Diapause in the Boll Weevil (Coleoptera: Curculionidae): Life-Stage Sensitivity to Environmental Cues

Freshly fertilized eggs, eyed eggs, yolk-sac fry, and swim-up fry of brook trout (Salvelinus fontinalis) were exposed to a matrix of 84 combinations of pH (4.0–6.5), aluminum (0–1000 μg/L), and calcium (0.5–8.0 mg/L) in 21–91-d experiments. The response to pH, aluminum, and calcium exposure was dependent on life stage. Sensitivity to acid toxicity generally decreased with age (freshly fertilized eggs>eyed eggs>yolk-sac fry = swim-up fry). Survival or hatching of freshly fertilized and eyed eggs decreased at pH 5.2 and below, whereas survival of yolk-sac and swim-up fry was reduced at pH 4.4–4.0. Sensitivity to aluminum toxicity generally increased with age (freshly fertilized eggs = eyed eggs<yolk-sac fry<swim-up fry). At low pH, survival of freshly fertilized and eyed eggs increased with exposure to increasing aluminum concentrations, in contrast, elevated aluminum [Formula: see text] was often toxic to fry. Increasing calcium was beneficial to all life stages, although the magnitude of this benefit depended on life stage and on the specific pH and aluminum concentration. Survival after previous exposure to toxic combinations of pH, aluminum, and calcium generally improved during a post-exposure recovery period at pH 6.5. However, increased mortality in many exposure combinations did not begin until this recovery period.

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Compatibility of Insecticides with Natural Enemies to Control Pests of Greenhouses and Conservatories

Journal of Entomological Science ◽

10.18474/0749-8004-41.3.189 ◽

2006 ◽

Vol 41 (3) ◽

pp. 189-197 ◽

Cited By ~ 3

Author(s):

Raymond A. Cloyd

Keyword(s):

Natural Enemies ◽

Natural Enemy ◽

Life Stage ◽

Host Acceptance ◽

Insect Growth Regulators ◽

Plant Feeding ◽

Sensitivity Rate ◽

Bacteria And Fungi ◽

Life Stage Sensitivity ◽

Microbial Agents

Natural enemies used as biological control agents may not always provide adequate control of plant-feeding insects in greenhouses and conservatories. Research continues to assess the utilization of natural enemies in conjunction with biorational insecticides including insect growth regulators, insecticidal soaps, horticultural oils, feeding inhibitors, and microbial agents (entomogenous bacteria and fungi, and related microorganisms); and the potential compatibility of both strategies when implemented together. A variety of factors influence the ability of using natural enemies with insecticides. These include whether the natural enemy is a parasitoid or predator, the species of the natural enemy, life stage sensitivity, rate and timing of insecticide application, and mode of action of the insecticide. Insecticides may impact natural enemies by affecting longevity (survival), host acceptance, sex ratio, reproduction (fecundity), foraging behavior, emergence, and development. Despite the emphasis on evaluating the compatibility of natural enemies with insecticides, it is important to assess if this is a viable and acceptable pest management strategy in greenhouses and conservatories.

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Species and Life Stage Sensitivity of Chinese Rare Minnow ( Gobiocypris rarus ) to Chemical Exposure: A Critical Review

Environmental Toxicology and Chemistry ◽

10.1002/etc.5165 ◽

2021 ◽

Author(s):

Yunfei Bai ◽

Deru Lian ◽

Tenghui Su ◽

Yolina Yu Lin Wang ◽

Dainan Zhang ◽

...

Keyword(s):

Critical Review ◽

Life Stage ◽

Chemical Exposure ◽

Gobiocypris Rarus ◽

Rare Minnow ◽

Chinese Rare Minnow ◽

Life Stage Sensitivity

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Senescence: The Compromised Time of Death That Plants May Call on Themselves

Genes ◽

10.3390/genes12020143 ◽

2021 ◽

Vol 12 (2) ◽

pp. 143

Author(s):

Matin Miryeganeh

Keyword(s):

Proper Time ◽

Life Stage ◽

Environmental Cues ◽

Developmental Phase ◽

Time Of Death ◽

Future Studies ◽

Cascading Effects ◽

Fitness Consequences ◽

External Signals ◽

Whole Life Cycle

Plants synchronize their life history events with proper seasonal conditions, and as the fitness consequences of each life stage depend on previous and/or subsequent one, changes in environmental cues create cascading effects throughout their whole life cycle. For monocarpic plants, proper senescence timing is very important as the final production of plants depends on it. Citing available literatures, this review discusses how plants not only may delay senescence until after they reproduce successfully, but they may also bring senescence time forward, in order to reproduce in favored conditions. It demonstrates that even though senescence is part of aging, it does not necessarily mean plants have to reach a certain age to senesce. Experiments using different aged plants have suggested that in interest of their final outcome and fitness, plants carefully weigh out environmental cues and transit to next developmental phase at proper time, even if that means transiting to terminal senescence phase earlier and shortening their lifespan. How much plants have control over senescence timing and how they balance internal and external signals for that is not well understood. Future studies are needed to identify processes that trigger senescence timing in response to environment and investigate genetic/epigenetic mechanisms behind it.

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