scholarly journals Phenological Features of (Mamestra Brassicae L. 1758) Development in Agrocoenosis of Cabbage in the Kamin-Kashyrskyi District (Volyn Region, Ukraine)

2019 ◽  
Vol 9 (3) ◽  
pp. 71-73
Author(s):  
I. Ya. Truskavetska

The animal world of Ukraine is characterized by a large variety of species. Among the lepidoptera there are a lot of pests whose larvae cause significant damage to agriculture. In the paper, we investigated the seasonal and perennial dynamics of vegetable crops pests’ population of Mamestra brassicae in the agrobiocenoses of white cabbage. The basis of our study was the investigation of the relative quantity of the pest larvae, we demonstrated the damage to plants, as well as the periods of intensive emergence of the imago and the number of generations per year. In future, this will enable the development of effective ecologically sound methods for controlling the number of species of white cabbage pests in the conditions of Kamin-Kashyrskyi district of Volyn region. Kamin-Kashyrskyi area has a flat terrain and is characterized by a warm temperate continental climate with sufficient amount of moisture, the presence of impoverished sod-podzolic soils. The area is mostly plain, with large marsh massifs, which are favorable conditions for the existence of Mamestra brassicae, as this species is moisture-loving. Observation of biocenotic connections in the agrobiocenoses of white cabbage and stationary research on the development of protection, testing and implementation systems was carried out during 2017-2018 at the garden sites of Kamin-Kashirsky district during the entire vegetation period of the plants. White cabbage is damaged throughout the period of vegetation, however, the damage that appear after emergence of seedlings and planting of seedlings into the soil are dangerous due to their consequences. In the second half of summer and in autumn, the larvae of Mamestra brassicae caused significant damage to cabbage plants in the gardens of Novi Chervyshcha. Within this area, Mamestra brassicae develops two generations per year, causing tangible damage to the agrocoenosis of cabbage of different sowing dates. The contamination of cabbage by the larva of the first and second generations approximately accounts to 24%, where 2-3 larvae live on one plant. The massive emergence of the imago occurs in the middle of May the first half of June while the average daily temperature is +20°С to +22°С. The first egg laying was recorded at the end of May, which the female lays in groups, 20-80 units on the underside of the leaves, and the embryonic development lasts 6 to 8 days. Pupae hibernate in the soil, at a depth of 8-12 cm. Significant damage to white cabbage plants was caused by the larvae of the first generation in June and early July, and of the second generation in August and early September. They intensively feed at night and at dawn, and in the daytime there is a decline in mobility and nutritional activity. Second-generation larvae often bite into cabbage heads where they make holes and pollute them with their liquid excrement, which leads to a decrease in crops. The use of microbiological drugs Dimilin and Insehar are some of the most effective ways to get rid of Lepidoptera, including larvae of Mamestra brassicae, which provide protection of cabbage plants by 93-97%.

1956 ◽  
Vol 46 (4) ◽  
pp. 845-848 ◽  
Author(s):  
T. R. E. Southwood

Recent taxonomic studies have recognised that Lygus pratensis (L.) consists of several species and other workers have shown that the Tarnished Plant Bug of N. America is L. lineolaris (P. de B.), a species confined to that continent. Although it is impossible to be certain what species is referred to in all of the earlier works on biology and pest incidence of L. pratensis in the Palaearctic region, evidence is given which shows that L. rugulipennis Popp. is the more important pest in this region and it is to this species that the name European Tarnished Plant Bug should be applied. Observations on the life-cycle of L. rugulipennis in England have been carried out and they show that there are normally two generations per year; the second generation becomes adult in the autumn and overwinters in this stage, egg-laying occurring the following spring. This agrees in general with that previously described for L. pratensis, sens. lat.


2020 ◽  
Vol 180 ◽  
pp. 03016
Author(s):  
Adriana Muscalu ◽  
Cătălina Tudora ◽  
Constantin Coţa ◽  
Zoltan Gyorgy ◽  
Floarea Burnichi ◽  
...  

In the context of the current climate change, it has become urgently necessary to develop adequate systems to protect horticultural crops. In Romania, the losses caused to these cultures by the extreme weather phenomena, as well as the lack of active intervention measures to combat or limit them, represent the main argument for addressing this field in particular. Vegetable crops are generally sensitive to extreme weather phenomena. In the climatic conditions in our country, the extreme phenomena occur between March and September, which coincides with the vegetation period of the crops. Of these, hail causes significant damage, and in some cases, at high intensity and long-lasting, can cause the calamity of vegetable crops. Another effect can arise in the drought years, when, in the absence of rainfall, the weeds enter into a fierce competition with vegetables, as regards the specific consumption of water and nutrients. The paper presents a review regarding the current methods of vegetable crops protection against the extreme weather phenomena and of weed control in these crops, grown in organic system. Combining the available solutions, adopting integrated strategies for non-chemical weed control can be an important premise for researchers and farmers to protect vegetable crops.


