scholarly journals Effects of Growing Medium Type and Moisture Level on Predation by Adult Rove Beetle, Dalotia coriaria (Coleoptera: Staphylinidae), on Fungus Gnat, Bradysia sp. nr. coprophila (Diptera: Sciaridae), Larvae under Laboratory and Greenhouse Conditions

HortScience ◽  
2017 ◽  
Vol 52 (5) ◽  
pp. 736-741 ◽  
Author(s):  
Nathan J. Herrick ◽  
Raymond A. Cloyd

The fungus gnat, Bradysia sp. nr. coprophila (Lintner) (Diptera: Sciaridae), is an insect pest of greenhouse production systems. The rove beetle, Dalotia coriaria [Kraatz] (Coleoptera: Staphylinidae), is a commercially available predator of certain greenhouse insect pests that reside in growing media, including fungus gnats. There is minimal information discussing how growing medium type and moisture level (watering treatment) impact the interactions between pests and natural enemies. Therefore, we conducted laboratory and greenhouse experiments to investigate the influence of two growing media (Sunshine® LC1 Professional Growing Mix and Fafard® 3B Mix Professional Formula) and two moisture levels (“constantly saturated” and “initially saturated”) on predation by adult D. coriaria on B. sp. nr. coprophila larvae after releasing one or two rove beetle adults. In the laboratory experiment, moisture content or the amount of water retained by the growing medium did not significantly influence the recovery of adult fungus gnats for any of the rove beetle treatments. However, there was a significant difference in the recovery of fungus gnat adults between the two growing media. Fewer fungus gnat adults emerged from the Sunshine® LC1 Professional Growing Mix (0.9 ± 0.2 adults) than the Fafard® 3B Mix Professional Formula (6.0 ± 0.9 adults). Significantly fewer adult fungus gnats were recovered in the treatments where one rove beetle adult was released (2.7 ± 0.7 adults) and two rove beetle adults were released (2.3 ± 0.5 adults) compared with the control without rove beetles (5.4 ± 1.4 adults). However, there was no significant difference between the number of rove beetle adults released. In contrast to the laboratory experiment, moisture content in the greenhouse experiment significantly influenced the recovery of adult fungus gnats. More adult fungus gnats were recovered from the “constantly saturated” treatment (9.9 ± 1.4 adults) than the “initially saturated” treatment (3.8 ± 1.0 adults). Similar to the laboratory experiment, there was a significant difference in the recovery of fungus gnat adults between the two growing media, with fewer adults captured from the Sunshine® LC1 Professional Growing Mix (3.2 ± 0.8 adults) than the Fafard® 3B Mix Professional Formula (10.4 ± 1.4 adults). However, the treatments with rove beetle adults [one rove beetle (6.6 ± 1.8 adults) or two rove beetles (5.3 ± 1.5 adults)] were not significantly different from the control without rove beetles (8.6 ± 1.5 adults), suggesting that the growing media and moisture levels were acting directly on fungus gnat survival. The results of our study demonstrate that survival of fungus gnat larvae that reside in the growing medium and the success of rove beetle adults used to regulate these pests can be influenced by growing media and the moisture content within growing media.

HortScience ◽  
2008 ◽  
Vol 43 (5) ◽  
pp. 1528-1530 ◽  
Author(s):  
Raymond A. Cloyd ◽  
Amy Dickinson

Fungus gnats, Bradysia spp., are major insect pests in greenhouses and interiorscapes. Management typically involves the use of either insecticides or biological control agents such as entomopathogenic nematodes. Efficacy trials provide information to greenhouse producers on the effectiveness of these management options. However, a simple procedure that rapidly evaluates the performance of control products against fungus gnat larvae is needed. Because fungus gnat larvae inhabit the growing medium, excess or deficient growing medium moisture may reduce adult fungus gnat emergence, thus confounding effects from efficacy trial treatments. Therefore, it is important to determine the amount of moisture and moisture content that results in the highest recovery of fungus gnat adults. We conducted two replicated experiments in a completely randomized design using a range of initial water volumes (treatments) and two larval stages (second and third) of the fungus gnat, Bradysia sp. nr. coprophila. The success of the procedure was based on the number of fungus gnat adults that emerged per treatment. In the first experiment, initial water volumes of 0, 25, 50, 75, 100, 150, and 200 mL were applied to 300 mL of a soilless growing medium consisting of 50% composted pine bark, 20% Canadian sphagnum peatmoss, 10% perlite, and 20% medium coarse vermiculite (SB300 Universal Mix). In general, the highest mean numbers (range, 11.2 to 14.6) of fungus gnat adults were recovered from growing medium treated with 50, 75, and 100 mL of water. In the second experiment, initial water volumes (treatments) of 50, 55, 60, 65, 70, and 75 mL were applied to 300 mL of the soilless growing medium (SB300 Universal Mix). There were no significant differences in the mean number of fungus gnat adults recovered regardless of the larval instar (second instar: 15.8 to 17.7; third instar: 14.4 to 17.4). The final percent moisture content ranged from 65% to 68% for the second instars and 56% to 66% for third instars. This study demonstrates that the highest number of fungus gnat adults may be recovered from soilless growing medium (SB300 Universal Mix) treated with between 50 and 75 mL of water, thus enhancing the confidence in any data set generated when evaluating insecticides or biological control agents for control of fungus gnats.


