Effects of physical barriers and eradication on recolonization of rodents in poultry farms

Abstract

Mus musculus, Rattus rattus and Rattus norvegicus are pests in poultry farms, causing economic losses and transmitting diseases. Control is commonly conducted through anticoagulant rodenticides, but this control is not effective through time. We aimed to assess the effect of rodent exclosure on long-term success of rodent control in poultry farms of the pampean region, Argentina, and to evaluate indirect estimators of rodent abundance. In both exclosure and non-exclosure sheds rodent abundance decreased significantly after eradication but mice populations showed a recovery, suggesting that the eradication was not complete. Rats did not recover, but the low abundance found at the beginning of the experiment does not allow an accurate conclusion.     

The control of mole,water vole and muskrat with phosphine1

The number of rodenticides for control of outdoor rodents and the number of uses of the remaining products is declining. Phosphine is valued highly because it causes no secondary poisoning and is considered to be environmentally safe. Although it has been used against mole (Talpa europaea) and water vole (Arvicola terrestris) in some countries for decades, in other countries a breakthrough is more recent. The development of a new formulation, generating phosphine rapidly, may also contribute to a wider use. In the Netherlands investigations have been undertaken on the mode of application against mole and water vole. Experiments against muskrats (Ondathra zibethicus) show promising results. The use of phosphine against this rodent could save on labour considerably, when compared to trapping.     

Management of resistance to pesticides in cotton pests

Abstract

In recent years, nationwide insecticide resistance management (IRM) strategies in Zimbabwe, Egypt and Australia have successfully overcome existing resistance problems on cotton and prevented further outbreaks in some key pests. These strategies, which rely heavily on pragmatic assumptions regarding the efficacy of counter‐measures and the biology of the pest, relate little to theoretical models of resistance management whose tenets have so far not been experimentally appraised. These IRM strategies are compared with a simple but rigid programme used throughout Francophone countries of Africa that has successfully controlled the pest complex on cotton and increased yield without eliciting resistance in any pests. We examine the motivations, philosophies and logistics of these control programmes on cotton, and outline scope for improvements to existing and future IRM.     

Weed Control Work in Progress at the University of the West Indies

Abstract

The annual reports of the Herbicide Research Unit of the University of the West Indies were a regular feature of past issues of PANS. Although the Herbicide Research Unit is no longer in being, investigations on weed control problems are still in progress, as part of the programme of the newly-formed Agronomy Research Unit. This article briefly reports some of the weed control work carried out by this unit in Jamaica during 1970.     

Insect Repellents

Abstract

Many countries in the Arabian Peninsular are anxious to develop fully their limited agricultural resources. A knowledge of plant diseases and nematodes which attack their crops is essential before this is achieved. A survey of these in The Sultanate of Oman shows that soil-borne pathogens predominate and that the damage they cause is exacerbated by soil conditions. Nevertheless, some important pathogens are absent and hopefully their introduction to the relatively new agricultural areas in this part of the world can be prevented.     

The influence of anticoagulant resistance on effective rodent control in the UK1

Widespread use of warfarin, and other multiple-dose anticoagulants, selected populations of warfarin-resistant rodents in the UK and in other countries. The effectiveness of rodent control was dramatically reduced when the resistant animals formed a large proportion of a population. The second-generation anticoagulants were developed to overcome these practical control problems with warfarin and were considered to be effective rodenticides against warfarin-resistant populations. In the UK, however, difenacoum showed reduced efficacy for controlling an established warfarin-resistant Rattus norvegicus population covering a substantial area of farmland in southern England. Continued use of difenacoum selected for difenacoum-resistant animals, so that the rodenticide is now ineffective for controlling rats in three counties. Brodifacoum was subsequently used to control some infestations and there is evidence that these treatments selected for animals with an increased level of resistance to brodifacoum. Anticoagulant resistance in Mus domesticus is less of a practical problem because of the availability of non-anticoagulant rodenticides for the control of this species. There is evidence, however, of bromadiolone resistance in M. domesticus trapped on farms in the UK. Recent investigations of the mechanism of anticoagulant resistance in R. norvegicus have indicated that vitamin K3 (menadione) is an antidote to anticoagulants in resistant animals. This form of the vitamin is included as a dietary supplement in poultry and pig food and would aid the survival, and therefore increase the selection, of resistant animals when anticoagulants are used exclusively.     

