scholarly journals Plant-pollinator interactions in Crambe abyssinicaHochst. (Brassicaceae) associated with environmental variables

2015 ◽  
Vol 87 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Lívia C. Simioni ◽  
Rosilda M. Mussury ◽  
Munir Mauad ◽  
Daiane M. Dresh ◽  
Fabricio F. Pereira ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Environmental Variables ◽  
Insect Pests ◽  
Economic Importance ◽  
Alternative Methods ◽  
Regression Equations ◽  
Weekly Basis ◽  
Pollinator Visitation ◽  
Crambe Abyssinica ◽  
Plant Pollinator

Despite the economic importance of Crambe abyssinica, the present study is the first report on bees that occur with this species, and could aid in developing alternative methods for controlling insect pests without seriously impacting pollinators. The present study examined the following questions: (1) Which species are potential pollinators of C. abyssinica? (2) How do environmental conditions influence pollinator visitation fluctuations? Insects were sampled on a weekly basis between 08:00 and 16:00 during five weeks of flowering. When the results of analyses of variance were significant, the data was adjusted using regression equations at a 5% level of probability; the environmental variables were examined using Pearson's correlation coefficient. Apis mellifera, Geotrigona mombuca, Exomalopsis (Exomalopsis) fulvofasciata, Plebeia sp. and Dialictus sp. were observed visiting C. abyssinica flowers. A. melliferaand G. mombucawere observed to be potential pollinators, with the former demonstrating visitation peaks during flowering weeks II and IV at 12:00 and 08:00, respectively and the latter visiting during weeks III and IV at 12:00 and 10:00, respectively. Environmental factors such as temperature, relative humidity, and wind speed have different effect on the activity of bees.

Ascosphaera apis. [Descriptions of Fungi and Bacteria].

1979 ◽  
Author(s):  
B. L. K. Brady
Keyword(s):  
Apis Mellifera ◽  
Geographical Distribution ◽  
Honey Bee ◽  
Economic Importance ◽  
Ascosphaera Apis ◽  
Adverse Conditions ◽  
Leaf Cutting

Abstract A description is provided for Ascosphaera apis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Apis mellifera and Megachile spp. DISEASE: Chalkbrood of the honey bee (Apis mellifera) with a few poorly documented records on leaf cutting bees Megachile spp. (Melville & Dade, 1944) and M. internis (Baker & Torchio, 1968). The spores are ingested by young larvae and germinate in the gut, breaking out of the hind end when larvae are sealed in their cells prior to pupation. If one strain only is present this forms the typical chalkbrood. If both strains are present a layer of grey cysts forms on the surface of the larva. Larvae are most susceptible at 3-4 days old and are then chilled briefly immediately after sealing. Although fatal to the larvae, this rarely destroys a whole colony and individual dead larvae are ejected by the bees. Ascospores persist many years providing periodic trouble in adverse conditions. GEOGRAPHICAL DISTRIBUTION: Europe; USA. Until 1968 chalkbrood was considered to be a European disease and it was only in 1971 that it became recognised as of economic importance in USA (Hitchcock & Christensen, 1972). TRANSMISSION: By ascospores within the cells of the comb to young larvae. From hive to hive probably by robber bees. More prevalent in cold, wet summers.

scholarly journals Variation in floret size explains differences in wild bee visitation to cultivated sunflowers

2018 ◽  
Vol 16 (6) ◽  
pp. 498-503 ◽  
Author(s):  
Zoe M. Portlas ◽  
Jonathan R. Tetlie ◽  
Deirdre Prischmann-Voldseth ◽  
Brent S. Hulke ◽  
Jarrad R. Prasifka
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Significant Variation ◽  
Inbred Lines ◽  
Floral Traits ◽  
Pollinator Visitation ◽  
Wild Bee ◽  
Residual Variation ◽  
Trade Offs ◽  
Nectar Rewards

