Soil moisture and relative humidity effects during postdiapause on the emergence of western cherry fruit fly (Diptera: Tephritidae)

2013 ◽  
Vol 145 (3) ◽  
pp. 317-326 ◽  
Author(s):  
Wee L. Yee

AbstractPupae of western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), from Kennewick and Roslyn in Washington State, United States of America, were subjected to different soil and air moisture conditions to test the hypotheses that adult emergence from dry and moist soil is similar and is greater and occurs earlier at high than low relative humidities (RHs). Adult fly emergence from 0–57% saturated loam soil did not differ in Kennewick (64.8–75.1%) and Roslyn (81.7–86.6%) populations. Emergence did not occur from 76% saturated loam soil. In a RH experiment using dry soil, emergence of Kennewick flies was highest at 97% RH (76.8%), intermediate at 12–74% RH (66.4–69.6%), and lowest at 3% RH (58.0%). Emergence of Roslyn flies was higher at 97% RH (85.6%) than 3% (69.2%) and 12% RH (74.3%), but it did not differ from that at 33% (76.9%) and 74% RH (79.4%). Flies emerged ∼2–3 days earlier at 97% RH than at 3–12% RH. An unnaturally low RH of 3% caused more flies to be deformed than higher RHs. High emergence of R. indifferens in dry and moist conditions likely contributes to its presence in a wide range of native and nonnative habitats.

2016 ◽  
Vol 149 (2) ◽  
pp. 241-250 ◽  
Author(s):  
W. L. Yee

AbstractWestern cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), is a pest of cherry (Prunus Linnaeus, Rosaceae) in western North America that can be monitored using traps baited with ammonia. However, ammonia-based attractants also attract non-target Diptera that clutter traps. Here, the hypothesis that ammonium carbonate (AC) loss rates from lures differentially affect numbers of R. indifferens and non-target flies caught on sticky yellow rectangles in sweet cherry trees was tested in Washington State, United States of America. Ammonium carbonate loss rates were varied from seven-dram plastic vials hung ~1 cm above traps. A total of six experiments were conducted in which progressively lower AC loss rates within a range of 0.10–26.19 mg AC/hour were tested. For captures of R. indifferens, no AC loss rate comparisons within 0.19–26.19 mg/hour differed, and captures were not reduced until losses were lowered to 0.10–0.13 mg/hour. In contrast, captures of medium to large (⩾5 mm long) non-target flies, which were mostly Sarcophagidae (Diptera), were reduced at a rate ~30 times higher, at 3.34 or 3.80 mg AC/hour. Results suggest that using lures with an AC loss rate of 0.19 mg/hour can maintain high R. indifferens captures while reducing non-target fly captures and thus can improve monitoring efficiency.


1978 ◽  
Vol 18 (95) ◽  
pp. 834 ◽  
Author(s):  
RJK Myers

Different nitrogen carriers, and placements and strategies of application to dryland grain sorghum growing in a clay loam soil were compared in field experiments at Katherine, Northern Territory. The nitrogen carriers were ammonium sulphate, ammonium nitrate, urea and anhydrous ammonia ; placements were banding, mixing into the topsoil, and broadcasting; and strategies consisted of split application, and varying time of broadcasting. The rate used throughout was 50 kg N ha-1.Responses to the various treatments varied between the two seasons (1970-71, 1971-72) due to differing soil moisture conditions. There was a response to broadcasting nitrogen after emergence, giving higher grain yield and nitrogen yield than earlier broadcasting or application with the seed. Banded nitrogen (both seasons) and split nitrogen (one season) were superior to other methods of applying nitrogen with the seed. The only yield differences between sources of nitrogen were with broadcast application, where ammonium sulphate proved superior in one season, and with respect to apparent recovery of nitrogen by the crop, when the order ammonium nitrate > ammonium sulphate > urea was observed in both seasons. It is suggested that in this environment and on this soil, nitrogen is not particularly susceptible to volatilization, and broadcasting urea and ammonium fertilizer onto dry soil may retain nitrogen within the rooting zone, in comparison with nitrate, which is more susceptible to leaching. Incorporated fertilizer is more susceptible to nitrification and subsequent leaching, while banded nitrogen appears to resist nitrification and leaching.


