Testing Insect Population Density Relative to Critical Densities with 2-SPRT

1993 ◽  
Vol 22 (2) ◽  
pp. 346-351 ◽  
Author(s):  
Madhuri S. Mulekar ◽  
Linda J. Young ◽  
J. H. Young
Keyword(s):  
Population Density ◽  
Insect Population

scholarly journals Changes in the Activities of Protective Enzymes Induced by Mepiquat Chloride (DPC) in Cotton to Defend Against Aphids

2021 ◽  
Author(s):  
Quancheng Zhang ◽  
Xiaoxia Deng ◽  
Jungang Wang
Keyword(s):  
Population Density ◽  
Soluble Protein ◽  
Defense Mechanism ◽  
Specific Activity ◽  
Induced Defense ◽  
Insect Population ◽  
Detoxification Enzymes ◽  
Sod Activity ◽  
Mepiquat Chloride ◽  
Protective Enzymes

Abstract Background: Mepiquat chloride (DPC) enhances the resistance of cotton plants, and it is widely used as a growth regulator. DPC can stimulate photosynthesis, stabilize the structure of cotton leaves, and affect population reproduction and energy substances in cotton aphids, but interactions between DPC and cotton aphids remain unclear. In this study, we analyzed the physiological responses of cotton to DPC, and the toxicity of DPC toward cotton aphids, before and after feeding, to explore the DPC-induced defense mechanism against cotton aphids.Results: Measurements of protective enzyme activity in cotton showed that the soluble protein contents, peroxidase (POD) activity, and catalase (CAT) activity in cotton treated with different concentrations of DPC were higher than in the control. Superoxide dismutase (SOD) activity was higher than that of controls when the concentration of DPC was <0.1 g/L. Under aphid stress, POD activity of cotton treated with a low insect population density was significantly lower than that of controls, but the reverse was true for cotton treated with a high insect population density, and SOD activity was positively correlated with population density. The activities of detoxification enzymes in field and laboratory experiments showed that DPC promoted the specific activity of glutathione S-transferase (GST) in cotton aphids, while the specific activities of carboxylesterase and acetylcholinesterase were decreased.Conclusions: DPC enhanced the resistance of cotton by increasing the activity of protective enzymes. It also had a toxic effect on cotton aphids by increasing GST activity (the main DPC target) and lowering carboxylesterase and acetylcholinesterase activities. DPC increased the soluble protein content and SOD activity in cotton under aphid stress, and thereby enhanced tolerance to cotton aphids.

scholarly journals Population Abundance of Insect Trapped on Different Colours of Sticky Trap in Pumpkin (Cucurbita moschata) Field

2020 ◽  
Vol 11 (1S) ◽  
Author(s):  
Salmah Mohamed ◽  
Siti Nur Shafiqa Abdullah ◽  
Nur Syafiqah Musa ◽  
Norhayati Ngah
Keyword(s):  
Population Density ◽  
Low Cost ◽  
Sticky Trap ◽  
Insect Population ◽  
Cucurbita Moschata ◽  
Population Abundance ◽  
Yellow Colour ◽  
Yellow Sticky Trap ◽  
Essential Knowledge ◽  
Trap Colour

A study was conducted to attract insects using different colours of sticky trap in pumpkin (Cucurbita moschata) field. Sticky trap was chosen as it is one of a method to estimate the insect population density in field as it requires a low cost and less skilled labour. Four different colours of sticky traps (i.e. red, white, blue and yellow) were used to determine the insect population abundance at the pumpkin field. All the traps were installed at the height of 100 cm at a random of 1 ha of pumpkin plot with five replicates for each colour and the insect samples were collected weekly for three months (October-December 2019). Overall, a total of 13,052 insects were collected throughout 11 weeks of sampling. The results showed that the percentage of insect population abundance recorded the highest was on week eight (15.01%) whilst the least abundance of insects trapped was on week one (2.28%). The most attractive colour to attract insects was significantly the yellow colour (44.34%) followed by blue (20.12%) and white (19.15%) whilst the lowest insect trapped was on red colour (16.40%). A total of nine insect orders recorded were; Diptera, Hemiptera, Coleoptera, Hymenoptera, Lepidoptera, Orthoptera, Blattodea, Isoptera and others. Diptera was the most abundant of insect’s order trapped in the yellow trap with 3427 individuals and followed by Hemiptera order (1022 individuals). Whilst the Isoptera order was the least number of insects caught on a red colour trap with only one individual. In conclusion, our findings showed that the yellow sticky trap colour is the most attractive to attract insects of C. moschata compared to other colours. Therefore, this study could provide essential knowledge that may be useful for the future ecological survey of insects of C. moschata.

