scholarly journals Influence of The Different Onion Varieties on the Population Density of the Main Insect Pests Infesting Onion Crop in Kafr El-Shekh Region.

2017 ◽  
Vol 8 (8) ◽  
pp. 403-406
Author(s):  
S. Awadalla ◽  
A. Taman ◽  
A. Aboria
2005 ◽  
Vol 5 (1) ◽  
pp. 24-31
Author(s):  
Hamim Sudarsono ◽  
Rosma Hasibuan ◽  
Damayanti Buchori

Biology and Transformation of the Migratory Locust Locusta migratoria manilensis Meyen (Orthoptera: Acrididae) at Several Laboratory Population Density Levels.  The migratory locust, Locusta migratoria manilensis Meyen (Orthoptera: Acrididae) is one of insect pests in Indonesia that undergoes a unique polymorphic biology.  The locust develops a transformation phase which is triggered mainly by high population density.  Its recent outbreaks in several regions of Indonesia cause major concern and control strategies must be developed to strengthen control efforts in the future. Its unique polymorphic phenomenon, therefore, must be investigated thoroughly for the basis of management of the outbreak.  Due to its agility and its long range flying ability, the most realistic technique to study behavioral and morphological change of the locust is in controlled condition at a laboratory or a green house facility. The experiment was aimed to study effects of colony densities on the biology and transformation process of the migratory locust.  More specifically, the experiment was to study effects of population density on the feeding activity, mortality rate, and the ratio of F/C and E/F of the migratory locust L. migratoria manilensis.  The population densities were simulated in colonies at 2, 5, 10, 20, dan 30 couples per cage (cage size: 45x45x90 cm) reared in a green house. Results of the experiment show that, in general, higher densities of the migratory locust colonies tended to feed more rigorously than those of the less dense colonies.  The locust remained in solitary phase at the density of 2-5 couples per cage whereas the transient phase occured at the density of 10-20 couples per cage.  The colonies transformed to gregarious stage when their densities were 30 couples per cage or higher.  Mortality percentage tended to be higher at colonies with higher density, especially for the third instar of the migratory locust. 


2020 ◽  
Author(s):  
Sakda Ratisupakorn ◽  
Sokchan Lorn ◽  
Nsa Dada ◽  
Aran Ngampongsai ◽  
Pawit Chaivisit ◽  
...  

ABSTRACTHigh rates of dengue, chikungunya, and zika morbidity occur in southern Thailand. The intensive application of insecticides in orchards could impact not only agricultural insect pests, but also non-target insects, such as mosquitoes, or non-target beneficial insects. In this study, the population density and insecticide susceptibility of Aedes albopictus populations to field application concentrations of four agrochemical insecticides – cypermethrin, chlorpyrifos, carbaryl, and imidacloprid were examined. Mosquito eggs were collected from durian cultivation sites in five provinces in southern Thailand and hatched and allowed to develop to the adult stage. The study sites were categorized into three groups based on insecticide application; intensive-application of insecticides (IA), less-application of insecticides (LA), and no application of insecticides (NA). Twenty ovitraps were deployed for at least three consecutive days at each study site to collect mosquito eggs and to determine the Ae. albopictus population density then WHO tube assays being used to determine the susceptibility of adult mosquitoes to selected insecticides. This study represents the first report of the agrochemical insecticide susceptibility status of Ae. albopictus collected from durian orchards in southern Thailand. The study found that the populations of Ae. albopictus were susceptible to chlorpyrifos, but showed reduced mortality following exposure to lambda-cyhalothrin, carbaryl, and imidacloprid which is suggestive of the existence of resistance. These findings provide new insights into mosquito insecticide resistance focusing on Ae. albopictus populations and has important implications for mosquito and mosquito-borne disease control in Thailand as well as providing baseline data on which future studies can develop.


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.