2021 ◽  
Vol 5 ◽  
Author(s):  
Chelsea Megan Gowton ◽  
César Cabra-Arias ◽  
Juli Carrillo

Intercropping can be used to reduce pest insects within agricultural systems, e.g., through deterring pests directly or by increasing habitat for their natural enemies. For example, plant produced volatile organic compounds (VOCs) can deter or confuse host-finding by insects through olfactory disruption. Drosophila suzukii is an invasive fruit fly of agricultural concern as it can lay its eggs in both ripening and fresh fruits and, uses olfactory cues to identify its wide range of host plants. Peppermint plants (Mentha × piperita) produce high levels of VOCs while growing and may, therefore, be suitable as an intercrop to reduce D. suzukii infestations in the field, as peppermint essential oil VOCs have previously been shown to deter D. suzukii in olfactory trials. We conducted a field intercropping experiment to evaluate the effectiveness of peppermint plants compared to traditional ryegrass/clover mixes in reducing D. suzukii oviposition in the field, and the effect of peppermint intercrops on other invertebrates. In the field, we monitored sentinel fruit baits weekly for D. suzukii infestation. Additionally, we monitored intercropping effects on the invertebrate community through weekly pitfall trap collection and through a pollinator point survey. We monitored for local, farm level presence of D. suzukii through apple cider vinegar traps within crop fields and along hedgerows and found high abundance of D. suzukii (>3,000 individuals trapped). Peppermint intercrops had fewer D. suzukii emerge from fruit baits and supported greater beneficial insect abundance (predators and pollinators) compared to ryegrass/clover. However, levels of D. suzukii were low across both intercrop types. Overall, we found that peppermint intercrops could be a potential aromatic intercrop used to reduce D. suzukii adult emergence from fruit compared to conventional ryegrass/clover mixes, however this trial should be replicated over multiple growing seasons, geographic locations, and host fruits. Furthermore, further study should determine the effects of the intercrop on the focal crop of interest.


HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 599E-600
Author(s):  
Regina P. Bracy ◽  
Richard L. Parish

Improved stand establishment of direct-seeded crops has usually involved seed treatment and/or seed covers. Planters have been evaluated for seed/plant spacing uniformity, singulation, furrow openers, and presswheel design; however, effects of presswheels and seed coverers on plant establishment have not been widely investigated. Five experiments were conducted in a fine sandy loam soil to determine effect of presswheels and seed coverers on emergence of direct-seeded cabbage and mustard. Seed were planted with Stanhay 870 seeder equipped with one of four presswheels and seed coverers. Presswheels included smooth, mesh, concave split, and flat split types. Seed coverers included standard drag, light drag, paired knives, and no coverer. Soil moisture at planting ranged from 8% to 19% in the top 5 cm of bed. Differences in plant counts taken 2 weeks after planting were minimal with any presswheel or seed coverer. Visual observation indicated the seed furrow was more completely closed with the knife coverer in high soil moisture conditions. All tests received at least 14 mm of precipitation within 6 days from planting, which may account for lack of differences in plant emergence.


1992 ◽  
Vol 70 (5) ◽  
pp. 1012-1016 ◽  
Author(s):  
S. N. Acharya ◽  
C. B. Chu ◽  
R. Hermesh ◽  
G. B. Schaalje

Seeds from 55 populations of native Alberta red-osier dogwood (Cornus stolonifera Michx.) were collected over 2 years (1984 and 1985) to determine the range of variability for seed germination and the effect of ecoregion and moisture conditions in the collection sites on this trait. Each year the unscarified seeds were stored at 3 °C for 30 days, stratified at 3 °C for an additional 30 days and then incubated on an 8 h light: 16 h dark cycle at a temperature of 25:10 °C (light:dark) for germination. A wide range of germination percentages was observed among populations collected in any 1 year. However, the variability was not due to the ecoregion or moisture condition of the collection site. Germination percentage of populations collected in 1984 and 1985 formed five and seven groups, respectively. A study involving eight sites that were common to 1984, 1985, and 1986 revealed a significant effect of population on seed germination. This population effect was not obscured by the combined effects of year, precipitation, temperature, and seed size. The year effect was significant only when population was used as a covariate. Precipitation during seed formation significantly influenced germination performance even after adjustments were made for population and year. Seed germination in red-osier dogwood appears to be influenced by the population from which the seeds are collected and by yearly environmental fluctuations. Therefore, germination studies in this species must include seeds from diverse populations collected over several years. Key words: red-osier dogwood, Cornus stolonifera Michx., germination, population, environment.


