Observations on Feeding Habits of First-instar Larvae of the Pale Western Cutworm, Agrotis orthogonia Morr. (Lepidoptera: Phalaenidae)

1950 ◽  
Vol 82 (9) ◽  
pp. 181-185 ◽  
Author(s):  
L. A. Jacobson ◽  
P. E. Blakeley ◽  
C. W. Farstad
Keyword(s):  
Plant Growth ◽  
Critical Period ◽  
Feeding Habits ◽  
Control Measures ◽  
Western Canada ◽  
First Instar ◽  
Cultural Measures ◽  
Major Pest ◽  
Volunteer Plant

The pale western cutworm, Agrotis orthogonia Morr., has been a major pest of cereals in the prairie region of Western Canada since 1911. Present control measures consist of (a) cultural measures that inhibit oviposition in fields being summer-fallowed and (b) starvation of the young larvae by destroying the volunteer plant growth by means of cultivation at a critical period. Cultural operations to minimize oviposition in fields being summer-fallowed have become accepted procedure throughout the area. Control by starvation is practised during outbreak years in fields that have-been “stubbled in” or in those tilled during the moth flight. This procedure has been recommended generally throughout potentially infested areas, but more precise methods of evaluating larval numbers are required so that control may be used only where critical populations are present.

scholarly journals Assortments of Digestive Enzymes Induced in First Instar Larvae of Busseola fusca Feeding on Different Plants

2019 ◽  
Vol 11 ◽  
pp. 117954331984352 ◽  
Author(s):  
Gérald Juma ◽  
Bruno Le Ru ◽  
Paul-André Calatayud
Keyword(s):  
Plant Species ◽  
Digestive Enzymes ◽  
Host Plants ◽  
Feeding Habits ◽  
Busseola Fusca ◽  
Stem Borer ◽  
Sub Saharan Africa ◽  
Host Acceptance ◽  
First Instar ◽  
Sub Saharan

The stem borer Busseola fusca (Fuller) (Lepidoptera: Noctuidae) is an important pest of maize and sorghum in sub-Saharan Africa. This insect has oligophagous feeding habits, feeding mostly on maize and sorghum with a narrow range of wild Poaceous plant species. We hypothesised that first instar B. fusca larvae, the critical stage for successful establishment on a host plant, can establish and then grow on a particular plant as a result of induction of a complement of digestive enzymes that mediates host acceptance at first instars. A fast semi-quantitative analysis of potentially digestive enzymatic activities present in the first larvae previously fed for 4 days on leaves of host and non-host plants was performed using the API-ZYM kit system able to detect a multiplex of enzyme activities. Regardless of the plant species, the larvae exhibited higher activities of the carbohydrate metabolising enzymes than of aminopeptidases and proteases. In addition, highest activities of carbohydrates degrading enzymes were exhibited by larvae that consumed leaves of the most preferred plant species of B. fusca. Conversely, esterases were only detected in neonate larvae that consumed leaves of the less preferred and non-host plants. No alkaline phosphatase and lipase activities were detected. The significance of these results was discussed in terms of food requirements of first instar larvae when settling on a plant.

scholarly journals Water Vapor Pressure Deficit in Portugal and Implications for the Development of the Invasive African Citrus Psyllid Trioza erytreae

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 229 ◽  
Author(s):  
Paulo Eduardo Branco Paiva ◽  
Tânia Cota ◽  
Luís Neto ◽  
Celestino Soares ◽  
José Carlos Tomás ◽  
...  
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Vapor Pressure ◽  
Vapor Pressure Deficit ◽  
Water Vapor Pressure ◽  
Control Measures ◽  
Effective Control ◽  
First Instar ◽  
Trioza Erytreae ◽  
Water Vapor Pressure Deficit

