Mung bean (<Emphasis Type="Italic">Vigna radiata</Emphasis>) cultivars mediated oviposition preference and development of <Emphasis Type="Italic">Callosobruchus chinensis</Emphasis> (Coleoptera: Chrysomelidae: Bruchinae)

The Azuki bean weevil, Callosobruchus chinensis (L.), is a destructive pest of stored mung bean [Vigna radiata (L.) Wilczek] as well as other leguminous seeds. The development of resistant seeds to manage this pest is of current great interest to plant breeders. In this study, we investigated the oviposition preference and development of C. chinensis on two susceptible mung bean cultivars (Seonhwa and Gyeongseon) and one previously reported resistant cultivar (Jangan), compared to the susceptible cowpea (Vigna unguiculata L.), cultivar (Yeonbun) using both multiple-choice and no-choice tests. In addition, the development of C. chinensis was also examined at four constant temperatures (20, 25, 30, and 35 °C). Both tests found cowpea to be the most suitable seed for oviposition. Total developmental time from oviposition to adult emergence ranged from 27.01 to 38.2 days, being shortest on cowpea and longest on the mung bean, cv. Jangan. However, no successful development of C. chinensis larvae on mung bean, cv. Jangan, occurred at any temperature. The highest rate of adult emergence and the longest adult longevity both occurred on cowpea and certain mung bean cultivars (Seonhwa and Gyeongseon), with the dramatic exception of cv. Jangan. These results suggest that the higher preference and performance of C. chinensis on cowpea (3.3 egg/seed) and least on mung bean, cv. Jangan (0.4 egg/seed). This information may facilitate the exploration of resistant genetic materials and chemicals associated with seeds for successful breeding. Further studies should examine the chemicals associated with mung bean cultivars and its resistant mechanism to develop a control method against bruchines.     

Evaluation of different leguminous seeds as food sources for the bean bug Riptortus pedestris

This study was conducted to determine the effects of six different leguminous seeds (cowpea, white kidney bean, soybean cultivars Cheongja and Daepung, mung bean, and azuki bean) on the life history traits of the bean bug Riptortus pedestris (F.) (Hemiptera: Alydidae). The total developmental time from the first instar nymph to adult ranged from 18 to 25 d; R. pedestris fed with white kidney beans were the slowest to develop. In addition, bugs fed with white kidney beans had the highest mortality (93%) and the shortest longevity (18 d). R. pedestris fed with cowpeas, soybeans, or azuki beans had high reproductive success, with the highest egg hatching success recorded in bugs fed cowpeas. The results suggest that cowpea may be a beneficial food source for the development and reproduction of bean bugs.     

Parasitism of grain legumes by Alectra species (Scrophulariaceae)

In glasshouse pot experiments in the United Kingdom, the host preference of nine seed samples of Alectra vogelii from Eastern, Western and Southern Africa and of two samples of A. picta from Cameroon and Ethiopia, to cultivars of cowpea, groundnut, bambara and mung bean, was assessed. A susceptible cowpea cultivar, Blackeye, and four cultivars of groundnut were attacked by all samples of both parasitic species regardless of whether the host of origin was cowpea, groundnut or bambara. Five “strains” of A. vogelii were distinguished using two criteria: their ability to parasitise bambara and/or mung bean and their ability to parasitise cowpea B301 and bambara TVU 870. The latter proved in an associated experiment to be resistant to collections of the parasite from some locations. Strain 1, including populations from Mali, Nigeria and Cameroon, attacked all groundnuts, cowpea cultivar Blackeye, but not cowpea line B301, mung bean or bambara. Strain 2, from Botswana, differed in attacking B301 and mung bean. Three other strains were identified which attacked susceptible lines of all four legume species. Strain 3 from Kenya failed to attack either cowpea B301 or bambara TVU 870, strain 4 from Malawi attacked cowpea B301, but not bambara TVU 870, while strain 5 from Northern Transvaal, South Africa, attacked bambara TVU 870, but not cowpea B301. Cowpea B359 was resistant to A. vogelii samples from all locations and also to A. picta, which has a similar host preference to strain 1 populations of A. vogelii from West Africa. Two out of 13 groundnut lines tested showed low susceptibility to A. vogelii from Cameroon suggesting there is scope for selecting resistance in this crop also.     