2009 ◽  
Vol 69 (3) ◽  
pp. 935-942 ◽  
Author(s):  
LA. Pires ◽  
VJM. Cardoso ◽  
CA. Joly ◽  
RR. Rodrigues

The germination response of Ocotea pulchella (Nees) Mez seeds to light, temperature, water level and pulp presence is introduced. The laboratory assays were carried out in germination chambers and thermal-gradient apparatus, whereas the field assays were performed in environments with distinct light, temperature and soil moisture conditions within a permanent parcel of Restinga forest of the Parque Estadual da Ilha do Cardoso, Cananéia, São Paulo. The seeds do not exhibit dormancy, they are non photoblastic, and a loss of viability in dry stored seeds can be related to a decrease in water content of the seed. The presence of the pulp and the flooded substratum influenced negatively the germination of O. pulchella seeds tested in the laboratory. Otherwise, light and temperature probably are not limiting factors of the germination of O. pulchella seeds in the natural environment of Restinga. The optimum temperature range for germination of Ocotea pulchella seeds was 20 to 32 ºC, the minimum or base temperature estimated was 11 ºC and the maximum ranged between 33 and 42 ºC. The isotherms exhibited a sigmoidal pattern well described by the Weibull model in the sub-optimal temperature range. The germinability of O. pulchella seeds in the understorey, both in wet and dry soil, was higher than in gaps. Germination was not affected by fluctuations in soil moisture content in the understorey environment, whereas in gaps, germination was higher in wet soils. Thus, the germination of this species involves the interaction of two or more factors and it cannot be explained by a single factor.


1975 ◽  
Vol 65 (3) ◽  
pp. 359-372 ◽  
Author(s):  
A. B. S. King

AbstractThe size and occurrence of the first brood of adults of Aeneolamia varia saccharina (Dist.) are examined in relation to the pattern of egg eclosion and rainfall. The proportion of eggs hatching within a month of oviposition in the laboratory (short-period eggs) decreased from over 90% in August to less than 20% in January, but the incubation periods of the remaining, long-period eggs were longest in those laid during October and November. The overall hatching distributions tended to be bimodal with most eggs hatching during the early months of the year under moist conditions at 26°C. Dry soil conditions delay eclosion, and eggs obtained from fields during the dry season and then incubated under moist conditions tended to hatch at the normally expected time of the first rains in May. The numbers of eggs expected to produce the first brood, computed from laboratory hatching data and estimates of the numbers and fecundities of froghoppers during the second, third and fourth broods, were less than the actual numbers sampled just before the first rains. There was a close relationship between the first rainfall of over one inch within 48 h and adult emergence 27 and 34 days later, and 85% of field egg populations in May had hatched and/or died by the week after the first rains. However some variation in the date of their occurrence accounted for non-synchrony of first broods over the region. The numbers of diapause eggs in fields sampled during the dry season failed to give a good predictive relationship with first brood adult populations, probably because of density dependent mortality of eggs or hatchling nymphs.


