Rhopalosiphum maidis (green corn aphid).

2021 ◽  
Author(s):  
Angela Whittaker
Keyword(s):  
Economic Losses ◽  
Feeding Damage ◽  
Virus Diseases ◽  
Rhopalosiphum Maidis ◽  
Important Pest ◽  
Young Leaves ◽  
Warm Temperate ◽  
Plant Sap ◽  
Temperate Climates

Abstract R. maidis is probably the most important pest of cereals in tropical and warm temperate climates. It causes direct feeding damage by the removal of plant sap from young leaves and growing points, and indirect damage via honeydew secretions and its ability to spread virus diseases. It causes particularly heavy economic losses in maize, sorghum, and barley. However, although it attacks wheat, oats, rye and other many cereals, significant economic losses on these crops are less common.

scholarly journals Sudden death associated with Niedenzuella stannea (Malpighiaceae) in cattle in the State of Mato Grosso, Brazil: importance and epidemiological aspects

2017 ◽  
Vol 37 (7) ◽  
pp. 662-666
Author(s):  
Flávio H.B. Caldeira ◽  
Geovanny B.G. Dias ◽  
Felipe P. de Arruda ◽  
Valdecy de M. Lourenço ◽  
Kalinne S. Bezerra ◽  
...  
Keyword(s):  
Sudden Death ◽  
Dry Season ◽  
The State ◽  
Acute Disease ◽  
Economic Losses ◽  
Control Methods ◽  
Mato Grosso ◽  
Araguaia River ◽  
Young Leaves ◽  
Plant Control

ABSTRACT: The aim of this study was to investigate the importance of an acute disease that was characterized by sudden death associated with exercise that affected cattle in the region of the Araguaia River, especially in the municipality of Torixoréu, southeastern Mato Grosso, Brazil. Between August and September 2013, eighty farms in the municipality were visited and the pastures of these farms were inspected. Epidemiological questionnaires were completed from 65 farms. A plant identified as Niedenzuella stannea (N. stannea) of the Malpighiaceae family was attributed to the cause of sudden death in cattle, what causes major economic losses. Sudden death reports have occurred since 1970, when livestock was introduced into the region, and sudden death reports still occur. Outbreaks were reported to occur from May to October, but mainly during the dry season between June and August. N. stannea was identified at 41 farms and was always found in near to rivers. The most effective plant control methods included plowing the pastures and fields followed by manual application of Tordon® (Picloram and 2.4D). The administration of 5g/kg of young leaves which were collected from a farm with a sudden death history in cattle also caused sudden death in a sheep. Thus, it is concluded that the sudden death of cattle in the region of the Araguaia River is caused by the consumption of N. stannea.

scholarly journals Mapping Quantitative Trait Loci for Resistance to Fall Armyworm (Lepidoptera: Noctuidae) Leaf-Feeding Damage in Maize Inbred Mp705

2020 ◽  
Vol 113 (2) ◽  
pp. 956-963 ◽  
Author(s):  
E D Womack ◽  
W P Williams ◽  
J S Smith ◽  
M L Warburton ◽  
D Bhattramakki
Keyword(s):  
Molecular Markers ◽  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Fall Armyworm ◽  
Phenotypic Variance ◽  
Feeding Damage ◽  
Artificial Infestation ◽  
Lepidopteran Insects ◽  
Trait Loci ◽  
Important Pest

Abstract The fall armyworm, Spodoptera frugiperda (J. E. Smith), is an agronomically important pest that severely limits maize (Zea mays (Linnaeus) [Poales: Poaceae]) production. This migrant insect devastates maize plants in many countries threatening the livelihood of millions. Quantitative trait loci (QTL) were mapped to identify chromosomal regions that control resistance to fall armyworm leaf-feeding and to identify molecular markers linked to the target loci for use in marker-assisted selection (MAS). A bi-parental mapping population, comprising 243 F2:3 families from the cross Mp705 (resistant) × Mp719 (susceptible), was evaluated for fall armyworm leaf-feeding damage under artificial infestation over 3 yr. A linkage map comprised of 1,276 single-nucleotide polymorphism and simple sequence repeat molecular markers was constructed. Quantitative trait loci analyses identified two major QTL in bins 4.06 and 9.03 that when combined, explained 35.7% of the phenotypic variance over all environments. Mp705 was responsible for the leaf-feeding damage reducing alleles for both large effect QTL and most of the small effect QTL identified in this study. The QTL identified in bin 9.03 co-locates with a previously identified QTL that controls resistance to leaf-feeding damage in maize by fall armyworm and other lepidopteran insects. The QTL in bin 4.06 is a new source of resistance identified in this study. Beneficial alleles derived from Mp705 for the application of an integrated QTL-MAS approach could accelerate breeding efforts to minimize fall armyworm leaf-feeding in maize.

scholarly journals First Report of Stem and Bulb Nematode Ditylenchus dipsaci on Garlic in New Mexico

