scholarly journals Streamlining leaf damage rating scales for the fall armyworm on maize

2021 ◽  
Author(s):  
Stefan Toepfer ◽  
Patrick Fallet ◽  
Joelle Kajuga ◽  
Didace Bazagwira ◽  
Ishimwe Primitive Mukundwa ◽  
...  
Keyword(s):  
Rating Scales ◽  
Damage Index ◽  
Fall Armyworm ◽  
Leaf Damage ◽  
Plant Damage ◽  
Time Investment ◽  
Data Analyses ◽  
Parametric Data ◽  
Whole Plant ◽  
Field And Laboratory Conditions

AbstractThe fall armyworm (Spodoptera frugiperda, Lepidoptera: Noctuidae), which is native to the Americas, has recently invaded Africa and Asia. There, it has become a major pest of maize (Zea mays). The variety of methods used to assess feeding damage caused by its caterpillars makes it difficult to compare studies. In this paper, we aim at determining which leaf damage rating scales for fall armyworm are most consistently used for which purposes, might provide most possibilities for statistical analyses, and would be an acceptable compromise between detail and workload. We first conducted a literature review and then validated the most common scales under field and laboratory conditions. Common leaf damage scales are the nominal “yes-no damage scale” that only assesses damage incidence, as well as difficult-to-analyse ordinal scales which combine incidence and severity information such as the “Simple 1 to 5 whole plant damage scale”, “Davis’ 0 to 9 whorl & furl damage scale”, or “Williams’ 0 to 9 whole plant damage scale”. These scales have been adapted many times, are sometimes used incorrectly, or were wrongly cited. We therefore propose simplifications of some of these scales as well as a novel “0.0 to 4.0 fall armyworm leaf damage index” which improves precision and possibilities for parametric data analyses. We argue that the choice of a scale to use should depend on the desired level of detail, type of data analyses envisioned, and manageable time investment.

scholarly journals Intensitas serangan Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae) pada pertanaman jagung di Kabupaten Garut dan Tasikmalaya, Jawa Barat

2020 ◽  
Vol 17 (3) ◽  
pp. 163
Author(s):  
Wara Asfiya ◽  
Vani Nur Oktaviany Subagyo ◽  
Anik Budhi Dharmayanthi ◽  
Fatimah Fatimah ◽  
Rina Rachmatiyah
Keyword(s):  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
The Other ◽  
Leaf Damage ◽  
Control Methods ◽  
West Java ◽  
Corn Production ◽  
Plant Damage ◽  
Lepidoptera Noctuidae ◽  
Attack Intensity

<p>The presence of <em>Spodoptera frugiperda</em> J.E. Smith or fall armyworm (FAW) have now detected in West Java. However, no information is available on their attack intensity even though the data is crucial for the implementation of appropriate control methods. The investigations were carried out in Garut (Limbangan, Wanaraja, dan Banyuresmi) and Tasikmalaya (Sukaratu) Regencies from 25 to 27 February 2020. At each location, 100 plants were selected for recording observations on leaf damage following the Davis Scale. The results showed the attack intensity in Wanaraja (34,78%), Banyuresmi (34.78%), and Sukaratu (39.89%) showed moderate damage. On the other hand, Limbangan one of the corn production center, showed high damage with the intensity of the pest up to 52.78%. The attack intensity of FAW tends to correlate with their attack level. This means that plant damage levels increasing at higher attack levels.</p>

Sources of resistance to the erineum strain of Colomerus vitis (Acari: Eriophyidae) in grapevine cultivars

2018 ◽  
Vol 23 (3) ◽  
pp. 405 ◽  
Author(s):  
Saeid Javadi Khederi ◽  
Mohammad Khanjani ◽  
Mansur Gholami ◽  
Enrico De Lillo
Keyword(s):  
Damage Index ◽  
Leaf Damage ◽  
Plant Responses ◽  
Sources Of Resistance ◽  
Western Iran ◽  
Potted Plants ◽  
Mite Density ◽  
Bud Breaking ◽  
Almost All ◽  
The Impact