AbstractWild and managed bees are needed to move sunflower (Helianthus annuus L.) pollen, both to create hybrid seed and to encourage high, consistent yields when those hybrids are subsequently grown. Among floral traits that influence bee preference, floret size may be critical, as the depth of the corolla affects the accessibility of nectar. Sampling and observation of inbred maintainer (HA) lines were used to assess variation in floret size, and to measure any effects of floret size on pollinator visitation. Among 100 inbreds sampled, there was significant variation among the lines, with floret lengths of 6.8–9.9 mm. Floret length, measured before anthesis, was closely related to corolla depth during anthesis and was consistent between 2 years (environments). Pollinator observations on 30 inbred lines showed floret size explained a majority (52%) of the variation in wild bee preference, with a reduction in floret length of 2 mm more than doubling pollinator activity. Though honey bee, Apis mellifera L., colonies were located ≈ 60 m from the plots, near-zero honey bee activity in the sunflowers precluded an assessment of how strongly this managed pollinator is affected by floret length. Production of inbreds and hybrids with smaller florets could enhance sunflower pollination, but genetic markers for floret size are needed to facilitate selection, and an understanding of potential trade-offs also is required. Information on variation and heritability of other traits, such as pollen and nectar rewards, could help explain residual variation in wild bee visitation to sunflowers.

Organochlorine and Organophosphorus Residues in Fat of Bovine and Porcine Carcasses Marketed in Ontario, Canada from 1969 to 1981

1983 ◽  
Vol 46 (10) ◽  
pp. 893-900 ◽  
Author(s):  
R. FRANK ◽  
H. E. BRAUN ◽  
G. FLEMING
Keyword(s):  
Insect Pests ◽  
Regression Equations ◽  
Industrial Chemicals ◽  
Organophosphorus Insecticides ◽  
Organochlorine Insecticides ◽  
Maximum Residue Levels ◽  
Order Of Magnitude ◽  
Residue Levels ◽  
Low Levels ◽  
Control Insect

Between 1969 and 1981, 2482 bovine and 554 porcine carcasses were sampled at provincially inspected abattoirs across Ontario. Abdominal fats were composited into 505 bovine and 122 porcine samples for analyses of organochlorine insecticides and industrial chemicals. Mean ∑DDT residues decreased from 257 μg/kg in 1969–70 to 12 μg/kg in 1981 for bovine fats and from 356 μg/kg in 1971–72 to 5 μg/kg in 1981 for porcine fats. Similar decreases in residue levels were observed for PCB. Dieldrin, with lower initial residues (i.e. 33 μg/kg in bovine fat and 12 μg/kg in porcine), decreased an order of magnitude over this same period. All decreases fitted first order logarithmic regression equations. Chloradane and heptachlor epoxide were rarely observed in bovine or porcine fat; however, the incidence in bovine fat increased after 1973 following the removal of aldrin, dieldrin and heptachlor in 1969 for soil insect control and the subsequent increased use of chlordane. Chlordane appeared at low levels (1–2 μg/kg) in bovine fat during the mid 1970s and remained detectable through 1981. Lindane residues in both bovine and porcine fat fluctuated from year to year and appeared to vary with the need to control insect pests. While present (2 to 39 μg/kg) in the early 1970s, lindane residues disappeared by mid 1970 but reappeared in fatty tissues in 1981 (3–13 μg/kg). A limited number of samples were analyzed for organophosphorus insecticides between 1973 and 1980 and residues were occasionally found. In 1981, the analyses became routine and 3.6% of bovine samples were found to contain detectable residues of fenthion; only 2 of 197 bovine samples exceeded the maximum residue levels permitted under the Food and Drug Act.

scholarly journals Nematicidal activity of crambe extracts on Meloidogyne spp.

2016 ◽  
Vol 37 (4) ◽  
pp. 1857 ◽  
Author(s):  
Sidiane Coltro-Roncato ◽  
José Renato Stangarlin ◽  
Affonso Celso Gonçalves Jr. ◽  
Odair José Kuhn ◽  
Edilaine Della Valentina Gonçalves ◽  
...  
Keyword(s):  
High Performance ◽  
Plant Secondary Metabolites ◽  
Allyl Isothiocyanate ◽  
Alternative Methods ◽  
Inhibitory Effects ◽  
Crambe Abyssinica ◽  
Hydroalcoholic Extract ◽  
Second Stage ◽  
Acetone Water ◽  
Meloidogyne Spp