2016 ◽  
Vol 20 (1) ◽  
pp. 59-64
Author(s):  
MN Islam ◽  
MM Rahman ◽  
MJA Mian ◽  
MH Ali

Leaching loss of nutrients hampers plant growth and contributes to environmental pollution. An experiment was conducted at the net house of Soil Science Department, Bangladesh Agricultural University, Mymensingh during January to May 2009 to find out the leaching loss of N, P, K and S from sandy loam soil. Each pot received 6.67 kg dry soil with an opening at the bottom for collecting leachates. Six treatments were used: T0 = control, T1 = NPKS (120, 25, 60 and 20 kg ha-1), T2 = NPKS (180, 37, 90 and 30 kg ha-1), T3 = NPKS (90, 5, 28 and 17 kg ha-1) + cowdung (2.5 t ha-1), T4 = NPKS (109, 25, 60 and 20 kg ha-1, N as USG) and T5 = as T1 but N applied as foliar spray. Treatments were arranged in a completely randomized design with three replications. Leachates were collected at 15 days interval for determination of NPKS. The total leaching loss of N, P, K and S due to different treatments ranged from 16.00 to 90.21, 0.07 to 0.29, 9.60 to 11.20 and 3.75 to 17.81 kg ha-1, respectively. Application of chemical fertilizer at higher rates resulted in greater loss of nutrients. Integrated fertilizer management with cowdung (T3) minimized such losses. Use of USG also reduced leaching loss of N, P, K and S. The application of cowdung and USG with recommended balanced fertilizer might be useful for minimizing N, P, K and S loss from wetland rice field.Bangladesh Rice j. 2016, 20(1): 59-64


2015 ◽  
Vol 10 (2) ◽  
Author(s):  
M. Murwantoko ◽  
Chio Oka ◽  
Masashi Kawaichi

HtrA which is characterized by the combination of a trypsin-like catalytic domain with at least one C-terminalPDZ domain is a highly conserved family of serine proteases found in a wide range of organisms. However theidentified HtrA family numbers varies among spesies, for example the number of mammalian, Eschericia coli,fruit fly-HtrA family are 4, 3 and 1 gene respectively. One gene is predicted exist in zebrafish. Since no completeinformation available on zebrafish HtrA, in this paper zebrafish HtrA (zHtrA) gene was analyzed. The zHtrA isbelonged to HtrA1 member and predicted encodes 478 amino acids with a signal peptide, a IGF binding domain,a Kazal-type inhibitor domain in the up stream of HtrA-bacterial homolog. At the amino acid sequence the zHtrA1showed the 69%, 69%, 68%, 54% and 54% with the rat HtrA1, mouse HtrA1, human HtrA1, human HtrA3 andmouse HtrA4 respectively. The zHtrA1 is firstly expressed at 60 hpf and mainly in the vertebral rudiments in thetail region.


2013 ◽  
Vol 353-356 ◽  
pp. 911-917 ◽  
Author(s):  
Mohd Hazreek Zainal Abidin ◽  
Fauziah Ahmad ◽  
Devapriya Chitral Wijeyesekera ◽  
Rosli Saad ◽  
Mohamad Faizal Tajul Baharuddin

In the past, most of the soil electrical resistivity charts were developed based on stand-alone geomaterial classification with minimal contribution to its relationship to some of geotechnical parameters. Furthermore, the values cited a very wide range of resistivity with sometimes overlapping values and having little significance to specific soil condition. As a result, it created some ambiguities during the interpretation of observations which were traditionally based on qualitative anomaly judgments of experts and experienced people. Hence, this study presents soil resistivity values based on laboratory experiment with a view to predict the soil moisture content and density in loose and dense soils. This study used a soil box and a resistivity meter to test a clayey silt soil, increasing its water usage from 1-3% based on 1500 gram of dry soil. All the moisture contents and density data were observed concurrently with 25 electrical soil resistance observations being made on the soil. All testing and formula used were in accordance with that specified in BS1377 (1990). It was apparent that the soil resistivity value was different under loose (L) and compact (C) condition with moisture content (w) and density (ρbulk) correlations being established as follows; ρbulk(C) = 2.5991ρ-0.037, ρbulk (L) = -0.111 ln (ρ) + 1.7605, w(L) = 109.98ρ-0.268, and w(C) = 121.88ρ-0.363 with determination coefficients, R2 that ranged between 0.69 0.89. This research therefore contributes a means of predicting these geotechnical parameters by related persons such as geophysicist, engineers and geologist who use these resistivity techniques in ground exploration.


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