The underlying adaptive mechanisms by which insect strains are associated with specific plants are largely unknown. In this study, we investigated the role of herbivore-induced defenses in the host ...plant association of fall armyworm (Spodoptera frugiperda) strains.
We tested the expression of herbivore-induced defense-related genes and the activity of plant-defensive proteins in maize and Bermuda grass upon feeding by fall armyworm strains.
The rice strain caterpillars induced greater accumulation of proteinase inhibitors in maize than the corn strain caterpillars. In Bermuda grass, feeding by the corn strain suppressed induction of trypsin inhibitor activity whereas the rice strain induced greater activity levels. Differences in elicitation of these plant defenses by the two strains seems to be due to differences in the activity levels of the salivary enzyme phospholipase C. The levels of plant defense responses were negatively correlated with caterpillar growth, indicating a fitness effect.
Our results indicate that specific elicitors in the saliva of fall armyworm stains trigger differential levels of plant defense responses that affect caterpillar growth and thus may influence host plant associations in field conditions. The composition and secretion of plant defense elicitors may have a strong influence in the host plant association of insect herbivores.
We DNA barcoded 2,597 parasitoid wasps belonging to 6 microgastrine braconid genera reared from parapatric tropical dry forest, cloud forest, and rain forest in Area de Conservación Guanacaste (ACG) ...in northwestern Costa Rica and combined these data with records of caterpillar hosts and morphological analyses. We asked whether barcoding and morphology discover the same provisional species and whether the biological entities revealed by our analysis are congruent with wasp host specificity. Morphological analysis revealed 171 provisional species, but barcoding exposed an additional 142 provisional species; 95% of the total is likely to be undescribed. These 313 provisional species are extraordinarily host specific; more than 90% attack only 1 or 2 species of caterpillars out of more than 3,500 species sampled. The most extreme case of overlooked diversity is the morphospecies Apanteles leucostigmus. This minute black wasp with a distinctive white wing stigma was thought to parasitize 32 species of ACG hesperiid caterpillars, but barcoding revealed 36 provisional species, each attacking one or a very few closely related species of caterpillars. When host records and/or within-ACG distributions suggested that DNA barcoding had missed a species-pair, or when provisional species were separated only by slight differences in their barcodes, we examined nuclear sequences to test hypotheses of presumptive species boundaries and to further probe host specificity. Our iterative process of combining morphological analysis, ecology, and DNA barcoding and reiteratively using specimens maintained in permanent collections has resulted in a much more fine-scaled understanding of parasitoid diversity and host specificity than any one of these elements could have produced on its own.
Advances in spring phenology are among the clearest biological responses to climate warming. There has been much interest in how climate impacts on phenology because the timings of key events have ...implications for species interactions, nutrient cycling and ecosystem services. To date most work has focused on only one aspect of population phenology, the effects of temperature on the average timing. In comparison, effects of temperature on the abundance of individuals and their seasonal spread are understudied, despite their potential to have profound impacts on species interactions.
Here we develop a new method that directly estimates the effect of spring temperatures on the timing, height and width of the phenological distribution and apply it to temperate forest caterpillars, a guild that has been the focus of much research on phenology and trophic mismatch.
We find that warmer spring conditions advance the timing of the phenological distribution of abundance by −4.96 days °C−1 and increase its height by 34% °C−1 but have no significant effect on the duration of the distribution. An increase in the maximum density of arboreal caterpillars with rising temperatures has implications for understanding climate impacts on forest food chains, both in terms of herbivory pressure and the resources available to secondary consumers.
The new method we have developed allows the thermal sensitivity in the full phenological distribution to be modelled directly from raw data, providing a flexible approach that has broad applicability within global change research.
Read the free Plain Language Summary for this article on the Journal blog.
Read the free Plain Language Summary for this article on the Journal blog.
