Description of the third of variomaculatus Brigham & Sanderson with notes on larvae of Nearctic (Coleoptera)

Bernhard J. van Vondel

The third instar larva of Haliplus variomaculatus Brigham & Sanderson, 1973 is described and compared with earlier described larvae of Nearctic Haliplidae. A key to the known third stage larvae of Nearctic Haliplidae is given. The differences between the larvae of the subgenera Liaphlus and Paraliaphlus are discussed. Bernhard J. van Vondel, Natural History Museum Rotterdam, p/o Roestuin 78, 3343 CV Hendrik-Ido-Ambacht, The Netherlands. [email protected]

Introduction impetus to this study, which aims at describing for The Haliplidae of the Nearctic region comprise the first time the third instar of Haliplus variomac- 67 (Majka et al. 2009). Of these, for only ulatus and at comparing this species with those of 12 species the larvae have been described: Haliplus other Nearctic Haliplidae known as larvae. (Haliplus s.str.) immaculicollis Harris, 1828 (Math- General information on the morphology of Hali- eson 1912; Hickman 1930), H. (Haliplus s.str.) api- plidae larvae, specifically for , Haliplus and calis Thomson, 1868 (Bertrand 1942), H. (Liaphlus) are given in van Vondel (1997). fulvus (Fabricius, 1801) (Schiødte, 1864), Peltodytes edentulus (LeConte, 1863) (Matheson 1912; Hick- man 1930), P. muticus (LeConte, 1853) (Matheson Material and methods 1912), P. lengi Roberts, 1913 (Hickman 1930), The single larva used for this description was stored P. sexmaculatus Roberts, 1913 (Hickman 1930), in alcohol. After having it photographed the left Apteraliplus parvulus Roberts, 1913 (Leech & Chan- legs and the right mandible were separated from the dler 1956), Brychius hungerfordi Spangler, 1954 specimen. After about three hours in Euparal essence (Strand & Spangler 1994) and B. hornii Crotch, body and body parts were transferred to Euparal on a 1873 (Mousseau & Roughley 2007). microscope slide. Drawings were made using a Zeiss Recently I had the opportunity to study a small stereo-microscope with photo-tube; measurements collection of Haliplidae from Missouri, results of a were made using a micrometer eyepiece. For detailed project by Megan M. Zeller from the University of drawings a Swift universal microscope was used. Tax- Missouri. In that material were three adults of Hali- onomic terms are according to Jaboulet (1960) and plus variomaculatus Brigham & Sanderson together van Vondel (1997). All known third stage larvae can with a third instar Haliplus larva, all collected from be distinguished with the following key, except for the same locality at two different dates. It is postu- the species of the subgenus Haliplus s.str. as I was not lated that this larva is indeed the third instar larva able to find reliable distinguishing characters. of H. variomaculatus. Such finding provided the

Tijdschrift voor Entomologie 154: 127–133, Table 1, Figs 1–29. [ISSN 0040–7496]. http://www.nev.nl/tve © 2011 Nederlandse Entomologische Vereniging. Published 1 June 2011.

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2 3 4 5 6

7 8 9 10

1

11 12 13

14

15 16 17 Figs 1–17. Haliplidae, third instar larva details. –1, Dorsal view of Peltodytes caesus; 2, spine on dorsal projection of Peltodytes muticus; 3, spine on dorsal projection of Peltodytes sexmaculatus; 4, spine on dorsal projection of Peltodytes lengi; 5, spine on dorsal projection of Peltodytes edentulus; 6, of Brychius; 7, antenna of Haliplus; 8, fore leg of Brychius; 9, fore leg of Haliplus subgenus Liaphlus; 10, fore leg of Haliplus subgenus Haliplus s.str.; 11, pronotum of Haliplus immaculicollis; 12, pronotum of ; 13, pronotum of Apteraliplus parvulus; 14, pronotum of ; 15, pronotum of Haliplus triopsis; 16, part of fore leg of Haliplus triopsis; 17, mandible of Haliplus triopsis. (Figs 1,6, 7, 8, 9, 10, 14 after van Vondel, 1997; Fig. 2 after Matheson 1912; Figs 3, 4, 5, 11, 15, 16, 17 redrawn from Hickman 1930; Figs 12, 13 original).

