Megarhyssa atrata adults have been captured from mid May to early August. The main flight period is in June. The species is divided into two subspecies. The range of M. atrata atrata is from Wyoming, Minnesota to Massachusetts in the North to eastern Texas and Georgia in the South (host data by Walsh and Riley 1868, Riley 1870, Thomas 1876, Riley 1888, Packard 1890). The range of M. atrata lineata Porter is from Ontario, Quebec, New York and New Hampshire (Townes and Townes, 1960). [Video 
]
Megarhyssa greeni adults have been captured from mid May to early August for M. greenei greenei or March, April and September for M. greenei florida Townes. The main flight period is in June and early July. The range of M. greenei greenei is from Minnesota and Quebec in the North to Alabama and Georgia in the South. The range of M. greenei florida Townes is central Florida (Townes and Townes 1960).
Megarhyssa macrura adults have been captured from mid May to late September. The main flight period is in late June and July. This widespread species is divided into three subspecies. The range of M. macrura lunator (Fabricius) is east of the Rocky Mountains from South Dakota, Ontario, Quebec and Maine in the North to New Mexico, Texas and Georgia in the South (host data by Walsh and Riley 1868, Riley 1870, Harrington 1882b, Riley 1888 (illustrated on larva of T. columba larva), Packard 1890, Felt 1905, Fyles 1917, Herrick 1935). The range of M. macrura macrura (Linnaeus) is Chihuahua (Mexico), Texas, South Carolina and Florida. The range of M. macrura icterosticta Michener is Utah, Colorado Arizona and New Mexico (Townes and Townes 1960). [Video ]
Megarhyssa nortoni adults have been captured from late May to early August. The main flight period is in July. The species is divided into two subspecies, both associated with conifers. The range of M. nortoni nortoni is from southern British Columbia and southwestern Alberta in the North to southern California and New Mexico in the south. The range of M. nortoni quebecensis (Provancher) is from Ontario to Nova Scotia in the North to North Carolina in the South (Townes and Townes 1960).
Rhyssa alaskensis adults have been captured from late May to early September. The main flight period is in June and July. The range is from Alaska and Alberta in the North to California and New Mexico in the South (Townes and Townes 1960).
Rhyssa creveiri adults have been captured from late May to early September. The main flight period is in June. The range is from Minnesota, Ontario and Nova Scotia in the North to North Carolina in the South (Townes and Townes 1960).
Rhyssahoferi adults have been captured from April to August. The main flight period is in July (Kirk 1975). The range is Colorado to Arizona (Townes and Townes 1960).
Rhyssa howdenorum adults have been captured in April and June. The range is Alabama, Georgia, Nebraska, North Carolina, South Carolina and Virginia (Townes and Townes 1960, Kirk 1974).
Rhyssa lineola adults have been captured from mid May to late September. The main flight period is in July and August. The range is from southern British Columbia and Nova Scotia in the North to Wyoming and South Carolina in the South (Townes and Townes 1960).
Rhyssa persuasoria adults have been captured from late May to early September. The main flight period is late May to early July (Kirk 1975). The range is from southern British Columbia, Minnesota, Quebec and New Hampshire in the North to California, Arizona and North Carolina in the South (Townes and Townes 1960). The biology was treated by Hanson (1939).
Rhyssa ponderosae adults have been captured in April, May and June. The range is California (Townes and Townes 1960).
Pseudorhyssa nigricornis adults are cleptoparasites of Rhyssa. Adults have been captured from late May to late June (Townes and Townes 1960). Females search for an oviposition shaft of Rhyssa and oviposit into the same shaft with their narrower ovipositor. Wet siricid frass and vaginal gland secretions are attractants. The larva of P. nigricornis eliminates the Rhyssa larva and develops on the siricid larva (Couturier 1949, Spradbery 1969, Spradbery 1970).
