Fofana Fatoumatou, Descombes Corentin, Kouamé Assiri Patrice, Lefort François
Plants and Pathogens Group, Research Institute Land Nature Environment, Geneva School of Engineering Architecture and Landscape, HES-SO University of Applied Sciences and Arts Western Switzerland, 150 Route de Presinge, 1254 Jussy, Switzerland.
Faculty of Natural Sciences, University Nangui Abrogoua, 02 B.P. 801 Abidjan 02, Côte d'Ivoire.
Microorganisms. 2023 Aug 18;11(8):2104. doi: 10.3390/microorganisms11082104.
The fall armyworm, (Lepidoptera: Noctuidae), is a polyphagous pest highly damaging to maize and other food crops in Africa, particularly in Côte d'Ivoire. Chemical pesticides not only have often proved to be unsuccessful, but cause adverse effects on the environment and human health; therefore, entomopathogenic fungi could represent an alternative biocontrol solution. Against this background, fungi were isolated from soil samples collected in maize fields in three regions of Côte d'Ivoire, by the methods of soil dilution and baiting with . The resulting 86 fungal isolates were phenotypically and genetically identified. The pathogenicity of seven isolates of spp., three isolates of and two isolates of sp. was evaluated on fifth instar larvae (L5) of . Larval mortality rates and the median lethal time (LT) were determined seven days after inoculation for each of these selected isolates. The median lethal concentration (LC) was determined for a selection of isolates. isolate A214b was the most effective, causing 100% mortality, with an LT of 2.64 days and an LC of 1.12 × 10 conidia mL. Two other promising isolates, A211 and A214a, belonging to caused 100% mortality with LT values of 3.44 and 4.04 days, respectively. Mortality caused by isolates varied from 65.38% to 100%, with isolate T331 causing 100% mortality with an LT of 3.08 days at an LC of 3.33 × 10 conidia mL. sp. isolates were the least pathogenic ones. and isolates showed to be virulent against the model Lepidopteran and will be tested on .
草地贪夜蛾（鳞翅目：夜蛾科）是一种多食性害虫，对非洲尤其是科特迪瓦的玉米和其他粮食作物造成严重破坏。化学农药不仅常常效果不佳，还会对环境和人类健康产生不利影响；因此，昆虫病原真菌可能是一种替代性的生物防治解决方案。在此背景下，通过土壤稀释法和用[具体诱饵]诱捕法，从科特迪瓦三个地区玉米田采集的土壤样本中分离出真菌。对得到的86株真菌分离株进行了表型和基因鉴定。对草地贪夜蛾五龄幼虫（L5）评估了7株[某种真菌属]分离株、3株[另一种真菌属]分离株和2株[又一种真菌属]分离株的致病性。接种后7天测定这些选定分离株各自的幼虫死亡率和半数致死时间（LT）。对部分分离株测定了半数致死浓度（LC）。分离株A214b最有效，死亡率达100%，LT为2.64天，LC为1.12×10分生孢子/毫升。另外两株有前景的属于[某种真菌属]的分离株A211和A214a，死亡率也达100%，LT值分别为3.44天和4.04天。[某种真菌属]分离株引起的死亡率在65.38%至100%之间，分离株T331在LC为3.33×10分生孢子/毫升时死亡率达100%，LT为3.08天。[某种真菌属]分离株致病性最弱。[两种真菌属]分离株对模式鳞翅目昆虫[具体昆虫名]表现出毒性，并将在[具体对象]上进行测试。