Alternative methods for the control of nematodes, such as the use of plant secondary metabolites, can be explored for integrated pest management systems. The objective of this work was to assess the best solvent for obtaining allyl isothiocyanate from Crambe abyssinica leaves, and the effects of this extract on Meloidogyne incognita and M. javanica. Dry leaves of C. abyssinica at 200 mg L-1 were used to prepare extracts by using water (by infusion and grinding), acetone, water + ethanol (hydroalcoholic extraction), methanol, hexane, and chloroform as solvents. Following the evaporation of the solvents, the residue was resuspended in water for use in the experiments. Distilled water and chemical nematicide were used as control treatments. Once the most effective extracts were defined, the following dosages of dried crambe leaves were used: 0, 200, 300, 400, and 500 mg L-1. High performance liquid chromatography (HPLC) was used to quantify the allyl isothiocyanate present in the extracts. After the solvents evaporated, the residues were eluted with water and used in assays with 200 eggs for the hatching test or 200 second stage juveniles (J2) for mobility and mortality tests. The hydroalcoholic extract was the most effective in reducing the hatching of M. incognita and M. javanica juveniles, by 71.6 and 74.4 percentage points, respectively. The mortality of M. incognita and M. javanica in the hydroalcoholic extract was 93.2 and 64.4%, respectively, followed by the methanol extract (17.6 and 34%) and the extract obtained by grinding (9.2 and 28%). The hydroalcoholic extract at 250 mg L-1 showed high nematicidal effect. The HPLC analysis of the extracts revealed that only the methanol and hydroalcoholic extracts had allyl isothiocyanate, indicating that the inhibitory effects on the hatching, mobility, and mortality were not solely attributed to the presence of this compound.

scholarly journals The factors influencing the pollinators visitation of the oilseed rape cultivars

2019 ◽  
Vol 65 (No. 12) ◽  
pp. 574-580
Author(s):  
Jan Kazda ◽  
Aneta Bokšová ◽  
Martina Stejskalová ◽  
Tomáš Šubrt ◽  
Jan Bartoška ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Oilseed Rape ◽  
Honey Bees ◽  
Bumble Bees ◽  
Major Influence ◽  
Winter Oilseed Rape ◽  
Pollinator Visitation ◽  
Factors Influencing ◽  
Visitation Rates ◽  
The Individual

Currently, the hybrid cultivars are predominant in the cultivation of winter oilseed rape in Europe. Cultivation of hybrid cultivars instead of the traditional line can affect the visitation of pollinators. Beekeepers and farmers claim that hybrid cultivars are not visited by pollinators as much as the line. Ten yellow and one white flowering oilseed rape cultivars were used to compare the visitation rates of pollinators (Apis mellifera L. and Bombus sp.) during flowering in the years 2015–2017. At the same time, the visitation of hybrid and line cultivars by pollinators was evaluated. Visitation of pollinators on each cultivar was calculated from observed visitations to flowering oilseed rape plants in an area 2.1 m<sup>2</sup> from the edge of single plots for 20 s. The results from this study clearly show that the individual cultivars, whether hybrids or lines, did not have a major influence on the pollinators’ visitation, either by honey bees or bumble bees. It is thus proved that hybrid cultivars do not affect the pollinator visitation and there is no need to worry about the prevalence of these cultivars in the Czech fields. However, a more significant effect for both pollinator groups appears to have been the color of the flower.

scholarly journals Acoustic, Pitfall Trap, and Visual Surveys of Stored Product Insect Pests in Kenyan Warehouses

Insects ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 105 ◽  
Author(s):  
Anastasia Njoroge ◽  
Hippolyte Affognon ◽  
Uwe Richter ◽  
Oliver Hensel ◽  
Barukh Rohde ◽  
...  
Keyword(s):  
Urban Areas ◽  
Background Noise ◽  
Insect Pests ◽  
Pitfall Trap ◽  
Economic Importance ◽  
Economic Losses ◽  
Prostephanus Truncatus ◽  
Postharvest Losses ◽  
Stored Product Pest ◽  
Insect Populations