During early summer 2019, the Netherlands experienced an outbreak of the exotic oak processionary caterpillar. The vast number of caterpillars, which live in large nests on oak trees before they turn ...into moths, possess thousands of small, barbed hairs (setae) that are disseminated with the wind. The hairs cause a range of primarily dermatologic problems. However, Dutch ophthalmologists started reporting patients with ophthalmologic complaints caused by the penetrating hairs of the oak processionary caterpillar. This paper focuses on the ophthalmologic complications caused by the caterpillar hairs. We collected a series of four cases with reports ranging from a corneal erosion with hairs lodged into the cornea, to a sterile endophthalmitis in which hairs were found in the vitreous. A literature review for similar cases was performed using the PubMed and Embase database. Together with the Dutch Ophthalmic Society (Nederlands Oogheelkundig Gezelschap, NOG), a national survey was issued to determine the scale of this new problem. This showed that oak processionary caterpillar related complaints are primarily limited to the south of the Netherlands. Suggested ophthalmic treatment guidelines are presented. With the next summer at the doorstep, and limited preventative measures against the caterpillar hairs, we expect a new wave of ophthalmologic complaints coming year as well.
Interval vertex coloring Maceková, Mária; Šárošiová, Zuzana; Soták, Roman
Applied mathematics and computation,
06/2024, Volume:
470
Journal Article
Peer reviewed
In this paper we consider various vertex versions of interval edge colorings. We distinguish two types of interval vertex colorings − an open and a closed interval vertex coloring, which are defined ...in such a way that colors used on open or closed neighborhood of each vertex form an integer interval, respectively. These colorings need not to be necessarily proper, and as coloring of all vertices with only one color is both open and closed, a natural goal is to maximize the total number of colors used for these colorings.
We discuss some properties of the corresponding chromatic numbers and conditions for the existence of a proper (open and closed) interval vertex colorings. In the case of open interval coloring we show that only bipartite graphs admit a proper open interval vertex coloring. We also describe a technique for obtaining a closed interval vertex coloring of a tree with the maximum possible number of colors, where the resulting coloring is in fact proper. Finally, we propose some open problems concerning interval vertex colorings in general.
Abstract
Modular caterpillar robots moving via locomotion waves play increasingly important roles in completing engineering tasks. Obstacle-crossing ability and stability are their crucial ...properties. Although the stability examinations in previous studies are similar, there are few unified quantitative approaches to study the obstacle-crossing ability. This study aims to propose proper quantification of the robot’s maximum obstacle-crossing ability, which is meaningful in terms of universality and practicality. This study also aims to design the gait that could enhance the robot’s properties. The enhancement of obstacle-crossing ability is achieved via static optimization, where the quantified obstacle-crossing ability is maximized. The relationship between obstacle size and the optimal wave parameters is obtained. The optimization results of the waves with large numbers of links can be forecast via data analysis, which greatly reduces computational cost. The enhancement of stability is achieved via dynamic optimization, where the moment induced by gravity (i.e., climbing instability) is minimized at every time node. The dynamic gait and the pattern of the moment induced by gravity during each movement unit is obtained. Overall, climbing caterpillar robots moving in the designed gait can make the best use of the wave to surmount obstacles in stable locomotion.
Gold nanoparticle (AuNP) assemblies (GNAs) have attracted attention since enhanced coupling plasmonic resonance (CPR) emerged in the nanogap between coupling AuNPs. For one dimensional GNAs ...(1D‐GNAs), most CPR from the nanogaps could be easily activated by electromagnetic waves and generate drastically enhanced CPR because the nanogaps between coupling AuNPs are linearly distributed in the 1D‐GNAs. The reported studies focus on the synthesis of 1D‐GNAs and fundamental exploration of CPR. There are still problems which impede further applications in nanomedicine, such as big size (>500 nm), poor water solubility, and/or poor stability. In this study, a kind of 1D flexible caterpillar‐like GNAs (CL‐GNAs) with ultrasmall nanogaps, good water solubility, and good stability is developed. The CL‐GNAs have a flexible structure that can randomly move to change their morphology, which is rarely reported. Numerous ultrasmall nanogaps (<1 nm) are linearly distributed along the structure of CL‐GNAs and generate enhanced CPR. The toxicity assessments in vitro and vivo respectively demonstrate that CL‐GNAs have a low cytotoxicity and good biocompatibility. The CL‐GNAs can be used as an efficient photothermal agent for photothermal therapy, a probe for Raman imaging and photothermal imaging.
