scholarly journals Native range assessment of classical biological control agents: impact of inundative releases as pre-introduction evaluation

2009 ◽  
Vol 100 (4) ◽  
pp. 387-394 ◽  
Author(s):  
W.H. Jenner ◽  
P.G. Mason ◽  
N. Cappuccino ◽  
U. Kuhlmann
Keyword(s):  
Classical Biological Control ◽  
Field Trials ◽  
Native Range ◽  
Naturally Occurring ◽  
Diadromus Pulchellus ◽  
Pupal Parasitism ◽  
Field Efficacy ◽  
Pupal Mortality ◽  
Field Plots ◽  
Leek Moth

AbstractDiadromus pulchellus Wesmael (Hymenoptera: Ichneumonidae) is a pupal parasitoid under consideration for introduction into Canada for the control of the invasive leek moth, Acrolepiopsis assectella (Zeller) (Lepidoptera: Acrolepiidae). Since study of the parasitoid outside of quarantine was not permitted in Canada at the time of this project, we assessed its efficacy via field trials in its native range in central Europe. This was done by simulating introductory releases that would eventually take place in Canada when a permit for release is obtained. In 2007 and 2008, experimental leek plots were artificially infested with pest larvae to mimic the higher pest densities common in Canada. Based on a preliminary experiment showing that leek moth pupae were suitable for parasitism up to 5–6 days after pupation, D. pulchellus adults were mass-released into the field plots when the first host cocoons were observed. The laboratory-reared agents reproduced successfully in all trials and radically reduced leek moth survival. Taking into account background parasitism caused by naturally occurring D. pulchellus, the released agents parasitized at least 15.8%, 43.9%, 48.1% and 58.8% of the available hosts in the four release trials. When this significant contribution to leek moth mortality is added to previously published life tables, in which pupal parasitism was absent, the total pupal mortality increases from 60.1% to 76.7%. This study demonstrates how field trials involving environmental manipulation in an agent's native range can yield predictions of the agent's field efficacy once introduced into a novel area.

scholarly journals Automating Uniformity Trials to Optimize Precision of Agronomic Field Trials

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1254
Author(s):  
Marcus Jones ◽  
Marin Harbur ◽  
Ken J. Moore
Keyword(s):  
Web Application ◽  
Unit Area ◽  
Field Trials ◽  
State University ◽  
Iowa State University ◽  
Plot Size ◽  
Maize Field ◽  
Process Uniformity ◽  
Field Plots ◽  
Uniformity Trials

Plot size has an important impact on variation among plots in agronomic field trials, but is rarely considered during the design process. Uniformity trials can inform a researcher about underlying variance, but are seldom used due to their laborious nature. The objective of this research was to describe variation in maize field trials among field plots of varying size and develop a tool to optimize field-trial design using uniformity-trial statistics. Six uniformity trials were conducted in 2015–2016 in conjunction with Iowa State University and WinField United. All six uniformity trials exhibited a negative asymptotic relationship between variance and plot size. Variance per unit area was reduced over 50% with plots 41.8 m2 in size and over 75% when using a plot size >111.5 m2 compared to a 13.9 m2 plot. Plot shape within a fixed plot size did not influence variance. The data illustrated fewer replicates were needed as plot size increased, since larger plots reduced variability. Use of a Shiny web application is demonstrated that allows a researcher to upload a yield map and consider uniformity-trial statistics to inform plot size and replicate decisions.

scholarly journals Exploiting Thrips Aggregation Pheromones to Develop a Lure-and-Kill Strategy for the Management of the Bean Flower Thrips

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1269
Author(s):  
David K. Mfuti ◽  
Amanuel Tamiru ◽  
William D. J. Kirk ◽  
Adeyemi O. Akinyemi ◽  
Heather Campbell ◽  
...  
Keyword(s):  
Field Experiments ◽  
Insect Pests ◽  
Field Trials ◽  
Aggregation Pheromones ◽  
Megalurothrips Sjostedti ◽  
Flower Thrips ◽  
Antifungal Effects ◽  
Field Efficacy ◽  
Management Alternative ◽  
Trap Catches

The potential of semiochemicals to lure insect pests to a trap where they can be killed with biopesticides has been demonstrated as an eco-friendly pest management alternative. In this study, we tested two recently characterized male-produced aggregation pheromones of the bean flower thrips Megalurothrips sjostedti (Trybom), namely (R)-lavandulyl 3-methylbutanoate (major) and (R)-lavandulol (minor), for their field efficacy. Moreover, compatibility of these pheromones and two other thrips attractants, Lurem-TR and neryl (S)-2-methylbutanoate, with the entomopathogenic fungus (EPF) Metarhizium anisopliae ICIPE 69 has been determined. Our study revealed that the M. sjostedti aggregation pheromones have dose-dependent antifungal effects on the EPF viability, but showed no fungistatic effect at a field-realistic dose for attraction of thrips. (R)-lavandulyl 3-methylbutanoate had similar antifungal effects as neryl (S)-2-methylbutanoate 8 days after exposure; whereas, Lurem-TR had a stronger antifungal effect than other thrips attractants. In the semi-field experiments, all autoinoculation devices maintained at least 86% viability of M. anisopliae conidia after 12 days of exposure. Field trials demonstrated for the first time that (R)-lavandulyl 3-methylbutanoate increases trap catches. Our findings pave a way for designing a lure-and-kill thrips management strategy to control bean flower thrips using autoinoculation devices or spot spray application.

