Ecological Archives M080-019-A4

Ellen D. Currano, Conrad C. Labandeira, and Peter Wilf. 2010. Fossil insect folivory tracks paleoclimate for six million years. Ecological Monographs 80:547–567.

Appendix D. New insect feeding damage types from the Bighorn Basin floras.

The new fossil damage types from this study, since Labandeira et al. (2007), are described here. Host specificity is assigned based on studies of modern insect feeding. A DT with a host specificity of 1 refers to generalized damage, 2 to intermediate specificity damage, and 3 to specialized damage (Wilf and Labandeira 1999). Generalized damage is typically made by insects that consume many taxonomically unrelated plant species (polyphagy). Intermediate specificity damage is made by insects that usually consume a group of phylogenetically related taxa (oligophagy). Specialized damage is made by insects that typically consume a single plant species or more than one related species (monophagy). Specialized damage is recognized by similarity to extant specialized feeders, by morphologically stereotyped damage patterns, and by restricted occurrences confined to particular host-plant species or tissue types in either fossil or extant host taxa (Johnson and Lyon 1991, Labandeira et al. 2002, Labandeira et al. 2007). Frass is the insect fecal debris left within the mine.


DT 151

Functional feeding group: Mine
Host specialization: 3
Host plant: Luehea newberryana
Locality: Site E5, USNM loc. 42400 and 42403
Specimen: USNM 539922
Figure: D1

Description: A small mine (1.5 cm long) whose trajectory follows the primary and secondary venation. Course is serpentine to loosely curvilinear, with a moderate increase in width, and ending in a round terminal chamber that is at least twice the width of the mine. The margins are approximately linear. The mine has a tightly packed sinusoidal frass trail (sometimes appearing massive and packed) that occupies the central third of the mine, and there is sometimes a ball of frass at the terminus.

 

DT152

Functional feeding group: Mine
Host specialization: 3
Host plant: Luehea newberryana
Locality: Site E5, USNM loc. 42403
Specimen: USNM 539913
Figure: D2

Description: A linear mine (~2.2 cm long) with a wide oviposition site. The mine increases in width to approximately three times its initial width and becomes blotch-like. One margin is straight and the other is lobate. Frass is lacking, except just before the terminus, where it occurs in a cluster of massive, stringy pellets.


DT153

Functional feeding group: Gall
Host specialization: 3
Host plant: "Platycarya" castaneopsis
Locality: Site E5, USNM loc. 42405
Specimen: USNM 539923
Figure: D3

Description: A globose gall, typically hemispherical or occasionally ellipsoidal, rarely flattened, that is 1.0 to 2.5 mm in diameter. It has a concentric texture of thick, woody (charcoalified) tissue, and a central chamber is barely evident in some specimens.

 

DT154

Functional feeding group: Hole feeding
Host specialization: 1
Host plant: "Platycarya" castaneopsis, Populus wyomingiana
Locality: Site E5, USNM loc. 42405; Site E4, USNM loc. 37650
Specimen: USNM 539924
Figure: D4

Description: A large blotch ~14 by 10 mm of necrotic tissue with peripheral holes (rarely slots) that are 0.5 to 1.0 mm in diameter. The outer margin of the blotch is surrounded by a weakly developed reaction front.

 

DT163

Functional feeding group: Gall
Host specialization: 3
Host plant: Populus wyomingiana
Locality: Site E4, USNM loc. 37560
Specimen: USNM 539925
Figure: D5,6

Description: A very circular, thick gall that is 1 to 2.5 mm in diameter and occurs throughout the leaf. It has a very thick rim containing concentric structures and a central region separated from the rim by a less thickened area. The central region probably represents a single, spheroidal chamber.


DT164

Functional feeding group: Mine
Host specialization: 3
Host plant: "Dombeya" novi-mundi
Locality: Site E3, USNM loc. 42409
Specimen: USNM 539926 and 539927
Insect Group: Beetle
Figure: D7,8

Description: A large, robust mine (0.75 to 2.25 mm wide). The course winds sinusoidally. The mine has a thick outer rim and a distinct frass trail that extends to the mine border. Frass is characterized in earlier instars by randomly arranged, elongate, cylindrical coprolites (L:W > 5:1) and changes to larger, thicker lenticular coprolites in latter instars.

 

DT165

Functional feeding group: Piercing and sucking
Host specialization: 3
Host plant: Dicot sp. WW037
Locality: Site E3, USNM loc. 37654
Specimen: USNM 539928
Figure: D9

Description: Broadly ellipsoidal surface marks that occur on areas between major veins. The L:W ratio ranges from 3:2 to 4:3, and lengths range from 1.7 to 9 mm. The marks have a pronounced outer reaction rim, that is often thickly carbonized, and the interior is skeletonized. An anterior beak is preserved on some specimens.

 

FIG. D1. DT 151, USNM 539922 (Luehea newberryana, Site E5) FIG. D2. DT 152, USNM 539913 (Luehea newberryana, Site E5) FIG. D3. DT153, USNM 539923 ("Platycarya" castaneopsis, Site E5)

 

FIG. D4. DT 154, USNM 539924 ("Platycarya" castaneopsis, Site E5 FIG. D5. DT 163, USNM 539925 (Populus wyomingiana, Site E4) FIG. D6. DT 163, USNM 539925 (Populus wyomingiana, Site E4)

 

FIG. D7.USNM 539926
("Dombeya" novi-mundi, Site E3)

FIG. D8.USNM 539927
("Dombeya" novi-mundi, Site E3)

FIG. D9.USNM 539928
(Dicot sp. WW037, Site E3)


 

LITERATURE CITED

Johnson, W. T., and H. H. Lyon. 1991. Insects that Feed on Trees and Shrubs, Second edition. Cornell University Press, Ithaca, New York, USA.

Labandeira, C. C., K. R. Johnson, and P. Wilf. 2002. Impact of the terminal Cretaceous event on plant-insect associations. Proceedings of the National Academy of Sciences (USA) 99:2061–2066.

Labandeira, C. C., P. Wilf, K. R. Johnson, and F. Marsh. 2007. Guide to insect (and other) damage types on compressed plant fossils. Version 3.0. Smithsonian Institution, Washington, D.C., USA http://paleobiology.si.edu/pdfs/insectDamageGuide3.01.pdf

Wilf, P., and C. C. Labandeira. 1999. Response of plant-insect associations to Paleocene-Eocene warming. Science 284:2153–2156.


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