Othim Stephen T O, Ramasamy Srinivasan, Kahuthia-Gathu Ruth, Dubois Thomas, Ekesi Sunday, Fiaboe Komi K M
Kenyatta University, School of Agriculture and Enterprise Development, P.O. Box 43844-00100, Nairobi, Kenya.
International Centre of Insect Physiology and Ecology (ICIPE), Plant Health Unit, P.O. Box 30772-00100, Nairobi, Kenya.
Insects. 2018 Jun 8;9(2):62. doi: 10.3390/insects9020062.
F. is a major pest moth of amaranth ( spp.) flowers worldwide, with a potential of causing complete foliage loss under severe outbreaks. Chemical insecticides are uneconomical for resource-poor farmers and pose health and environmental risks. Host plant resistance (HPR) to insects is an effective, economical and environmentally friendly alternative that is poorly understood and largely unexploited among traditional leafy vegetables. A total of 35 amaranth accessions were evaluated for the expression of their antixenotic and antibiotic traits against , focusing on their effects on the biology of the pest in comparison with a susceptible accession. The accession VI036227 was found to be highly resistant against the pest, exhibiting exemplary antibiosis by causing 100% larval mortality within the first 36 h, despite not being deterrent for oviposition. The accessions VI048076, VI056563 and VI047555-B demonstrated moderate resistance against the pest for specific parameters including low oviposition, moderate early stage larval mortality and reduced adult longevity. Total mortality and weight gain in these three accessions were, however, not significantly different from the susceptible control. Higher numbers of eggs were laid in no-choice compared to choice situations. The implications of these findings in the management of on amaranths are discussed.
F.是一种世界性的苋菜（苋属物种）花的主要害虫，在严重爆发时可能导致叶片完全损失。化学杀虫剂对资源匮乏的农民来说不经济，而且存在健康和环境风险。寄主植物对昆虫的抗性（HPR）是一种有效、经济且环保的替代方法，但在传统叶菜类蔬菜中却鲜为人知且基本上未被利用。对总共35份苋菜种质进行了评估，以研究它们对该害虫的抗生性和抗虫性特征的表达，重点是与一个感虫种质相比，它们对害虫生物学特性的影响。发现种质VI036227对该害虫具有高度抗性，尽管对产卵没有驱避作用，但通过在最初36小时内导致100%的幼虫死亡，表现出典型的抗生性。种质VI048076、VI056563和VI047555 - B在包括低产卵量、适度的早期幼虫死亡率和缩短成虫寿命等特定参数方面表现出对该害虫的中等抗性。然而，这三个种质的总死亡率和体重增加与感虫对照相比没有显著差异。与有选择的情况相比，在无选择的情况下产卵数量更多。讨论了这些发现对苋菜上该害虫管理的意义。