Evaluation of the efficacy of Trichogramma evanescens Westwood (Hym., Trichogrammatidae) inundative releases for the control of Maruca vitrata F. (Lep., Pyralidae)

Abstract: The bean podborer, Maruca vitrata (F.), is a serious pest on leguminous crops in the tropics. There are several natural enemies of M. vitrata present in the Philippines, but none of them suppress pest populations naturally below an economic threshold. The egg parasite Trichogramma evanescens Westwood is commercially available for augmentative biological control and a known parasite of podborer eggs. The objective of the present study was to evaluate the efficacy of inundative releases of the egg parasite T. evanescens for controlling M. vitrata in the Philippines. In 1999 and 2000, controlled releases of T. evanescens were made in fields of yardlong bean, Vigna unguiculata, during the dry and rainy seasons in Central Luzon, Philippines. Adult populations of M. vitrata were monitored using light traps. Population density of M. vitrata was found to be positively correlated with rainfall and was subsequently higher during the rainy season, relative to that in the dry season. In quality control experiments, emergence of locally available T. evanescens was found to be highly variable between years, 72% in 1999 and 58% in 2000. The percentage of female parasites was 54% in both years. Survival of T. evanescens in the laboratory after 7 days was found to be only 29 and 21% in 1999 and 2000, respectively. Four parasite releases (each 150 000 wasps per hectare) spaced 7 days apart during the reproductive stage of V. unguiculata were made in three 5 × 5 m plots. Host finding efficacy was identified by exposing M. vitrata eggs laid on cowpea leaves in rearing chambers for 24 h in the fields. Percentage parasitism was higher during the dry season, relative to that in the rainy seasons. In release plots, parasitism increased by 53% during dry and by 43% during rainy season compared with control plots. Despite significant reductions in larval numbers during the dry season, no difference in percentages of pods damaged was found. In the rainy season, the number of larvae per plant and the percentage of pods damaged by M. vitrata larvae were not reduced by T. evanescens releases. The experimental results are critically discussed as a possible part of an integrated pest management system.     

Bionomics of the parasitoid Apanteles taragamae as influenced by different diets fed to its host,Maruca vitrata

The parasitoid Apanteles taragamae Viereck (Hymenoptera: Braconidae) has been introduced into Benin by the International Institute of Tropical Agriculture (IITA-Benin station) from Taiwan in an attempt to control the cowpea pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae), a serious pest of flowers and pods of cowpea Vigna unguiculata Walp. (Leguminosae: Fabaceae). Both the pest and its parasitoid are currently mass-reared using a cowpea and maize flour-based meridic diet. In this study, the suitability of germinating seeds from three cowpea varieties, Kpodji-guèguè, Tawa and TVX3236, as substrates, was tested for rearing A. taragamae under laboratory conditions. The seeds that were soaked for 48 h were the most suitable for M. vitrata larval rearing with up to 87 % survival. The highest parasitism rate of M. vitrata larvae by A. taragamae was observed on the local variety Tawa. Compared to meridic diet, the development cycle of the parasitoid was shorter on Tawa sprouts which also lead to the highest lifetime fecundity. The parasitoid sex ratio varied significantly between feeding substrates with a higher proportion of female wasps on the improved varieties TVX2336 and local variety Kpodji-guèguè. Rearing M. vitrata larvae on germinating cowpea grains is 4.38 times cheaper than on meridic diet. The data are discussed with emphasis on the effects of feeding substrates quality on life history parameters of insect pests and their parasitoids.     

