Sugarcane Aphid Research Articles

Species Diversity of Entomopathogenic Fungi Infecting the Sugarcane Aphid <i>Melanaphis sacchari</i>: A Recently Introduced Pest in Mexico

The sugarcane aphid, Melanaphis sacchari, is a key pest that affects sorghum in Mexico. During 2014 to 2016, in South of Tamaulipas sites and Bajio region in Guanajuato, the populations of this aphid were infected by different species of Hypocrealean fungi. Based in the morphometric identification and molecular characterization, the species associated with sugarcane aphid in South of Tamaulipas were Lecanicillium longisporum, Beauveria bassiana and Isaria javanica. In this region, the higher infection levels were caused by L. longisporum, mortality range from 30.0% to 50.0%. The presence of I. javanica and B. bassiana represented less than 26.0% and 10.0%, respectively. In Guanajuato, the species found corresponded to L. longisporum and B. bassiana. The infection levels of both species in sugarcane aphid populations in Guanajuato sites were less than 1.00%. The natural occurrence of entomopathogenic fungi on sugarcane aphid populations was associated with climactic factors such as temperature and relative humidity and development of infections was possibly affected by abiotic factors such as crop phenological stage and applications of chemical insecticides realized by farmers for control of this aphid. Further studies on the ecology and physiology of these fungi and trials to determine virulence and persistence in M. sacchari populations are needed. This is the first report on natural presence of L. longisporum, B. bassiana and I. javanica causing disease on Melanaphis sacchari in Guanajuato and Tamaulipas, Mexico.

Insecticide Seed Treatment Efficacy Against Sugarcane Aphid in Grain Sorghum, 2017

Insecticide Seed Treatment Efficacy Against Sugarcane Aphid in Grain Sorghum, 2017

The Effects of Flupyradifurone Application Method on Sugarcane Aphid in Forage Sorghum, 2018

The Effects of Flupyradifurone Application Method on Sugarcane Aphid in Forage Sorghum, 2018

The Effects of Insecticide Treatments on Sugarcane Aphid in Forage Sorghum in California, 2018

The Effects of Insecticide Treatments on Sugarcane Aphid in Forage Sorghum in California, 2018

Insecticide Efficacy Against Sugarcane Aphids in Sorghum, 2016

Insecticide Efficacy Against Sugarcane Aphids in Sorghum, 2016

Registration of R.LBK1 and R.LBK2 Sorghum Germplasm with Resistance to the Sugarcane Aphid [Melanaphis sacchari (Zehntner)

The sorghum [Sorghum bicolor (L.) Moench] germplasm lines R.LBK1 (Reg. No. GP‐865, PI 687244) and R.LBK2 (Reg. No. GP‐866, PI 687245) were developed and released by the USDA in Lubbock, TX, in 2017 because of their high degree of resistance to the sugarcane aphid (SCA) [Melanaphis sachari (Zehntner) (Hempitera: Aphidae)]. Both lines were developed using the pedigree method of plant breeding and are confirmed to be restorer lines. The breeding crosses for both lines were made in Lubbock, TX, and selections were made in Lubbock and Corpus Christi, TX. Evaluation for SCA resistance was conducted in two field locations in Texas in 2016, as well as a greenhouse experiment at the USDA‐ARS laboratory in Lubbock. Both lines express strong resistance to SCA pressures at both seedling and mature plant stages. Preliminary hybrids using highly susceptible seed parents have also shown strong resistance to SCA, indicating that the resistance is dominantly expressed in F1 hybrids using these two lines. R.LBK1 and R.LBK2 are not completely immune to the SCA, but damage is greatly reduced and resistance is extremely apparent when compared to other susceptible sorghum lines and hybrids. These lines provide much needed resistance to the SCA and are suitable as germplasm in a plant breeding program or as parental lines for hybrid development.

Detecting Change in a Sorghum Field Infested by Sugarcane Aphid

The sugarcane aphid, Melanaphis sacchari (Zehntner), is a destructive insect pest of sorghum, Sorghum bicolor (L.) Moench. Outbreaks of sugarcane aphids were reported in commercial sorghum fields in Kansas, Louisiana, Mississippi, Oklahoma, and Texas. Infestations of sugarcane aphids in sorghum fields are initiated when winged aphids land on plants in the field and produce nymphs. Infestations in a field are not uniform and can increase rapidly in size and intensity. The study used airborne multispectral remote sensing to assess change over time in infestations by sugarcane aphids in sorghum fields. Differencing of bi-temporal normalized differenced vegetation index images followed by analysis of change depicted numerically in the image was effective for assessing the extent of temporal change in infestation by sugarcane aphids in a commercial sorghum field. Classification of normalized differenced vegetation index imagery from two dates into land-cover categories including one for sorghum infested with sugarcane aphid, followed by comparison of change in area and distribution of categories was also a useful method for assessing temporal change in infestations by sugarcane aphids in sorghum. Results indicated it was possible to detect and assess change in sorghum fields infested by sugarcane aphids, with 65% increase in area in a field severely infested by sugarcane aphids in only 1 week.

