Destruction Of Natural Enemies Research Articles

Preface

The emerging pest and disease incursions in coconut growing countries result in great economic yield losses and negative impact to the industry, biodiversity loss, and disrupted native and agricultural system.Repeated use of the same active ingredient of pesticide to control pests and diseases could lead to pest and disease resistance. The inevitable effect of climate change, other environmental factors, and the destruction of natural enemies could trigger the incursion and migration of devastating pests and diseases. The massive planting and replanting could create homogeneity in coconut farms, predisposing these to disease infection and pest infestation. The concurrent reported outbreaks of Brontispa in Southeast Asia, Coconut Rhinoceros Beetle, Guam type (CRB-G) in Guam, and Asia-Pacic countries, Coconut Scale Insect in the Philippines, Lethal Yellowing in Jamaica, and Mexico, Bogia Coconut Syndrome in Papua New Guinea, Sexava, Rhyncophorus in Indonesia, and the recognition of the need to develop international biosecurity protocols for safe germplasm exchange have prompted the International Coconut Community (ICC) to hold the 1st IPM symposium.We know that pests and diseases reduced the ability of the industry to fully benefit from the market opportunities. In the face of this situation ICC Sessions and Ministerial meetings as the highest authority and the ICC recommended the ICC Secretariat to convene an IPM symposium to help countries overcome low coconut production due to pests and diseases.The general objective of the symposium is to establish an international IPM network system and synergy to protect the coconut producers & industries and conserve the coconut genetic resources and diversity from the adverse impact of pests and diseases through expertise and experience sharing.The specific objectives of the symposium are:1. To bring together key members of the scientific community for an interactive discussion on emerging issues and advances related to IPM, that will help enhance and develop IPM extension and research on invasive coconut pests and diseases2. To craft ecologically sound, science-based, and sustainable pest and disease management approaches based on IPM practices across countries.3. To create an international platform/network among coconut growing countries to strengthen the development of IPM strategies, pest and disease risk assessment, and inter-country collaborations that will address the research gaps and challenges of managing invasive pests/diseases losses and negative impact on the industry, biodiversity loss, and disrupted native and agricultural system.List of Editor-in-Chief, Managing Editor, Associate Editor, Scientific Committee of IPM Symposium Proceedings are available in this Pdf.

Application of the local entomopathogenic fungus Beauveria Bassiana Vuill against larvae Oryctes rhinoceros L. in immature oil palm plants in Sei Siasam, Rokan Hulu Regency, Riau Province, Indonesia

The decline in oil palm production can be caused by pest attacks. The main pest that attacks oil palm is the horn beetle. Control is usually done by using chemical pesticides. The use of chemical pesticides can cause resistance, resurgence, destruction of natural enemies, and environmental pollution. The use of chemical insecticides can be minimized by using environmentally friendly and sustainable control alternatives, namely by using the local entomopathogenic fungus B. bassiana. This study aimed to obtain the best dose of local B. bassiana Vuill in controlling O. rhinoceros larvae in immature oil palm plantations in Sei Siasam, Rokan Hulu Regency, Riau Province. The study was carried out in Sei Siasam, Rokan Hulu Regency and the Plant Pest Laboratory, Faculty of Agriculture, University of Riau. Completely Randomized Design with five treatments doses of local entomopathogenic fungus B. bassiana 30 g/hole, 35 g/hole, 40 g/hole, 45 g/hole, 50 g/hole and four replications, in order to get 20 experimental units. The results showed that the application of local Riau B. bassiana at a dose of 40 g/hole was the best dose capable of causing death of 72.5%. Early death 77 hours after application and Lethal time 50 180.75 hours after application.

Effect of Larval Density of Helicoverpa armigera (Hubner) on Pod Damage and Yield of Chickpea

Background: Chickpea (Cicer arietinum L.) is cultivated in almost all parts of world covering more than 50 countries spread over Asia, Africa Europe, Australia, north America and South America countries and is the second most important food legumes crop after common bean (Phaseolus vulgaris L.). Chickpea has played a major role in realization of pulse Revolution in india making the country near self-sufficient in pluses. Gram is extensively grow in india. Due to its high nutritional value and its ability to fix atmospheric nitrogen, its more widely cultivated rabi pulse crop. The gram pod borer Helicoverpa armigera (Hubner) is most important pest of chickpea. Many pesticides were so far tested against this pest but due to over use of these pesticides resistance, residue and resurgence problems arises, beside destruction of natural enemies. Methods: To determination of per cent pod damage and yield of chickpea due to different larval density of H. armigera is an important tool to reduce the cost of cultivation by avoiding the unnecessary use of pesticides. Therefore, a pot experiment was conducted in arranged in a completed randomized design with four replications. The pots were placed under natural field conditions and take observation at Research farm, Rajasthan Agricultural Research Institute, Durgapura, Jaipur during 2015-16 and 2016-17. Result: The results revealed that least per cent pod damage (29.05, 24.78%) was recorded when the larval population was one per plant, while the maximum pod damage (64.55 and 67.76%) was recorded during 2015-16 and 2016-17, respectively. The simple liner correlation analysis indicated that there was a significant positive correlation (r= 0.989 and 0.999) between the larval density and per cent pod damage. Further, a significant correlation was noticed between larval density and number of healthy pods per plant, reduction in yield, yield per plant, total number of pod and damaged pods were -0.964, -0.976; 0.98, 0.986; -0.98, -0.986; 0.117, 0.126 and; 0.985 and 0.992, respectively during 2015-16 and 2016-17.