The biological bases of resistance in cowpea to the cowpea moth, Cydia ptychora (Lepidoptera: Olethreutidae)

Intensive greenhouse screening using potted plants demonstrated a high level of resistance in the wild cowpea, Vigna unguiculata (ssp. mensensis), to the cowpea moth, Cydia ptychora. Two closely related cvs (TVu 946 and TVu 2994) also showed some resistance. Further investigations in the laboratory and in the greenhouse indicated that resistance was due mainly to oviposition preference and to antibiosis. Pods of the wild cowpea, and those of cvs TVu 946 and TVu 2994, were not attractive to egg-laying females whereas no oviposition preference was seen among the genetically improved cultivars. Pronounced antibiosis was detected in the wild cowpea, and to a lesser extent in the closely related cvs, when pods were infested with first-instar larvae. Fecundity of females was also significantly reduced. These effects were thought to be partly due to nutritional deficiencies in the resistant cvs but there may also be an antibiotic factor in the wild cowpea progenitor. Apparently, pod-wall thickness was not related to resistance although differences in successful penetration of pods by larvae were observed.     

Bruchid pest management in pulses: past practices,present status and use of modern breeding tools for development of resistant varieties

Bruchids (Callosobruchus spp.) are recognised as the most detrimental storage pest of pulses, especially in the tropics and subtropics. They invade matured pods as well as seeds during storage and, to some extent, farming fields, in turn reducing the net yield of the crops. Several approaches including cultural, biological, physical and chemical control measures have been implemented with the aim of managing these pests, but none of these have been successful across time and space. Recently, transgenic‐ and marker‐assisted breeding approaches have appeared as promising tools for the successful management of these pests. Although some efforts have been made on the development of bruchid‐resistant transgenic crops, the cultivars developed are yet to be commercialised worldwide because of various limitations. In contrast, marker‐assisted breeding involving the identification of DNA‐based markers linked to host resistance against bruchids, have shown some success in the quest for the development of bruchid‐resistant cultivar(s). DNA markers linked to bruchid resistance have been identified in various grain legumes, particularly in the genus Vigna, and include mung bean (Vigna radiata), azuki bean (Vigna angularis), rice bean (Vigna umbellata), cowpea (Vigna unguiculata) and black gram (Vigna mungo). After their validation in different genetic backgrounds, these markers could be utilised for marker‐assisted selection and breeding ventures to protect pulse crops. The present study discusses the pros and cons of different approaches for the successful management of the bruchid pests in pulses. The review also highlights about the integrative approach aided with molecular interventions to improve productivity by avoiding losses incurred due to bruchids, and to attain sustainable yields for major pulse crops.     

Annual cycle of the legume pod borer Maruca vitrata Fabricius (Lepidoptera: Crambidae) in southwestern Burkina Faso

Maruca vitrata is an economically significant insect pest of cowpea in sub-Saharan Africa. Understanding the seasonal population patterns of M. vitrata is essential for the establishment of effective pest management strategies. M. vitrata larval populations on cultivated cowpea and adult flying activities were monitored in addition to scouting for host plants and parasitoids during 2 consecutive years in 2010 and 2011 in southwestern Burkina Faso. Our data suggest that M. vitrata populations overlapped on cultivated cowpea and alternate host plants during the rainy season. During the cowpea off-season, M. vitrata maintained a permanent population on the wild host plants Mucuna poggei and Daniella oliveri. The parasitoid fauna include three species, Phanerotoma leucobasis Kri., Braunsia kriegeri End. and Bracon sp. Implications of these finding for pest management strategies are discussed.     

Inheritance of resistance to potyviruses in Phaseolus vulgaris L. III. Cosegregation of phenotypically similar dominant responses to nine potyviruses

We have identified monogenic dominant resistance to azuki bean mosaic poty virus (AzMV), passionfruit woodiness potyvirus-K (PWV-K), zucchini yellow mosaic potyvirus (ZYMV), and a dominant factor that conditioned lethal necrosis to Thailand Passiflora potyvirus (ThPV), in Phaseolus vulgaris Black Turtle Soup 1. Resistance to AzMV, PWV-K, ZYMV, watermelon mosaic potyvirus, cowpea aphid-borne mosaic potyvirus, blackeye cowpea mosaic potyvirus, and lethal necrosis to soybean mosaic potyvirus and ThPV cosegregated as a unit with the I gene for resistance to bean common mosaic potyvirus.     