Ultrasmall nanogaps in caterpillar‐like gold nanoparticle assemblies (CL‐GNAs) bring enhanced coupling plasmonic resonance that determines enhanced near‐infrared absorption of CL‐GNAs. Furthermore, the 1D flexible structure of CL‐GNAs allows for easy interaction with the excitation of electromagnetic waves. Based on their unique optical property, CL‐GNAs play an important role in the photothermal therapy and dual‐modal imaging of tumors.
Let G be a simple undirected graph. A broadcast on G is a function f:V(G)→N such that f(v)≤eG(v) holds for every vertex v of G, where eG(v) denotes the eccentricity of v in G, that is, the maximum ...distance from v to any other vertex of G. The cost of f is the value cost(f)=∑v∈V(G)f(v). A broadcast f on G is independent if for every two distinct vertices u and v in G, dG(u,v)>max{f(u),f(v)}, where dG(u,v) denotes the distance between u and v in G. The broadcast independence number of G is then defined as the maximum cost of an independent broadcast on G.
In this paper, we study independent broadcasts of caterpillars and give an explicit formula for the broadcast independence number of caterpillars having no pair of adjacent trunks, a trunk being an internal spine vertex with degree 2.
BACKGROUNDEntrapped rings can be dangerous, leading to increased pressure and damage to soft tissue, nerves, and vasculature. In order to properly care for these injuries, it is important for ...emergency medicine clinicians to be aware of the different approaches to remove entrapped rings. METHODSWe searched PubMed to determine the different techniques and supporting literature for ring removal. DISCUSSIONThere are a number of approaches that can be used to remove an entrapped ring. Clinicians should first consider the role of lubricants to reduce surface tension. Specific removal techniques include compression-based methods, traction-based techniques, rotation-based approaches, and the use of ring-cutting devices. There are unique advantages and limitations of each technique that are important to consider. CONCLUSIONSEmergency medicine clinicians need to be familiar with several different approaches to ring removal. This article summarizes the key techniques, variations on these techniques, advantages, and disadvantages for each approach.
The effects of competition can have far‐reaching consequences for individuals, populations, and communities and therefore we should strive toward a deeper understanding of competitive interactions. ...In some cases, dietary generalists may be predicted to experience weak competition effects because of their ability to use a wide range of host plants. However, competition between insects frequently occurs indirectly, which can hinder insects' abilities to avoid competitive interactions. Therefore, competition may be as strong among dietary generalists as among dietary specialists. Yet competition between insects that are dietary generalists is infrequently studied. We tested for evidence of competitive interactions between two common, temporally separated, generalist insects: the western tent caterpillar (Malacosoma californicum), which feeds early in the season, and the fall webworm (Hyphantria cunea), which feeds later in the season. Both species frequently use a common host plant species (chokecherry) as a preferred host at our field sites. We tested the relative strength of bottom‐up effects resulting from competitive interactions between these two generalists with laboratory‐rearing trials at the relevant time of year for each insect. We recorded three common fitness measures (development time, pupal mass, and survival) for caterpillars reared on chokecherry with no damage from either of our focal species, with tent caterpillar damage, and with fall webworm damage. To test the strength of top‐down pressures on fall webworm larval fitness and any potential interactions with bottom‐up effects, we reared larvae in the field either exposed to or protected from predators on host plants that either did or did not have tent caterpillars feeding on them earlier in the season. We found evidence of bottom‐up fitness effects on tent caterpillars and top‐down and bottom‐up fitness effects on fall webworms confirming that tent caterpillars and fall webworms compete indirectly. Tent caterpillars had lower pupal mass when reared on leaves from shrubs damaged by fall webworms. Fall webworms had lower pupal mass and longer development time when reared on leaves from shrubs damaged by tent caterpillars. In field trials, fall webworms reared on shrubs damaged by tent caterpillars had a lower survival and pupal mass. We show evidence of indirect competition in temporally separated generalists through leaf quality (bottom‐up effects) and natural enemies (top‐down effects).
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