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Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/15/2011 Publication Date: 4/20/2011 Citation: Tillman, P.G. 2011. Natural biological control of stink bug (Heteroptera:Pentatomidae) eggs in corn, peanut, and cotton farmscapes in Georgia. Environmental Entomology. 40(2):303-314. Interpretive Summary: Stink bugs have increased in importance as pests of agricultural crops over the past several years, but there is very little information available on biological control of stink bugs in farmscapes in which stink bugs develop. Therefore, this 5-yr on-farm study was conducted to examine parasitization and predation of stink bug eggs in Georgia farmscapes composed of corn, cotton, and peanut. Stink bug eggs were parasitized by seven species of egg parasites, and overall the greatest diversity of parasites emerged from stink bug eggs in corn. A variety of insect predators preyed on stink bug eggs. Generally, parasitization of eggs was higher than predation in corn, and predation of eggs was higher than parasitization in peanut. Overall, predation of eggs was higher than parasitization in cotton. Natural enemies of stink bug eggs apparently dispersed from crop to crop in the farmscapes to parasitize and prey on stink bug eggs. In conclusion, natural enemies of stink bugs are prevalent and important biological control agents in farmscapes in which stink bugs develop, and thus an important management strategy for stink bugs in these farmscapes is the strategic addition of habitats to conserve these natural enemies. Technical Abstract: In Georgia, corn, peanut, and cotton can be closely associated with each other. Thus, this 5-yr study was conducted to determine parasitism and predation of sentinel and natural occurring Euschistus servus (Say) and Nezara viridula (L.) egg masses in corn-cotton, corn-peanut, peanut-cotton, and corn-peanut-cotton farmscapes in Georgia. A wide variety of parasitoids including six scelionids, Trissolcus basalis (Wollaston), Trissolcus brochymenae (Ashmead), Trissolcus euschisti (Ashmead), Trissolcus thyantae Ashmead, Telenomus podisi Ashmead, and Gyron obesum Masner, and one encyrtid, Ooencyrtus sp., were recovered from E. servus and N. viridula egg masses in the farmscapes, but overall the greatest diversity of parasitoids emerged from stink bug eggs in corn. Only T. basalis and T. podisi parasitized both N. viridula and E. servus eggs in all three crops over all farmscapes. Orius insidiosus (Say), Geocoris spp., larvae of lady beetles, and Solenopsis invicta Buren preyed on stink bug eggs in the farmscapes. When differences were detected, generally percent parasitization per egg mass was higher than predation in corn, and percent predation was higher than parasitization in peanut. Overall, percent predation per egg mass was higher than parasitization in cotton, but on one occasion percent parasitization was higher than predation in cotton associated with corn. Seasonal occurrence and abundance of natural enemies, levels of parasitization and predation of stink bug eggs, and percent egg predation by sucking and chewing predators indicate that natural enemies of stink bug eggs dispersed from crop to crop in the farmscapes to parasitize and prey on stink bug eggs. In conclusion, this study has shown that natural enemies of stink bugs are prevalent and important biological control agents in farmscapes in which stink bugs develop, and thus an important management strategy for stink bugs in these farmscapes is the strategic addition of multifunctional habitats to conserve these natural enemies. |