Effects of sugarcane aphid herbivory on transcriptional responses of resistant and susceptible sorghum

BackgroundSugarcane aphid (Melanaphis sacchari) outbreaks in sorghum that were first reported in 2013 are now the most significant threat to this crop in all major sorghum production areas in the U.S. The outcomes of interactions between sugarcane aphid and sorghum and thus the severity of the outbreaks depend on sorghum genotype and potentially also on the phenology of sorghum. Mechanisms underlying these interactions are not known, however. Thus, the goal of this research was to characterize transcriptional changes in a commercially available resistant and a susceptible genotype of sorghum at 2- and 6-wk post-emergence exposed to M. sacchari herbivory. The effects of sorghum age and genotype on the daily change in aphid densities were also evaluated in separate greenhouse experiments.ResultsA higher number of diffentially expressed genes (DEGs) was recovered from the 2-wk plants exposed to aphid herbivory compared to the 6-wk plants across genotypes. Further, gene ontology and pathway analysis indicated a suite of transcriptional changes in the resistant genotype that were weak or absent in the susceptible sorghum. Specifically, the aphid-resistant genotype exposed to M. sacchari up-regulated several genes involved in defense, which was particularly evident in the 2-wk plants that showed the most robust transcriptional responses. These transcriptional changes in the younger resistant sorghum were characterized by induction of hormone-signaling pathways, pathways coding for secondary metabolites, glutathion metabolism, and plant-pathogen interaction. Furthermore, the 2-wk resistant plants appeared to compensate for the effects of oxidative stress induced by sugarcane aphid herbivory with elevated expression of genes involved in detoxification. These transcriptional responses were reflected in the aphid population growth, which was significantly faster in the susceptible and older sorghum than in the resistant and younger plants.ConclusionThis experiment provided the first insights into molecular mechanisms underlying lower population growth of M. sacchari on the resistant sorghum genotype. Further, it appears that the younger resistant sorghum was able to mount a robust defense response following aphid herbivory, which was much weaker in the older sorghum. Several pathways and specific genes provide specific clues into the mechanisms underlying host plant resistance to this invasive insect.

The effects of sugarcane aphid density in sorghum on predation by lady beetles and lacewings

The sugarcane aphid, Melanaphis sacchari Zehntner (Hemiptera: Aphididae), is a new and devastating pest of sorghum (Sorghum bicolor (L.)) in the United States. Arthropod predators, especially lady beetles and green lacewings, are often abundant in sugarcane aphid-infested sorghum, but little is known about the effects of these predators on sugarcane aphid populations. We quantified the effect of two species of lady beetles (larvae and adults of Coccinella septempunctata L. and Harmonia axyridis Pallas) (Coleoptera: Coccinellidae) and green lacewings (larvae of Chrysoperla rufilabris Burmeister) (Neuroptera: Chrysopidae) on aphid colony growth across several aphid densities (20, 40, 80, 160). We found that all predator species and life stages significantly reduced the growth of sugarcane aphid populations at low to intermediate aphid densities (20, 40, and 80 aphids per colony). At the highest aphid density (160 aphids), however, H. axyridis larvae were much less effective than C. septempunctata larvae and adults and H. axyridis adults and lacewing larvae did not suppress sugarcane aphid colony growth. We incorporated these predator effects into a dynamic predator-prey model to predict the impact of predators on the short-term population dynamics of sugarcane aphids in sorghum (2–14 days) and the ability of these predators to suppress aphids below action thresholds (50–75 aphids per leaf). The model illustrated that all the predators we studied prevented aphid densities between 20 and 40 per leaf from reaching action thresholds. At initial densities of 80 aphids per colony, all predators were able to suppress aphids below threshold in two to four days. At the highest initial aphid density (160), however, H. axyridis larvae could not suppress aphids below the action threshold by four days and lacewing larvae never suppressed aphids below the threshold. Our results suggest that common predators in sorghum have the potential to suppress sugarcane aphid population growth and reduce the number of insecticide applications needed to control sugarcane aphids.

