scholarly journals Temperature and population density: interactional effects of environmental factors on phenotypic plasticity, immune defenses, and disease resistance in an insect pest

2016 ◽  
Vol 6 (11) ◽  
pp. 3672-3683 ◽  
Author(s):  
Farley W. S. Silva ◽  
Simon L. Elliot
2017 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
Elmi Kamsiati ◽  
Emmy Darmawati ◽  
Yadi Haryadi

<p>Beras merupakan komoditas penting karena merupakan makanan pokok sebagian besar penduduk Indonesia. Selama penyimpanan, beras dapat mengalami kerusakan karena pengaruh lingkungan, maupun serangan serangga hama pascapanen. Sitophilus oryzae merupakan serangga hama pascapanen yang banyak menyerang beras, menyebabkan susut bobot dan pencemaran kualitas selama penyimpanan. Tujuan dari penelitian ini adalah mempelajari pengaruh jenis kemasan terhadap kematian Sitophilus oryzae dan menentukan kemasan yang sesuai untuk penyimpanan beras. Tiga varietas beras lokal Kalimantan Tengah (Siam Jurut, Siam Unus dan Karang Dukuh) yang diinfestasi dengan Sitophilus oryzae dikemas dengan plastik “hermetik” laminat, polipropilen (PP) dan poli etilen densitas rendah (LDPE). Hasil dari penelitian ini menunjukkan bahwa jenis plastik berpengaruh nyata pada kematian Sitophilus oryzae dalam kemasan. Total kematian Sitophilus oryzae dicapai setelah tiga hari dalam plastik “hermetik” laminat, tujuh hari dalam plastik PP. Sedangkan dalam plastik LDPE, total kematian dicapai setelah 20 hari penyimpanan.</p><p>Kata kunci :beras, kemasan plastik, Sitophilus oryzae, penyimpanan</p><p>English Version Abstract</p><p>Rice is an important agricultural commodity serves as staple food for most of Indonesian people. During storage, rice can be damaged due to environmental factors as well as postharvest pest. Sitophilus oryzae is insect pest that attacks rice during storage causing quantity and quality losses. The objective of this research was to study the effects of type of packaging on the S.oryzae mortality and determine the appropriate packaging for rice during the storage. Three varieties of Central Kalimantan local rice (Siam Jurut, Siam Unus and Karang Dukuh) that infested by S.oryzae were packaged using three types of packaging, i.e “hermetic” laminat, polypropilen (PP) and low density polyetylen (LDPE) plastics. The result of showed that the type of packaging significantly effected the S.oryzae mortality. Total mortality of S.oryzae reached after three days, seven days, and 20 days in hermetic, PP, LDPE respectively.</p><p>Keywords :rice, plastics packaging, Sitphilus oryzae, storage</p>


2014 ◽  
Vol 1010-1012 ◽  
pp. 635-638
Author(s):  
Yan Juan Xi ◽  
Zhen Liang Zhao ◽  
Chun Long Zhao ◽  
Yan Qin Xi ◽  
Li Yan ◽  
...  

Based on the environmental survey data in off-shore of Qin Huangdao from May to June 2011,correlation analysis was made between population density of Noctiluca scintillans and environmental factors. The results indicates that population density of Noctiluca scintillans does not exist linear correlation with nitrite, nitrate, ammonia, nitrogen, phosphate,dissolved oxygen and PH ,it is positive correlation with temperature and silicate noctiluca and negatively correlation with transparency and salinity.


Author(s):  
Guido Bonello ◽  
Cristiano Angelini ◽  
Luigi Pane

Tigriopus fulvus (Fischer, 1860) is a benthic harpacticoid copepod of the Mediterranean supralittoral zone. The transitional characteristics of this environment forced this species to develop high resistance to changes of environmental parameters. Nevertheless, Tigriopus fulvus life-cycle is influenced from the splashpools physical-chemical parameters. In this paper, we present the results of a supralittoral monitoring performed in 2014, confirming the influence of some of these environmental parameters on population buildups. Because of recent worldwide climate change effects, a threat might have been posed on this particularly exposed organism, whose population density decreased of a sixfold value in the last 30 years. During the three pools (A, B, C) monitoring, the maximum copepod density recorded was 1456 Ind/l (September 2014, Pool C), alongside first records of extinction event for Tigriopus fulvus.