Common vole (Microtus arvalis) ecology and management: implications for risk assessment of plant protection products

Common voles (Microtus arvalis) are common small mammals in some European landscapes. They can be a major rodent pest in European agriculture and they are also a representative generic focal small herbivorous mammal species used in risk assessment for plant protection products. In this paper, common vole population dynamics, habitat and food preferences, pest potential and use of the common vole as a model small wild mammal species in the risk assessment process are reviewed. Common voles are a component of agroecosystems in many parts of Europe, inhabiting agricultural areas (secondary habitats) when the carrying capacity of primary grassland habitats is exceeded. Colonisation of secondary habitats occurs during multiannual outbreaks, when population sizes can exceed 1000 individuals ha^?1. In such cases, in‐crop common vole population control management has been practised to avoid significant crop damage. The species' status as a crop pest, high fecundity, resilience to disturbance and intermittent colonisation of crop habitats are important characteristics that should be reflected in risk assessment. Based on the information provided in the scientific literature, it seems justified to modify elements of the current risk assessment scheme for plant protection products, including the use of realistic food intake rates, reduced assessment factors or the use of alternativee focal rodent species in particular European regions. Some of these adjustments are already being applied in some EU member states. Therefore, it seems reasonable consistently to apply such pragmatic and realistic approaches in risk assessments for plant protection products across the EU. © 2013 Society of Chemical Industry     

The control of commensal rodents in Britain1

Rattus norvegicus and Mus domesticus are the only significant commensal rodents in Britain, though Rattus rattus is also present in a few places. R. norvegicus is by far the most important pest of agriculture. No recent quantitative information is available on the status of rodent infestation, damage or control, though these are generally considered to be satisfactory and to have altered little in the last few years. In particular, there seem to be no infestation problems of practical significance that cannot be adequately resolved by currently available control techniques. Recent developments of practical interest include the occurrence of rodent damage to the plastic bags in which big bale silage is preserved, low-grade resistance to difenacoum in R. norvegicus in one locality, and the continued introduction of improved rodenticides. New legislation has been introduced giving government comprehensive powers over the use of pesticides, under which rodenticides must now be assessed for safety, efficacy and humaneness. Responsibility for research, training and extension in rodent control has largely been devolved to the private, academic and local government sectors, with central government now undertaking these activities only on a commercial basis. The nature and significance of these changes is discussed.     

The Chain Scythe,a Simple Tool for Controlling Aquatic Weeds in Irrigation Canals

Abstract

Use of the chain scythe for aquatic weed control in irrigation canals in developing countries is described. Each weeding operation involves comparatively little effort and cost, although regular weeding rounds are necessary to maintain control. The optimum interval between operations depends on local conditions. On the basis of a calculation given in the paper, the costs of cleaning canals can be estimated.     

Tenth international congress of plant protection,Brighton, November 1983

Abstract

Field trials were conducted to control rodent pests of wheat crop by improving bait acceptability through taste enhancers (additives). Egg shell, egg yolk, yeast, minced meat, sheep blood and chicken blood were mixed 2% by weight individually in a bait base of broken rice and wheat flour. Brodifacoum and bromadiolone bait with egg shell additive ranked first, and egg yolk second, in preference over other additive poison baits and poison bait without additive. Poison baiting yielded 93.3% and 86.7% reduction in rodent population with brodifacoum and bromadiolone (0.005% each), respectively. Three baitings, at tillering, flowering and maturity stage of the crop, gave 91.0% tiller damage reduction with brodifacoum and 86.0% with bromadiolone as compared to control (untreated). It is concluded that three poison baitings containing egg shell additive should be initiated at tillering stage followed by flowering and maturity of the wheat crop for increased yield.     