Effects of DIMBOA levels in wheat on the susceptibility of the grain aphid (Sitobion avenue) to deltamethrin

The effects of DIMBOA in cultivars of wheat on aphid antibiosis and tolerance to the insecticide deltamethrin were investigated for the aphid Sitobion auenae. Over 48 hours the mean relative growth rate differed significantly between nymphs of S. auenae reared on wheat cultivars containing different levels of DIMBOA. Nymphs on the resistant cv. Altar showed a significantly greater susceptibility to deltamethrin, with nearly a three-fold increase in the relative toxicity of deltamethrin, compared with the susceptible cv. Dollarbird. The LC₅₀, adjusted for weight, was reduced by 91% for nymphs reared on the high DIMBOA cultivar. The potential for the enhancement of predation under a reduced pesticide régime is discussed in relation to this research.     

Host resistance enhances susceptibility of Callosobruchus maculatus (Coleoptera: Chrysomelidae) to herbal extract of Echinophora platyloba

It has been argued that resistant cultivars may enhance the susceptibility of insect pests to insecticides, and thus can reduce crop production costs by lowering the rate of insecticide application. Here we studied the susceptibility of the cowpea seed beetle, Callosobruchus maculatus (Coleoptera: Chrysomelidae), reared on either a susceptible or resistant cultivar of the mung bean (Vigna radiate ), to a herbal extract taken from the prickly parsnip, Echinophora platyloba (Umbelliferae). After selection of a susceptible (Parto) and a resistant (Sahar) cultivar, the median lethal concentration (LC₅₀) of the herbal extract was determined as 24.41 and 20.28 μL/250 mL air against beetles reared on susceptible and resistant cultivars, respectively. Rearing on resistant cultivar had a significant effect on biological parameters of C. maculatus regardless of insecticide application. However, herbal extract showed a significant interaction with host resistance in terms of oviposition rate and pre‐adult development time. These results provide evidence that the resistant cultivar increases the susceptibility of C. maculatus to herbal extract. The use of plant resistance in combination with narrow‐spectrum insecticides seems to be of both economic and environmental importance, as it can reduce the costs of crop production and lower the doses of insecticides required for satisfactory pest control.     

Impact of density of Aphis craccivora (Aphididae) on growth and yield of susceptible and resistant cowpea cultivars

Impact of initial density of cowpea aphid Aphis craccivora Koch (Aphididae) at infestation on the growth and yield of aphid-susceptible cowpea cultivar ICV-1 and aphid-resistant cultivar ICV-12, was investigated. Plants at the seedling, flowering and podding stages of development were infested with five aphid densities consisting of 0, 2, 5, 10 and. 20 aphids per plant and maintained for 22 days. Extended leaf heights of plants and aphid counts were recorded at 7, 12, 17 and 22 days after infestation. Two crop growth parameters (biomass duration and leaf area duration), and two plant yield parameters (number of pods per plant and number of seeds per pod) were recorded. Due to the occurrence of parthenogenesis and changes in population dynamics during infestations, aphid densities were converted into cumulative cowpea aphid-days, to facilitate data analyses and interpretation. ANOVA indicated that there was significant (P=s 0.05) difference in aphid-day accumulations between the two cultivars when infested at the seedling stage. Accumulations on cv. ICV-1 were greater than on cv. ICV-12. However, no such differences between the cultivars were detected when plants were infested at flowering and podding stages. Therefore, the seedling stage was used for comparisons of the impact of cowpea aphid-days on the growth and yield parameters of the two cultivars. At the 95% confidence intervals, ICV-12 plants were consistently taller than ICV-1 plants. Infested ICV-1 seedlings showed stunting and other growth deformities which were not observed on ICV-12 plants. Regression analyses revealed substantial reductions in the growth and yield parameters of ICV-1 relative to ICV-12. Overall, cowpea aphid-days provided a convenient and reliable method for studying the aphid population dynamics and the subsequent impact on plant growth and yield performance.     

