Insect palaeoichnology deals with insect trace fossils preserved in sedimentary rocks, plant remains, and other less frequent substrates, such as bones and vertebrate coprolites. Recorded traces comprise locomotion trails and resting traces in water-saturated sediments; Trichoptera, Hymenoptera and Lepidoptera cocoons; weevil pupal chambers in palaeosols; dermestid pupal chambers in fossil bones; burrows in vertebrate coprolites, and different kinds of plant damage. However, most described trace fossils attributable to insects are nests preserved in palaeosols and borings occurring in fossil wood.  

Despite their abundance and diversity, insect trace fossils have only recently been incorporated in the theoretical background of ichnology that was mostly based on marine and lacustrine traces. This incorporation is producing important changes in classical concepts and classifications. On the other hand, palaeoentomology and insect palaeoichnology were hardly integrated in the past in comprehensive studies, although the latter is contributing significantly to our knowledge of the evolutionary history of insects, extending backwards and completing the fossil record of important groups. For example, all the information on extinct bees from the Southern Hemisphere is provided by their fossil nests. 
 

Miocene leave with feeding traces  (Bellver de Cerdanya, Spain)	Miocene caddis-fly case  (Bellver de Cerdanya, Spain)

Dekosichnus meniscatus.  Cross-section of an araucarian fossil stem showing a coleopteran gallery system from the Jurassic of Patagonia (Argentina).	Right: Carporichnus maximus in a Cretaceous fruit from Patagonia (Argentina).  Left: a similar extant trace produced by the emergence of a bruchid in a palm fruit.

 

The abundance of insect trace fossils in palaeosols is a direct consequence of the highly diversified insect behaviour, the colonizing capacity of insects, and the high preservational potential of constructed nests. Consequently, most described traces in palaeosols are attributable to bees, termites, ants and dung-beetles, those insects that construct the most elaborate nests. In contrast to many trace fossils, it is precisely the complexity of these nests which shows features that allow attribution to particular taxa of organisms and consequently to join with palaeoentomology in completing the fossil record of insects.  

Palaeosols mostly preserve nests constructed in the original soils but also sub-aerial wasp nests such as Chubutolithes (a pompilid mud nest from the Eocene-Oligocene of Patagonia) and B. favosites (a Cretaceous wasp paper nest from the USA) dropped by accident into soil from overhanging roots and tree branches. In contrast, Masrichnus represents a true underground wasp nest from the Eocene-Oligocene of Egypt. Fossil ant nests are known from the Miocene of Argentina (Attaichnus), the Palaeocene of the USA (Parowanichnus), and Pleistocene localities of Argentina and the Arab Emirates. However, most described fossil nests of Hymenoptera belong to soil-nesting bees.  

 

The record extends back to the Cenomanian and reaches its highest diversity during the Tertiary. Different ichnogenera comprise: Celliforma, represented by isolated casts or chambers of bee cells attributable to different families; Palmiraichnus, which include isolated bee cells having discrete walls and antechambers resembling oxaeid cells; Uruguay, Rosellichnus and Corimbatichnus, which include clusters of cells, in some cases similar to those of sweat bees; and finally, Ellipsoideichnus and a new ichnogenus in which cells are attached to tunnels in the manner of halictine nests. 

 

Dung-beetle brood masses are one of the most common trace fossils from the South American Tertiary palaeosols of various ages. Some of them are spherical and bear the adult's emergence hole as in Coprinisphaera and Fontanai; others have a more cylindrical design, as Monesichnus (Late Cretaceous-Early Tertiary of Uruguay) which preserves the meniscus packing of provisions, or Eatonichnus (Palaeocene of the USA) which shows a helicoidal external wall. Other coleopteran traces comprise Pallichnus (Oligocene of the USA) - dung-beetle pupal chambers; Fictovichnus (Late Cretaceous of the Gobi Desert and Pleistocene of Australia) - weevil pupal chambers; Rebuffoichnus and Teisseirei (Late Cretaceous-Early Tertiary of southern South America) - undetermined coleopteran pupal chambers. 

