Insect pests and their management in yam production and storage: a world review

Yam (Dioscorea spp.) is a tropical tuber crop produced for food and medicinal purposes. Yams are infested by a broad taxonomic diversity of insect pests. We reviewed a total of 73 insect species associated with Dioscorea species in different parts of the world. Yam is infested by 48 species when the crop is in the field, and after harvest (i.e. in storage) the tubers are attacked by 27 species. The majority of these insects belong to the order Coleoptera (35 species) followed by the orders Hemiptera (15), Lepidoptera (13), Isoptera (5), Hymenoptera (2), Diptera (1), and Thysanoptera (1). Yam scales, mealybugs, and a few beetles cause significant losses to tubers both in the field and in storage. We review various methods of management for these insect pests. An integrated approach towards managing these pests, both in the field and in storage, is essential. Post-harvest losses in storage of yam can be reduced, partly, by using biocontrol agents for mealybugs and scales. Alternative strategies for the management of insect pests of tubers in storage are discussed.     

Sensitivity of caterpillars of the pine tree lappet moth Dendrolimus pini to native isolates of entomopathogenic nematodes

Abstract

The pine tree lappet moth Dendrolimus pini (Lasiocampidae) is one of the most dangerous pests of pine Pinus sylvestris stands in Central Europe. To develop biological control method of this pest, the bioassay was made to assess the sensitivity of D. pini caterpillars to native EPMs strains representing two species: Steinernema feltiae and Heterorhabditis megidis in laboratory conditions. The results showed higher activity of S. feltiae strains which parasitized 86.7 - 100% of D. pini caterpillars, compared to the 20-100% of insects parasitized by H. megidis strain. Most nematodes were found in caterpillars treated with S. feltiae (in average 40 IJs/caterpillar), the least – in individuals parasitized by H. megidis (in average IJs/caterpillar). No effect of dose and temperature on parasitizm was found with S. feltiae strains while in H. megidis increased doses resulted in higher extensity of parasitism. The results indicate higher biological activity of S. feltiae strains and advisability of their further studies in field experiments.     

Host-based life cycle traits and detoxification enzymes of major looper pests (Lepidoptera: Geometridae) of tea from Darjeeling Terai,India

Three polyphagous looper caterpillars, Buzura suppressaria Guenée, Hyposidra talaca Walker and Hyposidra infixaria Walker, have established themselves as severe pests of tea [Camellia sinensis (L.) Kuntze] in the plantations of sub Himalayan West Bengal (Terai region). Schima wallichii (DC.) Korth. is a naturally occurring alternative host of all these looper species. To gain an insight into looper and host plant relationships, the present work contemplates studies on host preference, host-based life cycle traits and levels of detoxification enzymes, such as general esterases (GEs) and glutathione S-transferases (GSTs). From the study, host-induction of feeding preference was evident in all the three looper species. Hyposidra spp. exhibited similar post-embryonic development periods both on tea and S. wallichii, whereas B. suppressaria reared on tea needed a longer development period than on S. wallichii. Tea-reared caterpillars of Hyposidra spp. were significantly heavier, having higher quantities of GEs and GSTs than S. wallichii-reared ones. B. suppressaria, however, exhibited similar body weights on tea and S. wallichii. While GST level was higher in tea-reared B. suppressaria, its GE quantity was higher on S. wallichii. Although tea was found to be a more suitable host for Hyposidra spp., the host S. wallichii proved marginally better than tea for supporting B. suppressaria. However, all the three looper species could utilize the foliage of tea and S. wallichii successfully. So S. wallichii trees can act as a sylvan reservoir of the looper species, prompting their possible invasion of tea plantations and thus making management of looper pests in tea more difficult.     

Development of an integrated pest management programme for cotton. Part 1: Establishing and utililizing natural enemies

The strategy for the control of cotton pests, notably Helicoverpa spp., in Australia is insecticide-dependent with limited consideration of the role of beneficial insects. A programme for the development of an integrated pest management (IPM) approach commenced in cotton fields at Norwood near Moree in New South Wales in 1992. In this approach, an alternative crop, lucerne (Medicago sativa), was used in an interplant system plus spraying of cotton with a supplementary food (Envirofeast®), which served to attract and retain predators in treated plots. The predator complex consisted of predatory beetles, bugs, lacewings and spiders. The deployment of these two components, interplants and predator retention, reduced the number of Helicoverpa spp. eggs, very small and small larvae (first, second and third stages), medium and large larvae (fourth and fifth stages) and resulted in a cotton yield (2.72 bales ha^?1) that was significantly higher (p < 0.01) than the yield from the untreated control plot (0.59 bales ha -1 ). However, the yield from the interplants and food sprayed plot was significantly lower (p < 0.01) than in the insecticide-managed plot (7.12 bales ha^?1). Whenever the ratio of predators to Helicoverpa spp. (pests) per metre row of cotton was S 0.5, Helicoverpa pest numbers were maintained below the economic damage threshold. Though not successful in suppressing Helicoverpa spp. numbers, to avoid significant yield loss, further improvement could be made by introducing other potential components to the IPM strategy.     

