[. . .]
2 also calico bug, calico beetle: Any of several variegated and brightly-colored insects, but esp the harlequin cabbage bug n.
1880 Arthur’s Home Mag. 48.624, In the same way, the beautiful “calico-bug” or “lady-bird,” differs from other beetles, in having no means of defense and seeking none. 1890 (1892) Webster’s Internatl. Dict. 204, Calicoback . . . An hemipterous insect (Murgantia histrionica) which injures the cabbage and other garden plants;—called also calico bug and harlequin cabbage bug. 1895 Acad. Nat. Sci. Philadelphia Entomol. Sec. Entomol. News & Proc. 6.286 swNE, I was told by a resident that he had seen this insect [=Cicindela limbata] in large numbers at a large “blow-out” eight or ten miles farther up the valley of the Frenchman. He called them “calico” bugs. 1895 Comstock–Comstock Manual Insects 145, The Harlequin Cabbage-bug or Calico-back . . is very destructive to cabbages, radishes, and turnips in the Southern States. 1908 U.S. Bur. Entomol. Circular No. 103 1, A moderate-sized red and black plant-bug, variously known as “calico back,” “fire bug,” and “terrapin bug,” as well as harlequin cabbage bug, is the most destructive insect enemy of cabbage and related crops in the southern part of the United States. 1924 U.S. Dept. Ag. Farmers’ Bulletin 1371.18, The harlequin cabbage bug, also called the calico bug, fire bug, or terrapin bug, is about half an inch long and red, spotted with black. It is a southern insect, commonly found from Virginia to California, but often works northward. 1942 Aiken Std. & Rev. (SC) 10 July 2/4, Handpick and destroy by dropping in cup of kerosene all Harlequin bugs or Calico bugs. 1969 DARE (Qu. R30) Inf MI93, Calico beetle—spotted.