Minnesota Leucorrhinia species are contrasted with one another through the use of male and female characters . Included in the key lo species are two species (frigida and glacialis) not previously reported from Minnesota. All North American species are discussed

Carlson, Robert Evans

Glass, Arthur W.

Hamrun, Charles L.

English

University of Minnesota, Morris (UMM): Digital Well

Journal of the Minnesota Academy of Science Volume 33 Number 1 Article 8 1965 Identification and Distribution of Minnesota Leucorrhinia Species (Odonata, Libellulidae) Charles L. Hamrun Gustavus Adolphus College Robert Evans Carlson Gustavus Adolphus College Arthur W. Glass Gustavus Adolphus College Follow this and additional works at: https://digitalcommons.morris.umn.edu/jmas  Part of the Entomology Commons Recommended Citation Hamrun, C. L., Carlson, R. E., & Glass, A. W. (1965). Identification and Distribution of Minnesota Leucorrhinia Species (Odonata, Libellulidae). Journal of the Minnesota Academy of Science, Vol. 33 No.1, 23-26. Retrieved from https://digitalcommons.morris.umn.edu/jmas/vol33/iss1/8 This Article is brought to you for free and open access by the Journals at University of Minnesota Morris Digital Well. It has been accepted for inclusion in Journal of the Minnesota Academy of Science by an authorized editor of University of Minnesota Morris Digital Well. For more information, please contact skulann@morris.umn.edu. Identification and Distribution of Minnesota Leucorrhinia Species (Odonata, Libellulidae) CHARLES L. HAMRUN, ' ROBERT EVANS CARLSON, 2 and ARTHUR W. GLASS 0 Gustavus Adolphus College ABSTRACT-Minnesota Leucorrhinia species are contrasted with one another through the use of male and female characters. Included in the key lo species are two species (frigida and glacialis) not previously reported from Minnesota. All North American species are discussed. In the field , Leucorrhinia are easily recognized by their small size, white face, and dark color. In flight, they stay near the water surface, resting frequently on emergent vegetation or on algal mats. They are not known as strong fliers but may be artful net dodgers. They are par-ticularly abundant around swamps and ponds in the spring. Oviposition is accomplished by dipping the ab-domen into the water. The nymphs are generally climb-ers and may be collected from submerged vegetation. Adults are seldom found far from the nymphal habitat. Minnesota species are generally described as having a white face, ivory labrum, and black dorsum on the head. The wings are generally clear , except for a few deep brown cells at the wing bases. The thorax ground color is dark red or dull brown, heavily marked with black. These thoracic patterns are obscured by dense tufts of long black hair. The legs are black. The males appear to be larger than the females. Although the selection of key characteristics for spe-cies identification has not always proved effective, clear descriptions of our North American species are avail-able. Hagen ( l 890), who described three of the five spe-cies found in Minnesota, provided a useful synopsis of the genus, including valuable illustrations. Needham and Westfall ( 1955) consider seven species of Leucorrhinia to reside in North America, three of which they report as occurring in Minnesota. Whedon ( 1914) reported two Leucorrhinia species from Southern Minnesota. Our studies indicate that Minnesota's varied aquatic habitat supports a good sample of these northern ranging insects. The genus is holarctic with the greatest number of spe-cies occurring in the northern portions of the range. It is hoped that this study will facilitate the identifica-tion and encourage the study of these engaging insects. Supported by the Research Corporation and National Science Foundation Grant GE 6374 . Special acknowledgment is due Dr. E. F. Cook of the Depart-ment of Entomology, Fisheries, and Wildlife, University of Min-nesota, for the generous loan of specimens. 1 B.A., Gustavus Adolphus College; M .S.: Pennsylvania State University; Ph .D., Iowa State University in entomology. Currently, Professor of Biology. 2 At Gustavus Adolphus College since 1962. Currently, Junior Biology major. • B.A., Gustavus Adolphus College : M .A .. and Ph .D. at Uni-versity of Minnesota in genetics. Currently, Professor of Biology and Department Chairman. Journal of, Volume Thirty-three, No. I , 1965 Key to Minnesota leucorrhinla l . R adial planate subtends two rows of cells in at least some wings; basal abdominal segments usually red . . . . . . . . . . . . . . . . . . . . . . . . . glacialis Radial planate subtends a single row of cells; ba-sal abdominal segments not red, often pruinose (Fig. 5) .. . ... . ... ... .. . .. . . . .. . ... .. . . . 2 2. Males . .. ... . .. . 3 Females . . .. . . .. . . 6 3. Mid-abdominal segments entirely black ( except in teneral specimens) ; apex of superior appendage acute (Fig. 