Hesler L S, Berg R K
Northern Grain Insects Research Laboratory, United States Department of Agriculture-Agricultural Research Service, 2923 Medary Avenue, Brookings, SD 57006, USA.
J Econ Entomol. 2003 Dec;96(6):1792-7. doi: 10.1093/jee/96.6.1792.
We compared infestation levels of cereal aphids (Homoptera: Aphididae) in spring-seeded wheat and barley grown with and without preplant tillage for 8 site yr in eastern South Dakota. Crop residue covered approximately 25% of the soil surface with preplant tillage, whereas without preplant tillage 50% or more of surface residue was conserved. Rhopalosiphum padi (L.) comprised nearly 90% of all cereal aphids sampled, and R. maidis (Fitch), Schizaphis graminum (Rondani), and Sitobion avenae (F.) collectively comprised the remainder. R. padi routinely infested lower parts of tillers and were generally concealed by surface residue in plots with no preplant tillage. Across 7 site yr, R. padi were more abundant in plots with no preplant tillage than with preplant tillage (272.6 +/- 54.4 versus 170.1 +/- 37.2 aphid days per 25 tillers). However, in comparisons at individual site years, R. padi were greater in no-preplant tillage plots only once. For all cereal-aphid species combined, infestations were greater in plots with no preplant tillage for 1 of 8 site yr, but did not differ with tillage when compared across all site years. Cereal aphids were never more abundant in plots with preplant tillage. Our results show that conservation tillage leads to greater infestations of R. padi in spring small grains, as increased surface residue provides a favorable microhabitat for this aphid.
我们比较了南达科他州东部8个地点年中，种植前进行翻耕和未进行翻耕的春播小麦和大麦上谷物蚜虫（同翅目：蚜科）的侵染水平。种植前翻耕时，作物残茬覆盖了约25%的土壤表面，而未进行种植前翻耕时，50%或更多的地表残茬得以保留。麦长管蚜（Rhopalosiphum padi (L.)）占所有采样谷物蚜虫的近90%，其余为玉米蚜（R. maidis (Fitch)）、麦二叉蚜（Schizaphis graminum (Rondani)）和禾谷缢管蚜（Sitobion avenae (F.)）。麦长管蚜通常侵染分蘖的下部，在没有种植前翻耕的地块中，它们通常被地表残茬所遮蔽。在7个地点年中，未进行种植前翻耕地块中的麦长管蚜比进行种植前翻耕地块中的更为丰富（每25个分蘖的蚜虫日数分别为272.6±54.4和170.1±37.2）。然而，在各个地点年的比较中，麦长管蚜仅在一次未进行种植前翻耕的地块中数量更多。对于所有谷物蚜虫种类而言，在8个地点年中的1年里，未进行种植前翻耕的地块中的侵染情况更为严重，但在所有地点年进行比较时，与翻耕与否并无差异。进行种植前翻耕的地块中，谷物蚜虫数量从未更多。我们的结果表明，保护性耕作导致春季小粒谷物中麦长管蚜的侵染更为严重，因为地表残茬增加为这种蚜虫提供了适宜的微生境。