Author(s):  
R. E. Kazakhmedov ◽  
М. А Magomedova

One of the modern selection tasks in vegetable growing is quality products improving, obtaining high yields of environmentally safe wide assortment vegetables. To the new varieties of vegetable crops including winter white cabbage are specified new requirements such as market competitiveness, resistance to unfavorable environmental conditions, heat resistance of the varieties and F1 hybrids. The article is shown investigation results about studies of exogenous treatment by solutions on the base of physiologically active compounds of hormonal nature on the started process of stem extension stage activation and flowering of winter white cabbage plants. For the first time in the Dagestan conditions has been studied the possibility of hormonal regulation of the premature stem extension stage and flowering prevention of winter white cabbage after the initiation of natural induction. In our studies with an early planting there are not more than 20% of blooming plants, most varieties showed a high propensity to premature stem extension stage and flowering. The possibility of the hormonal exogenous regulation of the unfavorable winter white cabbage flowering has been revealed. The most pronounced effect on the transition to stem extension stage and flowering were provided by auxin nature preparations. In particular, treatment with NAS at a dose of 5 mg / l significantly reduced the number of blossom plants, krezatsin (50 mg / l) had a similar effect, but it was less pronounced. The use of cabbage in winter crops makes it possible to obtain two or three yields per year from the same area. Creation and introduction into production of promising and high-yielding varieties and hybrids will allow increasing production and reducing its cost.


2021 ◽  
Author(s):  
Ivan Rwomushana

Abstract The fall armyworm, Spodoptera frugiperda, is a lepidopteran pest that feeds in large numbers on the leaves, stems and reproductive parts of more than 350 plant species, causing major damage to economically important cultivated grasses such as maize, rice, sorghum, sugarcane and wheat but also other vegetable crops and cotton. Native to the Americas, it has been repeatedly intercepted at quarantine in Europe and was first reported from Africa in 2016 where it caused significant damage to maize crops. In 2018, S. frugiperda was first reported from the Indian subcontinent (Ganiger et al., 2018; Sharanabasappa Kalleshwaraswamy et al., 2018). It has since invaded Bangladesh, Thailand, Myanmar, China and Sri Lanka (IPPC, 2018b, 2019; FAO, 2019c). The ideal climatic conditions for fall armyworm present in many parts of Africa and Asia, and the abundance of suitable host plants suggests the pest can produce several generations in a single season, and is likely to lead to the pest becoming endemic.


2002 ◽  
Vol 127 (6) ◽  
pp. 1013-1017 ◽  
Author(s):  
Carmen Feller ◽  
Matthias Fink

To reduce nitrogen (N) losses from vegetable fields, fertilizer recommendations should be adjusted according to the large range in yield and thus in N uptake of vegetable crops. Therefore, a model was used to predict total N uptake based on expected yield. The model has been validated successfully in a series of studies for Brussels sprouts (Brassica oleracea L. var. gemmifera), white cabbage (Brassica oleracea L. var. capitata) and kohlrabi (Brassica oleracea L. var. gongylodes). The objective of this study was to validate the model for table beet (Beta vulgaris L. var. conditiva), a crop with a considerable variability in N uptake, which is caused by a large potential range of selecting sowing dates, plant densities and cultivars. Field experiments were carried out over two years. Fifty-five combinations of N fertilizer levels, plant densities, cultivars and sowing dates were tested. Plants were sampled at 2- or 3-week intervals, and fresh matter, dry matter and N content of leaves and roots were measured. Crop specific model parameters for table beets were determined from independent data. The model wverestimated N uptake for N-limiting conditions, but for optimally fertilized table beets measured and estimated N uptake showed a close correlation (R2 = 0.93) when total yield was used as an input parameter for the model. Although the error of estimation (35 kg·ha-1) was considerable, studies with other vegetable crops using the model found the error even higher if other tools, such as look-up tables, were used for predicting N uptake.