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Mid-abdominal segments marked with yellow ( at least one segment); apex of superior appendage truncate ( Fig. 2) . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Trigonal interspace with two rows of cells in basal area; tip of inferior appendage at the most slightly notched as seen from below ( Fig. 3); labium black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . f rigida Trigonal interspace with three rows of cells in most of the basal area; tip of inferior appendage more Id FIG. l FRIGIDA, ci M- 1N,UION APPlNDAtc ~ 1u,r••o• AnfNDAIE FIG. 3 FRIGIDA, i5 FIG. 2 INTACTA, 6 FIG. 4 PROXIMA, i5 L.. ..... _ •• • • • •• - · - .. . ···-·__J FIG. 5 1 CM. 23 VULVAR LAMIN>\ ~ULVAR LAMINA FIG. 6 INTACTA, 9 FIG. 8 PROXIMA, Q VULVAR LAMINA VULVA~ L.A,,.INA FIG. 7 HUDSONICA, 9 FIG. 9 FRIGIDA, Q deeply notched when seen from below (Fig. 4); labium usually with whitish sides . . . . . . . proxima 5. Middle and posterior abdominal segments bearing broad , triangular yellow spots on dorsal surface hudsonica A yellow twin spot on dorsum of the seventh ab-dominal segment ( teneral specimen ts may have yellow markings on segments preceding segment seven) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . intact a 6. Abdomen with a yellow spot on dorsum of seventh segment ... .... ... . . ...... .. . ... ... . . .... 7 Abdomen without a yellow spot on dorsum of sev-enth segment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 7. Plates of vulvar lamina narrow and widely separ-ated (Fig. 6) ... . . .... .... ... . . ...... . intacta Plates of vulvar lamina in contact on at least part of mesa} surface ( Fig. 7) . . . . . . . . . . . . hudsonica 8. Vulvar lamina reduced to a pair of rounded knobs Fig. 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . proxima Vulvar lamina triangular with the bases usually in contact (Fig. 9) ... . . . .. . . ... ..... ... . frigida The foregoing key only differs from the well known work of Garman ( 1927) and others in that some of the characteristics described by Hagen ( 1890) and Calvert (1890) have been used in combination with generally employed key characteristics. This review of classifica-tion should help prevent misidentification because of variation of a single character. Using previously prepared keys, it also was often dif-ficult to identify females or teneral specimens. Com-monly employed classifications characteristics were ex-amined in 200 intacta specimens and most were found to vary considerably. Similar examinations of small frig-ida and proxima series indicated the necessity for male and female sections in the key. These studies proved the genital plate characteristic of the female to be the only consistently reliable characteristic for female identifica-tion. 24 Leucorrhinia intacta Hagen. A conspicuous yellow spot on the seventh abdominal segment readily distin-guishes the male of this species. This species appears to breed in lakes and ponds throughout most of the United States and Canada. The intacta collection sites are shown in Fig. I 0. This species is not only widely distributed throughout the state, but is clearly our most abundant Leucorrhinia. The 366 intacta specimens examined in this study were collected from May to early August. The peak of the adult population seems to occur from June I 5 to July 15. FIG. 10 INTACTA COLLECTION SITES An examination of 6 characteristics on 200 specimens not only provided the basis for selection of characteris-tics used in this key, but revealed some interesting intra-specific variations . The labium color is normally black with light colored patches. Of the 39 specimens with totally black labia, 33 were males. Infuscated wings were found only among females. The extension of yellow markings on the abdominal segments was also a trait of intacta females except in teneral specimens. The num-ber of cell rows in the trigonal interspace developed into another sex-associated character. The female tendency for more cell rows in the forewing trigonal interspace is shown in Table 1. It is suspected that similar sex dimor-phisms exist in other Leucorrhinia species. Table J. Variation in cell rows in the forewing trigonal interspace among Leucorrhinia inlacta males and females. Cell rows in trigonal interspace Males Females 3 27 51 3-2-3 25 II 2-3 66 16 The Minnesota A cademy of Science leucorrhinia proxima Calvert. A northern ranging species ( see Fig. 11) easily separated from intacla by the black abdomen except for the pruinose swollen basal segments. Of the 37 specimens encountered in this study, none were taken south of Duluth. June appears to be the month of greatest abundance. The unusual genital plate of the female (Fig. 8) is an excellent definitive charac-ter. FIG. 11 COLLECTION SITES FOR PROXIMA •, FRIGIDA X, HUDSONICA 6, GLACIALIS 0 . leucorrhinia frigida