Application of Riau local entomophatogenic fungi Beauveria bassiana toward brown planthopper pest and production of rice

The decrease in rice production can be caused by pests that can damage the quality and quantity. Pests that always attack rice plants are Brown planthopper. The BPH causes several effects, namely hopperburn, as a virus vector and can cause crop failure. The control of BPHs by farmers to date is by using synthetic pesticides. The use of synthetic pesticides can cause residues, resistance, resurgence, and the destruction of natural enemies. The use of synthetic insecticides can be minimized by using environmentally friendly and sustainable control alternatives, namely by using the local entomopathogenic fungi B. bassiana. This study aims to determine the effect of the application of local Riau B. bassiana on BPH and rice production.The research was conducted at the Laboratory of Plant Pests and Experimental Gardens, Faculty of Agriculture, Riau University from April to July 2020. The research was designed a completely randomized design with five treatments local entomopathogenic fungi concentrations B. bassiana 0 g.l-1 water, 10 g.l-1 water, 20 g.l-1 water, 30 g.l-1 water, 40 g.l-1 water and four replications, in order to obtain 20 experimental units. The results showed that application of Riau local B. bassiana with a concentration of 40 g.l-1 for six days was able to cause the highest mortality of 92.5%. The higher the concentration of Riau local B. bassiana, the lower the attack intensity. The attack of brown planthopper nymphs affects the quality of rice production, but did not affect the quantity of rice production.

A Global Perspective of Rice Brown Planthopper Management Ⅱ- After Green Revolution Era

Rice Brown Plant hopper, Nilaparvata lugens (Stal) (BPH) has started becoming a major pest in tropical rice growing countries only after major areas were covered by dwarf varieties or high yielding varieties (HYVs). Detailed discussion both historical and experimental evidence on several possible causes like Changed architecture of rice plant, Associated change in agricultural practices, change in micro-climate in rice crop ecosystem, Lack of insect resistance in dwarf varieties, Increased use of insecticides, Consequent destruction of natural enemies, Development of insecticide resistance is presented. Among these, microclimatic factors in rice ecosystem, notably optimum temperature, low wind movement, high water vapor pressure and consequent high relative humidity among abiotic factors and nitrogen rich plant sap among biotic factors appeared to be the most important. Lack of BPH resistance in HYVs does not appear to be the primary cause. Higher insecticide usage in HYVs appeared to be responsible for persistence of BPH menace partially due to destruction of natural enemies and more importantly through development of insecticide resistance and resurgence. However this seems to be secondary cause for BPH problem in all tropical rice growing countries of Asia including China and India.

Preliminary Studies on Inherited Sterility for Field Management of Diamondback Moth (Plutella xylostella) (Lepidoptera: Plutellidae) on Crucifers in Ghana

The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae) is the most destructive insect pest of crucifers in Ghana and the world over. It is estimated to cost about USD 1 billion to control annually worldwide. Reliance on chemicals as the sole control measure for diamondback moth has resulted in the development of a myriad ofproblems including resistance, high residue levels on produce, destruction of natural enemies and pest resurgence among others. Inherited sterility in Lepidoptera insects has a potential for suppressing DBM populations. We conducted this study to evaluate the use of the technique to manage the diamond back moth in Ghana. When 3 – 4 day old pupae were treated with 130 Gy and 150 Gy of gamma radiation, 47% and 46% respectively of the male pupae developed as normal adults whiles 40% and 17% respectively of the female pupae developed as normal adults. However, radiation-induced reductions in fecundity and egg viability were expressed in the parental and first filial (F ) generations. Sterility exceeded 1 66% in the treated parental male and 92% in the treated parentalfemale in both treatments as compared with 78% and 95% in treated F male and female, respectively. The sex ratio was 1 skewed in favour of males in the parental progeny. These results indicate the possibility of using inherited sterility for DBM control. Keywords: Diamondback moth Plutella xylostella , irradiation, inherited sterility, F 1 sterility.