Plant Resistance in Sorghums to the Sugarcane Aphid (Hemiptera: Aphididae)

Abstract Ten sorghum, Sorghum bicolor (L.) Moench, lines near or in commercial release were evaluated with the intent of identifying the phenotypic expression of host-plant resistance to the sugarcane aphid Melanaphis sacchari (Zehnter) (Hemiptera: Aphididae). Two of the 10 entries (OL2042 and SP7715) expressed a high degree of resistance to the sugarcane aphid, with damage ratings 4.0 and were statistically lower than the susceptible check Tx7000. Chlorophyll loss and damage ratings exhibited a linear relationship (R2 = 0.87), followed by a slight improvement (R2 = 0.89) in the regression models when the difference in plant height was added as a second independent variable. The relationship helps e...

A Sugarcane Aphid “Super‐Clone” Predominates on Sorghum and Johnsongrass from Four US States

The sugarcane aphid [SCA, Melanaphis sacchari (Zehntner), Hemiptera: Aphididae], is the predominant pest of US‐grown sorghum [Sorghum bicolor (L.) Moench]. A previous study found that a single clone was prevalent on samples collected from sorghum in seven states and one territory of the United States in 2015. We sought to determine if this clone was still prevalent on sorghum grown in 2016 and if this clone is also found on Johnsongrass [S. halepense (L.) Pers.]. Forty‐six SCA samples were collected from primarily sorghum and Johnsongrass from 10 cities in four states, and three aphid samples from different genera (Sipha, Rhopalosiphum, and Acyrthosiphon) were obtained. These aphid samples were genotyped with 43 SCA simple sequence repeat (SSR) markers. The predominant aphid clone found on sorghum in 2015 was again the predominant genotype in the 2016 SCA samples collected from sorghum. This same genotype was also found for the SCA samples collected from Johnsongrass in 2015 and 2016, although two samples differed at a single locus. Mixtures of this predominant genotype with three additional genotypes of SCAs were detected for three samples (excluding the control), indicating that multiple genotypes do exist in the United States but at low levels. This study provides evidence that a SCA “super‐clone” has maintained its dominance on sorghum, and it is using the perennial Johnsongrass as an alternative host.

Registration of RTx3410 through RTx3428 Sorghum Germplasm Resistant to Sugarcane Aphid [Melanaphis sacchari (Zehntner)

The sorghum [Sorghum bicolor (L.) Moench] germplasm lines RTx3410 through RTx3428 (Reg. No. GP‐846 to GP‐864, PI 686993 to PI 687011) were developed and released by Texas A&M AgriLife Research, Lubbock, TX, in 2018. The lines are resistant to damage caused by the sugarcane aphid [Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae)] (SCA). All lines were developed by intentional plastic bag emasculation crosses and selected using the pedigree method of plant breeding. Resistance in RTx3410 through RTx3426 was identified after the SCA became a consistent pest of sorghum in the United States in 2013. To develop RTx3427 and RTx3428, crosses and selections were made in the Texas A&M AgriLife Research program at various Texas locations and resistance to the SCA in southern Africa was identified in Botswana and South Africa. Resistance in the United States was confirmed following identification of virulent SCA in 2013. All lines at seedling and adult plant stages expressed moderate to high levels of resistance to SCA. Resistance in RTx3412 to RTx3426 is derived either from Tx2783 or an early generation sib. Resistance in RTx3410, RTx3411, RTx3427, and RTx3248 is from unknown sources of resistance. The genetic relationship between the resistance gene(s) from the different sources is not known. The lines with potentially diverse sources of resistance provide the sorghum industry with a diversity of elite germplasm with resistance to SCA.

Field efficacy of biorational insecticides against Melanaphis sacchari (Zehntner) in sorghum

The sugarcane aphid, Melanaphis sacchari (Zehntner), is a major pest in diverse sorghum-growing regions, affecting yields if no effective control measures are implemented. The objective of this study was to evaluate the field efficacy of commercial formulations of biorational insecticides against this pest. All the evaluated biorational insecticides exerted acceptable biological efficacy for at least 7 days after application. The insecticides based on fatty acid potassium salts (Ultralux® S and Impide®) maintained aphid density below the established threshold of 50 aphids per leaf up to 14 days after application. The results obtained suggest that biorational insecticides can be included in the integrated management of M. sacchari.