Some new pests of glasshouse crops in Bulgaria and their control by an IPM programme1

Growing of vegetables and ornamentals in the open or as protected crops all the year round is a factor responsible for changes in the biology and ecology of some insects and mites, which can be summarized as follows: (1) the life cycle closes and development occurs all the year round; (2) pests adapt and new strains and populations appear (anholocyclic forms of Aphis naslurtii on capsicum; (3) northwards movement of distribution limits (Peridroma saucia, Chrysodeixis chalcites, Aculops lycopersici, Polyphagotarsonemus latus, Empoasca decipiens); (4)indifferent organisms become pests (Udea ferrugalis). From this point of view, the idea of a new pest must be given a wider interpretation. Details are given on P. latus, E. decipiens, U. ferrugalis and C. chalcites and their control. The following treatments are suitable for IPM programmes: seedling treatment with the systemic insecticide oxamyl, spraying with Thiozol 80 (a.i. 80% wettable sulphur) and Morestan (a.i. 25% quinomethionate) against P. latus; use of light traps and electric killers against Lepidoptera and spraying with Lepidocide (Bacillus thuringzensis) against caterpillars.     

Control of three major bollworm pests of cotton in Pakistan by a single application of their combined sex pheromones

Abstract

In the Punjab province of Pakistan, cotton is subject to attack by three major bollworm pests: Pectinophora gossypiella, Earias vittella and £ insulana. Because of the difficulty of controlling these pests once their larvae have penetrated the bolls, early season control is essential. A non‐toxic method is desirable if beneficial insects are not to be destroyed. Tests with a Mitsubishi ‘twist‐tie’ pheromone formulation containing the major components of Pectinophora and the two Earias spp. achieved almost complete trap suppression of all three species for up to eight weeks duration following a single application at the pin‐square stage. Visual observations confirmed a complete lack of moth activity indicating that control by mating disruption was attainable.     

Conference Reports

Abstract

In an insect pests survey of soybean during 1977–1980, in the rabi and kharif seasons, 14 species were more, and 33 species less abundant, representing 19 families under seven orders. The occurrence of Aphis spp., Atractomorpha spp., Spilosoma obliqua W., Monolepta signata Olv., Nezara viridula L., Myllocerus spp., Riptortus spp., and Jassids were most notable.     

Note: Histology of the midgut and peritrophic membrane inLymantria dispar caterpillars fed on leaves ofQuercus cerris orRobinia pseudoacacia

The structure of the columnar cells, goblet cells and peritrophic membrane was studied in the midgut of gypsy moth (Lymantria dispar L.) caterpillars fed with a suitable (Quercus cerris L.) or an unsuitable (Robinia pseudoacacia L.) host. Columnar cells in the midgut of caterpillars fed onR. pseudoacacia leaves were elongated with small nuclei, partial loss of microvilli and vacuolated cytoplasm. The number and height of goblet cells and their nuclei were greater in caterpillars fed onQ. cerris leaves in comparison with larvae fed onR. pseudoacacia leaves. Peritrophic membranes were thin and delicate in the midgut of caterpillars fed onR. pseudoacacia leaves. http://www.phytoparasitica.org posting Nov. 8, 2005.     

Insect Pests of Rice in Laos

Abstract

The insect species feeding on rice in Laos were investigated during 1973–75. Populations were usually small but the most common species were Patanga succincta (L.), Leptocorisa spp. and Nezara viridula (L.) on the upland rice; Oxya and Euscyrtus spp. in the seedbeds and Chilo polychrysus (Meyr.), C. suppressalis Wlk. and Sesamia inferens (Wlk.) in the transplanted paddy rice of the lowlands. The natural enemies of these species were recorded.     