Search for Climatic Models for Forecasting Microtine Outbreaks1

Models for forecasting outbreaks of harmful Microtines are discussed in terms of the three most important types of rodent damage to agriculture and forestry in the European part of EPPO region: problems to field crops by Microtus arvalis and related species, to horticulture and forestry by M. agrestis and some other species, and injury to the underground parts of various crops by Arvicola terrestris. Two models were developed in parallel but independently for M. arvalis, one in the USSR, the other in France; the former approach included M. socialis. A joint Scandinavian project resulted in models for M, agrestis and Clethrionomys glareolus: the outcome is exemplified by the former case and a few comments are given on other types of model development. The probable mechanism of climatic influence through the food chain on the population dynamics of Microtine rodents is discussed and it is concluded that climatic models are a useful tool in planning rodent control strategies. The role of the EPPO Working Party on Field Rodents as a coordinating body in the development of rodent forecasts is also reviewed.     

Armyworm Control

Abstract

An account is given of the African armyworm, Spodoptera exempta (Walk.), as a noctuid pest of agriculture, and of the recent research into its biology and control in East Africa. Salient features in its biology and zoogeography are discussed, from the standpoint of the way in which they determine control methods and strategy. Special attention is given to the forecasting of outbreaks. Comparative reference is made to forecasting systems and techniques as practised in other countries and with different insects.     

1977 British Crop Protection Conference —Pests and Diseases,Brighton, November 1977

Abstract

The golden apple snail, Pomacea canaliculata (Lamarck, 1822) (Mesogastropoda: Pilidae), has recently been introduced to several Asian countries where it has unexpectedly developed into a pest of rice. Reasons for the introduction as well as the economic and ecological impact of the snail are described. Most farmers have resorted to chemical control, with implications for human health and the environment. Integrated snail management practices are summarized including the use of the snail as a valuable aquatic resource. It is concluded that research on control strategies is urgently needed but requires sound knowledge of the ecology of the snail in its natural habitat.     

The Effect of Numerous Herbicides on the Germination of Orobanche aegyptiaca and Striga hermontheca

Abstract

Two hundred and thirty seven chemicals were tested to determine their effect on the germination of Orobanche aegyptiaca and Striga hermontheca. From their activity in these tests and a knowledge of their general properties the following are regarded as being the most promising for the pre-em. control of (1) Orobanche — oryzalin, dichlobenil, chlorthiamid, nitralin and chloramben. (2) Striga — 2, 4-D, MCPA and a range of other phenoxy compounds, chlorfenac, with MON 097, prynachlor, PH 40–21, PRB-8, RU 12068 and U 27658 showing the most interesting activity among the newer compounds.     

The European Weed Research Council's 3rd Symposium on Aquatic Weeds

Abstract

Parthenium has been recognised as a serious weed in Queensland only since 1974, but subsequently it has spread explosively mainly along roads in rangeland country. The weed has become the subject of an intensive research and control programme and large sums of Government money are being made available for its containment. The distribution and biology of this weed in Australia are described, and possible control measures discussed.     

Insect Enemies of Aquatic Weeds

Abstract

The Agricultural Research Service of the USDA has been actively engaged in research on the biological control of aquatic weeds since 1959. Research emphasis until 1967 was on alligatorweed, Alternanthera philoxeroides (Mart.) Griseb. As a result of this research, three species of insects from Argentina were released in the southeastern United States. Alligatorweed control with these natural enemies has been variable; but indications are that control will be substantial over most of the range of the weed.

One species of weevil, Neochetina eichhorniae Warner, has been released against water hyacinth, Eichhornia crassipes (Mart.) Solms, in the USA as a result of research in Argentina. A second closely related species, N. bruchi Hustache, is presently undergoing final clearance procedures. Several other arthropods are being studied in Argentina as possible biological control agents of water hyacinth.