Biomass ◽  
1982 ◽  
Vol 2 (3) ◽  
pp. 175-185 ◽  
Author(s):  
Avigad Vonshak ◽  
Aharon Abeliovich ◽  
Samy Boussiba ◽  
Shoshana Arad ◽  
Amos Richmond

2005 ◽  
Vol 85 (2) ◽  
pp. 481-506 ◽  
Author(s):  
Mihai Costea ◽  
François J. Tardif

A review and assessment of biological information as well as personal data are provided for Polygonum aviculare in Canada. The species has been revised taxonomically and the six subspecies that occur in Canada are presented. Three of the subspecies, P. aviculare subsp. aviculare, P. aviculare subsp. neglectum and P. aviculare subsp. depressum are weeds introduced to Canada from Europe. A fourth subspecies, P. aviculare subsp. buxiforme is apparently native to North America. The geographical distribution of the latter four subspecies is very wide. Plants exhibit a high phenotypic plasticity and genetic variability, and they easily adapt to a multitude of agrestal and ruderal habitats. The seeds have a variable dormancy and polymorphic germination as a result of heterocarpy, genetic and environmental factors. In other areas (Europe), the species has developed resistance to triazines. Plants are hosts to nematodes, viruses, and fungi that also affect cultivated plants. Key words: POLAV, ecology, distribution, taxonomy


Author(s):  
Emilia MISZEWSKA ◽  
Maciej NIEDOSTATKIEWICZ ◽  
Radosław WIŚNIEWSKI

The popularity of Floating Homes in Western Europe and North America is noticeable. The interest in these facilities in Poland is also constantly growing. The popularity of Floating Homes is due to climate change, rising land prices and population density in city centers. However, environmental factors play a significant role in their development. The publication presents the results of research on the impact of environmental factors on the development of Floating Homes in Poland. As part of the research, the most important environmental factors were identified and then, using the State of the Surroundings Scenarios (SSS) method, an initial scenario of their development was developed. The most probable scenario was developed, the purpose of which was to identify the most favorable factors - strengths and unfavorable factors - weaknesses responsible for the development opportunities of Floating Homes in Poland. Additionally, a surprise scenario was prepared, which indicated factors that may unexpectedly accelerate the development of Floating Homes in Poland or slow it down.


2021 ◽  
Author(s):  
Aqeel Alyousuf ◽  
Dawood Hamid ◽  
Mohsen A. Desher ◽  
Amin Nikpay ◽  
Henk-Marten Laane

Abstract Tomato (Solanum lycopersicum L) is an important vegetable crop in Iraq. This horticultural crop is attacked by several insect pest species. Among them, the whitefly Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) and the tomato leaf miner Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) are the major threat of greenhouse tomatoes in Basrah province in south Iraq. The management of these pests is heavily based on application of chemical pesticides. Vast application of pesticides caused harmful damage to the environment, human health and may increasing the risk of pest resistance on insect populations. One of the promising strategies which are compatible with organic farming is application of silicon for enhancing plant vigor and resistance to pest damage on various agricultural crops. Due to these facts, the experiments have been carried out at Basrah University to evaluate the effects of silicon (Si) fertilization on tomato plants for reducing damage of these two major pests. Treatments comprised two type of Si applications (Soil drench treatment and foliar spraying) with four Si concentrations (0, 0.5, 1 and 2%) of AB Yellow ® silicic acid formulation. The population density of B. tabaci and T. absoluta were studied weekly during the growth season. The results clearly demonstrated that Silicon applications significantly decreased the population of immature of both whiteflies and tomato leaf miner on tomato crop in the greenhouse; Si-Foliar spraying was more effective in reducing the population density of these key pests compared to Si- soil drench application.


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