Evaluation of the chinaberry Melia azedarach extract against the tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae) in vitro

The South American tomato leaf miner (TLM), Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is an important pest of tomato, potato and other solanaceous species of economic relevance. Pest management of TLM based on the use of conventional insecticides can be problematic due to various causes, among them, the reduced economical profits from high insecticide costs, the destruction of natural enemies’ populations, the presence of insecticide residues on tomato fruits and the rapid development of insecticide resistance, especially when high levels of infestation are reached. The search for less-persistent active compounds would benefit horticultural production, as well as the environment and consumers. In the current study, we evaluated the toxicity of a hexane extract at different concentrations obtained from the chinaberry tree Melia azedarach L. (MA) fresh fruits, on TLM eggs, 2nd instar larvae and pupae by means of contact tests in the laboratory. Results indicated that with increasing concentrations, mortality of eggs, larvae and pupae also increased. Analysis of probit data showed that LC50 for MA extract in TLM eggs, 2nd instar larvae and pupae were 948.93, 346.72 and 1.75 μl/ml, respectively. We conclude that this extract has potential for controlling T. absoluta but further ecotoxicological studies should be carried out to conclude on its safety in other organisms and the environment.

The role of biodiversity in the dynamics and management of insect pests of tropical irrigated rice—a review

AbstractBiodiversity relevant to pest management of tropical irrigated rice pests is discussed in terms of variation within rice plants, rice fields, groups of rice fields and rice associated ecosystems. It is concluded that, in the unique cropping conditions and stable water supply of tropical irrigated rice, the manipulation of a relatively few manageable components of diversity can confer stability such that pests are mostly kept at levels which do not justify the use of insecticides. Durable rice plant resistance, including moderate resistance, together with ability to compensate for damage by certain key pests, are regarded as fundamental to successful biological control by the natural enemy complex. Reliable natural enemy action is also considered to depend on all-year-round continuity of prey or hosts made possible by the relatively short fallow periods between staggered two to three rice crops per year and by proximity of certain non-rice habitats, notably the vegetation-covered bunds (levées) surrounding each field. In contrast, synchronous cropping could upset stability by destroying the continuity needed for natural enemy success. Such conclusions are supported by the experience of farmers who use little or no insecticide. Much evidence on destruction of natural enemies by certain insecticides supports the contention that insecticide use, especially early in the crop season, upsets natural enemy control of insects such as Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) and also creates heavy selection pressure for strains of pests that can overcome previously resistant rice cultivars. Such circumstances create outbreaks of secondary pests and impair biological control of some key primary pests such as stem borers. It is concluded that pest management of much tropical irrigated rice must be based on natural controls rarely supplemented by insecticides. The success of this approach depends in particular on further research on dynamics of natural enemy and pest communities in rice ecosystems, especially where climatic conditions and water supply are marginally stable. Much more needs to be known about the nature and utilization of rice plant compensation for damage, particularly by defoliators and stem borers. The justification for, and supplementary use of, insecticides needs to be radically reassessed. There is no evidence that a natural control-based approach, as recommended in this review, is incompat ible with farmer practicability or with future developments in rice production technology, except perhaps the possible mechanization-driven increase in field size which would decrease bund area. In contrast, the insecticide-based approach is not only harmful to natural controls but is costly and mostly demands impracticable decision making by farmers on need-based use.

Resurgence of Nilaparvata lugens1 (Stål)Populations as Influenced by Method and Timing of Insecticide Applications in Lowland Rice

Resurgence of Nilaparvata lugens (Stål) after insecticide application is a common phenomenon in rice in South and Southeast Asia. Among other insecticides inducing resurgence, carbofuran, decamethrin, and methyl parathion were selected for this study. Of the various methods of carbofuran application tested, foliar sprays were most active in inducing resurgence. Extent of resurgence was highly influenced by time of insecticide application. Sprays of methyl parathion and decamethrin applied 50 and 65 days after transplanting (DT) induced resurgence in the third generation of N. lugens at ca. 90 DT, whereas earlier applications had little effect. The cause(s) for resurgence was not definitely established, but stimulation of N. lugens reproduction appeared to be of more significance than destruction of natural enemies.

An Ecological Approach to the Insecticide Problem

Insecticides effected important changes in the structure and physiology of the Brassica oleracea L. (Cruciferae) community. The number of species in some insecticide-treated communities were reduced to one-half, relative to the control community. Insecticides severely reduced the numbers of many species populations, but with some insect populations the insecticides caused density increases and in a few cases the populations increased 10-fold. The significant increase in pest populations resulted in most instances from insecticide destruction of natural enemies. Insect control without the usual complications of outbreaks, resistance, and residues is possible if the ecology of populations and communities is thoroughly understood and then insecticides are selectively applied.