Monday, December 11, 2006 - 10:47 AM

Integrated pest management of the sugarcane grub, Tomarus subtropicus (Coleoptera: Scarabaeidae), in turfgrass

Olga Kostromytska, and Eileen A. Buss, University of Florida, Entomology and Nematology Department, Bldg.970 Natural Area Dr, Gainesville, FL

The sugarcane grub, Tomarus subtropicus Blatchley (Coleoptera: Scarabaeidae) is a major pest of turfgrass along Florida’s Gulf Coast. Little is known about its biology in lawns and turfgrass managers have been struggling to control its populations. To study adult flight activity, three blacklight traps were placed in Cape Coral and Punta Gorda and continuously run from 1 April to 30 November 2005 and from 1 April to 31 August 2006. Adults were collected every 1-2 weeks from the traps. Soil sampling was concurrently conducted to determine when each life stage was present. In addition, preventive and curative insecticide greenhouse and field tests were conducted. Peak flight activity occurred from July to August 2005 and eggs were present from 22 June to 5 August. First instars were prevalent in the soil from July – August. Second instars were present in August and September, and only third instars were present in the soil after early October. Although T. substropicus seems more damaging to St. Augustinegrass in home lawns, a host range test showed that third instars can also survive on bahiagrass, centipedegrass, zoysiagrass and seashore paspalum. A preventive insecticide trial demonstrated that clothianidin, halofenozide and imidacloprid can provide >75% control if the insecticides can reach the first instars. Carbaryl and trichlorfon were the most effective curative products. No parasitioids were recovered from the field collected larvae, and < 5% of second and third instars were naturally infected with the milky spore disease, Paenibacillus popilliae.

Species 1: Coleoptera Scarabaeidae Tomarus subtropicus (sugarcane grub)

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