

Body length is 20-30 mm. Males are dark gray dorsally, pale whitish ventrally, with short wings humped up and wrinkled like a loosely-folded blanked heaped on the insect's back; male subgenital plate with a ventrally-directed process shaped like the nail-pulling claw of a hammer. Female either lacks wings or has them reduced to small stubs.

Naming

Other Common Names
Monster Haglid

Subspecies
Cyphoderris monstrosa subsp. monstrosa Uhler, 1864
Cyphoderris monstrosa subsp. piperi Caudell, 1904

Distribution

Southern British Columbia and Alberta, south to northern California and southern Idaho

Behavior

Adults hide beneath leaf litter during the day, and become active at night, climbing tree trunks and continuing high into the branches to feed, sing (males), and mate.
Males stridulate to attract females or to announce territory; males also have fierce fights over territory and/or females.
Song at 25°C: A succession of short trills consisting of short duration pulses produced at a rate of about 76/sec. The carrier frequency is nearly pure and about 13 kHz. Males begin calling at late dusk at the bases of tree trunk and climb higher as the night progresses. An hour after sunset most are out of reach; calling from heights of more than 5 m is common.

Habitat

Habitat is coniferous forests containing Lodgepole Pine, Englemann Spruce, and Mountain Hemlock.

Reproduction

Like most insects, male grigs have two pairs of wings. The first pair, slightly hardened and modified into sound organs, is used to produce a song that guides the female to him. The second pair, however, is somewhat dispensable, and it has evolved into a pair of big, fleshy organs filled with the male’s blood (hemolymph), and this is what the female grigs lust for.
Once a female locates an interested male, she climbs on his back and immediately starts devouring his wings. While she is busy with her cannibalistic hors d’oeuvre, the male attaches his reproductive organs to those of the female and transfers a packet of sperm. He also leaves with the female a package of nutritious carbohydrates and proteins, known as the spermatophylax, which the female consumes after the mating. It seems that the role of these nuptial gifts is to ensure that the sperm he delivered has enough time to get where it needs to, and it also precludes her from mating again with another male, at least until she is done eating. More importantly, his edible wings and the spermatophylax provide the female with nutrients that she will be able to use to produce her eggs, making the male an active and invested participant in parenthood.
Although both the male and the female will soon be ready to mate again, the male now has a problem — he is not ready to retire quite yet, but he no longer has the tasty wings that attracted his first partner. Luckily for him females are not very good at distinguishing the song of an unmated male from that of one who has already lost his virgin wings (but there is evidence that the females preferentially mate with virgins). And once she climbs the back of a male and realizes that he no longer carries the tasty snack, it is too late. Male grigs have evolved an ingenious, if somewhat insidious, device on their abdomen, appropriately called the gin trap, which effectively locks the female in place and gives him extra time to transfer his reproductive cells. It takes a female a considerable amount of effort to disengage from the male, and there is plenty of time for him to pass on his genes.
Great grigs overwinter as a late-instar nymph or young adult in burrow in ground; one generation per year; adults from June to August.

Food

Great grigs eat staminate flowers of coniferous trees, and flower parts & pollen of broadleaved shrubs; sometimes they eat fruit and small insects.