The erineum strain of Colomerus vitis (GEM) is the most destructive pest of vineyards in western Iran and sometimes causes considerable damages to the grapevine. Little information is available on the susceptibility of the grapevine to this pest and its knowledge can be useful for a sustainable management of GEM. The present study was aimed at evaluating the responses of the plants to the infestation of GEM in order to compare the resistance/susceptibility of some native cultivars to this pest. Also, the profiling of JA, SA and IAA in leaves of infested plants of Sezdang was studied. The experiment was carried out on eighteen native cultivars and the non-native Muscat Gordo which were selected amongst the most common in southern and western Iran. Potted plants were cultivated under greenhouse conditions at a temperature of 32 ± 3.8°C, 75 ± 5% R.H. and a photoperiod of L16: D8 h. The impact of GEM was evaluated on the basis of the leaf area and weight, number and size of the erinea, and percentage of leaves with erinea three months after the infestation. The cane length was measured, too. Mite density on galled leaves (three months after the infestation) and in buds (at the bud breaking) was assessed.        Cluster analysis based on the leaf damage index induced by GEM allowed to distinguish highly affected (Sezdang, Khalili, Ghalati and Rishbaba), moderately affected (Neyshaboori, Gazne, Muscat, Lale, Shahani Sefid, Ahmad, Monagha and Sia) and scarcely affected (Yaghuti, Rotabi, White Thompson, Atabaki, Koladari and Sahebi and Shahani Gerd) cultivars. The mite density into the buds and on the galled leaves was higher in the medium-late (Rishbaba and Khalili) and late ripening (Sezdang and Ghalati) cultivars rather than in the early (Sahebi and Shahani Gerd) and early-medium (Atabaki) ripening ones. The leaf damaged area, the leaf weight, the shoot length and the erineum development were correlated to the mite density and were the highest on Sezdang, Khalili, Ghalati and Rishbaba and the lowest on Atabaki, Koladari, Sahebi and Shahani Gerd. The highest density of the overwintering population was detected in proximal buds of all treated cultivars.        The plant responses and the mite density were investigated also in the second and third year after the first mite infestation on highly affected (Sezdang, Khalili, Ghalati, Rishbaba), a few of the moderately affected (Neyshaboori, Gazne, Muscat) and the scarcely affected cultivars (White Thompson, Atabaki, Koladari, Sahebi, Shahani Gerd). The leaf damaged area, the percentage of galled leaves, the percentage of cane length reduction and the mite density strongly decreased during all three years of observations on the highly affected Sezdang, Khalili and Gazne. On the contrary, Ghalati and Rishbaba displayed an increase of the leaf damaged area, leaf damaged index and mite density on galled leaves during the same period in comparison to the first year of observation. The percentage of the leaves with erinea, the leaf damaged area and the mite density of Sezdang were highly and positively correlated with IAA while a negative correlation was found between the leaf damaged area and the mite density with SA and JA in the assayed years. Almost all data currently collected allowed a recognition of White Thompson, Atabaki, Koladari, Sahebi and Shahani Gerd as the least affected cultivars.

scholarly journals PENGARUH APLIKASI ABAMEKTIN TERHADAP KEMELIMPAHAN LALAT PENGOROK DAUN DAN PARASITOIDNYA PADA PERTANAMAN KENTANG

2004 ◽  
Vol 4 (1) ◽  
pp. 18-22
Author(s):  
Purnomo Purnomo
Keyword(s):  
Leaf Damage ◽  
Leaf Sample ◽  
West Java ◽  
Plant Damage

Effect of application of abamectine on the abudance of leafminer flies and its parasitoids on potato fields. The objective of research was to investigate the effect of the application of abamectine insecticide on the infestation of potato leafminer and its parasitoid. The fields experiment was conducted on potato fields in Pangalengan – Bandung, West Java in 2000. The result showed that the abamectine-insecticide significantly reduce the plant damage intensities, the number of mining per plants, and the percentage of leaf damage. In addition, the application of abamectine insecticide was not significantly affected the level of parasitism and the number of parasitoid Hemiptarsenus varicornis (Girault) (Hymenoptera:Eulophidae) and Opius sp. (Hymenoptera: Braconidae) that were emerged from leaf sample. The abamectine insecticide has a good possibilities to be used as an alternative for controlling of the leafminers before another technology was found.

scholarly journals Fall Armyworm, Spodoptera frugiperda Infestations in East Africa: Assessment of Damage and Parasitism

Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 195 ◽  
Author(s):  
Birhanu Sisay ◽  
Josephine Simiyu ◽  
Esayas Mendesil ◽  
Paddy Likhayo ◽  
Gashawbeza Ayalew ◽  
...  
Keyword(s):  
Biological Control ◽  
East Africa ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Egg Parasitoid ◽  
Leaf Damage ◽  
Parasitism Rate ◽  
Maize Production ◽  
Larval Parasitoid ◽  
Percent Parasitism

