Daves C A, Williams W P, Davis F M, Baker G T, Ma P W K, Monroe W A, Mohan S
Department of Plant and Soil Sciences, Box 9555, Mississippi State University, Mississippi State, MS 39762, USA.
J Econ Entomol. 2007 Jun;100(3):976-83. doi: 10.1603/0022-0493(2007)100[976:praieo]2.0.co;2.
The southwestern corn borer, Diatraea grandiosella Dyar (Lepidoptera: Crambidae), is a serious pest of corn, Zea mays L., in the southern United States. Corn germplasm lines with conventional genetic leaf-feeding resistance to this pest, the fall armyworm, Spodoptera frugiperda (J.E. Smith), and other lepidopterans have been released to the public by USDA-ARS scientists located in Mississippi. Recent studies suggest the insect resistant lines disrupt the integrity of the peritrophic membrane of the fall armyworm. The objectives of this study were to investigate any morphological differences in the structure of the peritrophic membrane of southwestern corn borer larvae feeding on resistant and susceptible corn hybrids and to quantify the damage. Larvae were reared under field and laboratory conditions on three corn hybrids (two resistant and one susceptible). Scanning electron microscopy was used to examine the peritrophic membrane for abnormalities such as holes or tears and to count the holes or tears in the membrane. Differences in the degree of damage to peritrophic membrane of larvae fed on resistant and susceptible plants were not detected. Up to five distinct layers of the membrane were observed in each larva. Variation in the amounts of damage to the peritrophic membrane observed from larvae feeding on all plant material was high. Plant resistance adversely affects growth and development of southwestern corn borer larvae, and further investigations are needed to explain the role of plant resistance and its relation to peritrophic membrane in southwestern corn borer larvae.
西南玉米螟，Diatraea grandiosella Dyar（鳞翅目：草螟科），是美国南部玉米（Zea mays L.）的一种严重害虫。位于密西西比州的美国农业部农业研究局的科学家已向公众发布了对这种害虫、秋粘虫Spodoptera frugiperda（J.E. Smith）以及其他鳞翅目昆虫具有传统遗传食叶抗性的玉米种质系。最近的研究表明，抗虫品系会破坏秋粘虫围食膜的完整性。本研究的目的是调查取食抗性和感病玉米杂交种的西南玉米螟幼虫围食膜结构的任何形态差异，并对损害进行量化。幼虫在田间和实验室条件下以三种玉米杂交种（两种抗性和一种感病）为食。使用扫描电子显微镜检查围食膜是否存在诸如孔洞或撕裂等异常情况，并计数膜中的孔洞或撕裂数量。未检测到取食抗性和感病植物的幼虫围食膜受损程度的差异。在每个幼虫中观察到多达五层不同的膜层。从取食所有植物材料的幼虫中观察到的围食膜受损程度差异很大。植物抗性对西南玉米螟幼虫的生长和发育有不利影响，需要进一步研究来解释植物抗性的作用及其与西南玉米螟幼虫围食膜的关系。