Spontaneously Aborted Embryos in the Sugarcane Aphid (Hemiptera: Aphididae)

A spontaneously abortive embryo (SAE) process in field and greenhouse populations of sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae) is described, as well as the occurrence of SAE in populations from Chiapas, Durango, Guanajuato, Nayarit, Michoacan, Queretaro, Sinaloa, and San Luis Potosi states in Mexico. This phenomenon was observed from November 2014 to December 2017 in sugarcane aphid populations grown on Sorghum bicolor (sorghum), Sorghum drummondi (Sudan grass), and Sorghum halepense (Johnson grass). No reports of this phenomenon have been recorded earlier, perhaps due to the small size of the aborted embryos (200–500 μm), the dark color they acquire within few hours of exposure, their frequent drop from the plant, and the crowded populations of aphids. The abortion process, both simple as well as multiple and complex events, are described. Also, embryos in vivo, alcohol-fixed, and mounted individuals are described. Embryogenic stages 13 and 16–19 were identified in the aborted embryos. It is suggested that specific biotic and/or abiotic situations may intervene on the reproductive physiology of these particular populations, most probably, on the hormone balance. However, the presence of a complex symbiotic/pathogenic microbial association is not discarded, according to some observations, which are still to be studied.

Evaluation of Greenbug and Yellow Sugarcane Aphid Feeding Behavior on Resistant and Susceptible Switchgrass Cultivars

Switchgrass (Panicum virgatum L.) is an emerging biofuel crop that serves as host for aphids. To discern the effects of plant age and possible resistance mechanisms, the feeding behavior of greenbugs (Schizaphis graminum Rondani.) and the yellow sugarcane aphid (Sipha flava Forbes.) was monitored on three diverse switchgrasses by the electrical penetration graph (EPG) technique. Callose deposition and genes associated with callose metabolism were also analyzed to discern their association with plant resistance. There was a strong host effect on greenbugs feeding on lowland cultivar Kanlow at the V3 stage of development, as compared to the greenbug-susceptible upland cultivar Summer and plants derived from Kanlow (♂) × Summer (♀) (K×S) crosses. These data confirmed that Kanlow at the V3 stage had antibiosis to greenbugs, which was absent in the Summer and K×S plants. In contrast, similar effects were not observed for yellow sugarcane aphids, excluding significant differences in the time to first probe on Kanlow plants at the V1 stage and reduction in time spent on pathway processes on Kanlow plants at the V3 stage. These data demonstrated that Kanlow plants may have multiple sources of resistance to the two aphids, and possibly some were phloem based. Microscopy of leaf sections stained with aniline blue for callose was suggestive of increased callose deposition in the sieve elements in Kanlow plants relative to Summer and K×S plants. RT-qPCR analysis of several genes associated with callose metabolism in infested plants was equivocal. Overall, these studies suggest the presence of multiple defense mechanisms against aphids in Kanlow plants, relative to Summer and K×S plants.

Invasion of sorghum in the Americas by a new sugarcane aphid (Melanaphis sacchari) superclone.

In the United States (US), the sugarcane aphid (SCA) Melanaphis sacchari (Zehnter) (Hemiptera: Aphididae) was introduced in the 1970s, however at that time it was only considered a pest of sugarcane. In 2013, a massive outbreak of M. sacchari occured on sorghum, resulting in significant economic damage to sorghum grown in North America including the US, Mexico, and Puerto Rico. The aim of the present study was to determine if the SCA pest emergence in American sorghum resulted from the introduction of new genotypes. To this end we used microsatellite markers and COI sequencing to compare the genetic diversity of SCA populations collected in the Americas after the 2013 SCA outbreak on sorghum (during 2013–2017) to older samples collected before the pest outbreak (during 2007–2009). Our results show that the SCA outbreak in the Americas and the Caribbean observed since 2013 belong to populations exhibiting low genetic diversity and consisting of a dominant clonal lineage, MLL-F, which colonizes Sorghum spp. and sugarcane. The comparison of MLL-F specimens collected post-2013 with specimens collected in Louisiana in 2007 revealed that both populations are genetically distinct, according to COI sequencing and microsatellite data analyses. Our result suggest that MLL-F is a new invasive genotype introduced into the Americas that has spread rapidly across sorghum growing regions in the US, Mexico, Honduras and the Caribbean. The origin of this introduction is either Africa or Asia, with Asia being the most probable source.