The fall armyworm (FAW), Spodoptera frugiperda, threatens maize production in Africa. A survey was conducted to determine the distribution of FAW and its natural enemies and damage severity in Ethiopia, Kenya and Tanzania in 2017 and 2018. A total of 287 smallholder maize farms (holding smaller than 2 hectares of land) were randomly selected and surveyed. FAW is widely distributed in the three countries and the percent of infested maize fields ranged from 33% to 100% in Ethiopia, 93% to 100% in Tanzania and 100% in Kenya in 2017, whereas they ranged from 80% to 100% and 82.2% to 100% in Ethiopia and Kenya, respectively, in 2018. The percent of FAW infestation of plants in the surveyed fields ranged from 5% to 100%. In 2017, the leaf damage score of the average of the fields ranged from 1.8 to 7 (9 = highest level of damage), while 2018, it ranged from 1.9 to 6.8. In 2017, five different species of parasitoids were recovered from FAW eggs and larvae. Cotesia icipe (Hymenoptera: Braconidae) was the main parasitoid recorded in Ethiopia, with a percent parasitism rate of 37.6%. Chelonus curvimaculatus Cameron (Hymenoptera: Braconidae) was the only egg-larval parasitoid recorded in Kenya and had a 4.8% parasitism rate. In 2018, six species of egg and larval parasitoids were recovered with C. icipe being the dominant larval parasitoid, with percentage parasitism ranging from 16% to 42% in the three surveyed countries. In Kenya, Telenomus remus (Hymenoptera: Scelionidae) was the dominant egg parasitoid, causing up to 69.3% egg parasitism as compared to only 4% by C. curvimaculatus. Although FAW has rapidly spread throughout these three countries, we were encouraged to see a reasonable level of biological control in place. Augmentative biological control can be implemented to suppress FAW in East Africa.

scholarly journals Evaluation of African Maize Cultivars for Resistance to Fall Armyworm Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) Larvae

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 392
Author(s):  
Xavier Chiriboga Morales ◽  
Amanuel Tamiru ◽  
Islam S. Sobhy ◽  
Toby J. A. Bruce ◽  
Charles A. O. Midega ◽  
...  
Keyword(s):  
Fall Armyworm ◽  
Growth Index ◽  
Pupal Weight ◽  
Plant Damage ◽  
Maize Cultivars ◽  
Artificial Infestation ◽  
Important Pest ◽  
And Performance ◽  
Food Assimilation ◽  
Neonate Larvae

The fall armyworm (FAW) has recently invaded and become an important pest of maize in Africa causing yield losses reaching up to a third of maize annual production. The present study evaluated different aspects of resistance of six maize cultivars, cropped by farmers in Kenya, to FAW larvae feeding under laboratory and field conditions. We assessed the arrestment and feeding of FAW neonate larvae in no-choice and choice experiments, development of larvae-pupae, food assimilation under laboratory conditions and plant damage in a field experiment. We did not find complete resistance to FAW feeding in the evaluated maize cultivars, but we detected differences in acceptance and preference when FAW larvae were given a choice between certain cultivars. Moreover, the smallest pupal weight and the lowest growth index were found on ’SC Duma 43′ leaves, which suggests an effect of antibiosis of this maize hybrid against FAW larvae. In contrast, the highest growth index was recorded on ‘Rachar’ and the greatest pupal weight was found on ‘Nyamula’ and ‘Rachar’. The density of trichomes on the leaves of these maize cultivars seems not to be directly related to the preference of neonates for feeding. Plant damage scores were not statistically different between cultivars in the field neither under natural nor artificial infestation. However, plant damage scores in ‘Nyamula’ and ‘Jowi’ tended to be lower in the two last samplings of the season compared to the two initial samplings under artificial infestation. Our study provides insight into FAW larval preferences and performance on some African maize cultivars, showing that there are differences between cultivars in these variables; but high levels of resistance to larvae feeding were not found.

scholarly journals Effects of distance from semi-natural habitat on fall armyworm (Spodoptera frugiperda, J. E. Smith) and its potential natural enemies in Ghana

2021 ◽  
pp. 1-11
Author(s):  
Matthew W. Jordon ◽  
Talya D. Hackett ◽  
Fred Aboagye-Antwi ◽  
Vincent Y. Eziah ◽  
Owen T. Lewis
Keyword(s):  
Natural Enemies ◽  
Spodoptera Frugiperda ◽  
Natural Habitat ◽  
Fall Armyworm ◽  
Agricultural Landscapes ◽  
Sub Saharan Africa ◽  
Leaf Damage ◽  
Crop Damage ◽  
Biological Pest Control ◽  
Sub Saharan

