38 PIWC. E:\TmLOL. Soc. BruT. C OL1JMllIA, VOL. 62 (1965) , D EC . 1, 1965

THE NOTONECTIDA.E () OF BRITISH COLUMBIA

G. G. E. SCUDDER

Department of Zoology, University of British Columbia, Vancouver

A study of the NO'tonectidae in overwinters in the adult instal': British Columbia has shown that. six Hungerford (1933) states that tln­ species are present in the Province. published records of the species in Distribution, habitat notes and a Michigan, indicate that there it key to species is given below. overwinters in the egg stage. The B.C. specimens were captured in Subfam i Iy Notonectinae small freshwater ponds, of less than borealis Bueno & Hus­ a n acre in extent and with a profuse sey. - Cariboo, Springhouse, 15. ;I ii. growth of submerged and emergent 1962, 18. viii. 1962, 31. viii. 1962, 26 . vegetation. These ponds had a pH of v. 1963 (G. G. E. Scudder) ; Chilcotin, 8.03 - 8.3 5, and a water -conductivity 21. ix. 1963 (G. G. E. S.) [U.B.C.I. of 300 - 1050 microhmos/ cm. (equiv­ Hungerford (1933) records N . borealis alent to 0.0135 - 0.0525 % NaCl). from Michigan, Minnesota, Quebec and Bearfoot Mountains, B .C.: the N. kirbyi Hungerf. - Comox, vii latter record was repeated by Downes (J. L. Jones); Forbidden Plateau, (1927) . I have been unable to locate vii; Malahat, viii (W. Downes); Met­ the Bearfoot Mountains locality, and chosin; Saturna Is., v (J. Boone); so it is possible that this record 20 mls. S. Port Clements, iii (A. B. refers to some neighbouring state or Acton) ; Hope, ii (G. H. Asche); Mil­ province. ner, v (K. Graham); Nancy Lake, Mt. Seymour, ix (R. E. Leech); To the above distribution, also can Stanley Park, Vancouver, iv (G. G. be added the Northwest Territories E. Scudder); Vancouver, vii (H. B. and Alberta. Material examined in­ Leech); Oliver, ix (J. Boone) ; Kere­ cludes: - N.W.T ., M. 37, Yellowknife, meos, ix (W. Downes); Olalla, viii 21. vii. 1961 (T. G . Northcote ); (G. G. E. S.); Westbank, ix (W. D.); N.w.T., M. 10 . 5, Yellowknife, 21. 'Iii. Enderby, vi (W. D.); Vernon, 29 . iv. 1961 (T. G. N.); N.W.T ., trib. to 1918, in flight on road (M. Ruh­ Birch Lake, 4 mi. E. Birch Lake ?t mann); Vernon, ix (H. B. L.), x mi. 74 E. of Fort Providence, on Ft. (W. D.); Salmon Arm, v (H. B. L.); Providence-Fort Rae Hwy., 31. vii. Quick, viii (G. J . Spencer); Nicola, 1961 (C. C. Lindsey). ALTA., Hay vi (G. J . S.); Kamloops, vii-viii (G. River, 8 mi. N. of Meander River, 20. J . S.); Edith Lake, viii; Savona, vii; vii. 1961 (T. G . N.) [U.B.C.l Clinton, 6 mls. S., ix (G. G. E. S.) ~ 13 ml. Lake, Dog Creek Rd, N. Clin­ The specimens from near Birch ton, x (H. B. L. & C. V. Morgan); 14:9 Lake, N.W.T. and Hay River, Alta. mile, Cariboo Hwy., ix (G. G . E. S.); were taken in slOW flowing rivers. At Chilcotin, v-ix (G. G. E. S.); Mc­ the former the river was 10 feet wide, Intyre Lake, Chilcotin, x (G. G. E. 4 feet deep and with a weed bed at S.) ; Boitano Lake, Cariboo, v (G. G. margin; at the latter, the river was E. S.); Westwick La ke, Cariboo, iv-ix 80 feet wide, 2 feet deep and the (G. G . E. S.); Springhouse, Cariboo, bottom was mud with small stones iv-x (G. G . E. S.); Kootenay (Horse­ and some Potamogeton. In contrast shoe Lake, New Lake), x (H. Spar­ to this, the B.C. specimens were row); Fort St. John, vi (A. B. Acton) taken in small ponds. [U.B.C.l Oliver, v (J. E. H. Ma rtin); The captures of N. borealis in the Peachland, x (A. N. Gartrell); Sum­ Interior of British Columbia, indi­ merland, ix (A. N. G.) ; Westba nk, v cate that in this area, the species (A. Thrupp); Kaleden, xii (A. ~. G.); PUOC.,ENTOMOr.. Soc. B nIT. COLU;I[BIA. VOL . 62 (1965 ), DEC. 1, 1965 39