Wild and Weed Azuki Beans in Japan

Wild azuki bean, a progenitor of an Asiatic food legume (Vigna angularis var.nipponensis: Fabaceae), and its weed form are distributed widely in the Japanese Archipelago. The straggling or climbing wildform occurs in sleeve or mantle plant communities, and the weakly climbing or bushy weed form is found in relatively open human-disturbed habitats. The wild form has small seeds with a black-mottled pattern on green or grey skin; the weed form has larger seeds with variable color patterns. Wild and weed forms have black, easily dehiscent pods, distinct from their cultivated counterpart which has red large seeds and indehiscent light-colored pods. The wild form is not utilized, but the weed form is recognized by farmers and has several folk names as a weed, a contaminated form of azuki bean, and a substitute for azuki as a food. The frequent occurrence of weed azuki bean in Japan is attributable to adaptation of the wildform to lack of climbing support in human-disturbed habitats, escape from old cultivars, and natural establishment from the derivatives of hybrids between cultivars and wild forms.     

A genetic linkage map of azuki bean constructed with molecular and morphological markers using an interspecific population (Vigna angularis x V. nakashimae)

A genetic linkage map of azuki bean (Vigna angularis) was constructed with molecular and morphological markers using an F₂ population of an interspecific cross between azuki bean and its wild relative, V. nakashimae. In total, 132 markers (108 RAPD, 19 RFLP and five morphological markers) were mapped in 14 linkage groups covering 1250 cM; ten remained unlinked. The clusters of markers showing distorted segregation were found in linkage groups 2, 8 and 12. By comparing the azuki linkage map with those of mungbean and cowpea, using 20 RFLP common markers, some sets of the markers were found to belong to the same linkage groups of the respective maps, indicating that these linkage blocks are conserved among the three Vigna species. This map provides a tool for markerassisted selection and for studies of genome organization in Vigna species.     

Host‐Parasite Relationships in Root‐Knot Disease Caused by Meloidogyne inornata in Common Bean (Phaseolus vulgaris)

Bean crops have their productivity limited by biotic factors, as the phytonematodes. Several species have been reported causing damage to the crop, especially those from the Meloidogyne genus. Recently, a new species was reported parasitizing bean plants in Paraná State, Brazil, Meloidogyne inornata. The present work was aimed in order to study the pathosystem bean and M. inornata, through the evaluation of host reaction of 32 bean cultivars to the nematode, the potential damage of this pathogen to the crop, and the biology and parasitism of M. inornata on bean, under different temperatures, comparing with M. incognita. The host reaction was accessed under greenhouse conditions, with an initial population density of 2000 eggs of each nematode species per plant. Fifty days after inoculation, it was found that all tested cultivars were susceptible to M. inornata, however with varying extent. Pathogenicity of M. inornata on bean cv. Tuiuiú was also evaluated under greenhouse conditions, with the following initial population densities: 0 (check); 0.0625; 0.125; 0.25; 0.5; 1; 2; 4; 16; 32; and 64 eggs per cm³ of soil. Tolerance limit obtained to this cultivar was 9.9 nematodes per cm³. In relation to the comparative biology between M. inornata and M. incognita, under growth chamber and three different temperatures, 18, 25 and 32°C, results showed that under 18°C, both species have their life cycles retarded, while under 32°C, the cycle is accelerated.     

Effect of application of different concentrations and appropriate schedules of aqueous garlic (Allium sativum L.) bulb extracts against Maruca vitrata and Clavigralla tomentosicollis on cowpea,Vigna unguiculata (L.) Walp

Abstract

Three concentrations (5, 10 and 20% w/v) and spraying schedules (2×, 4× and 6× weekly applications) of garlic, Allium sativum L. bulb extracts were assayed for efficacy against Maruca vitrata Fab. and Clavigralla tomentosicollis Stal. on cowpea under rain fed conditions in two seasons. The results showed that application of aqueous garlic bulb extracts at all the treatment levels significantly (p < 0.05) reduced the populations of the target pests compared with the untreated check. Application of 10 and 20% garlic bulb extracts with 4 or 6 weekly applications gave better control of these pests, protected the pods from damage and increased grain yields on treated cowpea compared with 5% extract at all three application schedules and were comparable to the synthetic insecticide treatment. This material could play a role in the integrated management of M. vitrata and C. tomentosicollis on cowpea fields managed by limited resource farmers in developing countries. The plant material is readily available, cheap, safe, non phytotoxic and technologically simple to use.     