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20

22

? ? 18 19 21 23

Figs 18–23. Haliplus variomaculatus,larva third instar. –18, dorsal view; 19, lateral view; 20, head and thoracic seg- ments in dorsal view; 21, seventh to ninth abdominal segment in dorsal view; 22, antenna; 23, mandible. Scale lines for Figs 18–21 = 1.0 mm, for Figs 22, 23 = 0.1 mm.

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Key to the known third instar larvae of Nearctic Haliplidae between dorsoposterior extensions (Fig. 15) ...... Haliplus (Liaphlus) cribrarius 1. Body with long filamentous dorsal processes – Distance between lateroposterior extensions (Fig. 1) ...... Peltodytes.2 of thoracic segments about 3.5 distance – Body without (Fig. 13), with short (Figs 11, between dorsoposterior extensions (Fig. 14) . 12, 20) or with long (but not filamentous) ...... Haliplus (Liaphlus) fulvus dorsal processes (Fig. 14) ...... 5 11. Ventral side of tibia and tarsus of all legs 2. Length of spine on dorsal projections greater weakly serrate (Fig. 16). Inner face of mandi- than diameter of projections (Figs 2, 3) ...... 3 ble with three pointed projections (Fig. 17) . – Length of spine on dorsal projections not ...... Haliplus (Paraliaphlus) triopsis greater than or equal to diameter of projec- – Ventral side of tibia and tarsus of all legs tions (Figs 4, 5) ...... 4 smooth or with small hairs. Inner face of man- 3. Length of spine on dorsal projections about dible with a few tiny dull denticles (Fig. 23) . 1.3–1.4 diameter of projections (Fig. 3) ...... Haliplus (Paraliaphlus) variomaculatus ...... Peltodytes sexmaculatus – Length of spine on dorsal projections about Haliplus variomaculatus Brigham & Sanderson 2.0 diameter of projections (Fig. 2) ...... Figs 18–23 ...... Peltodytes muticus 4. Length of spine on dorsal projections equal Haliplus variomaculatus Brigham & Sanderson, 1972: 157 to about two thirds of diameter of projec- (original description of adult) tions (Fig. 5) ...... Peltodytes edentulus Material examined. 1?, 1/, USA, Missouri, Craw- – Length of spine on dorsal projections about ford Co., Onondaga Cave SP, Onondaga Spring, equal to diameter of projections (Fig. 4) . . . . 10 May 2007, M. Hedrick coll., orifice large pool, ...... Peltodytes lengi vegetation; 1/ and 1 third instar larva from same 5. Antenna with segments 2 and 3 of about the locality, 6 August 2008, M. Zeller coll. (2/ in same length (Fig. 6). Profemur with ventro- Univ. of Missouri coll., 1? and larva in authors distal lobe (Fig. 8) ...... Brychius.6 coll.). – Antenna with segment 3 twice as long as or longer than segment 2 (Fig. 7). Profemur Description of third instar larva without ventrodistal lobe (Figs 9, 10) ...... 7 Body. Total length 8.6 mm (urogomphi incomplete). 6. Head including mandibles about as wide as Elongate and subcylindrical (Figs 18, 19). Dorsal long ...... Brychius hornii and ventral surface covered with small tubercles – Head including mandibles 1.4 wide as (micro tracheal ). long ...... Brychius hungerfordi Color. Pale yellowish to yellow, tubercles slightly 7. Protibia distally dilated (Fig. 10) ...... darkened, tip of backward directed extensions of tho- . . Haliplus s. str.: H. apicalis or H. immaculicollis racic and abdominal segments dark brown; cephalic – Protibia distally not dilated (Fig. 9) ...... 8 capsule light brown to brown on vertex. 8. Dorsal posterior edge of thoracic and ab- Ratios and measurements aimed at characterizing dominal segments without backward di- the body shape are shown in Table 1. rected processes, but with a sparse row of Head. About circular in dorsal view, widest across the single tubercles (Fig. 13). sparsely ocelli (Fig. 20). Anterior margin straight to slightly covered with small tubercles (Fig. 13) ...... convex. Dorsal surface with dense microsculpture ...... Apteraliplus (1 species: A. parvulus) and about 12 sensilla. Behind eyes laterally two – Dorsal posterior edge of thoracic and ab- tubercles with sensilla. Antenna with four segments, dominal segments with backward directed fourth segment distally bears a bristle and has a par- processes consisting of three or more tu- allel segment attached to third segment (Fig. 22). bercles (Fig. 20), prothorax densely covered Mandible with a darkened narrow pointed tip, suc- with tubercles (Fig. 20) ...... 9 tion channel running to the tip with an oval opening 9. Lateroposterior extensions of thoracic and on ventral side, a few tiny dull denticles on inner abdominal segments strong (Fig. 14) ...... 10 margin, two (probably more) setae on outer margin – Lateroposterior extensions of thoracic and (Fig. 23). abdominal segments weak (Fig. 20) ...... 11 Thorax. Thoracic segments laterally with a weak 10. Distance between lateroposterior extensions backward directed extension, dorsally with 4 weak of thoracic segments about 2.5 distance extensions on hind margin (Fig. 20). Prothorax

