CRILAR

Entre Rios y Mendoza s/n

(5301) Anillaco

La Rioja, Argentina
 

marchangelsky@crilar.com.ar
 
 
 
 

"Evolutionary Trends in Morphological Adaptations of Immature Stages of Hydrophiloidea (Coleoptera)" (abstract number 2444)

Hydrophiloids represent an interesting group of beetles which have adapted to live in a wide variety of habitats and environments. They probably  originated in a terrestrial (riparian) habitat, from which they have been  able to colonize aquatic habitats and, from there, some groups have gone back to terrestrial environments. This has been possible due to several  morphological and behavioral adaptations both in adults and larvae. This paper focuses on some adaptations that relate to the preimaginal stages of hydrophiloids; when possible those modifications are viewed in a  phylogenetic context. The definition of Hydrophiloidea used here follows that of Hansen (1991) and Archangelsky (1998), excluding Hydraenidae and Histeridae; therefore Hydrophiloidea includes the following families:  Helophoridae, Epimetopidae, Georissidae,Hydrochidae, Spercheidae, and  Hydrophilidae.

Larval characters that define the ancestor of Polyphagaare few, but several of those characters have been modified in at least some hydrophiloids, most of these modifications are correlated with their aquatic and predatory habits. Among the characters of interest are: a-modification of the abdominal  segments eight to ten due to the development of a respiratory atrium; apparently this occurs once in the ancestor of Hydrochidae, Spercheidae and  Hydrophilidae. b- Reduction of the urogomphi (in number of segments and size). c- Modification of the respiratory system (from 8+1 functional  spiracles to 0+1, and in at least one genus, Berosus, 0+0). d-  Modifications of the legs in several groups: i) reductions (something that occurred at least 3 times, independently) and, ii) adaptations for  swimming. e- Development of directional asymmetries, it occurs in several groups, independently; it involves: mandibles, labium, and labroclypeus. f- Colonization of a variety of habitats (riparian, aquatic, semiaquatic and  terrestrial); more information on this subject is needed both from adult  and preimaginal stages. g- Feeding habits, hydrophiloids are mostly  predatory (generalists), but a few species have been reported to be  phytophagous and detritivorous (at least facultatively); only one of the predatory species is known to be a specialist.

     Hydrophiloidea, Immature stages, Evolutionary trends.
 
 
 

PERSONAL STATEMENT

I got my Bachelor degree in Argentina and my Ph.D from OSU (The Ohio State University).  I currently work for the CONICET (National Research Council) in a center located in Nortwestern Argentina (CRILAR), La Rioja province.  I'm also an Associate Professor at the La Rioja National University, teaching graduate courses in entomology for a Masters program (Insect Morphology and Insect Systematics).  My work deals with systematics and biology of immature Hydrophiloidea. I also use information from preimaginal stages to elucidate phylogenetic relationships within this superfamily. Other research interests are biology of other aquatic beetle families and immatures of Lampyridae.
 
 

RECENT PUBLICATIONS

Archangelsky, M. 1996 (1997). A bibliographic compilation on the immature stages of Hydrophilidae (Insecta: Coleoptera). Entomologica Basiliensia 19: 653-673.

Archangelsky, M. 1997 (1998). Studies on the biology, ecology, and systematics of the preimaginal stages of New World Hydrophiloidea (Coleoptera: Staphyliniformia). Bulletin of the Ohio Biological Survey (New Series) 12(1): ix + 207 pp.

Archangelsky, M. (1998). Phylogeny of Hydrophiloidea (Coleoptera:Staphyliniformia) using characters from adult and preimaginal stages. Systematic Entomology 23(1): 9-24.

Archangelsky, M. and M. A. Branham (1998). Description of the preimaginal stages of Pyractomena borealis (Randall, 1838) (Coleoptera,Lampyridae) and notes on its biology. Proceedings of the Entomological Society of Washington 100(3): 421-430.

Archangelsky, M. (1999). Adaptations of immature stages of Sphaeridiinae (Staphyliniformia, Hydrophiloidea, Hydrophilidae) and state of knowledge of preimaginal Hydrophilidae. The Coleopterists Bulletin53(1): 64-79.

Archangelsky, M. (1999). Larvae of Neotropical Berosus (Coleoptera, Hydrophilidae): B. aulus Orchymont, 1941 and B. auriceps Boheman,1859. Tijdschrift voor Entomologie 142(1): 1-8.

Archangelsky, M. (1999). Immature stages of Paracymus rufocinctus Bruch, 1915 and Enochrus (Methydrus) vulgaris (Steinheil, 1869)(Coleoptera: Hydrophilidae: Hydrophilinae). Elytron 13:

Archangelsky, M. (2000). Immature stages of Neotropical Hydrophilidae (Coleoptera): Hydramara argentina (Knisch, 1925) and Hemiosusbruchi Knisch, 1924. Proceedings of the Entomological Society of Washington102(2): 280-291.

Branham, M. A. and M. Archangelsky. (2000). Description of the last larval instar and pupa of Lucidota atra (Olivier, 1790) (Coleoptera:Lampyridae), with a discussion of abdominal segment homology across lifestages. Proceedings of the Entomological Society of Washington 102(4):869-877.
 
 

ELECTRONIC PUBLICATIONS
 

Archangelsky, M. A bibliographic compilation on the immature stages of Hydrophilidae (Insecta: Coleoptera).

     En la "Web Page" de Water BeetleWorld:   http://www.zo.utexas.edu/faculty/sjasper/beetles/index.htm