African citrus psyllid (Trioza erytreae (Del Guercio)) is a vector insect of the bacterium Candidatus Liberibacter africanus, the putative causal agent of Huanglongbing, the most devastating citrus disease in the world. The insect was found on the island of Madeira in 1994 and in mainland Portugal in 2015. Present in the north and center of the country, it is a threat to Algarve, the main citrus-producing region. Trioza erytreae eggs and first instar nymphs are sensitive to the combination of high temperatures and low relative humidity. Daily maximum air temperature and minimum relative humidity data from 18 weather stations were used to calculate the water vapor pressure deficit (vpd) from 2004 to 2018 at various locations. Based on the mean vpd and the number of unfavorable days (vpd < 34.5 and vpd < 56 mbar) of two time periods (February to May and June to September), less favorable zones for T. erytreae were identified. The zones with thermal and water conditions like those observed in the Castelo Branco and Portalegre (Center), Beja (Alentejo), Alte, and Norinha (Algarve) stations showed climatic restrictions to the development of eggs and first instar nymphs of African citrus psyllid. Effective control measures, such as the introduction and mass release of Tamarixia dryi (Waterson), a specific parasitoid, and chemical control are necessary in favorable periods for T. erytreae development, such as in spring and in areas with limited or no climate restrictions.

scholarly journals Effects of plant growth regulator applications on malting barley in western Canada

2020 ◽  
Vol 100 (6) ◽  
pp. 653-665
Author(s):  
B.D. Tidemann ◽  
J.T. O’Donovan ◽  
M. Izydorczyk ◽  
T.K. Turkington ◽  
L. Oatway ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Kernel Weight ◽  
Western Canada ◽  
Malting Barley ◽  
Seeding Rate ◽  
Malt Quality ◽  
Days To Maturity

Malting barley is important in western Canada, yet many malting cultivars do not meet malt quality standards, in part due to lodging. Lodging can decrease barley yield and quality thereby reducing the acceptability for malting. In other countries, plant growth regulator (PGR) applications are used to mitigate lodging. Chlormequat chloride (chlormequat), trinexapac-ethyl (trinexapac), and ethephon were tested at five locations over 3 yr in western Canada for their ability to limit lodging, as well as their effects on yield, agronomic traits, and pre-malt quality characteristics. PGR applications occurred between Zadoks growth stage (GS) 30–33 for chlormequat and trinexapac and GS 37–49 for ethephon. Seeding rates of 200, 300, and 400 seeds m−2 of CDC Copeland barley were used to increase the likelihood of lodging. Increased seeding rate decreased tillers per plant, height, days to maturity, kernel protein, and kernel weight. Ethephon increased the number of tillers per plant and decreased plant height, kernel plumpness, and kernel weight. Trinexapac decreased plant height and kernel weight. Days to maturity was investigated across site-years, with ethephon increasing maturity in 60% of comparisons. Trinexapac and chlormequat had limited effects on maturity. Lodging was investigated across site-years, with trinexapac showing the largest number of lodging reductions and scale of reductions. Ethephon reduced lodging in 36% of comparisons, while chlormequat had inconsistent effects. None of the products affected yield or grain protein. The results suggest PGRs may not be the solution to lodging for CDC Copeland barley on the Canadian Prairies; however, trinexapac shows the most promise of the products tested.

FIRST RECORD OF TRICHOGRAMMA INYOENSE (HYMENOPTERA: TRICHOGRAMMATIDAE) ATTACKING THE BERTHA ARMYWORM, MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE)

1998 ◽  
Vol 130 (1) ◽  
pp. 105-106 ◽  
Author(s):  
P.G. Mason ◽  
J.D. Pinto ◽  
Z.L. Long ◽  
J.L. Harris
Keyword(s):  
Current Trend ◽  
First Record ◽  
Management Program ◽  
Western Canada ◽  
Mamestra Configurata ◽  
Major Pest ◽  
Negative Impacts ◽  
Agriculture And Food ◽  
The Impact ◽  
Bertha Armyworm

