Disadvantages of living in a populous neighborhood for sit‐and‐wait predators: Competition for space reduces pit‐trap size in antlion larvae

Ethology ◽  
2020 ◽  
Vol 126 (11) ◽  
pp. 1031-1037
Author(s):  
Alejandro G. Farji‐Brener ◽  
Agostina S. Juncosa‐Polzella ◽  
Daniela Madrigal Tejada ◽  
Diego Centeno‐Alvarado ◽  
Mariana Hernández‐Soto ◽  
...  
Keyword(s):  
Competition For Space ◽  
Trap Size ◽  
Antlion Larvae

scholarly journals Past thermal conditions affect hunting behaviour in larval antlions

2021 ◽  
Vol 8 (6) ◽  
pp. 210163
Author(s):  
Krzysztof Miler ◽  
Marcin Czarnoleski
Keyword(s):  
Elevated Temperatures ◽  
Prey Capture ◽  
Thermal Conditions ◽  
Thermal Exposure ◽  
Hunting Behaviour ◽  
Abiotic And Biotic Factors ◽  
Trap Size ◽  
Harsh Conditions ◽  
Antlion Larvae ◽  
Past Conditions

Some sit-and-wait predators, such as antlion larvae, construct traps to capture passing prey. The location of these traps depends on many abiotic and biotic factors, including temperature and the presence of conspecifics, which probably stimulate behaviours that minimize the costs and maximize the benefits of trap building. Here, we exposed second instar antlion larvae to elevated temperatures of 25°C (mild treatment) or 31°C (harsh treatment) for one month and then transferred them to common conditions (20°C) to examine the effects of previous thermal treatment on aggregation tendency and trap size. We predicted that antlions that experienced harsh conditions would subsequently increase the neighbouring distance and trap diameter to reduce competition with conspecifics and improve prey capture success, compensating for past conditions. In contrast with these predictions, antlions exposed to harsh conditions displayed a trend in the opposite direction, towards the decreased neighbouring distance. Furthermore, some of these antlions also built smaller traps. We discuss possible reasons for our results. The effects of previous thermal exposure have rarely been considered in terms of trap construction in antlions. Described effects may possibly apply to other sit-and-wait predators and are significant considering that many of these predators are long-lived.

scholarly journals Influence of the microhabitat on the trap construction of Myrmeleon brasiliensis (Neuroptera: Myrmeleontidae) larvae

2020 ◽  
Vol 110 ◽  
Author(s):  
Tatiane N. Lima
Keyword(s):  
Energy Expenditure ◽  
Direct Action ◽  
High Energy ◽  
Building Process ◽  
Trap Size ◽  
Antlion Larvae

ABSTRACT Antlion larvae of Myrmeleon brasiliensis (Návas, 1914) build their traps in a microenvironment with protection from the direct action of rain and other perturbations as well as microhabitats that are less protected from disturbances that can destroy the traps. Differences in microhabitats may affect the characteristics of the trap-building process due the high energy expenditure exerted in building and maintaining these traps, which led to the following question: Do antlion larvae of M. brasiliensis build larger traps in protected microhabitats? Considering the occurrence of M. brasiliensis larvae in two microhabitats and the measurements of the size of the larvae and their traps, the hypothesis was that larvae would occur in greater abundance and the trap size would be larger in more protected microhabitats. The results showed that antlions occurred in equal abundance in both microhabitats, but density was greater in the protected microhabitat. Even in months with more rainfall, M. brasiliensis larvae continued to forage throughout the year in the protected microhabitat and the investment in trap size was greater in this microhabitat. This suggests that the larvae of the protected microhabitat have an advantage, given that they have the possibility of foraging throughout the year.

scholarly journals The effect of colonization dynamics in competition for space in metacommunities

2021 ◽  
Author(s):  
Jorge Arroyo-Esquivel ◽  
Nathan G. Marculis ◽  
Alan Hastings
Keyword(s):  
Continuous Time ◽  
Habitat Suitability ◽  
Limiting Factor ◽  
Modeling Framework ◽  
Competition For Space ◽  
Time Modeling ◽  
Functional Forms ◽  
Colonization Dynamics ◽  
Main Factors ◽  
Metacommunity Dynamics

