Department of Agricultural and Forestry Sciences, ETSIAM, University of Cordoba, Building C4, Campus of Rabanales, 14071 Cordoba, Spain.
Center for Infectious Disease Dynamics and Department of Entomology, 001 Chemical Ecology Lab, Penn State, University Park, PA 16802, USA.
J Invertebr Pathol. 2019 Feb;161:61-69. doi: 10.1016/j.jip.2018.12.009. Epub 2018 Dec 28.
The effects of single and mixed infections with Beauveria bassiana (EABb 90/2-Dm) and Metarhizium acridum (IMI 330189) strains on survival, feeding and reproduction of thermoregulating Dociostaurus maroccanus were evaluated. Adult locusts (2-3 days post fledging) were treated with low dosages of both fungal pathogens alone and in mixture (total dosage for single treatments and combinations = 1 × 10 and 1 × 10 spores per insect). M. acridum IMI 330189 was more virulent than B. bassiana EABb 90/2-Dm at both dosages. In the mixed infections, in which half of the infective units of the more virulent pathogen were replaced by the less virulent pathogen, the analysis of the cumulative insect mortality after 30 days suggested additive interaction in the lethal effects between the two strains. All fungal treatments, except EABb 90/2-Dm at 1 × 10 spores per insect showed reduction in per capita feeding, as indicated by fecal production per insect per day when insects were maintained at 27 ± 2 °C (32-51% of reduction compared with the control); but only IMI 330189 caused significant reduction in per capita feeding (50%) when those insects were allowed to thermoregulate. Both strains and their mixtures caused a significant reduction of locust fecundity, with a 21-53% reduction in the number of egg-pods per female, and 30-65% reduction in the number of fertile eggs per female. In both sublethal effects (feeding and fecundity) a potential antagonistic interaction between the fungal strains was detected. Locust fecundity (egg-pods per female) and per capita feeding were positively correlated (r = 0.783). Implications of these findings on the potential use of both strains to control D. maroccanus populations are discussed.
评估了球孢白僵菌（EABb 90/2-Dm）和金龟子绿僵菌（IMI 330189）单菌株和混合菌株对体温调节的沙漠蝗（Dociostaurus maroccanus）生存、摄食和繁殖的影响。用低剂量的两种真菌病原体单独和混合处理（单处理和组合处理的总剂量为 1×10 和 1×10 个孢子/昆虫）处理 2-3 天龄的成年蝗虫。金龟子绿僵菌 IMI 330189在两种剂量下均比球孢白僵菌 EABb 90/2-Dm 更具毒力。在混合感染中，用毒力较弱的病原体替换一半的更具毒力的病原体的感染单位，对 30 天后昆虫累计死亡率的分析表明，两种菌株在致死作用上存在相加作用。除了球孢白僵菌 EABb 90/2-Dm 用 1×10 个孢子/昆虫处理外，所有真菌处理都显示出摄食量减少，这表现为每只昆虫每天的粪便产量（与对照相比减少 32-51%）；但只有金龟子绿僵菌 IMI 330189 导致在允许蝗虫体温调节时，摄食量显著减少（50%）。两种菌株及其混合物都显著降低了蝗虫的繁殖力，每只雌虫的卵荚数减少 21-53%，每只雌虫的可育卵数减少 30-65%。在亚致死效应（摄食和繁殖力）中，检测到真菌菌株之间存在潜在的拮抗相互作用。蝗虫的繁殖力（每只雌虫的卵荚数）和摄食量呈正相关（r=0.783）。讨论了这些发现对利用这两种菌株控制沙漠蝗种群的潜在影响。