 

Fossil termite nests are common in Tertiary and Quaternary palaeosols of many localities around the world but possible termite nests (Archeoentomichnus) were described from formations as old as the Chinle (Triassic of the USA). Different ichnogenera attributable to Macrotermitinae (Termitichnus, Vondrichnus, Fleaglellius) represented by spheroidal chambers interconnected by tunnel systems have been described from the Eocene-Oligocene of Egypt. Another ichnogenus, Krausichnus, from the same locality comprises flat and tiered chambers. Syntermesichnus and Tacuruichnus - possible Nasutitermitinae nests composed of chambers and galleries - were described from the Miocene and Pliocene of Argentina respectively. Finally, a large number of Pliocene and Pleistocene trace fossils attributable to termites were described and remain unnamed from different localities in the world. 
 
 

Selected Bibliography 

Brown, R. W. 1934.- Celliforma spirifer, the fossil larval chambers of mining bees. Journal of the Washington Academy of Sciences, 24: 532-539. 

Bown, T.M., Hasiotis, S. T., Genise, J.F., Maldonado, F. & Brouwers, E.M. 1997.-Trace fossils of Hymenoptera and other insects and paleonvironments of the Claron Formation (Palaeocene and Eocene), Southwestern Utah. U.S. Geological Survey Bulletin (USA), 2153: 42-58. 

Bown, T.M. & Laza, J.H. 1990.- A Miocene fossil termite nest from southern Argentina and its paleoclimatological implications. Ichnos, 1: 73-79. 

Buatois, L.A., Mángano, M. G., Genise, J.F. & T. N. Taylor. 1998.- The ichnologic record of the continental invertebrate invasion: evolutionary trends in environmental expansion, ecospace utilization, and behavioral complexity. Palaios, 13: 217-240. 

Chin, K. & Gill, B.D. 1996.- Dinosaurs, dung beetles, and conifers: participants in a Cretaceous food web. Palaios, 11: 280-285. 

Elliott, D. K. & Nations, J. D. 1998.- Bee burrows in the Late Cretaceous (Late Cenomanian) Dakota Formation, Northeastern Arizona. Ichnos, 5: 243-253. 

Frenguelli, J. 1938.- Nidi fossili di Scarabeidi e Vespidi. Bolletino Societta Geologia Italiana, 57: 77-96. 

Frenguelli, J. 1939.- Nidos fósiles de insectos en el Terciario del Neuquén y Río Negro. Notas del Museo de La Plata (Paleontología), 4 (18): 379-402. 

Genise, J.F. 1993.- Trazas fósiles de insectos en petrificaciones vegetales. pp. 41-47. En Melchor, R.N. Nuevas tendencias en el estudio de trazas fósiles. La Pampa. Fac. Cs. Exactas y Naturales (UNLPam). 

Genise, J.F. 1993.- Trazas fósiles de insectos en paleosuelos. pp. 49-59. En Melchor, R.N. Nuevas tendencias en el estudio de trazas fósiles. La Pampa. Fac. s. Exactas y Naturales (UNLPam). 

Genise, J. F. 1995.- Upper Cretaceous trace fossils in permineralized plant remains from Patagonian Argentina. Ichnos, 3: 287-299. 

Genise, J.F. 1997.- A fossil termite nest from the Marplatan stage-age (late Pliocene) of Buenos Aires province Argentina, as palaeoclimatic indicator. Palaeogeography, Palaeoclimatology, Palaeoecology, 136: 139-144. 

Genise, J. F. 1999.- Paleoicnología de Insectos. Revista de la Sociedad Entomológica Argentina, 58: 104-116. 

Genise, J.F. & Bown, T.M. 1994.- New Miocene scarabeid and hymenopterous nests and Early Miocene (santacrucian) paleoenvironments, Patagonian Argentina. Ichnos,3: 107-117. 

Genise, J.F & Bown, T.M. 1994.- New trace fossils of termites (Insecta: Isoptera) from the Late Eocene-Early Miocene of Egypt, and the reconstruction of ancient isopteran social behavior. Ichnos, 3: 155-183. 

Genise, J.F. & Hazeldine, P.L. 1998.- The ichnogenus Palmiraichnus Roselli for fossil bee cells. Ichnos, 6: 151-166. 

Hasiotis, S. T., Aslan, A. & Bown, T. M. 1993.- Origin, architecture, and paleoecology of the Early Eocene continental ichnofossil Scaphichnium hamatum, integration of ichnology and paleopedology. Ichnos, 3: 1-9. 

Hasiotis, S. T. & Bown, T. M. 1992.- Invertebrate Trace Fossils: the Backbone of Continental Ichnology. In Maples, C. G. and West, R. R. Trace Fossils. Short Courses in Paleontology, 5 pp.15-33. 