AbstractOne of the main factors that determines habitat suitability for sessile and territorial organisms is the presence or absence of another competing individual in that habitat. This type of competition arises in populations occupying patches in a metacommunity. Previous studies have looked at this process using a continuous-time modeling framework, where colonizations and extinctions occur simultaneously. However, different colonization processes may be performed by different species, which may affect the metacommunity dynamics. We address this issue by developing a discrete-time framework that describes these kinds of metacommunity interactions, and we consider different colonization dynamics. To understand potential dynamics, we consider specific functional forms that characterize the colonization and extinction processes of metapopulations competing for space as their limiting factor. We then provide a mathematical analysis of the models generated by this framework, and we compare these results to what is seen in nature and in previous models.

scholarly journals Split-footed lacewings declined over time: indications from the morphological diversity of their antlion-like larvae

PalZ ◽  
2021 ◽  
Author(s):  
Gideon T. Haug ◽  
Carolin Haug ◽  
Serita van der Wal ◽  
Patrick Müller ◽  
Joachim T. Haug
Keyword(s):  
Morphological Diversity ◽  
Single Specimen ◽  
Burmese Amber ◽  
The Past ◽  
The World ◽  
Poor Group ◽  
Outline Analysis ◽  
Loss Of Diversity ◽  
Over Time ◽  
Antlion Larvae

AbstractNymphidae, the group of split-footed lacewings, is a rather species-poor group. Split-footed lacewings nowadays are restricted to Australasia, while fossil forms are also known from other areas of the world, indicating that the group was more species-rich and therefore likely diverse in the past. Split-footed lacewings have rather distinct larvae, roughly resembling antlion larvae, but differing from the latter especially with regard to the mandibles. Antlion larvae usually have three prominent teeth on each mandible, while at least extant larvae of split-footed lacewings only have a single prominent tooth per mandible. Fossils interpreted as larvae of split-footed lacewings are well known from amber from Myanmar (ca. 100 myr; Burmese amber) and by a single specimen from Baltic amber (about 40 myr). We here report additional fossil specimens from Myanmar amber, expanding the known record of fossil forms from six depicted specimens to 15. For the extant fauna, we could compile 25 larvae. We compare the diversity of shape of extant and fossil larvae through time using an outline analysis (based on elliptic Fourier transformation) of the head. The results of this analysis indicate that the morphological diversity, or disparity, of split-footed lacewing larvae was higher in the past than it is today. With this type of analysis, we can show a loss of diversity over time, without the necessity to identify the fossil larvae down to a narrow taxonomical range. A similar pattern has already been recognised in silky lacewings, Psychopsidae. This might indicate a general loss of diversity of lacewing larvae.

New Devonian microconchids (Tentaculita) from the Holy Cross Mountains, Poland

2011 ◽  
Vol 85 (4) ◽  
pp. 757-769 ◽  
Author(s):  
Michał Zatoń ◽  
Wojciech Krawczyński
Keyword(s):  
Sedimentation Rate ◽  
Distal Portion ◽  
Taxonomic Composition ◽  
Soft Bottom ◽  
Holy Cross Mountains ◽  
Competition For Space ◽  
High Sedimentation ◽  
New Material ◽  
Three New Species ◽  
Hard Substrates

