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Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/25/2010 Publication Date: 10/1/2010 Citation: Tillman, P.G. 2010. Composition and abundance of stink bugs (Heteroptera: Pentatomidae) in corn. Environmental Entomology. 39(6):1765-1774. 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 the abundance of these pests in corn. Therefore, the objectives of this 5-yr on-farm study were to determine the species of stink bug pests occurring on corn, and the abundance of these pests and their natural enemies in this crop in Georgia. The predominant stink bug pests were the southern green stink bug and the brown stink bug. Predators, such as the big-eyed bug, the pirate bug, spiders, and lady beetles, ate stink bugs on corn. Stink bug adults were parasitized by fly parasites. Stink bug eggs were parasitized by tiny wasp parasites. Adult stink bugs laid eggs on corn in mid-May and mid-June regardless of corn developmental stage. They also laid eggs in mid-to-late July if corn was still available. Subsequently, planting date of corn fields had a major impact on stink bug abundance in this crop. In early-planted corn, the July egg lay generally was eliminated, but even if adults did lay eggs at this time, the resulting nymphal population did not produce adults in corn. In-late planted corn, stink bugs consistently laid eggs in mid-July. So, another adult population was generated in corn, and this population could increase, reaching high levels in maturing corn. In summary, because corn does harbor populations of stink bug pests in Georgia, the role this crop plays in the distribution and abundance of stink bugs throughout the agricultural landscape needs to be clearly understood in order to manage stink bug populations. Technical Abstract: The objective of this 5-yr on-farm study was to determine species composition and abundance of stink bugs (Heteroptera: Pentatomidae) and their natural enemies in corn in Georgia. Seven species of phytophagous stink bugs occurred on corn. The predominant stink bug species were Nezara viridula (L.) and Euschistus servus (Say). The remaining five species, Oebalus pugnax pugnax (F.), Euschistus quadrator (Rolston), Euschistus tristigmus (Say), Euschistus ictericus (L.) and Acrosternum hilare (Say), were found in relatively low numbers. Orius insidiosus (Say), Geocoris punctipes (Say), spiders, lady beetles, and Podisus maculiventris (Say) preyed on stink bugs in corn. Adult N. viridula were parasitized by the tachinid parasitoid Trichopoda pennipes (F.). Stink bug eggs were parasitized by the scelionids, Trissolcus basalis (Wollaston), Trissolcus thyantae Ashmead, Trissolcus brochymenae (Ashmead), Trissolcus euschisti (Ashmead), Telenomus podisi Ashmead, and Telenomus calvus Johnson. Predation and parasitism of both stink bug species could reach very high levels. The timing of stink bug phenology in corn followed a similar pattern for both N. viridula and E. servus across the 5-yr study. Adults laid eggs on corn in mid-May and mid-June regardless of corn development. They also laid eggs in mid-to-late July if corn still was available. Subsequently, field planting date had a major impact on stink bug abundance in corn. In early-planted corn, the July egg lay generally was eliminated, but even if adults did lay eggs at this time, the resulting nymphal population did not produce adults in corn. In-late planted corn, stink bugs consistently laid eggs in mid-July. So, another adult population was generated in corn, and this population could increase, reaching high levels in maturing corn. In summary, corn harbors populations of stink bugs and their natural enemies, and thus the role this crop plays in the ecology of stink bugs needs to be ascertained to better understand how to manage stink bug populations in agricultural landscapes. |