The bertha armyworm, Mamestra configurata Walker, is a major pest of canola in western Canada. In 1994, 1995, and 1996 more than 670 000, 650 000, and 250 000 ha of canola were sprayed for bertha armyworm, respectively (Anonymous 1994, 1995, 1996). Despite the current trend towards increased acreage of canola production in western Canada, canola acreages declined markedly in 1996 from that planted in 1995 (Saskatchewan Agriculture and Food Statistical Facts 1996) in part because of the perception by farmers of the impact of bertha armyworm outbreaks in 1994 and 1995. Much research has been carried out in western Canada on the bertha armyworm with the aim of developing an integrated pest management program which includes the understanding of its biological control agents. Turnock (1984) reported that the native parasitoid complex of larval M. configurata consists of five species of Hymenoptera and 10 species of Diptera. Only two of these, namely Banchus flavescens Cresson (Hymenoptera: Ichneumonidae) and Athrycia cinerea (Coquillett) (Diptera: Tachinidae), have large negative impacts on its populations (Wylie and Bucher 1977).

FEEDING HABITS OF MULE DEER ON FALL, WINTER, AND SPRING RANGES NEAR KAMLOOPS, BRITISH COLUMBIA

1976 ◽  
Vol 56 (3) ◽  
pp. 531-542 ◽  
Author(s):  
W. WILLMS ◽  
A. McLEAN ◽  
R. RITCEY
Keyword(s):  
Plant Growth ◽  
Snow Depth ◽  
Growth Form ◽  
Feeding Habits ◽  
Mule Deer ◽  
Early Spring ◽  
Late Winter ◽  
Plant Growth Form ◽  
Early Fall ◽  
Tree Component

Diets of mule deer were studied in the Kamloops area from September to April. The forages of 67 rumen samples were sorted to grass, tree, shrub, and forb species and the percent oven-dry weights calculated for each. Polynomial regressions (to the third degree) were used to describe the use of each plant-growth form over time, as well as to determine the influence of snow depth on plant species consumption. Douglas fir formed most of the tree component of the diet of the deer. Consumption of this species was highest in December and January. Grass consumption was less than 10% until early spring when it increased to almost 100%. More forbs were consumed in fall than in winter, while shrubs were consumed more in early fall and late winter than in late fall. Species composition of each plant growth-form generally varied with season. Increasing snow depth altered the proportion of both small and large plants in the diet. As snow depth increased, fewer small plants but more large plants were consumed.

The Concept and Application of Early Economic Period Threshold: The Case of DCPA in Onions (Allium Cepa)

Weed Science ◽  
1995 ◽  
Vol 43 (4) ◽  
pp. 634-639 ◽  
Author(s):  
Claudio M. Dunan ◽  
Philip Westra ◽  
Edward E. Schweizer ◽  
Donald W. Lybecker ◽  
Frank D. Moore
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Crop Yields ◽  
Economic Feasibility ◽  
Control Measures ◽  
Economic Losses ◽  
Weed Competition ◽  
Critical Periods ◽  
Control Efficacy ◽  
The Impact

The question of when to control weeds traditionally has been approached with the calculation of critical periods (CP) based on crop yields. The concept of economic critical period (ECP) and early (EEPT) and late (LEFT) economic period thresholds are presented as a comprehensive approach to answer the same question based on economic losses and costs of control. ECP is defined as the period when the benefit of controlling weeds is greater than its cost. EEPT and LEFT are the limits of the ECP and can be used to determine when first and last weed control measures should be performed. Calculation of EEPT accounts for the economic losses due to weed competition that occur between planting and postemergence weed control. In this way it is possible to better evaluate the economic feasibility of using preplant or preemergence control tactics. The EEPT for DCPA application is analyzed in the context of onion production in Colorado. The EEPT for DCPA application was calculated from an empirical regression model that assessed the impact of weed load and time of weed removal on onion yields. The EEPT was affected by control efficacy, weed-free yield, DCPA cost, and onion price. DCPA application was economically advisable in only one of 20 fields analyzed because of the tow DCPA efficacy (60%).