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24

25

26

27

28

29

Figs 24–29. Haliplus variomaculatus, larva third instar. –24, front leg in anterior view; 25, front leg in posterior view; 26, mid leg in anterior view; 27, mid leg in posterior view; 28, hind leg in anterior view; 29, hind leg in pos- terior view. Scale line = 0.1 mm.

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Table 1. Measurements of the third instar larva of Haliplus variomaculatus in mm. (n=1)

Total length (probably with complete urogomphi) 8.6 (10.1) Mandible, length from tip to hind lobe 0.23 Length from mandible to end of 9th abdominal 7.1 Mandible, number of spines on outer margin 2 segment Length of 10th (last) abdominal segment. 1.5 (3.0) Pronotum, length 0.75 (probable length when complete) Length of head including mandibles 0.55 Pronotum, width 0.96 Width of head including ocelli 0.63 Mesonotum, length 0.47 Antenna, length of 2nd segment 0.03 Mesonotum, width 0.94 Antenna, length of 3rd segment 0.12 Metanotum, length 0.47 Antenna, ratio 3rd to 2nd segment 4:1 Metanotum, width 0.94

with six bristles on anterior margin and a bristle in observed in Haliplus species. The urogomphi of the front of dorsal extension, densely covered with small specimen described here are damaged on two places tubercles except in a small area besides the middle. (dark spots in fig. 19), probably due to predation. and with bristle in front This might have caused the curved shape. of lateral and dorsal extensions, covered with small tubercles, except along the middle line. Abdomen. Abdominal segments 1–9 laterally with Acknowledgements a weak backward directed extension. Segment 1–6 I thank Megan Zeller and Robert Sites (University dorsally with four weak extensions on hind margin, of Missouri) for the possibility to examine this mate- segment 7–8 with two weak extensions on hind rial. Yves Alarie is acknowledged for critically reading margin (Fig. 21). All segments with a bristle in the first draft of the manuscript and contributing to front of extension and covered with small tubercles the final version. The Uyttenboogaart-Eliasen Foun- in a pattern as in Figs 20 and 21. Segment 10 with dation is acknowledged for financial support of my basoventral anus and long fused urogomphi. In the research in general. only available specimen the urogomphi are strongly curved downward as in Brychius species and are miss- ing the apical part. References The ventral side is sparsely covered with small Bertrand, H., 1942. Captures et élevages de larves de tubercles. coléoptères aquatiques (9e note). – Annales de la So- Legs. Protibia simple, distally not dilated (Figs 24– ciété Entomologique de France 111:67–74. 