The Effect of Population Density on Fecundity in Insects

1960 ◽  
Vol 92 (9) ◽  
pp. 674-695 ◽  
Author(s):  
K. E. F. Watt
Keyword(s):  
Field Data ◽  
Insect Pest ◽  
Pest Species ◽  
Optimum Control ◽  
Pest Population ◽  
Life Table Data ◽  
Points Of View ◽  
Exhaustive Study ◽  
Table Data ◽  
Parameter Values

Four steps are necessary in constructing and utilizing a mathematical model for control of a specific insect pest. First, a large volume of field data must be collected according to a plan which is sound from both statistical and biological points of view (Morris, 1955). Secondly, a suitable procedure for developing component parts of the whole model and fitting these together must be developed (Watt, ms.). Thirdly, after exhaustive study of available data and testing of equations against these data we must determine the appropriate form of equation to express the action of each type of phenomenon governing dynamics of the pest population. This paper and other in the series (e.g., Watt, 1959) are designed to obtain such formulations. Which phenomena are worthy of smdv for a given pest species will become clear through mathematical analysis of life-table data of the type collected by Morris and Miller (1954). Finally, parameter values are obtained from the data and the equations are manipulated io determine optimum control practices, using methods outlined by Watt (ms.).

scholarly journals Identification of Insect Pest Species of Maize, Their Infestation and Damage Levels at Ziway Dugda Woreda, Arsi Zone, Ethiopia

2018 ◽  
pp. 1-11
Author(s):  
Lemmessa Gemmeda ◽  
Emana Getu
Keyword(s):  
Field Data ◽  
Insect Pest ◽  
Larval Density ◽  
First Record ◽  
Pest Species ◽  
Infestation Level ◽  
Maize Crop ◽  
Cropping Season ◽  
Significant Difference ◽  
Arsi Zone

The survey was carried out in 2017 main cropping season to support farmers for correct insect pest identification. Three Kebeles, Hallo, Sambaro and Herara with five farmer’s fields randomly selected. Ten representative plants were taken from each field. Data on mean larval density per plant, percentage leaf infestation and damage levels were assessed. Results from mean larval density per plant showed that significant difference between insect species (R2= 0.96, Pr (>|Z|=0.013) where the highest 1.55-2.30 was recorded from C. partellus. There was a significant difference between C. partellus and M. trapezalis; S. frugiperda and M. trapezalis in percentage leaf infestation (R2=0.75, Pr. (>|Z|=2e-16) where, the highest were recorded from C. partellus and S. frugiperda representing 50-90% and 40-90% respectively. From the above, C. partellus and S. frugiperda were at risk, as a result insecticide was recommended. M. trapezalis showed a lower infestation level so that hand picking was more economical than use of insecticide. Hence, registration and detail molecular identification will be needed as M. trapezals is the first record on maize crop in Ethiopia.

scholarly journals Insect fauna of pests and their natural enemies inhabiting sorghum-panicles in Egypt

2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Hosam M. K. H. El-Gepaly
Keyword(s):  
Natural Enemies ◽  
Dominant Species ◽  
Insect Pest ◽  
Pest Species ◽  
Parasitoid Species ◽  
Insect Fauna ◽  
Cryptoblabes Gnidiella ◽  
Arthropod Species ◽  
Lepidopteran Pests ◽  
Major Pest

AbstractSorghum panicles offer a very rich microenvironment for many insect pest species and their natural enemies. Thirty arthropod species belonging to 28 families, pertaining to 9 orders were obtained from sorghum panicles planted in Sohag Governorate, Egypt, during the 3 successive seasons of 2016–2018. Out of these species were 14 pests, 16 predators, and 3 parasitoids. Lepidopteran and hemipteran pests were the most dominant species-infested sorghum-panicles during the mature stages of the panicles. Three microlepidopteran pests, the noctuid, Eublemma (Autoba) gayneri (Roth.); the pyralid, Cryptoblabes gnidiella Millière, and the cosmopterigid, Pyroderces simplex Walsingham, were recorded as major pest species infesting sorghum panicles in Sohag Governorate. The dipteran parasitoid species, Nemorilla floralis (Fallen) (Tachinidae) emerged from the pupae of the E. gayneri and C. gnidiella, while the hymenopteran parasitoid, Brachymeria aegyptiaca (Chalcididae) was obtained from the pupae of all the studied microlepidopteran pests. Spiders, coccinellids, and Orius spp. were the dominant predators collected form panicles. Post-harvest, larvae, and pupae of lepidopteran pests, especially P. simplex recorded (147, 96, and 79 larvae) and (47, 30, and 73 pupae)/10 panicles in 2016, 2017, and 2018 seasons, respectively.