Tentaculitoid microconchid tubeworms from Devonian (uppermost Emsian-upper Givetian) deposits of the Holy Cross Mountains, Poland, include three new species from stratigraphically well-constrained lithological units:Polonoconchus skalensisn. gen. n. sp.,Palaeoconchus sanctacrucensisn. sp. andMicroconchus vinnin. sp. The microconchids inhabited fully marine environments during transgressive pulses, as is evidenced from facies and associated fossils.Polonoconchus skalensisn. gen. n. sp. andPalaeoconchus sanctacrucensisn. sp. inhabited secondary firm- to hard-substrates in deeper-water, soft-bottom environments. They developed planispiral, completely substrate-cemented tubes and planispiral tubes with elevated apertures, which is indicative of environments where sedimentation rate is low but competition for space (by overgrowth) may be high.Microconchus vinnin. sp., on the other hand, developed a helically coiled distal portion of the tube as a response to a high sedimentation rate. As the taxonomic composition of Devonian microconchids is poorly recognized at both regional and global scales, this new material contributes significantly to our understanding of the diversity of these extinct tube-dwelling encrusters.

The physical relationships of the abdominal organs in the pregnant ewe

1968 ◽  
Vol 70 (2) ◽  
pp. 171-177 ◽  
Author(s):  
J. M. Forbes
Keyword(s):  
Cross Sections ◽  
Abdominal Fat ◽  
Competition For Space ◽  
Abdominal Organs ◽  
Abdominal Content ◽  
Intestinal Contents ◽  
Medium Quality ◽  
Pregnant Ewe ◽  
In Pregnancy

SUMMARYFive non-pregnant ewes and seventeen ewes at various stages of pregnancy were fed on a medium quality hay for several weeks before being slaughtered and frozen. Each ewe was sawn into 5 cm cross-sections.The sections were photographed. The uterus was extracted from the sections and its volume measured. Volumes of reticulo-rumen contents, intestinal contents and abdominal fat were estimated from the photographs.Models of the uterus and rumen were constructed and examples of these and of the photographs are shown.The volume of the uterus increased steadily as pregnancy progressed, but rumen volume was not reciprocally depressed until the last 5 weeks of pregnancy. Volume of digesta was inversely related to volume of incompressible abdominal content (uterus and fat). Abdominal fat was a particularly important factor in the depression of rumen capacity in pregnancy when there was great competition for space in the abdomen.

Cellular Automaton Models of Interspecific Competition for Space--The Effect of Pattern on Process

1992 ◽  
Vol 80 (3) ◽  
pp. 527 ◽  
Author(s):  
Jonathan Silvertown ◽  
Senino Holtier ◽  
Jeff Johnson ◽  
Pam Dale
Keyword(s):  
Cellular Automaton ◽  
Interspecific Competition ◽  
Competition For Space

Competition for space and food in rainbow trout, Oncorhynchus mykiss, as related to ascorbic acid status

Aquaculture ◽  
1999 ◽  
Vol 180 (1-2) ◽  
pp. 79-87 ◽  
Author(s):  
J.H Blom ◽  
K Dabrowski ◽  
J.D Rapp ◽  
Y Sakakura ◽  
K Tsukamoto
Keyword(s):  
Ascorbic Acid ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Competition For Space ◽  
Acid Status

802.11ax

2020 ◽  
pp. 102-121
Author(s):  
Alison Harcourt ◽  
George Christou ◽  
Seamus Simpson
Keyword(s):  
Mobile Communications ◽  
Internet Access ◽  
The Internet ◽  
Organizational Contexts ◽  
Mobile Access ◽  
Competition For Space ◽  
Wireless Environment ◽  
Service Degradation

The local wireless environment has been the setting for the co-existence of licensed mobile communications operators and unlicensed WiFi Internet access providers. The IEEE802.11 family of standards, developed for WiFi services in the Institute of Electrical and Electronics Engineers (IEEE), has dominated standards-setting. However, the burgeoning demand for mobile access to the Internet has led to competition for space on the spectrum. Left unaddressed, this co-existence has created practical issues of potential territorial incursion, technical interference, and, ultimately, device underperformance and service degradation. The chapter focuses on the IEEE’s efforts to create a co-existence standard in a crowded and highly contested standards-making space. It shows how alternative standards-making organizational contexts, based on licensed spectrum standards traditions, were able to develop and insert co-existence standards for WiFi ahead of the IEEE initiative. The chapter explains how the IEEE developed its 802.11ax co-existence standard in this environment.

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