How to recognize the beetle

Adults: The adults of the air potato beetle are about 3/8 inch long and 3/16 inch wide. The wings are red, and the abdomen, thorax, head, and legs are black. The body shape somewhat resembles a square violin with a short neck.

Photo Credits: Overholt, W.

Eggs: Eggs are white and laid in groups on the underside of leaves. They are 1/32 inch long and hatch after four days.

Photo Credits: Overholt, W.

Larvae: Early instars are yellowish to reddish, and later instars are grayish to reddish. Larvae are often covered with a sticky secretion to which fecal material adheres.

Pupae: Fully grown larvae enter the soil and form a cocoon that is about 17/64 inch in length.

Photo Credits: Overholt, W.

Photo Credits: Overholt, W.

Biology and ecology of the beetle

The life cycle of the beetle begins when the female lays eggs on the underside of air potato leaves. Females lay an average of 1800 eggs but in some cases up to 4300. After four days, eggs hatch and larvae begin feeding in aggregations. When fully grown, larvae descend to the soil where they produce an oral secretion that hardens into a foam-like cocoon. Adults emerge after 12 to 16 days, and can live for five months or longer. The life cycle from egg to adult takes 30 days at 77^o F. Both adults and larvae feed on the foliage of air potato.

Photo Credits: Overholt, W.

Larvae can often be found in aggregations on the growing tips of air potato vines. The vine dies back during the winter, forcing the adult beetles to go several months without food, presumably in a resting state beneath leaf litter and other debris. The overwintered adults emerge in the spring, and females begin laying eggs.

The beetle only attacks Air Potato

Extensive host range testing by scientists at the USDA/ARS Invasive Plant Research Laboratory in Fort Lauderdale demonstrated that the air potato leaf beetle is a specialist feeder on air potato. It will not complete development on any other plant found in Florida and is only known to feed on Dioscorea bulbifera in its native range (Pemberton and Witkus 2010).

Damage to Air Potato

Larvae and adults of the air potato leaf beetle consume leaf tissue and occasionally feed on bulbils, thereby negatively affecting plant growth and reproduction. Damage to growing tips inhibits vine elongation and may reduce the ability of air potato to climb vertical structures. At initial release sites, extensive damage to air potato was evident within three months after the first release.

More information about the beetle:

- Biology and ecology of the air potato beetle: http://edis.ifas.ufl.edu/pdffiles/in/in97200.pdf

Scientific Publications

- Overwintering and host range tests of the air potato beetle:

Center, T. D., Rayamajhi, M., Dray, F. A., Madeira, P. M., Witkus, G., Rohrig, E., Mattison, E., Lake, E., Smith, M., Zhang, J. Purcell, M., Konstantinov, A. and Schmitz D. 2013. Host range validation, molecular identification and release and establishment of a Chinese biotype of the Asian leaf beetle Lilioceris cheni (Coleoptera: Chrysomelidae: Criocerinae) for control of Dioscorea bulbifera L. in the southern United States. Biocontrol Science and Technology, 23: 735-755.

http://www.tandfonline.com/doi/abs/10.1080/09583157.2013.790931#.U-EhjhFOUeg
- More details on host range tests of the air potato beetle:

Pemberton, R. W. and Witkus, G. L. 2010. Laboratory host range testing of Lilioceris sp. near impressa (Coleoptera: Chrysomelidae) – a potential biological control agent of air potato, Dioscorea bulbifera (Dioscoreaceae). Biocontrol Science and Technology, 20: 567–587.

http://www.tandfonline.com/doi/pdf/10.1080/09583150903531332

- Description of adults and biology in native range:

Tishechkin, A.K., Konstantinov, A.S., Bista, S., Pemberton, R.W., and Center T.D. 2011. Review of the continental Oriental species of Lilioceris Reitter (Coleoptera, Chrysomelidae, Criocerinae) closely related to Lilioceris impressa (F.). ZooKeys, 103: 63-83.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3131069/