Antibiosis and Tolerance Discovered in USDA-ARS Sorghums Resistant to the Sugarcane Aphid (Hemiptera: Aphididae)1

Abstract The sugarcane aphid Melanaphis sacchari (Zehntner) was discovered infesting grain sorghum close to Beaumont, TX, near the Texas and Louisiana state line a few kilometers inland from the Gulf Coast in the late summer of 2013, and has been a perennial pest of grain, forage, and sweet sorghums. Our research was aimed at identifying sorghum germplasm that expresses host-plant resistance to the sugarcane aphid. We originally screened 36 lines including two known resistant sorghums (Tx2783 and DKS-37-07) and two known susceptible sources (WSH 117 and MORCH 858). From this screen, two pollinator lines (R.11143 and R.11259) developed by the USDA-ARS in Lubbock, TX, exhibited tolerance as indicated by damage ratings and growth characteristics, such as plant height, number of leaves, and chlorophyll content. Line R.11143 had a slight net gain in chlorophyll content in the infested plants compared to the noninfested plants, indicating a highly tolerant sorghum. The R.11143 and R.11259 lines also expressed s...

Interactive effects of crop variety, insecticide seed treatment, and planting date on population dynamics of sugarcane aphid (Melanaphis sacchari) and their predators in late-colonized sorghum

Sugarcane aphids Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae) have recently become an eruptive and costly pest of sorghum, Sorghum bicolor (L). In contrast to its southern range in the United States, sugarcane aphid colonizes sorghum at flowering or just post-bloom in the central High Plains. Thus the goal of this work was to quantify how sorghum resistance (commercially available hybrid DKS37-07), timing of planting (early or conventional plant date), and insecticide seed treatment (clothianidin) affected population dynamics of sugarcane aphids in late-colonized sorghum in the central High Plains. The impacts of these factors on sugarcane aphid densities were measured over two growing seasons, and the numbers of natural enemies of the aphids were quantified as well. Host plant resistance emerged as the main driver of sugarcane aphid population dynamics while planting date and seed treatment had a variable impact on M. sacchari and their predators. Host plant resistance also affected predators of sugarcane aphids and, while not directly explored in this study, potentially altered predator-aphid interactions as well. Diverse natural enemies including Coccinellidae, Syrphidae, Chrysophidae, and Anthocoridae were readily recruited by sugarcane aphid infestations, and predators were strongly correlated with populations of M. sacchari regardless of the seed treatment application or sorghum variety and across planting dates. This research demonstrates that a commercially available resistant sorghum variety provides the most robust protection against this pest in the central High Plains. Further, an already present assemblage of aphid predators recruits readily to aphid-infested sorghum and is likely to provide important biological control services particularly in resistant sorghum.

Using Multispectral Imagery to Map Spatially Variable Sugarcane AphidInfestations in Sorghum

The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), is a major pest of sorghum (Sorghum bicolor (L.) Moench). Outbreaks of sugarcane aphid occurred in sorghum fields in Mexico and the Gulf Coast region of the United States in 2013 and subsequently spread throughout most of the sorghum-growing region. The aphid induces stress to sorghum by damaging foliage. Multispectral remote sensing can be used to detect plant stress in agricultural crops. The study investigated the utility of multispectral imagery to delineate spatially variable infestations of sugarcane aphid in commercial grain sorghum fields. Multispectral images were acquired from fields by using a Duncan Tech MS3100-CIR, a 3-band (NIR, R, G) digital camera, mounted nadir in an aircraft fuselage. ERDAS Image was used for unsupervised classification of multispectral images of five fields. The study indicated it is feasible to use multispectral imagery to detect and spatially delineate patches of plants infested by sugarcane aphids in sorghum fields. The overall classification accuracy ranged from 89 to 96% for differentiating areas damaged by sugarcane aphid from areas where plants were not damaged. Results indicated good potential for mapping spatially variable sugarcane aphid infestations in grain sorghum fields.

Sugarcane Aphid in Sorghum

Natural Sciences EducationVolume 47, Issue 1 180102 p. 1-2 Student Manuscript Sugarcane Aphid in Sorghum Logan Evers, Corresponding Author Logan Evers kimk@ksu.edu c/o Kim Kerschen, 1022 Throckmorton PSC, Kansas State University, 1712 Claflin Road, Manhattan, KS, 66506Corresponding author (logan21@ksu.edu, kimk@ksu.edu).Search for more papers by this author Logan Evers, Corresponding Author Logan Evers kimk@ksu.edu c/o Kim Kerschen, 1022 Throckmorton PSC, Kansas State University, 1712 Claflin Road, Manhattan, KS, 66506Corresponding author (logan21@ksu.edu, kimk@ksu.edu).Search for more papers by this author First published: 01 February 2018 https://doi.org/10.4195/nse2018.01.0102Citations: 1 This article is intended for readers in the production agriculture industry who deal with grain sorghum throughout the growing season. This publication will discuss the impacts of the sugarcane aphid in various crops and the ways to manage and identify them as they continue to advance north. All rights reserved Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume47, Issue1December 2018Pages 1-2 RelatedInformation