Benefits of a maize–bean–weeds mixed cropping system in Urubamba Valley,Peruvian Andes

Abstract

In the Urubamba Valley, Peruvian Andes, we evaluated the abundance of insect pests and natural enemies in experimental plots where maize was grown either as monoculture, intercropped with beans, or intercropped with beans plus associated weeds. We also assessed the consequences of the cropping system for maize yield. The main insect pests recorded were Diabrotica spp. (Coleoptera: Chrysomelidae), Carpophilus sp. (Coleoptera: Nitidulidae) and Pagiocerus frontalis (Coleoptera: Scolytidae), and their overall abundance did not differ among crop diversity treatments. However, there was a significant adverse effect of crop diversity on the maximum abundance of both Carpophilus and Pagiocerus. The main beneficial arthropods were Paratriphleps sp. (Hemiptera: Anthocoridae), ladybirds and spiders, and their density did not differ among treatments. Maize yield did not decrease with increasing plant diversity. The reported benefits of intercropping, together with the associated efficiency in land use, make this traditional agricultural practice a valuable alternative to the use of pesticides, particularly for resource-poor Andean farmers.     

National control measures for Globodera spp.1

Potato cyst nematodes (Globodera spp.) are present in most potato-growing areas of the EPPO region. Populations in infested fields are rather easily suppressed by crop rotation. Thus, further spread of these nematodes can be prevented by a national control campaign that prohibits the cultivation of potato on infested plots until the population has been shown by a standard soil test to have declined to a non-detectable level. Alternatively, resistant potato cultivars may be grown, or early ware potatoes which are harvested before cysts mature, or the soil may be disinfested (ware potatoes only). Such rules are widely applied in European countries, but have been successful only in containing the pest (the infested area has not declined). There is now discussion on the application of more stringent measures for seed potatoes, and less stringent (or even deregulation) for ware potatoes. The Globodera spp. might accordingly be treated as regulated non-quarantine pests.     

A review of the pest management situation in mango agroecosystems

Integrated pest management programs for mango must be based on sampling and on economic thresholds, and must take into account the effects of cultural practices, horticultural sprays and disease control on pest and natural enemy interactions. An analysis of the mass of information available on the different mango pests,viz., fruit flies(Bactrocera sp.,Ceratitis sp.,Anastrepha sp.), mango seed weevil(Sternochetus mangiferae), thrips(Frankliniella spp.), gall midges(Procontarinia sp.), scales, mites and mealybugs is given, as well as different examples for future entomological research.     

Problems caused by Sorghum halepense in Australia

Abstract

Sorghum halepense (L.) Pers. (Johnson grass) is an important weed in many countries. In Australia it invades crop lands, provides a harbour for diseases and insect pests of sorghum and maize, contaminates sorghum grown for seed and constitutes a safety hazard along roadsides.     

Evaluation of powdered fruits of four peppers (Capsicum spp.) for the control of Callosobruchus maculatus (F) on stored cowpea seed

Abstract

The efficacy of two application rates of powdered fruits of four types of peppers (Capsicum spp.) was evaluated for the control of Callosobruchus maculatus (F). The various pepper powders at 2.5 g‐5.0 g per 250 g of seed were effective in reducing oviposition and damage to cowpea seeds. The pepper type Capsicum frutescens var. yarmunchi was the most effective in discouraging oviposition and minimizing damage to the seed, as indicated by the significantly lower number of emergence holes. The seed quality and viability were not affected by the powdered pepper fruit treatment. The result is indicative of the potential for the use of powdered fruits of some peppertypes in protecting stored cowpea seeds against C. maculatus.     

Relative resistance or susceptibility of maple (Acer) species,hybrids and cultivars to six arthropod pests of production nurseries

BACKGROUND: Maples (Acer spp.) in production nurseries are vulnerable to numerous arthropod pests that can stunt or even kill the young trees. Seventeen cultivars representing various Acer species and hybrids were evaluated for extent of infestation or injury by shoot and trunk borers (Proteoteras aesculana, Chrysobothris femorata), potato leafhopper (Empoasca fabae), Japanese beetle (Popillia japonica), maple spider mite (Oligonychus aceris) and calico scale (Eulecanium cerasorum). Evaluations were done in replicated field plots in central and western Kentucky. RESULTS: All of the maples were susceptible, to varying degrees, to one or more key pest(s). Red maples (A. rubrum) were relatively vulnerable to potato leafhopper injury and borers but nearly free of Japanese beetle feeding and spider mites. Sugar maples sustained conspicuous Japanese beetle damage but had very low mite populations, whereas the opposite was true for Freeman maples (A. × freemanii). A. campestre was heavily infested by calico scale. Within each species or hybrid there were cultivar differences in degree of infestation or damage by particular pests. CONCLUSION: The results should help growers to focus pest management efforts on those plantings at greatest risk from particular pests, and to choose cultivars requiring fewer insecticide inputs to produce a quality tree. Copyright © 2012 Society of Chemical Industry     

Chemical Weed Control in Tobacco in Trinidad

Abstract

Ramie, the vegetable fibre, is obtained from the stem of Boehmeria 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 by Rosellinia necatrix, leaf spot caused by Cercosporo spp. and Phyllosticta spp., seedling rot caused by Rhizoctonia solani, cane rot caused by Macrophomina phaseolina and eye rot caused by Myrothecium roridum. A number of diseases of minor importance are also reviewed.     