Grain production is an important component of food security in Kenya but due to environmental conditions that favor rapid growth of insect populations, farmers and other agricultural stakeholders face ongoing and novel challenges from crop and stored product pest insects. To assist development of methods to reduce economic losses from stored product insect pests in Kenya, acoustic, visual, and pitfall trap surveys were conducted in five grain storage warehouses. Two commercially available acoustic systems successfully detected the pests of greatest economic importance, Sitophilus zeamais (Motschulsky) and Prostephanus truncatus (Horn). Other insects of lesser economic importance also were observed in the visual surveys, including Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae), and Tribolium castaneum (Herbst). This study demonstrated that the use of acoustic technology with visual surveys and pitfall traps can help managers to identify and target infestations within their warehouses, enabling them to reduce postharvest losses. With most warehouses being located in relatively noisy urban or peri-urban areas, background noise considerations are being incorporated into the design of future acoustic detectors for stored pest infestations. Kenya must import grain yearly to meet consumption needs; however, if the current yearly postharvest losses of 20–30% in warehouses decreased, import costs could be reduced considerably.

scholarly journals Entomopathogens : role of insect pest management in crops

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
AMAR BAHADUR BAHADUR
Keyword(s):  
Pest Management ◽  
Crop Yields ◽  
Insect Pests ◽  
Insect Pest ◽  
Food Resource ◽  
Alternative Methods ◽  
Natural Environments ◽  
Insect Pest Management ◽  
Natural Ecosystems ◽  
Chemical Pesticides

Entomopathogens are microorganisms that pathogenic to insect pest. Several species of naturally occurring viz; fungi, bacteria, viruses and nematodes, infect a variety of insect pests and play an important role in agricultural crops controlling insect pest management.  This kind of biopesticide has many advantages and alternative to chemical insecticides, highly specific, safe, and environmentally sustainable. Pest problems are an almost inevitable part of agriculture. They occur largely because agricultural systems are simplified and modifications of natural ecosystems. Viruses, bacteria are host specific and fungi generally have broader host range and can infect both underground and aboveground pests, soil-dwelling nature nematodes are more suitable for managing soil pests. Growing crops in monoculture provides concentrated food resource that allows pest populations to achieve higher densities in natural environments. Some of the most important problems occur when pests develop resistance to chemical pesticides. These cause highly significant damage to crops, there are also threats from emerging new strains of pests. Crops cultivation can make the physico-chemical environment more favourable for pest activity. Agricultural pests are reducing the yield and quality of produce by feeding on crops, transmitting diseases. Agricultural production significantly loss crop yields, suggest that improvements in pest management are significant forward for improving yields. Crop growers are under immense pressure to reduce the use of chemical pesticides without sacrificing yields, but at the same time manage of pests is becoming difficult due to pesticide resistance and the decreasing availability of products. Alternative methods are needed urgently. These need to be used as part of Integrated Pest Management safety and environmental impact.  

scholarly journals Honeybees prefer novel insect-pollinated flower shapes over bird-pollinated flower shapes

2018 ◽  
Vol 65 (4) ◽  
pp. 457-465 ◽  
Author(s):  
Scarlett R Howard ◽  
Mani Shrestha ◽  
Juergen Schramme ◽  
Jair E Garcia ◽  
Aurore Avarguès-Weber ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Choice Behavior ◽  
Prior Experience ◽  
Flower Color ◽  
Gray Scale ◽  
Visual Signaling ◽  
Flower Shape ◽  
Flower Evolution ◽  
Plant Pollinator ◽  
European Honeybee

AbstractPlant–pollinator interactions have a fundamental influence on flower evolution. Flower color signals are frequently tuned to the visual capabilities of important pollinators such as either bees or birds, but far less is known about whether flower shape influences the choices of pollinators. We tested European honeybee Apis mellifera preferences using novel achromatic (gray-scale) images of 12 insect-pollinated and 12 bird-pollinated native Australian flowers in Germany; thus, avoiding influences of color, odor, or prior experience. Independent bees were tested with a number of parameterized images specifically designed to assess preferences for size, shape, brightness, or the number of flower-like shapes present in an image. We show that honeybees have a preference for visiting images of insect-pollinated flowers and such a preference is most-likely mediated by holistic information rather than by individual image parameters. Our results indicate angiosperms have evolved flower shapes which influence the choice behavior of important pollinators, and thus suggest spatial achromatic flower properties are an important part of visual signaling for plant–pollinator interactions.

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