2017 ◽  
Vol 18 (2) ◽  
pp. 91-92
Author(s):  
Jason M. French ◽  
Jacki Beacham ◽  
Amanda Garcia ◽  
Natalie P. Goldberg ◽  
Stephen H. Thomas ◽  
...  
Keyword(s):  
International Trade ◽  
New Mexico ◽  
Sequence Data ◽  
The State ◽  
Economic Losses ◽  
First Report ◽  
Important Pest ◽  
Ditylenchus Dipsaci ◽  
Production Areas ◽  
Stem And Bulb Nematode

Taken together, symptoms present, microscopic characterization, and ITS-1 sequence data indicate New Mexico garlic samples infested with Ditylenchus dipsaci, making this the first known report of this pest in the state. This discovery is significant because D. dipsaci can be a persistent pest and has the potential to cause significant economic losses on agronomically important hosts including onion, garlic, and alfalfa. Its longevity in the soil and international trade issues will be concerns for producers. Monitoring of production areas in the region will be performed to determine if this was an isolated and contained introduction or if this important pest has become established in New Mexico.

scholarly journals Control Of Epilachna Vigintioctopuntata Fab. (Coleoptera: Coccinellidae) Using Some Indigenous Plant Extracts

1970 ◽  
Vol 6 ◽  
pp. 75-80 ◽  
Author(s):  
Kamrul Islam ◽  
M Saiful Islam ◽  
Zennat Ferdousi
Keyword(s):  
Ricinus Communis ◽  
Adult Emergence ◽  
Economic Losses ◽  
Calotropis Procera ◽  
Indigenous Plants ◽  
Female Ratio ◽  
Datura Metel ◽  
Important Pest ◽  
Indigenous Plant ◽  
Epilachna Vigintioctopunctata

Epilachna vigintioctopunctata is an important pest that causes considerable economic losses to many crops including egg-plants. The crude aqueous extracts of leaves from three indigenous plants namely Ricinus communis, Calotropis procera and Datura metel were used against this beetle aiming at its control under laboratory conditions. Larvicidal bioassays of the extracts showed the following order of toxicity: R. communis (LC50=18.40%) > C. procera (LC50=23.70%) > D. metel (LC50=29.61%). Subsequent data on some vital life-history traits were promising because the extracts significantly reduced both oviposition and egg-hatch, prolonged larval duration (P<0.001), and inhibited pupae formation and adult emergence (P<0.05). However, female ratio was not significantly affected by the treatments. Relevance of these findings on the control of this phytophagous species has been discussed. DOI: http://dx.doi.org/10.3329/jles.v6i0.9725 JLES 2011 6: 75-80

scholarly journals Relict groups of spiny frogs indicate Late Paleogene-Early Neogene trans-Tibet dispersal of thermophile faunal elements

2021 ◽  
Author(s):  
Sylvia Hofmann ◽  
Daniel Jablonski ◽  
Spartak Litvinchuk ◽  
Rafaqat Masroor ◽  
Joachim Schmidt
Keyword(s):  
Sequence Data ◽  
Gene Tree ◽  
Early Miocene ◽  
Phylogenetic Position ◽  
Published Data ◽  
Data Set ◽  
Sister Clade ◽  
Early Neogene ◽  
Warm Temperate ◽  
Temperate Climates

AbstractBackgroundThe Himalaya-Tibet orogen (HTO) presents an outstanding geologically active formation that contributed to, and fostered, modern Asian biodiversity. However, our concepts of the historical biogeography of its biota are far from conclusive, as are uplift scenarios for the different parts of the HTO. Here, we revisited our previously published data set of the tribe Paini extending it with sequence data from the most western Himalayan spiny frogs Allopaa and Chrysopaa and using them as an indirect indicator for the paleoecological development of Tibet.MethodsWe obtained sequence data of two mitochondrial loci (16S rRNA, COI) and one nuclear marker (Rag1) from Allopaa samples from Kashmir Himalaya as well as Chrysopaa sequence data from the Hindu Kush available from GenBank to complement our previous data set. A Maximum likelihood and dated Bayesian gene tree were generated based on the concatenated data set. To resolve the inconsistent placement of Allopaa, we performed different topology tests.ResultsConsistent with previous results, the Southeast Asian genus Quasipaa is sister to all other spiny frogs. The results further reveal a basal placement of Chrysopaa relative to Allopaa and Nanorana with an estimated age of ca. 26 Mya. Based on the topology tests, the phylogenetic position of Allopaa as a sister clade to Chaparana seems to be most likely, resulting in a paraphyletic genus Nanorana and a separation from the latter clade around 20 Mya. Both, the placements of Chrysopaa and Allopaa support the presence of basal Paini lineages in the far north western part of the HTO, which is diametrically opposite end of the HTO with respect to the ancestral area of spiny frogs in Southeast Asia. These striking distributional patterns can be most parsimoniously explained by trans-Tibet dispersal during the late Oligocene (subtropical Chrysopaa) respectively early Miocene (warm temperate Allopaa). Within spiny frogs, only members of the monophyletic Nanorana+Paa clade are adapted to the colder temperate climates, indicating that high-altitude environments did not dominate in the HTO before ca. 15 Mya. Our results are consistent with fossil records suggesting that large parts of Tibet were characterized by subtropical to warm temperate climates at least until the early Miocene.