Hagen. A delicate little species superficially resembling proxima. The labium is black. The swollen basal abdominal segments are markedly pruinosc in mature specimens. This species is smaller than proxima. The distribution of the few Minnesota specimens encountered is rather remarkable. They were collected in June at Ely, Orr, Brainerd, and Winona. White ( 1963) reported taking f rigida four out of five seasons at a central Pennsylvania pond. These records suggest that .f rigida may have a widely scattered distribu-tion in Minnesota. Leucorrl,inia hudsonica Selys . A small species more brightly marked with red or yellow than the previous species. It is not common in Minnesota. The Minnesota specimens used in this study were taken at Brainerd, Be-midji, Lake Itasca, Lake Saganaga, and Lake of the Woods county . Many specimens were collected in Mani-toba and Saskatchewan. White ( 1963) took one hud-sonica during his five-year study of a Pennsylvania pond. Muttkowski ( 1908) also reported isolated occurrences of lwdsonica in Wisconsin. Leucorrhinia glacialis Hagen. The only specimens en-countered in this study were in the University of Minne-sota collection. Two specimens bore labels from Lake Itasca and the other specimen was taken near Pine City (see Fig. I I) . This is a somewhat larger Leucorrhinia with more red in the color pattern than in the previously Journal of. Volume Thirty-three, No. I, 1965 described species. Neither glacialis nor frigida has previ-ously been reported from Minnesota. Among the Minnesota species, intacta and hudsonica seem to be closely related, and frigida and proxima show kinship. These judgments are based in large measure on the marked similarities in structure of the male abdomi-nal appendages, and, to a lesser degree, on general color patterns. Walker ( 1940) in describing patricia from an Ontario specimen, placed it near hudsonica. Walker's drawings and description certainly indicated kinshp to the intacta-hudsonica species. Hagen ( 1890) regarded glacialis as related to intacta. However, the overall size and superior appendages are very similar to proxima. Specimens of the remaining North Americna species, borealis Hagen, have not been seen. The literature indicates borealis to be the largest, the earliest to emerge, and the northernmost in range of all North American Leucorrhinia. Hagen ( 1890) placed it between two European species, pectoralis, and rubi-cunda. In general, ordinarily good specific characteristics such as hamules are not particularly distinctive among species in this genus. Wing venation and color patterns also merge among Leucorrhinia populations. The ham-ules have been used with very modest success to isolate species. In the writers' opinion, only the hamules of frigida are distinctive enough to be used. Another peculiarity of this species group is its restric-tion to the northern portion of the earth. In North Amer-ica, the greatest profusion of species occurs north of the United States. This raises some questions: Does this dis-tribution imply considerable post-glacial evolution? Is the wide spread distribution of intacta over the continent dependent on the ability to adjust to warmer waters? All species studied appear closely related, although two spe-cies groups seem to exist. The intacta-hudsonica group and the proxima-f rigida group represent the most obvi-ous divergence within the genus. When the populations within a genus can be readily identified, many other avenues of investigation become inviting. The biology of these insects offers many study opportunities. Only one specimen (intacta) has been reared to adulthood in our laboratories. The effects of diet , photoperiod, and temperature upon le11currhi11ia development have only been superficiaUy examined. The taxonomy of the immatures also should be reviewed. References CALVERT, P. P. 1890. Notes on some North American Odonata with descriptions of three new species. Trans. Amer. Ent. Soc. 17: 33-40. CARMAN, P. 1927. The Odonata or dragonflies of Con-necticut. Bull. 39, Conn. Geo/. & Nat. Hist. Survey. HAGEN, H. A. 1890. A synopsis of the Odonat Genus Leucorrhinia. Trans. Arner. Ent. Soc. 17: 229-236. MuTTK0WSKI, R. A. 1908. Review of the dragon-flies of Wisconsin. Bull. Wisc. Nat. Hist. Soc. 6: 57-123. NEEDHAM, J. G. and M. J . WESTFALL, JR. 1955. A man-25 ual of the dragonflies of North America. Berkeley and Los Angeles. Univ. California Press. WALKER, E. M. 1940. Odonata from the Patricia portion of the Kenora District of Ontario with description of a new species of Leucorrhinia. Can. Ent. 72: 4-15. WHELDON, A. D. 1914. Preliminary notes on the Odonata of Southern Minnesota. Rep. Minn. State Emomolo-gist. pp. 77-103. WHITE, III, H. B. 1963. Seasonal distribution and abun-dance of Odonata at a large pond in Central Pennsyl-vania. Proc. North Central Branch Ent . Soc. Amer. 18: 120-124. Dr.