New Host Records and Other Notes on North American Leaf-Mining Chrysomelidae (Coleoptera)
Author
Eiseman, Charles S.
text
The Coleopterists Bulletin
2014
2014-09-30
68
3
351
359
http://dx.doi.org/10.1649/072.068.0302
journal article
10.1649/072.068.0302
1938-4394
10101953
Octotoma marginicollis
Horn
In Madera Canyon on
6 November 2012
, I encountered adults of this species feeding on
B. betonicifolia
, creating networks of wavy-edged, skeletonized patches on the surfaces of the leaves. In the vicinity of the adults were several full-depth blotch mines that followed the leaf edges (
Fig. 8
). In contrast to the leaf mine on this plant discussed under
M. rubrolineata
, in these the frass was fairly sparse and consisted of compact pellets 1–2 times as long as wide. This would be atypical frass for a chrysomelid leafminer, but the short, squat larvae shown in my backlit photographs (
Fig. 8
) of the mines (solitary larvae in two leaves, and
four larvae
in a third) are shaped more like beetle than moth or sawfly larvae, and the lack of visible legs is consistent with
Octotoma
Dejean (Ford and Cavey 1985)
. However, I failed both to rear the larvae and to save their remains, so I cannot confirm
Brickellia
as a larval host for this beetle either. The only known larval host of
O. marginicollis
is
Perezia thurberi
(A. Gray) Reveal & King (Asteraceae)
, in which the leaves are said often to be completely mined out by several larvae whose mines have become confluent (Jones and Brisley 1925). Other existing descriptions of
Octotoma
leaf mines suggest that mine shape and frass deposition can vary from species to species.
Octotoma plicatula
(F.) forms tentiform mines in
Campsis radicans
L. (
Bignoniaceae
), with excrement accumulating as a black spot near the base of the leaf;
Octotoma championi
Baly
makes a very narrow mine in
Lantana
spp. (Verbenaceae)
, with a very faint fecal trail (
Staines 1989
); and
Octotoma scabripennis
Guérin-Méneville
, also on
Lantana
, produces a blotch mine with a central dark colored area and several radiating feeding galleries (
Harley 1969
;
Broughton 1999
).