ARS | Publication request: Timing of onset of evening activity of adult chinese rose beetles (Coleoptera: Scarabaeidae)

Submitted to: Journal of Asia-Pacific Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 16, 2012
Publication Date: August 24, 2012
Citation: Mcquate, G.T. 2012. Timing of onset of evening activity of adult chinese rose beetles (Coleoptera: Scarabaeidae). Journal of Asia-Pacific Entomology. 16:1-4.

Interpretive Summary: Adult Chinese rose beetles, Adoretus sinicus (Burmeister) are nighttime defoliators that feed on a wide variety of host plant species, including a number of economically important plants such as cacao, corn, eggplant, green beans, roses and taro. It is present in China, Taiwan, Indonesia, Cambodia, Laos, Singapore, Thailand, Vietnam, the Marianas Islands, the Caroline Islands, and the Hawaiian Islands. It has recently been demonstrated that illumination of plants at dusk has the potential to discourage feeding by adult Chinese rose beetles on the illuminated plants. This provides an environmentally friendly means of control. To effectively use lighting to minimize defoliation of host plants, it is critical to know the timing of the onset of host plant colonization by the beetles to ensure that illumination is initiated before host plant colonization begins. In this study, observations were made on the timing of colonization of a host plant. The observations confirmed that adult Chinese rose beetles initiate evening activity at dusk. Initiation of beetle colonization averaged over 21 minutes past sunset time, with the earliest observed beetle colonization occurring 11 min after sunset. These times corresponded to an average light level of 7.0 lux at first colonization and the earliest 1st colonization occurring at 26.9 lux. Based on these results, use of lighting to discourage colonization (and associated defoliation) by adult Chinese rose beetles should be initiated at about sunset.

Technical Abstract: Adult Chinese rose beetles, Adoretus sinicus (Burmeister) (Coleoptera: Scarabaeidae: Adoretini), present in China, Taiwan, Indonesia, Cambodia, Laos, Singapore, Thailand, Vietnam, the Marianas Islands, the Caroline Islands, and the Hawaiian Islands, are nighttime defoliators that feed on a wide variety of plant species. It has recently been demonstrated that illumination of plants at dusk has the potential to discourage feeding by adult Chinese rose beetles on the illuminated plants. To effectively use lighting to minimize defoliation of host plants, it is critical to know the timing of initial host plant colonization by the beetles to ensure that illumination is initiated before host plant colonization begins. Adult Chinese rose beetles were observed to colonize host plants at dusk, with initiation of beetle colonization averaging more than 21 minutes after sunset, with the earliest observed beetle colonization occurring 11 minutes after sunset. These times corresponded to an average light level of 7.0 lux at first colonization and the earliest first colonization occurring at 26.9 lux. Based on these results, use of lighting to minimize defoliation of host plants should be initiated at about sunset in order to discourage colonization (and associated defoliation) by adult Chinese rose beetles.