Kelowna, xi (A. N. G .); Creston, vii (N. Carter); Nr. Squamish, viii (G. (A. A. Dennys); Princeton, v (P. N. G . E. Scudder); Steelhead, ix (G. G . Vroom); Lavington, vi. (A. Thrupp) ; E. S.); Vancouver, x (D. C. Buck­ Copper Mt., ix (G. Stace Smith); land); Oliver, viii (W. D.); Vaseaux Minnie Lake, vii (N. Criddle); Clin­ Lake, viii (W. D.); Westbank, ix (W. ton, v (R. Hopping); 134 mile, viii D.); Keremeos, ix (W. D.); Kamloops, (R. Hopping); Barkerville, ix (G. viii (G. J. S.); Sheridan Lake, ix; Stace Smith); Revelstoke, 6000 ft., Williams Lake Distr., v (G. G. E. S.); vii (E. R. Buckell); Courtenay, vii Chilcotin, v-x (G. G . E. S.); Mc­ (J. G. Gregson) [C.N.C.J. Intyre Lake, Chilcotin, x (G. G. E. S.); Green Timbers Plateau, vi-x Hungerford (1933) notes material (G. G . E. S.); Beaverdam Lake, in the C.N.C. from Mt. Cheam, iii; Cariboo, x (G. G. E. S.); Spring­ Rolla, viii (P. N. Vroom), Aspen house, Cariboo, v-x (G. G. E. S.); Grove, v (P. N. Vroom), and reports Batholemew Lake, S . of Kimberley, the species as being confined to the v (I. Stirling); Kootenay (Horseshoe western United States and Canada. Lake,Jim Smith Lake, Enid Lake, Previous to 1933 N. kirbyi was con­ Lillian Lake, Hiawatha Lake, Bed­ fused with N . insulata Kirby. norski Lake, New Lake), x (H. Spar­ row) [U.B.C.J. 134 Mile (R. Hopping) ; In the B .C. Interior, N. kirbyi has Vernon (R. Hopping) [F.I.S., Vernonl been taken in a wide variety of Matson Lake, V.I., x (Downps & lakes, with pH 7.03 - 9.23 and con­ Hardy); Wellington, iii [Provo \1us. ductivity 60 - 6,800 microhmos/ cm., Victoria]. Peachland, x (A. N. Gar­ but has not so far been taken in trell); Salmon Arm, ix (A. Thrupp); waters above 7000 mi'crohmos/ cm. Summerland, x (A. N. G.); Oliver, x (about 0.4% NaCl). Some prelimin­ (A. N. G.); Victoria, vi (K. F. A.) ary measurements have been made [C.N.C.l Hungerford (1933) also gives on the haemolymph of this species: ChilliwaCk, ix; Mt. Cheam, ix, and the results are tabulated below. notes that N. undulata has a wide Lake Osmolarity Osmolarity range, extending from coast to coast of lake of in North America and from Canada water haemolymph to the Gulf of Mexico. (osmoles) (osmoles) In British Columbia, undulata A . . .. _-_._---_. 0.005 O . :~O seems to be relatively more abundant B -- --_.---_. _- - 0.135 0.36 in the south than in the central in­ C -----_. _------0.270 0.37 terior, and is more common in the south-east, than is kirbyi. In the In Lake B there was 47 meq. Nai L Cariboo and Chilcotin undulata and and in the insect haemolymph 153 kirbyi frequently occur in the same meq. Na/ L (based on five lake. They have a similar range of pooled) . salinity tolerance and haemolymph val ues appear identical. N. undulata Say.-Comox, vii (J. L. Jones); Colwood, x (W. Downes); Courtenay; Forbidden Plateau, 3000 N. spinosa Hungerf. - Oliver, 15. ft., vii (Jones); Goldstream, vii (K. viii. 1937 (W. Downes); Vernon, 4. X. F. Auden); Lower Quinsam Lake, iv 1921 (W. D.), 13. ix. 1930 (H. Leech) (in cop. 30 . iv. 1960) (J. Lanko); m.B.c.l Kelowna, xi (A. N. Gartrell) Malahat, viii (W. D.); Metchosin, [C.N.C,J. Downes (in litt.) reports this viii (W. D.); Nanaimo, v (G. J. Spen­ from slow flowing streams. It appea rs cer); Saanich Distr., viii-ix (W. D.); to be confined to the Okanagan Val­ TOfino, vi-viii (G. J. S.); Victoria, vi ley in B .C. Hungerford (1933) re­ (K. F. A.); Agassiz, vii; Haney, ix cords the species from B.C., Oregon, (W. D .); Prince Rupert, muskeg pool Montana, Nevada and Utah. 40 Pnoc . ENTO.MOL. Soc . BRIT. COLUlIIBIA, V OL. 62 (1965) , DEC. 1, 1965