25). The location of sensillae (setae, bristles, spines, Brigham, W.U. & M.W. Sanderson, 1972. A new species pores) as represented in Figs 24–29. of Haliplus from Illinois and South Dakota (Coleop- tera: Haliplidae). – Transactions of the Illinois Acad- emy of Science 65: 17–22. Discussion Hickman, J.R., 1930. Life-histories of Michigan Halipli- dae (Coleoptera). – Papers of the Michigan Academy Larvae of two of the 17 Nearctic species of the subge- (1929) 12: 399–424. nus Liaphlus are known and two of the 18 species of Jaboulet, H.C., 1960. Contribution à l’étude des larves the subgenus Paraliaphlus. The distinguishing char- d’Haliplides. – Travaux du Laboratoire de Zoologie et acter used in the key for Liaphlus, the strong latero- de la Station aquicole Grimaldi de la Facult. des Sci- posterior extensions of the thoracic and abdominal ences de Dijon 31:1–18, 30 figs. segments, is also present in eight other Liaphlus spe- Leech, H.B. & H.P. Chandler, 1956. Aquatic Coleoptera. cies, described so far from the Neotropical, Palaearc- Chapter 13 [pp.293–305]. – In: Aquatic of tic and Australasian regions (Moroni 1989, van Von- California. With keys to North American genera and del 1997, 2004). Probably this character is present California species (R.L. Usinger, editor). University of in all Liaphlus species. The absence of strong latero- California Press. Berkeley and Los Angeles, California. posterior extensions of the thoracic and abdominal Ix + 508 pp. segments may be characteristic for Paraliaphlus. But Matheson, R., 1912. The Haliplidae of North America, North of Mexico. – Journal New York Entomological more material is needed to confirm this assumption. Society 20: 156–193. The urogomphi of the specimen described here Majka, C.G., B.J. van Vondel & R.P. Webster, 2009. The are strongly bent downwards. This has never been

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Haliplidae of Atlantic Canada: new records, distribu- Strand, R.M. & P.J. Spangler, 1994. The natural history, tion and faunal composition. – In: Majka CG, Kli- distribution, and larval description of Brychius hun- maszewski J (Eds) Biodiversity, Biosystematics, and gerfordi Spangler (Coleoptera: Haliplidae). – Proc. Ecology of Canadian Coleoptera II. ZooKeys 22: Entomol. Soc. Wash. 96(2): 208–213. 249–266. Vondel, B.J. van, 1997. Haliplidae. – In: J. Schwoerbel Moroni, J., 1989. Aporte al conocimiento de los Hali- & P. Zwick (eds.), Süßwasserfauna von Mitteleuropa plidae de Chile I. Descripcion del tercer instar larval 20(2): 1–95. de Haliplus valdiviensis Moroni, 1980 (Coleoptera: Vondel, B.J. van, 2004. First description of larvae of Hali- Dytiscoidea). – Revista Chilena de Entomologia 17: plus-species from Australia (Coleoptera: Haliplidae). 89–93. – Tijdschrift voor Entomologie 147:57–61, figs 1–14, Mousseau, T. & R.T. Roughley, 2007. , Classifi- tables 1–2. cation, reconstructed Phylogeny and Biography of Ne- arctic Species of Brychius Thomson (Coleoptera: Hali- plidae). – The Coleopterist’s Bulletin 61(3): 351–397. Schiødte, J.C., 1864. De Metamorphosi Eleutheratorum observationes: Bidrag til Insekternes Udviklingshisto- Received: 16 September 2010 rie. – Naturhistorisk Tidsskrift 3. Raekke, 3: 131–224. Accepted: 7 February 2011

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