Author
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McQuate, Grant |
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Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/8/2011 Publication Date: 12/1/2011 Citation: Mcquate, G.T. 2011. Control of Chinese Rose Beetle (Coleoptera: Scarabaeidae) through the Use of Solar-Powered Nighttime Illumination. Journal of Applied Entomology. 141(3):187-196. Interpretive Summary: The Chinese rose beetle, Adoretus sinicus (Burmeister), is a scarab beetle found in Asia and the Pacific Islands. It was first reported in Hawaii in 1891, and, by 1898, was established on all major islands. Adults feed at night on leaves of a wide range of plant species, and this feeding can stunt or even kill host plants. Among commercial crops in Hawaii, Chinese rose beetle is one of the most serious pests of young cacao (Theobroma cacao L.) trees and can also seriously defoliate young longan (Dimocarpus longan Lour.) trees. Because commercial production of both of these crops is increasing in Hawaii, a control method (preferably environmentally friendly) needs to be developed that could be used to protect these plants from defoliation. As the name suggests, Chinese rose beetles also feed on rose foliage. It had been observed that rose plants grown under street lights are not damaged by Chinese rose beetles. We tested to see whether nighttime illumination could be used to deter Chinese rose beetle feeding on host plants. We used a portable solar-based LED spotlight system, so that the lighting could be applied at locations remote from AC current sources. For our test plant, we used castor bean, Ricinus communis L. (Euphorbiaceae), because it is readily fed on by the Chinese rose beetle as a host plant, its large leaves and relatively open canopy permit ready observation of the presence of the beetles, and experimental plants can readily be grown from seed. At two sites, we observed the effect of four nights of nighttime illumination of castor bean plants on numbers of beetles previously established on the plants. With plant illumination averaging 13.4 (Site 1) and 11.3 (Site 2) lux, average percentage control of beetle numbers increased from > 60% to > 90% at both sites from Days 1 to 4 of nighttime illumination. These results clearly show that nighttime illumination can be used as a means of reducing Chinese rose beetle population size, and presumed aggregate defoliation, on a host plant. We believe that this is the first report of the use of nighttime illumination as a means of suppressing damage of plants by insects. Further research is needed to assess levels of light necessary to deter Chinese rose beetles. Technical Abstract: Chinese rose beetle, Adoretus sinicus (Burmeister), a scarab beetle found in Asia and the Pacific Islands, was first reported in Hawaii in 1891. Adults feed at night on leaves of a wide range of plant species, including many that are economically important. Aggregate feeding can stunt or even kill host plants. Among commercial crops in Hawaii, Chinese rose beetle is one of the most serious pests of young cacao (Theobroma cacao L.) trees and has been a challenge for growers to control. One promising pesticide-free control method takes advantage of the avoidance of light by adult Chinese rose beetles when they select the host plant on which they will feed at night. Illumination of plants at dusk has the potential for pest management. We tested the effectiveness of nighttime illumination, provided by a portable solar-based LED spotlight system, as a means of reducing Chinese rose beetle populations on the host plant using castor bean, Ricinus communis L. (Euphorbiaceae), as a test plant. At two sites, beetles were established and counted nightly for 8 nights on two castor bean plants set 15 m apart, with illumination of one of the plants initiated at dusk on Day 5. With plant illumination averaging 13.4 (Site 1) and 11.3 (Site 2) lux, average percentage control of beetle numbers increased from > 60% to > 90% at both sites from Day 5 to Day 8. Our results clearly show that nighttime illumination can be used as a means of reducing Chinese rose beetle population size, and presumed aggregate defoliation, on a host plant. We believe that this is the first report of the use of nighttime illumination as a means of suppressing damage of plants by insects. Further research is needed to assess levels of light necessary to deter Chinese rose beetles. |