Author(s):  
Hari Prakash Namdev Ram Subhag Singh

An experiment was conducted at Agricultural Research Farm of Brahmanand Post Graduate College, Rath, Hamirpur (U.P.) during 2016-17 and 2019-20 cropping season. In the Bundelkhand agro climatic region seventeen species of insect belonging to seven orders and twelve families were recorded from chickpea agro ecosystem. Among which six species from Lepidoptera, four species from hymenoptera, two species from coleoptera and odonata and one species from hemiptera, isoptera, and dyctyoptera were identified. On the basis of economic importance nine species were insect pests, five species were predators, two species were insect parasitoids and one species was insect pollinator. Among the nine species of insect pests, chickpea pod borer, Helicoverpa armigera Hub. and gram cut worm, Agrotis ipsilon (Huf.) occurred regularly and chickpea pod borer was designated as a major pest while, gram cut worm infested with very low population density and considered as minor insect pest of chickpea. The five species of insect pest occurred occasionally i.e. armyworm, Mythmina separate (walker), tobacco caterpillar, Spodoptera litura (Fab), cow pea aphid, Aphis craccivora (Koch), termite, Odentotermes obesus (Rambur) and black flea beetle, Altica Species (unidentified species) were designated as minor pest of chickpea. While, two species namely, Bihar hairy caterpillar, Spilarctia obliqua (Walker) and beet armyworm, Spodoptera oxiqua (Hub) occurred intermittently in sporadic manner and designated as stray pest of chickpea. The eight species of insect’s ecofriendly fauna inhabiting chickpea agro ecosystem were observed, among which five species of predators, two species of parasitoids and one species of pollinators foraged on chickpea crop occasionally in very low population density. The maximum number of ecofriendly fauna was of the order hymenoptera, two species of parasitoids, one species of predators and pollinator i.e. Trichogrammatid wasp, Trichogramma chilonis (Ishii), ichneumonid wasp, Campoletis chloridae (Uchida), common yellow wasp, Vespa oreintalis (L.) and small honeybee, Apis floraea followed by odonata i.e. dragonfly, Croccothemis servielia (Drury) and damsel fly, Agriocnemis pygmiea (Rambur), coleoptera, rove beetle, Alleochara billienata and dyctyoptera, praying mantis, Mantis religiosa (L.).


Author(s):  
Sakda Ratisupakorn ◽  
Sokchan Lorn ◽  
Nsa Dada ◽  
Aran Ngampongsai ◽  
Pawit Chaivisit ◽  
...  

Abstract High rates of dengue morbidity occur in southern Thailand. The intensive application of insecticides in orchards could affect not only agricultural insect pests, but also nontarget mosquitoes or beneficial insects. In this study, the type and quantity of insecticides commonly used across durian plantations in southern Thailand were characterized, along with the population density of Aedes albopictus (Skuse) (Diptera: Culicidae). Our primary aim was to determine the susceptibility status of field-derived Ae. albopictus to typical application concentrations of four agrochemical insecticides; cypermethrin, chlorpyrifos, carbaryl, and imidacloprid. Mosquito eggs were collected from durian cultivation sites in five provinces in southern Thailand and used to generate adults for susceptibility tests. The cultivation sites were categorized into three groups based on insecticide application: intensive application of insecticides, low application of insecticides, and no application of insecticides. Twenty ovitraps were deployed for at least three consecutive days at each study site to collect mosquito eggs and to determine Ae. albopictus population density. WHO tube assays were used to determine the susceptibility of adult mosquitoes derived from field-collected eggs to selected insecticides. This represents the first report of the susceptibility status of Ae. albopictus from durian orchards in southern Thailand to agrochemical insecticides. Results showed complete susceptibility of these Ae. albopictus to chlorpyrifos, but reduced mortality following exposure to λ-cyhalothrin, carbaryl, and imidacloprid, which is suggestive of the development of resistance. These findings provide new insights into the status of insecticide susceptibility in Ae. albopictus populations, with important implications for mosquito and mosquito-borne disease control in Thailand.


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