Identifier

etd-11092011-110630

Degree

Doctor of Philosophy (PhD)

Department

Entomology

Document Type

Dissertation

Abstract

The redbanded stink bug, Piezodorus guildinii (Westwood), was identified as a pest of Louisiana soybean during 2000. Currently, this species has become established throughout Louisiana and into the soybean production regions of bordering states. Seasonal abundance, patterns of oviposition, and population dynamics of this species were surveyed in soybean during 2008-10. The redbanded stink bug comprised the largest percentage (54%) of the total stink bug complex collected at five survey sites followed by the southern green (27%), Nezara viridula L. and brown (7%) stink bugs, Euschistus servus L. Peak oviposition occurred during the (R5) soybean growth stage. Most (80%) egg clusters were observed on leaves and pods in the lower two-thirds of the soybean plant canopy. Additional field experiments evaluated redbanded stink bug effects on soybean seed yield, as well as susceptibility to selected insecticides. Both native and artificial infestations of redbanded stink bug significantly reduced yield and seed quality, and increased incidence of delayed crop maturity at population levels below the Louisiana recommended action threshold of nine insects per 25 sweeps. Native populations reduced yields up to 55% in the non-insecticide treated control plots. Yield losses (4.7 to 14.1%), stink bug damaged seed (4.1 to 8.1%), and incidence of green stems (4.7 to 32.3%) from artificial infestations occurred during the R4, R5, and R6 growth stages at infestations of 0.5-1 insect/0.3 row m. No significant effects were detected for yield, stink bug damaged seed, or incidence of green stem with infestations at the R7 growth stage. Populations of redbanded stink bug collected from Louisiana soybean fields were less susceptible to neonicotinoid, organophsphate, and pyrethroid insecticides compared to the southern green stink bug in field and laboratory tests. The occurrence of redbanded stink bug in Louisiana soybean has altered pest management strategies and increased production costs that are now necessary to reduce yield and quality losses.

Date

2011

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Leonard, Billy Rogers

DOI

10.31390/gradschool_dissertations.3691

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Included in

Entomology Commons

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