Microrhopala floridana Schwarz

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 : 20

Microrhopala floridana Schwarz

( Fig. 57 )

Collected mines. NORTH CAROLINA: New Hanover Co., Carolina Beach, 27.xi.2020, T.S. Feldman, Pityopsis graminifolia [with live larva] (BG 1919512) ; Onslow Co., near Camp LeJeune, 28.vii.2021, T.S. Feldman, Pityopsis graminifolia [with larva].

Host. Asteraceae : Pityopsis graminifolia (Michx.) Nutt. ( McCauley 1938) .

Biology. McCauley (1938) stated only that this species has been reared from larvae mining in the terminal portions of the leaves. Staines (2006) noted that adult feeding damage consists of linear stripes up to 2 cm long and 1.5 mm wide, parallel with the leaf veins. We were unable to rear adults, but we presume that the mines and larvae we observed represent M. floridana , as no other hispine has been associated with Pityopsis . The egg is deposited singly in the middle of the leaf on the upper surface, apparently in a chewed pit, and covered with excrement. The larva’s dark, threadlike frass is deposited in a dense elliptical mass adjacent to the egg ( Fig. 57 ). Presumably pupation takes place within this mass, as with M. excavata and M. xerene on other hosts.

Figures

FIGURES 53–57. Leaf mines of Microrhopala spp.; 53: M. excavata cyanea on Solidago sp.; 54: M. excavata excavata on Doellingeria umbellata (lower surface, with excrement-covered egg at upper right edge of dark spot); 55: same (upper surface); 56: M. excavata excavata on Euthamia graminifolia; 57: M. floridana (presumed) on Pityopsis graminifolia.