scholarly journals Feeding Preferences of the Endangered Diving BeetleCybister tripunctatus orientalisGschwendtner (Coleoptera: Dytiscidae)

2012 ◽  
Vol 2012 ◽  
pp. 1-3 ◽  
Author(s):  
Shin-ya Ohba ◽  
Yoshinori Inatani
Keyword(s):  
Survival Rate ◽  
Feeding Habits ◽  
Feeding Preference ◽  
Feeding Preferences ◽  
Ecological Information ◽  
First Instar ◽  
Diving Beetles

The numbers ofCybister tripunctatus orientalisGschwendtner diving beetles are declining in most regions of Japan, and it is included in the Red Data List of species in 34 of 47 prefectures of Japan. However, basic ecological information aboutC. tripunctatus orientalis, such as its feeding habits, remains unknown. In order to elucidate the feeding habits ofC. tripunctatus orientalislarvae, feeding preference experiments were carried out in 2nd and 3rd instar larvae. The number of Odonata nymphs consumed was significantly higher than the number of tadpoles consumed, indicating thatC. tripunctatus orientalislarvae prefer Odonata nymphs to tadpoles. In addition, all the first instar larvae ofC. tripunctatus orientalisdeveloped into second instars when they were supplied with motionless Odonata nymphs, but their survival rate was lower when they were supplied with motionless tadpoles. These results suggest thatC. tripunctatus orientalislarvae prefer insects to vertebrates.

scholarly journals Pesticide Options for Insect, Mite, and Mollusk Management in Commercial Strawberry Production in Florida

EDIS ◽  
2013 ◽  
Vol 2013 (5) ◽  
Author(s):  
James F. Price ◽  
Curtis Nagle ◽  
Susan E. Webb
Keyword(s):  
Control Measures ◽  
Effective Management ◽  
Timely Manner ◽  
Fact Sheet ◽  
Major Pest

Effective management of arthropod and gastropod pests of strawberry is critical to the profitability of the industry and requires that pests be detected in a timely manner through systematic scouting. Appropriate control measures should be applied as conditions warrant. The tables in this 22-page fact sheet list pesticides that are presently available to commercial strawberry producers in Florida and are organized alphabetically by major pest groups. Written by James F. Price, Curtis Nagle, and Susan E. Webb, and published by the UF Department of Entomology and Nematology, April 2013. http://edis.ifas.ufl.edu/in486

scholarly journals Plant Associated Rhizobacteria for Biocontrol and Plant Growth Enhancement

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiurong Jiao ◽  
Yoko Takishita ◽  
Guisheng Zhou ◽  
Donald L. Smith
Keyword(s):  
Disease Management ◽  
Plant Growth ◽  
Large Scale ◽  
Plant Disease ◽  
Plant Growth Promoting Rhizobacteria ◽  
Crop Productivity ◽  
Control Measures ◽  
Field Conditions ◽  
Growth Enhancement ◽  
Greenhouse Production

Crop disease remains a major problem to global food production. Excess use of pesticides through chemical disease control measures is a serious problem for sustainable agriculture as we struggle for higher crop productivity. The use of plant growth promoting rhizobacteria (PGPR) is a proven environment friendly way of controlling plant disease and increasing crop yield. PGPR suppress diseases by directly synthesizing pathogen-antagonizing compounds, as well as by triggering plant immune responses. It is possible to identify and develop PGPR that both suppress plant disease and more directly stimulate plant growth, bringing dual benefit. A number of PGPR have been registered for commercial use under greenhouse and field conditions and a large number of strains have been identified and proved as effective biocontrol agents (BCAs) under environmentally controlled conditions. However, there are still a number of challenges before registration, large-scale application, and adoption of PGPR for the pest and disease management. Successful BCAs provide strong theoretical and practical support for application of PGPR in greenhouse production, which ensures the feasibility and efficacy of PGPR for commercial horticulture production. This could be pave the way for widespread use of BCAs in agriculture, including under field conditions, to assist with both disease management and climate change conditions.

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