scholarly journals Life expectancy and disparity: an international comparison of life table data

BMJ Open ◽  
2011 ◽  
Vol 1 (1) ◽  
pp. e000128-e000128 ◽  
Author(s):  
J. W. Vaupel ◽  
Z. Zhang ◽  
A. A. van Raalte
Keyword(s):  
Life Expectancy ◽  
Life Table ◽  
International Comparison ◽  
Life Table Data ◽  
Table Data

scholarly journals A Way Forward to Combat Insect Pest in Rice

2021 ◽  
Vol 25 (1) ◽  
pp. 1-22
Author(s):  
MP Ali ◽  
B Nessa ◽  
MT Khatun ◽  
MU Salam ◽  
MS Kabir
Keyword(s):  
Yield Loss ◽  
Production Systems ◽  
Insect Pests ◽  
Insect Pest ◽  
Brown Planthopper ◽  
Mobile App ◽  
Rice Production ◽  
Economic Losses ◽  
Pest Species ◽  
Management Options

The damage caused by insect pest is the continual factor for the reduction of rice production. To date, 232 rice insect pest species are identified in Bangladesh and more than 100 species of insects are considered pests in rice production systems globally, but only about 20 - 33 species can cause significant economic loss. The major goal of this study is to explore all the possible ways of developed and proposed technologies for rice insect pests management and minimize economic losses. Insect pests cause 20% average yield loss in Asia where more than 90% of the world's rice is produced. In Bangladesh, outbreak of several insects such as rice hispa, leafroller, gallmidge, stem borers and brown planthopper (BPH) occurs as severe forms. Based on previous reports, yield loss can reach upto 62% in an outbreak situation due to hispa infestation. However, BPH can cause 44% yield loss in severe infestested field. To overcome the outbreaks in odd years and to keep the loss upto 5%, it is necessary to take some preventive measures such as planting of resistant or tolerant variety, stop insecticide spraying at early establishment of rice, establish early warning and forecasting system, avoid cultivation of susceptible variety and following crop rotation. Subsequent quick management options such as insecticidal treatment for specific insect pest should also be broadcasted through variety of information systems. Advanced genomic tool can be used to develop genetically modified insect and plants for sustainable pest management. In addition, to stipulate farmers not use insecticides at early crop stgae and minimize general annualized loss, some interventions including training rice farmers, regular field monitoring, digitalization in correct insect pests identification and their management (example; BRRI rice doctor mobile app), and demonstration in farmers field. Each technology itself solely or combination of two or more or all the packages can combat the insect pests, save natural enemies, harvest expected yield and contribute to safe food production in Bangladesh. Bangladesh Rice J. 25 (1) : 1-22, 2021

scholarly journals Evaluation of New Systemic Insecticides for Elm Insect Pest Control

1996 ◽  
Vol 14 (1) ◽  
pp. 22-26 ◽  
Author(s):  
D. Casey Sclar ◽  
Whitney S. Cranshaw
Keyword(s):  
Pest Control ◽  
Woody Plants ◽  
Insect Pests ◽  
Insect Pest ◽  
Leaf Beetle ◽  
Pest Species ◽  
Shade Trees ◽  
Insect Pest Control ◽  
Systemic Activity ◽  
Systemic Insecticides

Abstract Use of systemic insecticides that can be injected either into the root system or trunk of woody plants provides several potential advantages, notably in control of drift during application. Recently, new classes of insecticides with systemic activity have been developed, which may supplant the organophosphate and carbamate systemic insecticides that have previously been available. To evaluate their potential to control insects affecting shade trees, studies were conducted using imidacloprid and abamectin on elm. Soil injections of imidacloprid appeared particularly effective, controlling all three of the target pest species in this study (elm leaf beetle, European elm scale, elm leaf aphid). Both imidacloprid and abamectin also were effective against at least some elm insects when injected into trunks. Persistence of irnidacloprid was unusually long, providing second season control of all elm insect pests, although root uptake following soil injections was slow.

scholarly journals Integrating Temperature-Dependent Life Table Data into a Matrix Projection Model for Drosophila suzukii Population Estimation

PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e106909 ◽  
Author(s):  
Nik G. Wiman ◽  
Vaughn M. Walton ◽  
Daniel T. Dalton ◽  
Gianfranco Anfora ◽  
Hannah J. Burrack ◽  
...  
Keyword(s):  
Life Table ◽  
Population Estimation ◽  
Drosophila Suzukii ◽  
Temperature Dependent ◽  
Projection Model ◽  
Life Table Data ◽  
Table Data
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