N. unifasciata andersoni !lungerf. of the Province : it does not a ppar­ - Osoyoos, 29 . iii. 1941 (H. B . Leech) ; ently p enetrate far into the Interior, Westbank, 12. ix. 1954 (W. Downes ) but a lso it is not confined to the [U.B.C.l Oliver, v (A. N. Gartrell); Oka nagan. The locality nea r Squam­ Peachland, x (A. N . G.); Penticton, x ish is a very s mall road-side pond, (A. N. G .); Summerland, iv (A. N . with floating logs and a little vegeta­ G .); Vernon, vi (R. Hopping) [C.N.C.l tion. In August 1961 the species ,vas Like spinosa, apparently confined to a bundant and both adults and larvae the Okanagan Va lley in B.C. This were captured. Truxal (1953) r eports subspecies extends from B .C. through con/usa from Alberta, Manitoba, the W estern United States to Mexico, eastern and southern United States the type locality being Olive;:, B.C. and the W est Indies. In the northern part of its range, spec:mens are larger than those to the south a nd Subfamily Anisopinae the s pecies seems to show a clinal confusa Truxal - Duncan, type variation. Further, Truxa l (loc. 4. ix. 1926 (W. Downes) ; Beaver cit.) reports a variation in flight Lake, Saanich Dist., 9. viii. 2919 (W. wing development in different popu­ D.); Malahat, 30. viii. 1939 (W. D.); lations. In Manitoba and Alberta 32% Sooke,19 . viii. 1923 (K. F . Auden) ; were short-winged, while those from Nr. Squamish, 25 . viii. 1961 (G. G . E. Connecticut, Michigan, New York, Scudder); Oliver, 15. viii. 1957 (W. New Jersey and Kansas were all short D.); Premier Lake, Kootenay, 4. ix. winged. Other states had varying 1963 (1. Stirling ) . These constitute percentages of short-winged indiv­ the first definite records of this idua ls and the sample from the species in the Province: material Grand Cayman Island was all long­ from Vancouver Island was recorded winged. All specimens so far studi.ed under B. eZegans (Fieb). by Downes from British Columbia are short­ (1927) . Truxal (1953) has shown winged and thus the reduced wing that the North American specimens condition seems not to have a geo­ referred to eZegans are incorrectly graphical bas is. Perhaps it is r elated named, most of them being con/usa. to habitat stability, similar to the B. con/usa h as a very interesting conditions in Corixidae ar,d other distribution in that it occurs only in (Young, 1961, 1965; the southern drier and warmer areas S cudder, 1964).

Key to Notonectidae of brane and scutellum flavo·ochraceous ; British Columbia male genital capsule with distinct ven- 1. Hemielytral commissure with definite tral finger-like process ...... _.. .__ .... _.... . hair·lined pit on anterior end; hemiely· Notonecta borealis B. & H. tra hyaline; fore tarsi of male with two tarsomeres; male fore femora widened - Insects usually distinctly marked with at apex and with stridulatory area on black; membrane fuscous in basal half; inner surface; greatest width of head scutellum completely black; male at least 7x width of vertex; pronotum ge nital capsule with slight ventral tricarinate, the median carina distinct; co nical projection N. kirbyi Hung. synthlipsis narrow, less than half an- 4. Mesotrochanter angulate or spinose .... 5 terior width of vertex. _ ...... - Mesotrochanter rounded ...... Trux N. undulata Say' - Hemielytral commissure without defin­ 5. Mesotrochanter produced into a long ite hair-lined pit on anterior end; spine .. _...... '.' ... . N. spinosa Hung. hemielytra opaque .. ' ...... 2 -Mesotrochanter angulate ...... 2. Keel of fourth abdominal sternum bare, N. unifasciata andersoni Hung. hairs confined to sides . . _...... __ ...... __ ._.... . 3 Acknowledgements -Keel of fourth abdominal sternum not This paper results from research on the bare ...... _...... 4 aquatic insects of British Columbia, re­ 3. Insects pale and more or less uniform search supported by grants from the ochraceous; anterior margin of corium National Research Council of Canada and sometimes narrowly fuscous; mem- University of British Columbia.