Biology of <i>Aproida balyi</i> Pascoe, 1863 (Coleoptera: Chrysomelidae: Cassidinae: Aproidini) on Its Host Plant, <i>Eustrephus latifolius</i> R. Br. ex Ker-Gawl (Asparagaceae) in Australia

Within the leaf-beetle subfamily Cassidinae (Coleoptera: Chrysomelidae), Aproida Pascoe, 1863 (Aproidini) from Australia has been considered a transitional genus between mining cassidines (“hispines”) and exophagous cassidines (“tortoise beetles”). To illuminate this transition, a detailed study was conducted over one year of the biology of Aproida balyi Pascoe, 1863 on the host plant, Eustrephus latifolius R. Br. ex Ker-Gawl (Asparagaceae). Distribution maps of the host plant and three Aproida species are provided. The life cycle of A. balyi comprises single eggs in a foamy ootheca, three larval instars that feed openly, a pupa suspended from the larva III exuvia, and sexually dimorphic adults. The larva’s green color resembling the host and the narrow body fitted to the narrowed leaf blade allow them to camouflage. They possess a single long caudal process, unlike the paired processes of most other tortoise beetles. Fecal pellets are observed sometimes on this process, but accumulation is rare and lacks the permanent structure of exuvio-fecal shields that distinguishes the ten tribes of tortoise beetles. The larvae exhibit adhesive lobes on the abdominal sternites that appear to help their locomotion, a novel feature in Cassidinae. The pupa is suspended from the larva III exuviae and together they resemble the host’s pendant flower buds, suggesting mimicry. Males have the profemora and protibiae toothed. Both sexes can fly, unlike flightless Aproida cribrata Lea, 1929. These many morphological and behavioral findings contribute potential novel characters that underscore the aberrant nature of Aproidini within Cassidinae and point to another Australian evolutionary oddity.\nSupplementary film 1. Oviposition behavior in the beetle, Aproida balyi (Chrysomelidae: Cassidinae: Aproidini) from Australia. Film: Vivian Sandoval, 1 min 5 secs. Youtube link: https://youtu.be/YDaqXzUCga8 Video: 1H9A82987\nSupplementary film 2. Feeding by larva, Aproida balyi (Chrysomelidae: Cassidinae: Aproidini) from Australia. Note the caudal process with some fecal pellets. Film: Vivian Sandoval, 2 mins 44 secs. Youtube link: https://youtu.be/MMuL2pS6oEg Video: 1H9A3276\nSupplementary film 3. Retractable abdominal suckers used in locomotion in the beetle larva, Aproida balyi (Chrysomelidae: Cassidinae: Aproidini) from (Australia). This is instar I; note the caudal process with some fecal pellets. Film: Vivian Sandoval, 22 seconds. Youtube link: https://youtu.be/iZMUWGKYX0E Video: 1H9A3549\nSupplementary film 4. Retractable abdominal suckers (segments 1–VIII) used in locomotion in the beetle larva, Aproida balyi (Chrysomelidae: Cassidinae: Aproidini) from Australia. This is instar II; note the thoracic lobes at base of legs. Film: Vivian Sandoval, 1 min 56 secs. Youtube link: https://youtu.be/eyw9xC24El0 Video: 1H9A3235\nSupplementary film 5. Major movements, turning, and ambulation in the beetle larva (instar III), Aproida balyi (Chrysomelidae: Cassidinae: Aproidini) from Australia. Film: Vivian Sandoval, 1 min 55 secs. Youtube link: https://youtu.be/-_KervTVCPc Video: 1H9A3213\nSupplementary film 6. Temporary retention of fecal pellets in the beetle larva (instar I), Aproida balyi (Chrysomelidae: Cassidinae: Aproidini) from Australia. Film: Vivian Sandoval, 1 min 40 secs. Youtube link: https://youtu.be/qBiSWFoLGkw Video: 1H9B3327\nSupplementary film 7. Beetle larva (instar III) pupates, Aproida balyi (Chrysomelidae: Cassidinae: Aproidini) from Australia. Film: Vivian Sandoval, 9 mins 39 secs. Youtube link: https://youtu.be/0o7Pd75QfuQ Video: 1H9A3100\nSupplementary film 8. Beetle adult eclosion in Aproida balyi (Chrysomelidae: Cassidinae: Aproidini) from Australia. Film: Vivian Sandoval, 1min 26 secs. Youtube link: https://youtu.be/To2QFHSWk_c Video: H9A3517\nSupplementary film 9. Antennal movements of adult beetles, Aproida balyi (Chrysomelidae: Cassidinae: Aproidini) from Australia. Film: Vivian Sandoval, 2 mins 25 secs. Youtube link: https://youtu.be/O9bbslm4hlg Video: 1H9A3264