A USA sponsored programme in Yugoslavia under the direction of Dr M Leki? resulted in the discovery of two insect species that show potential as control agents for eurasian watermilfoil, Myriophyllum spicatum L. Further testing for host specificity of these insects will be carried out in the USA in quarantine in Florida.

A USA sponsored Pakistan programme under Dr M. A. Ghani is investigating insects and other phytophagous organisms attacking Hydrilla verticillata Royle. The results are encouraging. PANS 20: 444–450, 1974.     

Successful biological control of water hyacinth (Eichhornia Crassipes) by Neochetina eichhorniae (Coleoptera: curculionidae) in Bangalore,India

Abstract

Water hyacinth is the most serious aquatic weed in India, infesting more than 200000 ha of water surface. Successful biological control of this weed was achieved in a fully infested tank covering 20 ha at Bangalore. More than 95% of the infestation was cleared within 32 months by releases of Neochetina eichhorniae Warner. The insect also spread along a water channel and controlled water hyacinth infesting a nearby tank. Drying up of the tank after the insect population had spread throughout and increased to 3.1 adults/plant hastened weed control. Fresh plants emerging after rains were suppressed by the residual population of insects. N. eichhorniae along with N. bruchi Hustache is being supplied to centres throughout the country for multiplication and releases. Sustained efforts with these insects holds out promise of control of water hyacinth in India.     

Five-year Surveillance of Small Mammal Abundance in Scandinavian1

A large-scale surveillance system was established in 1971. It was based on the practical needs for information on the fluctuation in numbers of harmful rodents and the desirability of forecasts. The sampling method used was the Small Quadrat Method (SQM). The annual surveys covered about 50 localities in Norway, Sweden and Finland, the total number of SQ's being over 2,000, and the total number of specimens caught approaching 18,000. In terms of numbers, the dominant rodent species were Microtus agrestis (L.) and Clethrionomys glareolus (Schreber), the former clearly dominating in Finland, the latter in most regions of the other 2 countries. In southern Sweden and Norway, Apodemus species were also relatively abundant, as was Sorex araneus L. in certain regions. During the 5-year period under study, the numbers of M. agrestis peaked twice (1972 and 1975) in Finland but only once in Sweden and Norway. The peak years of C. glareolus mosdy coincided with those of M. agrestis but, in some areas, were slightly earlier. Fluctuation in numbers of Insectivora did not seem to be correlated with that of the rodents. The usefulness of the SQ indices as a basis of short-term forecasts is apparent, while criteria for long-term forecasts require further analysis.     

Weed Control in Wheat and Barley in the Middle East

Abstract

Wheat and barley constitute the bulk of agricultural production in the Middle East. Unfortunately, these crops are grown on marginal soils which are infested with annual and perennial weeds. The principal weed species include Avena sterilis L., Convolvulus arvensis L., and Sinapis arvensis L. and it has been estimated that yield losses due to weeds are between 20 and 30%. Control is mostly by hand pulling, hoeing or mechanical tillage, the use of herbicides being limited to about 2–5%, of the cereal area. The chemical used is usually 2,4-D but there are a few applications of barban. With the increase in wages, and unavailability of agricultural labour it is suggested that herbicide application should be widely used in the Middle East. Mixtures with benzonitriles and dicamba should be used in addition to the economical phenoxy herbicides to widen the spectrum of control of broadleaved weeds. Glyphosate may also be used after grain harvest for the control of perennial weeds and tri-allate, chlortoluron and other chemicals for the control of wild oats and other grasses. Plant breeders should study the genetic response of newly developed varieties to the most widely used herbicides.     

Metabolites of some biological control agents

The evidence is reviewed for the structure and biosynthesis of some metabolites of Trichoderma and Gliocladium species that are being considered as fungal biological control agents. The diverse biosynthetic capability of these organisms is proposed as a criterion for their potential application as bio-control agents.