Description of the third instar larva 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 species (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 Brychius, 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. 128 Tijdschrift voor Entomologie, volume 154, 2011

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, antenna 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).