Brachycoryna hardyi (Crotch)

Eiseman, Charles S., Feldman, Tracy S. & Palmer, Michael W., 2024, New larval host records, parasitoid records, and DNA barcoding data for North American leaf-mining leaf beetles (Coleoptera: Chrysomeloidea), Zootaxa 5549 (1), pp. 1-60 : 13-15

Brachycoryna hardyi (Crotch)

( Figs. 6 , 36–40 , 130 )

Reared specimens. CALIFORNIA: El Dorado Co., Pony Express trail, 38.767044, -120.326003, 22.vii.2023, em. 2–3.viii.2023, C.S. & A.B. Eiseman & J.A. Blyth, ex Ceanothus integerrimus , # CSE 8346 (1 adult, MLBM); Lake Co., McLaughlin Natural Reserve, 20.vi.2018, em. 28.vi–6.vii.2018, E. LoPresti, ex Hemizonia congesta , # CSE 4710 ( MLBM) .

Photographed mine. CALIFORNIA: Calaveras Co., Arnold Rim Trail , 38.268106, -120.346897, 23.vii.2023, C.S. Eiseman, Ceanothus integerrimus (iNat 183827420) .

Hosts. * Asteraceae : Hemizonia congesta DC. ; Rhamnaceae : Ceanothus *integerrimus Hook. & Arn. , C. leucodermis Greene , C. sanguineus Pursh , C. velutinus Douglas ex Hook. ( Grant 1969; Staines 1986b).

Biology. The only previously published information about the larval biology of Brachycoryna hardyi appears to be Grant’s (1969) brief account of having collected two pupae “in small blotch mines in leaves of Ceanothus sanguineus ” from which one adult emerged. In the three mines we observed on C. integerrimus , the egg was embedded in a pit chewed in the lower leaf surface, at the margin (near the base of the leaf in two examples and near the apex in the third), and largely concealed by a coating of dark brown excrement. The mines differed conspicuously from those of Baliosus californicus on the same host in being full-depth (rather than confined to the upper surface) with dense, dark mottling all over the lower surface due to frass deposited on the floor of the mine (not concentrated near the center as in B. californicus ) ( Figs. 37–40 ). The observed mines of B. californicus began away from the leaf margin and were initially green, whereas those of B. hardyi were whitish to pale brown throughout.

On Hemizonia congesta , the eggs of B. hardyi are similarly concealed by a coating of dark brown excrement, but they are embedded in pits chewed in the upper leaf surface ( Fig. 6 ). The mine occupies the full width of the narrow leaf and much of its length. Details of the frass cannot be seen in the photographed examples, but it appears to be aggregated in clumps ( Fig. 36 ).

Parasitoids. An undetermined Conura species ( Chalcididae ) emerged from the mine on Ceanothus integerrimus collected in Calaveras Co. (CSE8392, CNC / iNat 202990048). A Neochrysocharis sp. ( Eulophidae ) emerged from the collection of Hemizonia leaves (CSE4717, CNC / iNat 203110328).

Notes. According to S.M. Clark (in litt.), our specimens reared from Hemizonia are probably Brachycoryna hardyi , but most species in the genus cannot be identified satisfactorily using Staines (1986b, 2006) because the characters emphasized are difficult to see if in fact they are present at all. He reports that our specimens very closely match material identified by Staines as B. hardyi , and are noticeably different from material identified by Staines as B. dolorosa Van Dyke , which is the species for which Staines (1986b) reported an adult association with “ Hemizona sp.” No larval hosts have been reported for B. dolorosa , but Staines (1986b) stated that adults have been collected from Ceanothus cuneatus (Hook.) Nutt. in addition to various tarweeds ( Asteraceae : Madieae). S.M. Clark (in litt.) suggests that several western Brachycoryna species seem to be nearly identical, and that if the currently recognized names are not all synonyms, then some of the reported plant associations are probably based on misidentified insects; it also may be that multiple species are masquerading under a single name.

Figures

FIGURES 1–22. Eggs of Chalepini spp.; 1: Anisostena californica; 2: A. lecontii; 3: Baliosus californicus; 4: B. nervosus; 5: same; 6: Brachycoryna hardyi (photo by E. LoPresti); 7: B. pumila; 8: Chalepus bicolor; 9: C. walshii walshii; 10: Glyphuroplata pluto; 11: Microrhopala excavata excavata; 12: M. laetula; 13: M. vittata; 14: M. xerene; 15: Odontota dorsalis; 16: O. floridana; 17: O. horni (top view); 18: same (side view); 19: O. scapularis; 20: Sumitrosis ancoroides; 21: S. inaequalis; 22: S. rosea.

FIGURES 36–43. Leaf mines of Brachycoryna spp.; 36: B. hardyi on Hemizonia congesta (photo by E. LoPresti); 37: B. hardyi on Ceanothus integerrimus; 38: lower surface of same mine, with excrement-covered egg at tip of leaf; 39: B. hardyi on Ceanothus integerrimus; 40: lower surface of same mine, with excrement-covered egg at far right; 41: B. pumila on Sida rhombifolia; 42: B. pumila on Sphaeralcea lindheimeri; 43: same.

FIGURES 122–140. Chalepini adults; 122: Anisostena californica; 123: A. funesta; 124: A. kansana; 125: A. lecontii; 126: A. cf. perspicua; 127: Baliosus californicus; 128: B. nervosus (reared from Alnus serrulata); 129: B. nervosus with DNA barcode differing from that of previous specimen by>10% (reared from Tilia americana); 130: Brachycoryna hardyi; 131: B. pumila; 132: Chalepus bicolor; 133: C. walshii walshii; 134: Glyphuroplata pluto; 135: Microrhopala excavata cyanea; 136: M. excavata excavata; 137: M. laetula; 138: same; 139: M. rubrolineata; 140: M. vittata; 141: M. xerene.