摘要:

The Western Ghats squirrel,Funambulus tristriatusWaterhouse; the South Indian palm squirrel,F. palmarumLinnaeus and the black rat,Rattus rattusLinnaeus were observed to be causing much damage to cocoa in South India; the palm civet,Paradoxurus hermaphroditusPallas and the bonnet monkey,Macaca radiataGeoffroy were causing minor damage. Monthly surveys made for one year in Karnataka showed that the percentage of damage caused by rodents was 29.0; that by civets and monkeys 0.4 and 0.3 respectively. In Kerala and one district of Tamil Nadu rodents were estimated to be causing 15% damage and civets 3%; no monkey damage was found.

ISSN:0143-6147    

DOI:10.1080/09670878109413798

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Morphological characters are described and illustrated to permit identification of the females of five species ofAtherigona (A. soccataRondani,A. conigeravan Emden,A. trapeziavan Emden,A. laevigata(Loew) andA. (Acritochaetal orientalisSchiner).

ISSN:0143-6147    

DOI:10.1080/09670878109413799

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A search for natural enemies of leaf and planthoppers, especially egg parasites, for use in the integrated control programme, was carried out during 1976-78 in the Central Plain, the north and the north-east of Thailand. Parasitised batches of eggs ofNilaparvata lugens(Stål),Sogatella furcifera(Horv.),Nephotettix virescens(Dist.) andNephotettix nigropictus(Stål) were collected from the paddy fields and kept under room conditions for the emergence of adults of parasites; the parasites were then identified.Paracentrobia garudaSubba Rao,Oligositasp. A andConatocerussp. were found to be the egg endo-parasites ofN. virescensandN. nigropictusin the north and the north-east.Oligositasp. A had never been found in the Central Plain.P. garudawas dominant in the north whileOligositasp. A was dominant in the north-east in 1976 and 1978.Anagrussp. andOligositasp. B were egg endo-parasites ofN. lugensandS. furcifera. Anagrussp. was a dominant egg endo-parasite ofS. furciferaboth in the north and the Central Plain, and in the Central Plain ofN. lugens. The host-specificity of these rjarasites was also observed.

ISSN:0143-6147    

DOI:10.1080/09670878109413800

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A field trial was conducted during the cotton growing seasons of 1978-79 and 1979-80 at Hissar, Haryana (India) to determine the capture threshold of male pink bollworm moths in traps baited with gossyplure for timing the insecticidal application. It was found that application of insecticides when the number of male moths averaged 4 or 8 per trap per night was superior to fixed spray schedule (spraying at an interval of 13-14 days starting from middle of August) in reducing the pink bollworm incidence and obtaining higher yield of seed cotton. For effective and economic control of the pest, insecticides should be applied within 24-48 hours when the number of male moths captured in gossyplure baited traps reaches 8 per trap per night.

ISSN:0143-6147    

DOI:10.1080/09670878109413801

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A survey of termite damage to groundnuts and an estimation of loss in yield was made between 1977 and 1979 in northern Nigeria. The foliage was attacked byOdontotermes. Damage was restricted to the Sudan savanna and loss in yield was less than 5%. Much more important was the damage caused byMicrotermes lepidusSjöstedt which attacked the pods, the tap root and the haulms. There was a linear relationship between the percentage of stands with the tap root invaded byMicrotermesand the loss in yield. Damage varied from year to year, but the higher yield losses (up to 40%) were consistently recorded in the Sudan savanna. There was a significant relationship between the level ofMicrotermesdamage and rainfall, the latter having a marked influence on foraging behaviour and the level of foraging activity. The chemical control of termites is economically viable on mechanised farms in the Sudan savanna, but cannot be justified on peasant farms, where yields are too low.