scholarly journals Genome Analysis of an Alphabaculovirus Isolated from the Larch Looper, Erannis ankeraria

Viruses ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Long Liu ◽  
Zhilin Zhang ◽  
Chenglin Liu ◽  
Liangjian Qu ◽  
Dun Wang
Keyword(s):  
Insect Pests ◽  
Field Trials ◽  
Open Reading Frames ◽  
Parameter Analysis ◽  
Naturally Occurring ◽  
Larch Forests ◽  
Genome Phylogeny ◽  
Occlusion Bodies ◽  
Reading Frames ◽  
Core Genes

The larch looper, Erannis ankeraria Staudinger (Lepidoptera: Geometridae), is one of the major insect pests of larch forests, widely distributed from southeastern Europe to East Asia. A naturally occurring baculovirus, Erannis ankeraria nucleopolyhedrovirus (EranNPV), was isolated from E. ankeraria larvae. This virus was characterized by electron microscopy and by sequencing the whole viral genome. The occlusion bodies (OBs) of EranNPV exhibited irregular polyhedral shapes containing multiple enveloped rod-shaped virions with a single nucleocapsid per virion. The EranNPV genome was 125,247 bp in length with a nucleotide distribution of 34.9% G+C. A total of 131 hypothetical open reading frames (ORFs) were identified, including the 38 baculovirus core genes and five multi-copy genes. Five homologous regions (hrs) were found in the EranNPV genome. Phylogeny and pairwise kimura 2-parameter analysis indicated that EranNPV was a novel group II alphabaculovirus and was most closely related to Apocheima cinerarium NPV (ApciNPV). Field trials showed that EranNPV was effective in controlling E. ankeraria in larch forests. The above results will be relevant to the functional research on EranNPV and promote the use of this virus as a biocontrol agent.

scholarly journals Field efficacy of mandipropamid for the control of potato late blight

2010 ◽  
Vol 25 (2) ◽  
pp. 157-161
Author(s):  
Emil Rekanovic ◽  
Milos Stepanovic ◽  
Milan Stevic ◽  
Ivana Potocnik ◽  
Biljana Todorovic ◽  
...  
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Potato Late Blight ◽  
Field Trials ◽  
High Efficacy ◽  
Highly Effective ◽  
Field Efficacy ◽  
Disease Pressure

The efficacy of mandipropamid (Revus 250 SC) in controlling Phytophthora infestans in potato was evaluated in field trials. The efficacies of Revus 250 SC in comparison with standard fungicides Quadris (azoxystrobin) were tested in several localities in Serbia (Kasarske Livade, Valjevska Kamenica and Opovo) in 2007 and 2008. Both of the tested fungicides exhibited high efficacy in controlling potato late blight. The differencies in the efficacy of Revus 250 SC (96.3- 99.2%) and Quadris (94.1-95.5%) were insignificant. Our experiments showed that the investigated fungicide was highly effective against P. infestans even under high disease pressure.

Identification of leek-moth and diamondback-moth frass volatiles that stimulate parasitoid,Diadromus pulchellus

1989 ◽  
Vol 15 (4) ◽  
pp. 1391-1398 ◽  
Author(s):  
Jacques Auger ◽  
Chantal Lecomte ◽  
Jacky Paris ◽  
Eric Thibout
Keyword(s):  
Diamondback Moth ◽  
Diadromus Pulchellus ◽  
Leek Moth

Laboratory and field trials to determine the modes of action of malathion and diesel oil against Culicoides furens (Poey) (Dipt., Ceratopogonidae)

1971 ◽  
Vol 60 (3) ◽  
pp. 399-407
Author(s):  
John B. Davies
Keyword(s):  
Emerging Adults ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Field Trials ◽  
Diesel Oil ◽  
Modes Of Action ◽  
Marine Diesel ◽  
Pupal Mortality

One field and four laboratory trials were run to determine the reason for the success of 1–8% malathion in diesel oil in controlling Culicoides furens (Poey) in swamp mud in Jamaica. In the laboratory malathion and marine diesel oil (1:4000) was an effective larvicide for up to two days after application to the mud, but diesel oil alone gave only slight mortality even after six days. Judged by the emergence of adults, diesel oil gave 100% pupal mortality for five days and still showed some effect after four weeks; this effect was not improved by the addition of malathion. In the field, counts of emerging adults showed that diesel oil at 106–5 gal/acre gave 97–8% control of C. furens for up to eight weeks after application. It is concluded that, because of the possibility of pupicidal action, insecticides should be assessed on adult emergence rather than larval mortality.