HortScience ◽  
2018 ◽  
Vol 53 (10) ◽  
pp. 1441-1446 ◽  
Author(s):  
Nathan J. Herrick ◽  
Raymond A. Cloyd

Fungus gnats, Bradysia spp. (Diptera: Sciaridae), are major insect pests because the larvae can directly damage plants grown in greenhouse production systems. In general, insecticides are commonly used to suppress fungus gnat larval populations. However, the rove beetle, Dalotia coriaria (Kraatz) (Coleoptera: Staphylinidae), a commercially available predator of insect pests, including fungus gnat larvae, may be an alternative to using insecticides. Growing medium selection used for growing plants can influence insect pest and predator interactions in greenhouse production systems; however, quantitative information is limited. Therefore, we conducted greenhouse experiments and a laboratory experiment to determine the effects of growing medium type on D. coriaria adult predation and fungus gnat, Bradysia. sp. nr. coprophila (Lintner) (Diptera: Sciaridae), larval survival when feeding on the roots of coleus, Solenostemon scutellarioides (L.) Codd, plants. In addition, experiments were conducted to determine the number of rove beetle adults, based on predator:prey ratios, needed to regulate fungus gnat larval populations. In all three experiments, fewer fungus gnat larvae survived in Pro-Mix BX than the Berger BM1 growing medium, and rove beetles reduced the number of fungus gnat larvae in both growing media in the greenhouse experiments. Although predator:prey ratio was not significant, we found that 10 rove beetle adults per 15.2-cm diameter container (1834.82 cm3 with 2.0 L of growing medium) regulated fungus gnat larval populations at the densities investigated. Therefore, greenhouse producers should consider the effects of production practices, such as growing medium type, when using rove beetles to regulate fungus gnat larval populations.


HortScience ◽  
2005 ◽  
Vol 40 (6) ◽  
pp. 1806-1809 ◽  
Author(s):  
Raymond A. Cloyd ◽  
Amy Dickinson

Fungus gnats (Bradysia spp.) are major insect pests in greenhouses. The adult stage is primarily a nuisance whereas the larval stage is directly responsible for plant injury by feeding on plant roots or tunneling into stems. Insecticides are used to deal with fungus gnat larvae in growing medium, although sometimes with limited success. This study evaluated the potential of using a soil amendment—diatomaceous earth (DE) incorporated into growing media—for controlling the fungus gnat Bradysia sp. nr. coprophila. Two experiments were conducted by testing a series of growing media containing various concentrations of diatomaceous earth, and several without diatomaceous earth. The effects of the growing media containing diatomaceous earth on both the 2nd and 3rd instars of fungus gnat larvae were determined by recording the number of adults captured on yellow sticky cards (2.5 × 2.5 cm). Based on the results obtained from both experiments, the addition of DE to growing medium, at the concentrations tested, did not negatively affect or increase efficacy against both the 2nd and 3rd instars. This suggests that incorporating DE into commercially available growing medium may not be beneficial to greenhouse producers. However, further research is needed to assess whether differential larval susceptibility and moisture content influence the ability of DE to control soil-dwelling arthropods.


2020 ◽  
Vol 7 (1) ◽  
pp. 62-66
Author(s):  
Masniar Vina Kesti ◽  
Bambang Irawan ◽  
Priyambodo Priyambodo ◽  
Martha Lulus Lande

Green mustard is one type of vegetable that is easily cultivated and has good prospects to increase farmers' income and community nutrition. Growing media is a material that is useful as a place to stand upright seedlings, to develop seedling roots, to store water, gas, and nutrients needed for seedling growth. The purpose of this study is a). to determine the effect of using a combination of cocopeat and charcoal as a medium for planting mustard greens, b). to get the best dosage of the composition of the growing medium on the growth of mustard greens. The study was conducted in a completely randomized design (CRD) with 4 treatments and 6 replications. The data were analyzed by analysis of variance (ANOVA) and further tested with the Least Significant Difference test (LSD) = 5%. The results showed that the use of cocopeat growing media and charcoal influenced germination and vigor index. Cocopeat and charcoal have a significant effect on fresh and dry weight and chlorophyll content of mustard greens. The mixture of cocopeat growing media and charcoal on P1 did not affect the growth of green mustard on the dry weight. Fresh weight gave a significant effect on K1 and P1 was also significantly different from P2 and P3.


1998 ◽  
Vol 8 (3) ◽  
pp. 406-409 ◽  
Author(s):  
Michael R. Evans ◽  
James N. Smith ◽  
Raymond A. Cloyd

Coir and peat-based substrates were tested for their effectiveness in inhibiting the development of fungus gnat populations. The first experiment was conducted in July under relatively high temperatures (20 to 35 °C) and a second experiment was conducted in April under relatively low temperatures (20 °C). Euphorbia pulcherrima Willd. ex Klotzch `Freedom' plants were planted into 18-cm-diameter containers filled with substrates containing 80% sphagnum peat or coir, with the remainder being perlite. Half of the containers of each substrate were inoculated with fungus gnat larvae and sealed with either cheesecloth or thrips screen for Expts. 1 and 2, respectively. After 6 and 8 weeks for Expts. 1 and 2, respectively, fungus gnat adult and larval populations were sampled. Adults and larvae were recovered from coir and peat-based substrates in both experiments. In Expt. 1, significantly more adults and larvae were recovered from coir-based than peat-based substrates. In Expt. 2, significantly more adults and larvae were recovered from the peat-based than coir-based substrates. In a third experiment, the peat- and coir-based substrates used in Expts. 1 and 2 were used as well as the Iowa State greenhouse substrate, which contained 40% Sphagnum peat, 40% perlite, and 20% loam (v/v). Helianthus annuus L. `Pacino' seeds were sown into 18-cm-diameter containers filled with the test substrates. Natural infestation was allowed to occur for 6 weeks, after which time potato disks were used to sample the fungus gnat larvae population. Larvae were recovered from all substrates, and there was no significant difference in the number of larvae collected from the three substrates. Based on the results of these experiments, we concluded that coir does not inhibit the development of fungus gnat larvae populations and, when presented with options, fungus gnats will infest coir-based substrates as readily as peat-based substrates.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 436C-436
Author(s):  
Kimberly A. Klock

Ornamental horticulture industries have the opportunity to utilize compost products as components in growing media, but heterogeneity among compost products can cause unpredictability in the activity of some growth regulators when applied as a drenches to the growing medium. These experiments evaluated the effect of 0%, 30%, 60%, or 100% compost (by volume) in the medium on the efficacy of paclobutrazol applied as a drench on Impatiens wallerana Hook. In experiment 1, paclobutrazol was applied at active ingredient (a.i.) drench rates of 0, 0.016, 0.032, 0.06, or 0.125 mg/pot 16 days after transplanting impatiens `Accent Red'. In experiment 2, paclobutrazol was applied at a.i. drench rates of 0, 0.25, 0.50, 1.0, or 2.0 mg/pot 14 days after transplanting impatiens `Dazzler Punch'. In both experiments, final height and size were reduced by paclobutrazol treatments compared to untreated plants. In experiment 1, shoot dry mass of treated plants was on the average of 0.92 g less than untreated plants, while shoot dry mass, in experiment 2, did not show a significant difference between treated and untreated plants. In both experiments, final height, size and shoot dry mass were significantly different among the media, with the greatest growth in 100% compost.


HortScience ◽  
2009 ◽  
Vol 44 (5) ◽  
pp. 1366-1369 ◽  
Author(s):  
Raymond A. Cloyd ◽  
Karen A. Marley ◽  
Richard A. Larson ◽  
Bari Arieli

This study was conducted to assess the attractiveness of growing media containing parboiled rice hulls (PBH) to fungus gnat, Bradysia sp. nr. coprophila (Diptera: Sciaridae), adults. In comparing commercially prepared PBH with peatmoss (LC1) and pine bark (SB200)-based growing media, it was established that the fungus gnat adults were not specifically attracted to any of the growing media, even those containing PBH, with the mean proportion of fungus gnat adults recovered in the sample compartments ranging from 0.16 to 0.23. Moisture content was more important in terms of fungus gnat adult attractiveness to the growing media. In addition, the volatile constituents of the various growing media were determined using a steam distillation procedure. The component that was present in the highest concentration (39.2%) in the dried PBH as determined by gas chromatography analysis was palmitic acid, a straight-chain C16 fatty acid. S8 (cyclo-octasulfur), a well-known odoriferous component of degraded waste materials, was present at a higher concentration (6.2%) in the RH1 growing medium (80% peatmoss) compared with the other growing media evaluated. The data indicate that PBH, when incorporated in certain growing media, do not attract fungus gnat adults, and as such, greenhouse producers can use PBH as an amendment to growing medium without having to be concerned with the prospect of luring fungus gnat adults and sustaining plant damage.


2019 ◽  
Vol 2 ◽  
Author(s):  
David D. Nagy ◽  
Orsolya Valkó ◽  
Tibor Magura ◽  
Balázs Deák ◽  
Roland Horváth ◽  
...  

Fire supports landscape openness; thus, prescribed burning could be an effective management in open landscapes. In this study we tested the response of arthropods (spider, ground beetle, rove beetle and woodlouse) to dormant-season prescribed burning in dry grassland patches. We hypothesized that the unburned patches support the arthropods recolonizing the burned patches; thus, fire causes no serious damage to the arthropod assemblages. Epigeic arthropods (spider, ground beetle, rove beetle and woodlouse) were collected by unbaited pitfall traps containing ethylene glycol as a killing-preserving solution. Altogether 60 traps worked in 3 burnt and 3 control plots (10 traps/plot). Traps were emptied monthly from May to October in the year after burning. Collected arthropods were identified at species level using standard keys. We found no significant difference between the burned and control plots for the abundance, species richness, and Shannon diversity of spiders, ground beetles, rove beetles and woodlice. Differences in total abundance, species richness and diversity of arthropods were also not significant between the burned and control plots. Among from 12 most abundant species, ten species was not affected by burning, while the abundance of Titanoteca veteranica spider species increased and the abundance of Trochosa robusta spider species decreased in the burnt plots. Microcaves and other unburned microhabitats in and around the burned patches serve as refuge for epigeic arthropods supporting the fast recolonization after prescribed burning, although the abundance of some epigeic spider species (Titanoteca veteranica, Trochosa robusta) was affected by burning. Our findigs revealed that prescribed burning is a potentially promising conservation method. We also highlighted that preservation of unburned microhabitats and surroundings of the managed patches is essential during the prescribed burning.


2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.


Author(s):  
Abdul Ganiy O. Raji ◽  
John Alaba Victor Famurewa

Soybean protein is highly rich in the essential amino acid needed by human body. In the developing countries, its use will be more generally acceptable when converted to flour like wheat. This work focused on establishing the optimum conditions of some physical characteristics of soybean for high quality and acceptable soy flour. The characteristics studied for soybean samples subjected to heat treatment of boiling and oven drying were the effect moisture content (MC) and the hull thickness on the quality of the flours. Ten samples of Tax 1485 at different moisture levels ranging from 20.6% to 8.6% and five varieties (Tax 1440-1E, Tax 1740, Tax 1485, Tax 1456 and Tax 1448-2E) obtained from International Institute for Tropical Agriculture (IITA), having different hull thicknesses were used. Soybean with mixed varieties commonly found in the open markets was also used to compare the effects of MC on the studied parameters. Flours obtained from the samples milled in an attrition mill were subjected to proximate, sieve and organoleptic evaluations. The hull thickness was found to have no correlation with protein retention, acceptability and flour yield, but moisture content has a very significant effect on the qualities. Between moisture content of 20.6% and 8.6%, protein and acceptability reduced from 40.0% to 27.7% and 4.3 to 2.2 respectively while yield increased from 0.9% to 5.8%. Though protein was reducing with reduced MC, there was no significant difference (p<0.05) in protein retention between MC of 20.6% and 10.1% but it became significant at 9.4%. There was no significant difference in acceptability from 13.6% to 8.6% MC and between 8.9% and 11.0% MC for flour yield. Both Tax 1485 and mixed varieties followed the same trend only that they have different absolute values. The mixed varieties however had no significant difference in protein content between 19.8% and 10.2% MC. These results, therefore established that to obtain acceptable soyflour of high flour yield and protein content, moisture content of soybean after processing should be about 10% (dry basis).


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