ISSN:0143-6147    

DOI:10.1080/09670878109413802

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The incidence of termite-scarified groundnut pods and resulting kernel contamination in field and market samples were studied in northern Nigeria. Scarification was caused byMicrotermes lepidusSjöstedt and restricted to the more mature pods. In the field, scarification was more common in the Sudan Savanna vegetation zone. The incidence of scarification was much higher (40.9-87.9% of the pods) in the dead stands where the tap root had been invaded by Microtermes, than in healthy stands (7.9-31.6% of the pods). In the market samples, the number of scarified pods rarely exceeded 5%. 85-91% of the kernels from scarified pods were infected, the dominant fungi beingMacrophomina phaseoli(Maubl.) Ashby (37-61%) andFusariumspp. (8-26%). Less than 5% of kernels were infected byAspergillussp. The fungi carried by the termites bore little relation to those contaminating the kernels. 67% of the kernels from undamaged pods taken from dead stands were infected, indicating that - compared with premature plant death - scarification was of secondary importance in inducing fungal contamination. The quality of infected planting seed was not affected when the seed was dressed with Fernasan D.

ISSN:0143-6147    

DOI:10.1080/09670878109413803

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Pest control recommendations in Papua New Guinea cocoa plantings are based on an integrated approach to insect pest and disease management. The most damaging problems arePantorhytesweevils, black pod and bark canker disease (both caused byPhytophthora palmivora) but vascular streak dieback (VSD) disease is important in some areas of the country. Most other insect pests can be kept to insignificant levels by cultural or biological controls, but occasional outbreaks causing crop loss or tree damage may require spot treatments mainly of non-persistant insecticides. Recent investigations have shown that certain cocoa environments are unfavourable toPantorhytesand some other major pests. In particular, the selection of shade types and levels, the spot treatment of borer channels with penetrant insecticides and the introduction of antagonistic ant colonies can reduce populations of the main insect pests to low and stable levels. These measures would decrease the incidence ofP. palmivorapod rot by replacing some ant vectors with a non-vector and reduce bark canker infections which are frequently associated with borer attack. The improved condition of the cocoa canopy following control measures will also reduce weed growth. In addition, planting material resistant to VSD, black pod and bark canker is currently being propagated and released to growers.

ISSN:0143-6147    

DOI:10.1080/09670878109413804

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The recent spread of coffee rust, sugarcane rust, black leaf streak of banana andAlternariablight of wheat are recorded and the implications of new disease records are discussed.

ISSN:0143-6147    

DOI:10.1080/09670878109413805

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Surveys of maize for virus and mycoplasma-like diseases were conducted in Peru in 1978 and 1980. The following pathogens were discovered and identified: aphid-borne maize dwarf mosaic virus, beetle-borne maize chlorotic mottle virus,Peregrinus maidis-borne maize mosaic and maize stripe viruses, andDalbulus maidis-borne maize rayado fino virus, corn stunt spiroplasma (CSS) and maize bushy stunt mycoplasma (MBSM). Some of these insect-borne pathogens are important constraints to maize production in Peru. Maize chlorotic mottle in the department of Lima and Cajamarca and ‘puca poncho’, a disease caused by CSS and/or MBSM, in Ayacucho significantly limit maize yields. As a result of these surveys, we believe that the principal maize virus and mycoplasma-like diseases in Peru have been identified, an accomplishment unrealised in other Latin American countries at present.

ISSN:0143-6147    

DOI:10.1080/09670878109413806

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Ramie, the vegetable fibre, is obtained from the stem ofBoehmeria nivea(L.) Gaud, and is used in many textile products. It is grown in tropical, sub-tropical and temperate regions and the main countries where it is grown are China, Brazil and the Philippines. However, it is only a minor crop in terms of world trade. The diseases of ramie are discussed in relation to their occurrence, symptoms and control measures. The major and most widespread diseases are white fungus caused byRosellinia necatrix, leaf spot caused byCercosporospp. andPhyllostictaspp., seedling rot caused byRhizoctonia solani, cane rot caused byMacrophomina phaseolinaand eye rot caused byMyrothecium roridum. A number of diseases of minor importance are also reviewed.

ISSN:0143-6147    

DOI:10.1080/09670878109413807

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor