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Key Message The incorporation of antibiotics to field-collected Chilo suppressalis larvae significantly reduce bacterial quantities and affect larval performance on rice plants. Field-collected Chilo suppressalis larvae deposit abundant bacteria onto feeding sites through oral secretion, which modulate defense responses in rice plants. Bacteria isolated from larval oral secretion (such as Enterobacter and Acinetobacter) contribute to preventing rice plants to fully activate jasmonic acid-mediated antiherbivore defenses. Our results indicate insect-associated bacteria play an important role for C. suppressalis to adapt to rice plants, which could also be treated as targets for developing novel pest management strategies.

The innate machineries for regulation of plant defense responses against herbivores are strikingly based on stress response-associated phytohormones. However, the dynamics of the effects of distinct types of chewing herbivores’ oral secretion (OS) on phytohormone regulation are not well known. We explored the phytohormone regulation in maize leaves in response to OS from larvae of a specialist herbivore (Mythimna separata) and a generalist herbivore (Spodoptera litura). In response to mechanical damage with application of those OSs, maize leaves rapidly upregulated the endogenous levels of oxylipins and abscisic acid (ABA) in quantitatively similar manners. Moreover, it appeared that bacteria in OS were responsible for the coordination of ABA levels. Our findings suggest that, during predation by the specialist and generalist lepidopteran herbivores, their OSs similarly upregulate phytohormone levels and the presence of their oral bacterial community makes a minor impact on maize defense responses.

In this explorative mixed-method pilot study, we set out to have a closer look at the largely under-recognized and under-investigated symptom of thick mucus in patients with ALS and its impact on patients and relatives. Thick mucus is a highly distressing symptom for both patients and caregivers. It complicates the use of non-invasive ventilation and is therefore an important prognostic factor of survival. Methods: In our preliminary study, we used a cross-sectional design, including ten ALS patients with thick mucus who were matched to ten ALS patients without thick mucus. Lung function tests and laboratory and sputum analysis were performed and questionnaires administered in order to determine associated factors of thick mucus accumulation. In a qualitative study using semi-structured interviews, we analysed the impact of thick mucus on patients and caregivers. Results: Reduced respiratory parameters as well as a higher degree of bulbar impairment were associated with the presence of thick mucus. Quality of life of patients and caregivers was strongly impaired by thick mucus accumulation. Conclusions: Thick mucus in patients with ALS has a strong impact on quality of life. Reduced cough flow and severely impaired bulbar function appear to be indicative parameters. We suggest that healthcare providers actively explore the presence of thick mucus in their patients and that it becomes included in commonly used screening tools.

Cotton plants induce high levels of gossypol in response to herbivore damage. However, little is known about the mechanisms by which insect herbivory modulates gossypol biosynthesis in cotton plants. Here, we report the mechanism by which herbivore damage or insect-originated elicitors modulate the biosynthesis of gossypol and jasmonic acid (JA) in plants. Spodoptera exigua larval-damaged (HD) cotton plants and mechanically damaged plants treated with S. exigua oral secretion (MDOS) showed higher levels of gossypol and JA as well as increased transcript levels of genes involved in the biosynthesis of both secondary plant metabolites, compared to undamaged (UD) or mechanically damaged (MD) plants. In correlation with the observed induction of gossypol and JA, S. exigua larvae that fed on HD and MDOS cotton plants showed significantly reduced weight. The findings provide a better insight into the molecular mechanisms mediating herbivore-induced plant defense.

Immature stages of insects are generally susceptive to their natural enemies, but many species developed defensive and evasive mechanisms to circumvent predation. Gregarious larvae of the noctuid moth Dyops cf. cuprescens feed on leaves of young Cecropia pachystachya shrubs colonized by Azteca ants. Ants avoid contact with larval clusters, retreating to the nest when larvae are moving near the stems. Provoked encounters revealed that Dyops caterpillars present several specialized behaviors to avoid and overcome ant attacks, such as fleeing to under leaf, jumping off the leaf, curling and wriggling vigorously the anterior portion of the body, spitting droplets of oral fluids, or killing ants by pouncing them. These mechanisms allow the caterpillars to overcome ant attacks and consume leaves of ant-colonized plants. By feeding on a heavily protected plant, larvae can enjoy not only a competitor-free plant, but possibly also the enemy-free space created by the aggressive ants.