A multivariate analysis of growth and development parameters of the legume pod borer,Maruca testulalis on variably resistant cowpea cultivars

Principal component analysis was employed to study the variation patterns in 18 cowpea cultivars developed for resistance toMaruca testulalis Geyer (Lepidoptera: Pyralidae) based on 7 developmental parameters of the pest on floral buds, flowers and sliced pods. On the whole, three developmental parameters: percentage pupation (V2), percentage emergence (V5) and growth index (V7) were the most important for the grouping of the cultivars with respect toM. testulalis damage. However, out of the three parameters, growth index (V7) had the highest factor score. Using the cluster analysis technique, the cultivars were sorted into five distinct groups for each part. The importance of these findings in the determination of protection periods for particular cultivars and cultural control studies ofM. testulalis in cowpea are discussed.     

Variations of Natural 15N Abundances in Leguminous Plants and Nodule Fractions

Natural ¹⁵N abundances of various tissues from twelve speciesof leguminous plants and those of nodule fractions from threespecies grown in Japan were determined by mass spectrometry.The ¹⁵N concentrations of non-nodular tissues of nodulated plantswere close to the value of atmospheric N₂. The nodules of soybean,mung bean, cowpea, kidney bean, adzuki bean, sword bean, whiteclover, Leucaena leucocephala, and horsegram showed highly elevated¹⁵N concentrations, and those of pea had a slightly enriched¹⁵N concentration compared to other tissue, while the nodulesof peanut and lucerne had ¹⁵N values similar to those of theirshoot tissues. The bacteroid fractions from horsegram, swordbean and peanut had higher ¹⁵N concentrations than the cytosolfractions. (Received March 17, 1984; Accepted August 21, 1984)     

Effects of water table depth and calcium perioxide application on cowpea (Vigna unguiculata) and soybean (Glycine max)

Summary The effects of three water table (WT) depths (0, 15 and 40 cm) and calcium peroxide (Calper) on the growth and yield of cowpea (Vigna unguiculata, L.) and soybean (Glycine max) were investigated in field lysimeters for a sandy loam soil. Cowpea growth was the best at 40 cm WT depth. Leaf area, plant height, dry matter production, number of leaves and pods, grain yield and consumptive water use of cowpea increases with deeper (lower) WT depth. Application of calcium peroxide improved per cent emergence, leaf area, dry matter, number of leaves and pods, weight of 100 seeds, grain yield and water use in cowpea. The optimum WT depth for vegetative growth of soybean was 15 cm, although the highest grain yield was obtained at 40 cm WT depth. Number of pods, grain yield and water use efficiency of soybean increased with deeper water table depth. Application of calcium peroxide to soybean increased number of leaves and pods per plant, and grain yield for the 15 cm WT depth treatment.     

Studies on interspecies competition between the azuki bean weevil and the southern cowpea weevil

Experimental studies was made on the interspecies competition between the azuki bean weevil, Callosobruchus chinensis and the southern cowpea weevil, C. macultatus. And the following results were obtained.

1. The reverse result of competition between the two species observed under the air-tight condition and the air-free one. That is, the population of the azuki bean weevils destroyedby that of the southern cowpea weevils under the former condition and vice versa under the latter. It is thought that such a reversal is due to the difference of sensibility of each species to the air-tight condition.
2. Under the air-free condition, change of the time interval of food-supplying had no effect on the result of competition within the limits of this experiment. The population of the southern cowpea weevils was always destroyed by that of the azuki bean weevils. But there was a certain degree of correlation between the duration of co-existence and the interval of food-supplying.
3. From the results, it is possible to say that by changing the degree of air-tightness, or the time interval of food-supplying, the co-existence period and the final result of competition can be changed.
4. The different mechanism of competition between two species in the present experiment from the experiments ofUtida (1952) andYoshida (1957) were discussed.
5. A difference in the mechanism of interspecies competition and intraspecies competition was expected from the level of total population numbers of two species and the individual weight of C. chinensis.