scholarly journals Differential Cultivars and Criteria for Evaluating Resistance to Rhizoctonia solani in Seedling Brassica oleracea

Plant Disease ◽  
1997 ◽  
Vol 81 (8) ◽  
pp. 946-952 ◽  
Author(s):  
Anthony P. Keinath ◽  
Mark W. Farnham
Keyword(s):  
Rhizoctonia Solani ◽  
Brassica Oleracea ◽  
Field Experiments ◽  
Field Trials ◽  
Plant Weight ◽  
Progress Curve ◽  
Growth Room ◽  
Differential Cultivars ◽  
Field Plots ◽  
Sand Cultures

Growth-room and field experiments were conducted to develop methods of studying resistance in Brassica oleracea crops to Rhizoctonia solani anastomosis groups (AG) 2-1 and 4, causal agents of wirestem. Seedlings of 12 cultivars (3 each of broccoli, cauliflower, cabbage, and collard) at the four- to five-leaf stage were transplanted to trays in a growth room and covered with steamed soil infested with cornmeal-sand cultures or sclerotia of R. solani or to fumigated field plots infested with sclerotia. The percent healthy, diseased, and dead plants was assessed every 3 to 5 days for 2 weeks in the growth room and for 3 weeks in field trials. At harvest, plants were dug out with roots intact and rated for wirestem severity. In most experiments, wirestem incidence (percent diseased and dead plants) stabilized within 10 to 14 days after inoculation. Inoculation with cornmeal-sand cultures of both AGs and sclerotia of AG-4 resulted in severe wirestem in all experiments, whereas sclerotia of AG-2-1 were less effective in the growth room and not effective in the field. Percent healthy and surviving (healthy plus diseased) plants, area under the disease progress curve (AUDPC), and wirestem severity all separated the most susceptible from the partially resistant cultivars more consistently than fresh weight of inoculated plants expressed as a percentage of noninoculated plant weight. Wirestem severity and AUDPC were always negatively and significantly (P ≤ 0.01) correlated with percent healthy plants. Although genotype by environment interactions were observed, the cauliflower cvs. Snowcone and Snow Crown were severely diseased in all experiments, whereas collard cv. Blue Max was consistently and significantly (P ≤ 0.05) less diseased.

scholarly journals Synergistic effect of naturally occurring Granulosis virus isolates (PbGV) with phagostimulants against the cabbage butterfly, Pieris brassicae (L.) for its eco-friendly management

2022 ◽  
Vol 32 (1) ◽  
Author(s):  
Ramandeep Kour ◽  
R. K. Gupta ◽  
Barkat Hussain ◽  
Simranjeet Kour
Keyword(s):  
Field Experiments ◽  
Field Trials ◽  
Pieris Brassicae ◽  
Field Conditions ◽  
Leafy Vegetables ◽  
Granulosis Virus ◽  
Larval Population ◽  
Cabbage Butterfly ◽  
Combined Application ◽  
Naturally Occurring

Abstract Background To manage the cabbage butterfly, Pierisbrassicae (L.) (Lepidoptera: Pieridae), it is not wise to use insecticides on leafy vegetables which are eaten mostly fresh. During the past decades, the efforts to manage the pest, through chemical insecticides have raised serious health. Investigations were carried out to isolate naturally occurring GVs (PbGV) as a potent biopesticide against P.brassicae and to explore their efficacy with the application of phagostimulants. Results Among the four naturally occurring isolates obtained from Northwestern Himalayas, Sudhmahadev isolate was found to be the most promising based on virulence and speed of kill against all the instars tested in the laboratory, showing the natural incidence of PbGV infection in field conditions. In concentration and time–response bioassay, all the isolates of P.brassicae Granulosis virus were found high virulent against second instar larvae of cabbage butterfly. Therefore, for enhanced efficacy of PBGV, its combined application with phagostimulants (Lepidiumsativum + Teepol + jaggery) or sticker (Teepol + jaggery), applied in field trials, resulted into greater mortality of larval instars than the single one. Overall, the results indicated that the introduction of a more isolates PBGV strain into populations of P.brassicae could be of vital importance for eco-friendly suppression of this pest globally with the combination of phagostimulants. The application virus alone with the pre-standardized concentration of 1 × 1012 OBs/ha did not reduce the larval population density to the desirable extent in the greenhouse chamber and therefore was not included in field experiments. Overall, the most promising treatments in reducing the larval population of the pest were PbGV + Teepol + B.thuringiensis (93.49 and 91.39%) and PbGV + Teepol + L.sativum (88.79 and 86.97%) over control in both greenhouse and field trials, respectively. Conclusions In this study, the native isolates of PbGV from different target locations to test their efficacy against different instars of P.brassicae were explored. Using native PBGV isolates with phagostimulant combinations played an important role for regulating the pest effectively. These phagostimulants not only protected the OBs from degradation in the presence of sunlight but also increased the speed of killing. The biocontrol potential of PbGV in both laboratory and field conditions indicated that baculoviruses are sustainable alternative to chemical insecticides.

Sign in / Sign up

Export Citation Format

Share Document