Estimating insect population density from trap counts

2012 ◽  
Vol 10 ◽  
pp. 69-82 ◽  
Author(s):  
Sergei Petrovskii ◽  
Daniel Bearup ◽  
Danish Ali Ahmed ◽  
Rod Blackshaw
Keyword(s):  
Population Density ◽  
Insect Population

scholarly journals How to count your bugs?

2021 ◽  
Author(s):  
Ksenia S. Onufrieva ◽  
Alexey V. Onufriev
Keyword(s):  
Population Density ◽  
Local Population ◽  
Research Management ◽  
Insect Population ◽  
Upper And Lower Bounds ◽  
Data Sets ◽  
Trap Catch ◽  
Trapping Methods ◽  
The Relationship ◽  
Predictive Relationship

AbstractAbility to estimate local population density of an insect is critical in many fields, from pest management to conservation. No method currently exists that reliably connects trap catch with the insect population density, including the corresponding uncertainty. Here we report a simple and universal predictive relationship for a probability of catching an insect located a given distance away from the trap. This relationship allows to estimate, from a single catch, the most likely population density along with its statistical upper and lower bounds. To test the generality of this equation we used 10 distinct trapping data sets collected on insects from 5 different orders and major trapping methods: chemical-baited and light. For all of the datasets the equation faithfully describes the relationship between location of an insect and probability to catch it. The ability to estimate absolute population density from a single trap catch will significantly improve our understanding of insect population dynamics and allow for more effective research, management, and conservation programs.

Population Dynamics in Diffusive Coupled Insect Population

2018 ◽  
Vol 6 (4) ◽  
pp. 149-159
Author(s):  
Dongwook Kim ◽  
Dong-Hoon Shin
Keyword(s):  
Population Dynamics ◽  
Diffusion Coefficient ◽  
Population Density ◽  
Chaotic Dynamics ◽  
Total Population ◽  
Chaotic Behavior ◽  
Insect Population ◽  
Bifurcation Parameter ◽  
Diffusion Term ◽  
Lpa Model

A variety of ecological models exhibit chaotic dynamics because of nonlinearities in population growth and interactions. Here, we will study the LPA model (beetle Tribolium). The LPA model is known to exhibit chaos. In this project, we investigate two things which are the effect of noise constant and the effect of diffusion combined with the LPA model. The effect of noise is not only to change the dynamics of total population density but also to blur the bifurcation diagram. Numerical simulations of the model have shown that diffusion can drive the total population of insects into complex patterns of variability in time. We will compare these simulations with simulations without diffusion. And we conclude that the diffusion coefficient is a bifurcation parameter and that there exist parameter regions with chaotic behavior and periodic solutions. This study demonstrates how diffusion term can be used to influence the chaotic dynamics of an insect population.

scholarly journals Population density of Tibraca limbativentris on flood irrigated rice and alternative host plants

2018 ◽  
Vol 53 (3) ◽  
pp. 265-278 ◽  
Author(s):  
Mauricio Paulo Batistella Pasini ◽  
Alessandro Dal’Col Lúcio ◽  
Alberto Cargnelutti Filho ◽  
Ana Lúcia de Paula Ribeiro ◽  
João Fernando Zamberlan ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Host Plant ◽  
Host Plants ◽  
Insect Population ◽  
Alternative Host ◽  
Population Densities ◽  
Temporal Dependence ◽  
Phenological Stages ◽  
Irrigated Rice

Abstract: The objective of this work were to evaluate the population dynamics of the rice stem bug (Tibraca limbativentris) around and in flood irrigated rice cultivation area, to quantify the insect population flow between crops and host plants, and to determine the effect of the species, the diameter of the plant, and the distance of the host plant from the border on the rice stem bug population. The work was conducted in the 2012/2013 harvest and in the off-season, with sampling of rice, Andropogom bicornis, and Andropogon lateralis plants in six cultivated areas, in order to count the number of insects. The population density of the rice stem bug in irrigated rice and alternative host plants presents spatial and temporal dependence. In the cultivated areas, the population density of the rice stem bug increases according to the evolution of the rice phenological stages, with the highest densities concentrated in regions close to the crop borders. The diameter and species of the host plant affect the rice stem bug population. Andropogon bicornis plants have higher population densities than A. lateralis, and plants with larger diameters show higher population densities of the rice stem bug. In the off-season, the greatest population of the rice stem bug on host plants is concentrated up to 45 m from the crop border, but it can disperse until 150 m.

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