Silicon-mediated and constitutive resistance to Rhopalosiphum maidis (Hemiptera: Aphididae) in corn hybrids

2018 ◽  
Vol 109 (3) ◽  
pp. 356-364 ◽  
Author(s):  
C.A. Boer ◽  
M.V. Sampaio ◽  
H.S. Pereira
Keyword(s):  
Population Growth ◽  
Field Experiments ◽  
Aphid Population ◽  
Varietal Resistance ◽  
Corn Hybrids ◽  
Aphid Infestation ◽  
Rhopalosiphum Maidis ◽  
Constitutive Resistance ◽  
Important Pest ◽  
Different Levels

AbstractThe corn leaf aphid, Rhopalosiphum maidis (Fitch) (Hemiptera: Aphididae), is an important pest of corn, but no corn genotypes resistant to R. maidis are commercially available. Although the ability of silicon to induce plant resistance against some insects is known, the effect of silicon on R. maidis and in corn hybrids with different levels of constitutive resistance is still unknown. This study sought to determine the constitutive resistance of corn hybrids to R. maidis and silicon resistance induction in hybrids with different degrees of constitutive resistance. Field experiments with natural infestations of aphids were conducted in three locations in Brazil (Patos de Minas, Araguari, and Tupaciguara). Greenhouse trials were also used to evaluate the effect of varietal resistance on aphid population growth and identify resistant and susceptible genotypes. Aphid resistance induced by silicon was determined with resistant and susceptible corn hybrids. In the field, the corn hybrids BM8850, AS1625PRO, and DKB310PRO had the greatest proportion of plants infested by R. maidis in all three localities. The hybrids P30F53H, STATUS VIP, BM9288, DAS2B587HX, DKB175PRO, AS1633PRO, and DKB390PRO2 were the least infested in Patos de Minas and Araguari, and P30F53H was the least infested in Tupaciguara. When antibiosis effects were evaluated by aphid population growth, the hybrids AG7088PRO3 and DKB310PRO2 were susceptible, while P30F53YH was resistant. When natural aphid infestation was evaluated, wherein the effects of antibiosis and non-preference could not be discriminated, soil applications of silicon-induced resistance to R. maidis in both susceptible and constitutively resistant corn hybrids.

scholarly journals Population fluctuation and food preference of African snail by horticulture crops

2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Lindinalva dos Santos ◽  
Carla Ruth de Carvalho Barbosa-Negrisoli ◽  
Maciel Bispo dos Santos ◽  
Aldomário Santo Negrisoli Junior
Keyword(s):  
Food Preference ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Economic Losses ◽  
Achatina Fulica ◽  
Abiotic Conditions ◽  
The World ◽  
Important Pest ◽  
Almost All ◽  
Preference Tests

ABSTRACT: The African snail Achatina fulica (Bowdich, 1822), originally from Africa, was introduced in Brazil and since then became an important pest, because of its resistance to abiotic conditions, hermaphroditism, polyphagia and absence of natural enemies. Considered as one of the 100 worst pests in the world, with the record of establishment in almost all Brazilian states, it causes sanitary, ecological and economic losses. In this context, the objective of this study was to determine the population dynamics and food preference of the giant snail in three areas of lettuce, located in Alagoas, Brazil. There was no statistical difference between food preference tests with and without choice among the varieties offered. To the fluctuation of the population of A. fulica, the Pearson correlation coefficients were negative only for temperature, and there was no correlation with precipitation and relative humidity.

Acyrthosiphon pisum (pea aphid).

2021 ◽  
Author(s):  
Melaku Wale
Keyword(s):  
Acyrthosiphon Pisum ◽  
Yield Loss ◽  
Economic Losses ◽  
Virus Spread ◽  
Feeding Damage ◽  
Yield Losses ◽  
Severe Damage ◽  
Major Pest ◽  
Sooty Moulds ◽  
Economic Pest

Abstract A. pisum is a major pest of pea, lucerne and clover. Severe damage can occur to peas due to direct feeding and virus spread. Direct feeding on pea results in sap being removed from terminal leaves and the stem. Heavy infestations on pea can cause stunting, deformation, wilting and even death. Plants smaller than 15 cm can easily be killed by aphid infestations, although plants bigger than 15 cm usually suffer only relatively minor damage due to direct feeding. Aphids can also feed on pods, causing them to curl, shrink and only partially fill. Direct feeding therefore leads to yield loss and reductions in crop quality. Bommarco (1991) calculated economic losses in pea through a number of seasons due to A. pisum; with observed yield losses of up to 230 kg/ha. Although direct feeding damage is significant, this aphid is primarily an economic pest on pea due to its ability to transmit viruses. Broad beans and a range of other bean crops can also suffer yield losses, through similar direct feeding impacts, from heavy infestations of A. pisum. On peas and beans, A. pisum secretes honeydew from its siphunculi, which can coat plants, reducing photosynthetic efficiency and resulting in the growth of unsightly sooty moulds.

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