Larval population density affects female weight and fecundity in the dung beetle Aphodius ater

1999 ◽  
Vol 24 (3) ◽  
pp. 316-322 ◽  
Author(s):  
Petra Hirschberger
Keyword(s):  
Population Density ◽  
Dung Beetle ◽  
Larval Population ◽  
Female Weight

OPTIMAL SAMPLE SIZE FOR THE ESTIMATION OF SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE) POPULATIONS ON BALSAM FIR AND WHITE SPRUCE

1983 ◽  
Vol 115 (12) ◽  
pp. 1621-1626 ◽  
Author(s):  
Jacques Régnière ◽  
C. J. Sanders
Keyword(s):  
Population Density ◽  
Sample Size ◽  
Host Species ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Larval Population ◽  
Optimal Sample Size ◽  
Optimal Sample

AbstractAn equation is presented for the determination of sample sizes needed to estimate with a given precision the larval population density of spruce budworm on balsam fir and white spruce branch tips in Ontario. This equation is primarily applicable to low densities, but is valid to a density of 50 larvae/branch tip. The distribution of budworm larvae at densities below 0.1/branch tip is nearly random, and is aggregated at higher densities. Their distribution is the same on the two host species.

scholarly journals Larval densities of the protected Striped lychnis moth Shargacucullia lychnis (Lepidoptera: Noctuidae) in Buckinghamshire

2021 ◽  
Author(s):  
Juliano Morimoto ◽  
Lucy Kerr
Keyword(s):  
Natural History ◽  
Population Density ◽  
Developmental Stages ◽  
Larval Density ◽  
Natural Populations ◽  
Adaptive Responses ◽  
Larval Population ◽  
History Information ◽  
The Uk ◽  
Lepidoptera Noctuidae

Natural history information is essential for ecologically-relevant inferences about (adaptive) responses in organismal biology. Yet, natural history data can be difficult to obtain, particularly for the developmental stages of holometabolous insects. This gap can compromise our ability to design controlled experiments that provide useful understanding of insect responses to changing environments and precludes our ability to understand how natural populations may respond to unpredictable climatic changes in their natural environment. In this study, we collated data from previous reports from the Butterfly Conservation Upper Thames Branch on the larval population density of Shargacucullia lychnis (Lepidoptera: Noctuidae) in Buckinghamshire. In the UK, S. lychnis is a protected species, for which natural history information can be invaluable for its effective conservation. We report here that the natural range of larval densities observed for S. lychnis across locations and years is 0.001 to 6.417 larvae per spike. More importantly, S. lychnis larval density has overall declined from 1996 to 2020, which could support previous reports of a contraction in population range for this species. Overall, this study provides invaluable information about larval population density for an important protected Lepidopteran species of the UK.

scholarly journals Anticipatory flexibility: larval population density in moths determines male investment in antennae, wings and testes

2017 ◽  
Vol 284 (1866) ◽  
pp. 20172087 ◽  
Author(s):  
Tamara L. Johnson ◽  
Matthew R. E. Symonds ◽  
Mark A. Elgar
Keyword(s):  
Population Density ◽  
Developmental Plasticity ◽  
Adult Population ◽  
Larval Density ◽  
Fertilization Success ◽  
Mate Location ◽  
Distinct Advantage ◽  
Male Reproductive Success ◽  
Larval Population ◽  
Male Investment

Developmental plasticity provides individuals with a distinct advantage when the reproductive environment changes dramatically. Variation in population density, in particular, can have profound effects on male reproductive success. Females may be easier to locate in dense populations, but there may be a greater risk of sperm competition. Thus, males should invest in traits that enhance fertilization success over traits that enhance mate location. Conversely, males in less dense populations should invest more in structures that will facilitate mate location. In Lepidoptera, this may result in the development of larger antennae to increase the likelihood of detecting female sex pheromones, and larger wings to fly more efficiently. We explored the effects of larval density on adult morphology in the gum-leaf skeletonizer moth, Uraba lugens , by manipulating both the number of larvae and the size of the rearing container. This experimental arrangement allowed us to reveal the cues used by larvae to assess whether absolute number or density influences adult responses. Male investment in testes size depended on the number of individuals, while male investment in wings and antennae depended upon larval density. By contrast, the size of female antennae and wings were influenced by an interaction of larval number and container size. This study demonstrates that male larvae are sensitive to cues that may reveal adult population density, and adjust investment in traits associated with fertilization success and mate detection accordingly.

Dynamics of growth modified by larval population density in the flesh fly, Sarcophaga bullata

1983 ◽  
Vol 61 (3) ◽  
pp. 512-517 ◽  
Author(s):  
James A. Baxter ◽  
Paul E. Morrison
Keyword(s):  
Growth Rate ◽  
Population Density ◽  
Growth Curves ◽  
Feeding Period ◽  
Larval Population ◽  
Beef Liver ◽  
Flesh Fly ◽  
Sarcophaga Bullata ◽  
Growth Functions ◽  
Logistic Functions

Growth functions were fitted to the growth curves of larvae of the flesh fly, Sarcophaga bullata Parker (Diptera: Sarcophagidae), reared in conditions that were either uncrowded (25 larvae per 25 g beef liver) or crowded (400 larvae per 25 g beef liver). The growth curves took the form of logistic functions that were symmetrical for uncrowded larvae, but asymmetrical for crowded ones. Initially, crowded larvae grow faster than uncrowded larvae, a response in contrast with those of all other species of higher Diptera studied to date. Apparently, crowded larvae derived benefit from close intraspecific associations, for their rapid growth took place while they fed within dense aggregations. The growth rate of crowded larvae peaked early and growth ceased abruptly when the supply of food was exhausted. Their feeding period was reduced by 60% and their weight by 74% in comparison with those of uncrowded larvae.

Food Limitation of Larval Dragonflies: A Field Test of Spacing Behaviour

1986 ◽  
Vol 43 (9) ◽  
pp. 1720-1725 ◽  
Author(s):  
Robert L. Baker
Keyword(s):  
Population Density ◽  
Field Test ◽  
Food Limitation ◽  
Population Densities ◽  
Larval Population ◽  
Southern Ontario ◽  
Growth And Survival ◽  
Gut Fullness ◽  
Dependent Growth ◽  
Ischnura Verticalis

Density-dependent growth and survival of larval odonates may result from some larvae excluding others from profitable hunting sites. This hypothesis predicts that both degree and variation in food limitation should increase with population density; it also suggests that large larvae should show less food limitation than small larvae. I tested these predictions by analyzing food limitation, determined by mass of fecal pellets, and population density of larval Ischnura verticalis and Enallagma ebrium from a pond in southern Ontario. When data from all sampling days were combined, population densities of both species were negatively correlated with gut fullness but there was no correspondence between population density and gut fullness measured at different sites on any given day. Also, there was no correlation between population density and variation in food limitation and there was no evidence that small larvae suffered a greater degree of food limitation than larger larvae. A lack of discrete and persistent prey patches and/or low larval population densities may account for the lack of evidence that larvae are excluded from patches of prey.

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