Johnston, P.A., Eberth, D.A. & P.K. Anderson. 1996.- Alleged vertebrate eggs from Upper Cretaceous redbeds, Gobi Desert, are fossil insect (Coleoptera) pupal chambers: Fictovichnus new ichnogenus. Canadian Journal of Earth Sciences, 33: 511-525. 

Labandeira, C.C. 1998.- Early History of Arthropod and Vascular Plant Associations. Annu. Rev. Earth Planet. Sci., 26: 329-377. 

Labandeira, C., Dilcher, D.L., Davis, D.R. & Wagner, D.L. 1994.- Ninety-seven million years of angiosperm-insect association: Paleobiological insights into the meaning of coevolution. Proc. Natl. Acad. Sci. USA, 91: 12278-12282. 

Labandeira, C. & Phillips, T.L. 1996.- Insect Fluid-Feeding on Upper Pennsylvanian Tree Ferns (Palaeodictyoptera, Marattiales) and the Early History of the Piercing-and-Sucking Functional Feeding Group. Ann. Ent. Soc. Amer., 89: 157-183. 

Labandeira, C. & Phillips, T. 1996.- A Carboniferous insect gall: Insight into early ecologic history of the Holometabola. Proc. Natl. Acad. Sci. USA, 93: 8470-8474. 

Laza, J. 1982.- Signos de actividad atribuibles a Atta (Myrmicidae) en el Mioceno de la Provincia de La Pampa, República Argentina. Significación paleozoogeográfica. Ameghiniana, 19:109-124. 

Laza, J.H. 1995.- Signos de actividad de insectos. En: Alberdi, T.M., Leone, G. & Tonni, E.P. Evolución biológica y climática de la región pampeana durante los últimos cinco millones de años. Consejo de Investigaciones Científicas de España. Madrid. pp. 347-361. 

Laza, J.H. 1997.- Signos de actividad atribuibles a dos especies de Acromyrmex (Myrmicinae, Formicidae, Hymenoptera) del Pleistoceno en la provincia de Buenos Aires, República Argentina. Significado paleoambiental. Revista de la Universidad Guarulhos, Geociencias II(6): 56-62. 

Martin, L.D. & West, D.L. 1994.- The recognition and use of dermestid (Insecta, Coleoptera) pupation chambers in paleoecology. Palaeogeography, Palaeoclimatology, Palaeoecology, 113: 303-310. 

Retallack, G. J. 1984.- Trace fossils of burrowing beetles and bees in an Oligocene paleosol, Badlands National Park, South Dakota. Journal of Paleontology, 58: 571-592. 

Rivas, S. 1900.- Nueva teoría acerca de la formación geológica de algunas grutas del Uruguay. En Araújo, O. Diccionario Geográfico del Uruguay. Imprenta Artística. Montevideo. 548 pp. 

Roselli, F. L. 1938.- Apuntes de geología y paleontología uruguaya. Sobre insectos del Cretácico del Uruguay o descubrimiento de admirables instintos constructivos de esa época. Boletín de la Sociedad Amigos de las Ciencias Naturales "Kraglievich-Fontana" 1: 72-102. 

Roselli, F.L. 1987.- Paleoicnología: nidos de insectos fósiles de la cubertura Mesozoica del Uruguay. Publicaciones del Museo Municipal de Nueva Palmira 1(1): 1-56. 

Sauer, N. 1955.- Coprinisphaera ecuadorensis, un fósil singular del Pleistoceno. Boletín del Instituto de Ciencias Naturales del Ecuador, 1(2): 123-132. 

Scott, A.C. 1992.- Trace-fossils of plant-arthropod interactions. In: Maples, C.G. and West, R.R. Short Courses in Paleontology, 5: 197-223. 

Schütze, E. 1907.- Die Lagerungsverhalttenisse Bunter Breccie an der Bahnlinie Donaukworth-Trreuchtlingen und ihre Bedeutung fur das Riesproblem. In: Branca, W. and Fraas, E. Physilakische Abhandlungen der Koniglich Preussischen Akademie der Wissenschaften Berlin, 2: 25-26. 

Wenzel, J. W. 1990.- A social wasp's nest from the Cretaceous period, Utah, USA and its biogeographical significance. Psyche, 97: 21-29.