|Armstrong, John - Scott|
Submitted to: Annals of the Entomological Society of America
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/20/2008
Publication Date: 3/14/2009
Citation: Armstrong, J.S., Coleman, R.J., Setamou, M. 2009. Oviposition patterns of Creontiades signatus (Hemiptera: Miridae) on okra-Leaf and normal-Leaf cotton. Annals of the Entomological Society of America. 102:196-200. Interpretive Summary: Plants bugs (Lygus spp.), other than cotton fleahopper, Pseudatomoscelis seriatus (Reuter), have no history of being an economic problem in cotton in south Texas, however a green mirid, Creontiades signatus (Distant), has inconsistently caused economic problems in the Lower Rio Grande Valley, Coastal Bend, and Upper Coastal Bend production regions over the last ten years. Our research characterized the damage caused by C. signatus to cotton bolls, and compared actual feeding damage to a simulated damage technique to determine its usefulness for conducting economic injury studies. We also determined the oviposition behavior of C. signatus on two cotton genotypes that differ significantly in architectural structure. The findings indicate that C. signatus is a serious pest of cotton when it feeds on bolls. The simulated technique works well in mimicking the feeding of the insect to cotton bolls, indicating that it has the potential to be used in conducting economic threshold studies. The most preferred site for Creontiades signatus to lay eggs is in the leaf petiole tissue, followed by the main stem, and fruiting structures. The majority of the eggs are laid on the mid-portion of these plants. All of this information increases the knowledge of a newly recognized plant bug pest of cotton.
Technical Abstract: We report the boll injury and oviposition site preference of Creontiades signatus (Distant), a relatively new plant bug pest of cotton in the United States. We compared a technique of injecting bolls with pectinase to enclosing a 5th instar, C. signatus nymph, to investigate the techniques potential to simulate damage. C. signatus enclosed on 8 d old cotton bolls reduced seed cotton weight, lint weight, seed weight, and resulted in significantly higher injury scores, and the number of damaged seeds and growths on the carpal wall when compared to the control. In 2005, 10% pectinase injections were not as injurious to cotton bolls as C. signatus infestations, but all parameters separated out from the controls. In 2006, when 5% and 15% pectinase injections were added to the C. signatus, 10% pectinase and control treatments, the injury score, injured seeds and growths on the carpal wall all separated out significantly (control < all pectinase injections < Creontiades). However, the boll injury parameters for the C. signatus enclosures were not significantly different from any of the pectinase injections in terms of seed cotton weight, lint weight, and seed weight in 2006, partially because of drought conditions, where injury was magnified by drought stress. Our study demonstrates that pectinase injection simulates damage caused by the mirid. Creontiades signatus prefers to oviposit eggs on the distal or apical portion of the leaf petiole, followed by the main stem, and fruiting structures. The majority of eggs are laid in the mid-portion of the plant. This is significantly different oviposition behavior when compared to Lygus sp. infesting cotton in the United States.