Abstract Insect crop pests are a major threat to food security in sub-Saharan Africa. Configuration of semi-natural habitat within agricultural landscapes has the potential to enhance biological pest control, helping to maintain yields whilst minimising the negative effects of pesticide use. Fall armyworm (Spodoptera frugiperda, J. E. Smith) is an increasingly important pest of maize in sub-Saharan Africa, with reports of yield loss between 12 and 45%. We investigated the patterns of fall armyworm leaf damage in maize crops in Ghana, and used pitfall traps and dummy caterpillars to assess the spatial distribution of potential fall armyworm predators. Crop damage from fall armyworm at our study sites increased significantly with distance from the field edge, by up to 4% per m. We found evidence that Araneae activity, richness and diversity correspondingly decreased with distance from semi-natural habitat, although Hymenoptera richness and diversity increased. Our preliminary findings suggest that modifying field configuration to increase the proximity of maize to semi-natural habitat may reduce fall armyworm damage and increase natural enemy activity within crops. Further research is required to determine the level of fall armyworm suppression achievable through natural enemies, and how effectively this could safeguard yields.

scholarly journals Assessing the Biostimulant Effects of a Novel Plant-Based Formulation on Tomato Crop

2020 ◽  
Vol 12 (20) ◽  
pp. 8432
Author(s):  
Antonios Chrysargyris ◽  
Savvas Charalambous ◽  
Panayiota Xylia ◽  
Vassilis Litskas ◽  
Menelaos Stavrinides ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Essential Oils ◽  
Chlorophyll Content ◽  
Tomato Fruit ◽  
Damage Index ◽  
Soluble Solids ◽  
Leaf Damage ◽  
Total Phenols ◽  
Tomato Crop ◽  
Fruit Cracking

The aim of this research was to evaluate the biostimulant effects of an eco-product (EP) containing essential oils of rosemary and eucalyptus on tomato crop. Experiments were conducted to evaluate EP effects on plant growth and physiological parameters (e.g., chlorophyll content), total phenols and antioxidant activity, enzyme activities (e.g., catalase), plant macronutrient content and fresh tomato fruit quality. The application of an EP once (EP-1x) increased tomato plant height by 19%, stomatal conductance, and chlorophyll content compared to the control (sprayed with water). EP triplicate (EP-3x) application significantly increased yield (0.79 kg plant−1) compared to the control (0.58 kg plant−1). However, application of EP-3x was associated with a higher percentage of fruit cracking in comparison to the control. Total phenols and antioxidant activity were affected from both the use of EP and application frequency. EP application decreased by 27.3% the leaf damage index in comparison to the control. Nutrient content in leaves (N, Mg) was significantly decreased in the case of EP-3x treatment. Fruit firmness was decreased by 19.9% in the case of EP-1x application. Fruit marketability and tomato-like aroma, fresh weight and soluble solids did not differ among the treatments. Further research is required to examine the potential use of essential oils as biostimulants.

scholarly journals Effect of NaCl road salt on the ionic composition of soils and Aesculus hippocastanum L. foliage and leaf damage intensity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Katarzyna Łuczak ◽  
Izabela Czerniawska-Kusza ◽  
Czesława Rosik-Dulewska ◽  
Grzegorz Kusza
Keyword(s):  
Ionic Composition ◽  
Damage Index ◽  
Chloride Content ◽  
Magnesium Content ◽  
Leaf Damage ◽  
Aesculus Hippocastanum ◽  
Horse Chestnut ◽  
Roadside Soils ◽  
Tree Vitality ◽  
Wide Range

AbstractWe investigated the accumulation of sodium chloride in roadside soils and common horse chestnut Aesculus hippocastanum L. under urban conditions to evaluate changes in soil and leaf ionic content and their relationship with foliar damage, considering the visual assessment of trees of the same health status. A total of 15 field sites were assessed in late June 2016. The analysis included soil granulometric composition, pH, electrical conductivity, and the content of Cl−, Na+, K+, Ca2+, and Mg2+ ions in soil and foliage samples. The results showed increased salinity and alkalization of roadside soils together with the decreased magnesium content. Foliage samples manifested significantly higher concentrations of Na+ and Cl−. A wide range of Cl− content was noted in leaves (2.0–11.8% d.w.) regardless of their damage index. On the contrary, leaf damage was strongly correlated with increasing Na+ concentrations and decreasing K+ and Mg2+. A severe imbalance of nutrients, and therefore poor urban tree vitality, can be attributed to the excessive accumulation of de-icing salt. However, further research would be needed to clarify the discrepancy between the extent of leaf damage and chloride content.

Sign in / Sign up

Export Citation Format

Share Document