Over enige insecten in lisdodden

Summary Observations on the biology ofLimnaecia phragmitella Stt. (fam. Momphidae, Lepid.) — made in the Netherlands — are mentioned.The species was previously considered as being rare but now is known to be numerous in a few areas. The caterpillars live in the heads of Typha where they feed on the seeds and later on the core. They hibernate when halfgrown, develop further in the spring and early summer and pupate in June; the moths appear during July.The species has a worldwide distribution: England, Central and Southern Europe, Northern Africa, Australia, New Zealand and the United States of America. In the latter country it was studied byP. W. Claassen together with a number of other Typha-insects occurring in the U.S.A. (Cornell Un. Memoir 47, Oct. 1921).The present author has found an hemipteron,Chilacis typhae Perris (Lygaeidae), in Typha heads occurring together with the caterpillars ofLimnaecia. This insect has also been reported in the literature as being rare in the Netherlands. It is suspected of living on the caterpillars but this has not been shown.     

Estimation of Root-knot Nematode Infestation Levels on Roots Using a Rating Chart

Abstract

A rating chart is given which enables easy and accurate field assessment of damage by root-knot nematodes (Meloidogyne spp.) on many crops, based on the percentage and types of roots galled. It should be of use both to nematologists and untrained field workers.     

Nature and importance of weeds in sorghum in the Yemen Arab Republic

Abstract

Grain sorghum (Sorghum bicolor (L.) Moench) is the dominant crop in North Yemen agriculture, covering about 70–80% of the arable land. Weed control is still carried out mainly by hand. Many of the weeds are used as fodder for animals. A total of 137 weeds was collected in sorghum. Most frequent were Cynodon dactylon (L.) Pers. and Cyperus mtundus (L): their importance decreased, however, under a well‐established sorghum crop providing good shade cover and under conditions of increased crop fertilization with mineral nitrogen. Under these conditions, for example, Commelina spp. and Flaveria trinerva (Spreng.) Mohr became commoner. Thus increased use of nitrogen altered the nature and hierarchy of the weed flora. Relationships between the indicator figures of the weeds and the habitat, as defined by Ellenberg, were confirmed. Traditional methods of weed control have so far worked well, as witness an average cover of 60% sorghum and 20% weeds. In future, however, rising costs and labour shortages will increase the demand for less time‐consuming weed control strategies.     

Indirect interactions between rust (<Emphasis Type="Italic">Melampsora epitea</Emphasis>) and leaf beetle (<Emphasis Type="Italic">Phratora vulgatissima</Emphasis>) damage on<Emphasis Type="Italic">salix</Emphasis>

Willows (Salix spp.) are beneficial as a potential source of renewable energy, riparian barriers and riverbank control, yet are considered invasive weeds when they clog watercourses and lead to erosion and flooding. Interactions between willow rustMelampsora epitea (Thüm.) (Uredinales: Melampsoraceae) and leaf beetlePhratora spp. (Coleoptera: Chrysomelidae) feeding damage have an impact on effective pest management and biological control. The present study investigated the effects of(a) prior mechanical leaf damage on rust development, and(b) rust infection on beetle feeding under laboratory conditions for different time intervals and levels of damage. Willow rust infection significantly reduced the amount of leaf area consumed by beetles. The result was similar when a compatible or an incompatible rust pathotype was sprayed ontoSalix viminalis (L.) ‘Mullatin’ plants. There were no overall significant effects of mechanical damage on rust development, although the lowest level of rust infection was found with the incremental damage treatment. There were, however, differences of significance for leaf position and damage status, with damaged leaves at all positions having fewer pustules and a smaller pustule area than the corresponding undamaged leaves. There was no detectable effect of possible volatile emissions from crushed willow leaves on rust infection and development, although the volatile compoundcis-3-hexenyl acetate significantly reduced pustule diameter and overall pustule area. The results are discussed in terms of the implications for pest management and biological control. Corresponding author http://www.phytoparasitica.org posting April 6, 2003.