2021 ◽  
Author(s):  
Emily Rachel Awad

Rising levels of polybrominated diphenyl ethers (PBDEs) have been ovserved in the environment, humans, and animlas. Studies have shown that these compounds can elicit toxic effects in animals (e.g. neurotoxicity and thyroid toxicity). This research investigated the effects of BDE47 on the survival and reproduction of Daphnia magna over two generations. The impacts of water-borne exposure were compared to dietary exposure using the following treatments: dosed water (DW), dosed algae (DA) and dosed water and algae (DWA). In the first generation, significant impacts on reproduction were observed in daphnids in the DA and DWA treatments. In the second generation, no significant impacts on reproduction were observed indicating a recovery from maternal exposure. When second generation daphnids were exposed to BDE47, there was high mortality in the DWA treatment anad reduced reproduction in all dosed treatments. Dietary exposure to BDE47 had a more profound impact on daphnid reproduction than water exposure. In the second generation, dietary exposure affected both survival and reproduction and water exposure reduced reproduction, indicating that maternal exposure was a factor.


1979 ◽  
Vol 27 (5) ◽  
pp. 631 ◽  
Author(s):  
PW Weiss ◽  
DM Simmons

Australian populations of the widespread Emex australis and the more restricted E. spinosa were tested for subspecific variation. The plants were grown for two generations in a glasshouse from seed collected from field populations. The results from growing the first generation showed that two groupings of E. australis could be made on the basis of hierarchical grouping analysis, but the populations were much more similar in the second generation and such groupings could not be made. There were no marked differences between E. australis populations from Australia and South Africa, although one from Hawaii was less vigorous than the others. Amongst Australian populations of E. spinosa, one from Western Australia was less vigorous than the others. It was also found that Australian populations of E. spinosa were generally similar to those from Portugal and slightly more vigorous than those from Morocco.


1993 ◽  
Vol 71 (2) ◽  
pp. 233-237 ◽  
Author(s):  
Marta Martínez Wells

Courtship songs are an important reproductive barrier in lacewings of the genus Chrysoperla, so heterotypic matings should occur less readily than homotypic matings. In addition, if song morphs have become separate species, there may be some postzygotic isolation between song morphs. Two generations of crosses using sympatric P1 and P3 morphs of Chrysoperla plorabunda provide evidence for both hypotheses. In the first stage of the experiment, egg laying (an indication of mating success) was delayed by a week in heterotypic crosses compared with homotypic crosses, and hatching success of eggs from hybrid crosses was 16% lower than that from control crosses. In the second stage of the experiment, backcrosses involving P3 morph males or females were the least successful in mating. When pairs did mate, they did so a week later than in the other crosses. Thus, behavioral isolation delays heterotypic matings when females are not given a choice of mates. These results provide some genetic evidence that the song morphs of the C. plorabunda complex are biological species.


1986 ◽  
Vol 109 (2) ◽  
pp. 239-244 ◽  
Author(s):  
I. Pollard

ABSTRACT Persistent effects of stress were found in second generation rats bred from females whose own mothers had been stressed during pregnancy. The second generation rats grew more slowly, with a plateau in the growth being reached at the same age as in the controls. This resulted in adult animals of both sexes being permanently smaller than their control counterparts. When these offspring were subjected to short-term stress (one session) in adulthood, the response was not significantly different to that for the controls, indicating an intact emergency response. The male offspring from the stressed group, however, had a significantly (P < 0·01) higher plasma progesterone concentration, and a significantly (P < 0·01) lower testicular enzymic 3β-hydroxysteroid dehydrogenase activity at rest, when compared with the control offspring. The fertility of the mature female from the stressed group was not affected as a third generation of litters born did not differ from the controls. It is suggested that a changed genetic programme in the ovarian germ cells of the first generation and/or a changed uterine environment in the second generation may be implicated. J. Endocr. (1986) 109, 239–244


2004 ◽  
Vol 39 (2) ◽  
pp. 275-280 ◽  
Author(s):  
Yang Zhong-qi ◽  
Sun Jiang-hua ◽  
James P. Pitts

A new species of Tanaostigmodes (Hymenoptera: Chalcidoidea, Tanaostigmatidae) is described from China—Tanaostigmodes puerariae sp. nov. This is the first record of this family in China. This new species has potential as a biological control agent for control of kudzu, Pueraria lobate, in the U. S., because its preference for making leaf galls on kudzu. It was determined that the wasp has two generations per year, with the second generation overwintering as mature larvae in the gall on leaves that have dropped to the ground. Normally, only one wasp was found per gall, and a single kudzu leaf could have as many as 20 to 50 galls on its surface.


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