-Yes or No The following correspondence is reprinted from the cited issues of SCIENCE: Rank Discrimination Being a community rich in degree-holders of every kind, Princeton is likely to have Ph.D.'s, M.D.'s, D.D.'s, and so forth among its candidates for election to the school board. Under the auspices of the League of Women Voters, our recent candidates gathered before elections for public questioning. In front of each was a name plate. The title "Dr." appeared with the names of M.D.'s; the Ph.D.'s were designated "Mr." Searching for an explanation, I found that the League of Women Vot-ers solemnly believes that being identified by the title "Dr." embarrasses a Ph.D.-especially "after hours" (a reservation that apparently does not apply to M.D.'s or D.D.S.'s seeking public office "after hours"). Pundits on etiquette were also cited as authority, al-though with some controversy, since apparently they dif-fer. Incl us ion of the title in one's telephone-directory listing was an additional criterion for establishing the right to it (three Ph.D.'s are so listed in Princeton, in-cluding the president of Princeton University). Are degrees becoming obsolete? Are we headed toward the abolition of titles, or is this manifestation reserved for Ph.D. 's? M. A. BENARDE College of Engineering, Rutgers University, New Brunswick, New Jersey (30 July 1965, Vol. 149) Degrees and Titles A recent letter by Benarde ( "Rank discrimination," 30 July, p. 499) objects to not addressing Ph.D.'s as Dr. It is my impression that there are two entirely differ-ent types of titles in the English language-true titles and occupational titles. Examples of the first type are Hon., Lord, Mr., Esq.; of the second type, Coach, Sen., Offi-cer, Gov., Lt. The title Dr. can be either. That the distinc-tion between the two types is quite sharp can be seen by considering how they are used: True titles can never be used by themselves; only press-photographers yell, "Hey Duke, how about one more picture?" and very few peo-ple would say; "Will this cut be all right, Mrs.?" Unless the form of address is ceremonial, such as "Madam" or "Your Excellency," one must always add the name: 26 "Take a letter, Miss Green.' ' On the other hand, it is quite proper to address somebody by occupational title without the name: "Officer, I wasn't speeding!'' Indeed, this form is often used in an impersonal way to address people who are somewhat faceless and interchangeable. One way to indicate respect is to use an occupational title as if it were a true title and add the name to it. Fur-thermore, one never refers to oneself by true title, par-ticularly if it carries the connotation of distinction, but it certainly is proper to use one's occupational title; "I am the Hon. Joe Gray" will never do, but there is noth-ing wrong with "This is Senator Gray calling.·· In Latin, "doctor" means "teacher." As a true title it designates those upon whom it was bestowed for hav-ing taught the community of scholars something. that is, for having made a significant contribution to the body of knowledge in a field of science or humanities ( usually in a dissertation). It was first granted in the 13th century to theologians and lawyers. Later the word acquired its occupational meaning, designating those engaged in the healing professions. This came about because the only educated person the illiterate man of the street - who didn't know better but wanted to be respectful - ever came in contact with was the healer. Thus a veterinarian, or a chiropodist, or an M.D., or an optometrist, or a dentist, or a naturopath, or a napra-path, or a podiatrist, or a chiropractor, or an osteopath is addressed by occupational title alone: "Good morn-ing, Doctor," and he introduces and signs himself as Dr. (The foregoing list was compiled from the Chicago clas-sified telephone directory by looking up "Doctor" in the index.) This has nothing to do with having or not having a doctor's degree, although in this country, where aca-demic practice imitates popular usage, just about all these practitioners have one; in Britain or the Scandi-navian countries, for example, where the original sense of the degree is preserved, they don't. ( Some British phy-sicians do get an M.D., but this is comparable to ob-taining a Ph.D. on top of a medical degree here.) On the other hand, it is not good form in English for a Ph.D. or the holder of an honorary degree to refer to himself as Dr. - though in some fields it is customary to put an abbreviation of the degree after the name - be-cause in his case it is a true title, indeed one denoting (Continued on page 32) The Minnesota Academy of Science 

Identification and Distribution of Minnesota Leucorrhinia Species (Odonata, Libellulidae)

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Identification and Distribution of Minnesota Leucorrhinia Species (Odonata, Libellulidae)

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