Date of Graduation

12-2014

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Entomology (PhD)

Degree Level

Graduate

Department

Entomology

Advisor

Donn Johnson

Committee Member

Fred Stephen

Second Committee Member

Donald Steinkraus

Third Committee Member

Curt Rom

Fourth Committee Member

Damon Crook

Keywords

Entomology, Biological sciences, Health and environmental sciences, Insecticides, Trap

Abstract

The rednecked cane borer, Agrilus ruficollis (F.), is a pest of cultivated and wild blackberries in the Midwestern and Eastern parts of the United States. Feeding, mating, egg laying and development of A. ruficollis from larvae to adult only occurs on primocane, the first year vegetative growth stage of blackberries, and not on the second year fruiting stage called floricanes that die after fruiting. Damage from this pest is caused by the larva girdling the primocane and tunneling in the pith, causing the formation of a gall. Gall formation on the primocane increases the chance of winter injury and can also potentially reduce yields the following season. There is currently only one class of insecticide (imidacloprid) approved for use in managing the pest and no trap available for monitoring this pest. The research presented in this dissertation was to determine if other chemical classes of insecticides would provide equal adequate control of A. ruficollis as achieved by an application of imidacloprid and determine what visual and chemical cues act as stimulants for attracting A. ruficollis. An efficacy study of several insecticides only found that paraffinic oil (JMS Stylet Oil) provided a level of control of A. ruficollis similar to that achieved by the industry standard (imidacloprid). Paints that mimicked the spectral reflectance of blackberry leaves and canes of both primocane and floricane growth stages were applied to four dowel sizes (ranged from 0.3 to 2.5 cm diameters), covered with sticky Tanglefoot® and field evaluated for attractiveness to A. ruficollis for three years, with modifications to the trap each year. Commercially available green or purple plastic funnel traps covered with fluon were evaluated for attractiveness to A. ruficollis in 2014. In 2011, the greatest numbers of A. ruficollis adults were captured on one inch prism-shaped, vertical primocane mimic traps that reflected light at a peak wavelength between 540-560 nm (green). In 2012 and 2013, field tests demonstrated that the most A. ruficollis adults were captured on traps painted the same green color of traps used to monitor for emerald ash borer, Agrilus planipennis Fairmaire. The funnel trap testing in 2014 reinforced the previous findings that A. ruficollis is most attracted to the green color of emerald ash borer traps. In 2013, it was noted that colored traps usually captured significantly more A. ruficollis males than females (> 2.4 males: 1 female ratio). This indicated a need to determine if there was a chemical cue used by A. ruficollis adult females to find and select only blackberry primocanes and not floricanes. However, no differences were found in volatile compounds collected from blackberry primocanes and floricanes. Although peaks were identified, these collected volatiles did not stimulate antennae of A. ruficollis adults. Overall, this dissertation was able to show that certain green colors attracted A. ruficollis. Further research should be conducted to optimize trap design and determine if there is a pheromone or primocane plant odor that enhances colored trap catch of female and/or male A. ruficollis. A baited colored trap will improve the monitoring for this insect and timing of insecticide applications and lead to development of a mass trapping tactic that reduces the local density of A. ruficollis and lessen need for insecticide application.

Included in

Entomology Commons

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