Sugarcane Aphid Research Articles

Standardized Evaluation of Strafer for Control of Sugarcane Aphid, 2016*

Standardized Evaluation of Strafer for Control of Sugarcane Aphid, 2016*

Standardized Evaluation of Carbine for Control of Sugarcane Aphid in Early and Late-Planted Sorghum, 2016*

Standardized Evaluation of Carbine for Control of Sugarcane Aphid in Early and Late-Planted Sorghum, 2016*

Standardized Evaluation of Sivanto Prime for Control of Sugarcane Aphid, 2016*

Standardized Evaluation of Sivanto Prime for Control of Sugarcane Aphid, 2016*

Relative Toxicity of Two Aphicides to Hippodamia convergens (Coleoptera: Coccinellidae): Implications for Integrated Management of Sugarcane Aphid, Melanaphis sacchari (Hemiptera: Aphididae).

Flupyradifurone and sulfoxaflor present novel insecticide chemistries with particular efficacy against aphids, and the recent emergence of sugarcane aphid, Melanaphis sacchari (Zehntner), as a pest of sorghum in the United States has resulted in their widespread use. We examined their toxicity to Hippodamia convergens Guerin-Meneville, an important aphid biocontrol agent. We exposed beetles to topical applications of the field rate (FR) of these insecticides, fed them contaminated food (eggs of Ephestia kuehniella Zeller), and gave first-instar larvae 24-h exposures to leaf residues. More than half of fourth-instar larvae receiving topical applications of sulfoxaflor at FR survived, whereas flupyradifurone at 0.1× FR caused 90% mortality. Adults survived topical treatments better than larvae and without measurable mortality, except flupyradifurone at FR, which killed more than 80% of beetles. Survivors of all treatments had fertility similar to controls, whether treated as larvae or adults. Ingestion of contaminated food caused significant mortality in all treatments (15-40% for adults and 55-85% for larvae), with no significant differences between insecticides at FR. Leaf residues of sulfoxaflor at 1.0 and 2.0× FR caused approximately 60 and 80% mortality of first instars, respectively, whereas flupyradifurone at 0.1 and 1.0× FR caused > 90% mortality. Although sulfoxaflor was less toxic to H. convergens than flupyradifurone, the tested FR of flupyradifurone has now been reduced by half. We conclude that neither insecticide appears as toxic as other nicotinic acetylcholine receptor agonists, and that both materials are compatible with integrated pest management programs for M. sacchari.

Resistance to Melanaphis sacchari (Hemiptera: Aphididae) in Forage and Grain Sorghums.

The sugarcane aphid, Melanaphis sacchari (Zehntner), has established itself as a perennial pest of grain and forage sorghums in the United States since the summer of 2013. We conducted traditional plant resistance studies that determine tolerance, antibiosis, and antixenosis in 32 sorghum genotypes when challenged with sugarcane aphids. The genotypes included one exotic plant introduction and 31 seed and pollinator parental lines that are used to produce grain, sudangrass, and forage sorghum hybrids. One seed parent (B11055) and one grain pollinator parent (R13219) expressed significant degrees of tolerance, antibiosis, and antixenosis and were top performers in all three resistance type experiments. An additional group of seed parents (B13045 and B1057) and grain pollinator parents (R11159, R13422, and RTx2908) and the plant introduction (PI 550610) resulted in an intermediate range of phenotypic resistance (i.e., 4.0 < 6.0) indicative of antibiosis from reduced fecundity, increased intrinsic rate of increase, and increased generation times. The forms of resistance expressed in these lines, especially B11055 and R13219, have great potential in breeding programs that can be integrated into useable forms of resistant sorghums.

Insect and plant-derived miRNAs in greenbug (Schizaphis graminum) and yellow sugarcane aphid (Sipha flava) revealed by deep sequencing

Schizaphis graminum (green bug; GB) and Sipha flava (yellow sugarcane aphid; YSA) are two cereal aphid species with broad host ranges capable of establishing on sorghum (Sorghum bicolor) and several switchgrass (Panicum virgatum) cultivars. Switchgrass and sorghum are staple renewable bioenergy crops that are vulnerable to damage by aphids, therefore, identifying novel targets to control aphids has the potential to drastically improve yields and reduce losses in these bioenergy crops. Despite the wealth of genomic and transcriptomic information available from a closely related model aphid species, the pea aphid (Acyrthosiphon pisum), similar genomic information, including the identification of small RNAs, is still limited for GB and YSA. Deep sequencing of miRNAs expressed in GB and YSA was conducted and 72 and 56 miRNA candidates (including 14 and eight novel) were identified, respectively. Of the identified miRNAs, 45 were commonly expressed in both aphid species. Further, plant derived miRNAs were also detected in both aphid samples, including 13 (eight known and five novel) sorghum miRNAs and three (novel) barley miRNAs. In addition, potential aphid gene targets for the host plant-derived miRNAs were predicted. The establishment of miRNA repertoires in these two aphid species and the detection of plant-derived miRNA in aphids will ultimately lead to a better understanding of the role of miRNAs in regulating gene expression networks in these two aphids and the potential roles of plant miRNAs in mediating plant-insect interactions.

Evaluation of Foliar Insecticides for Management of the Sugarcane Aphid in Grain Sorghum, 2015: Table 1

A study was conducted at the LSU AgCenter Dean Lee Research Station in Alexandria, LA to evaluate insecticides for management of the sugarcane aphid. Six foliar insecticide treatments and an untreated check were assessed in an RCB design with four blocks (one replicate per block). Grain sorghum (Dekalb DKS53-67) was planted on 3 Jun on 38-inch centers at a density of 83,100 seeds per acre. Plots were four rows wide and 35 ft long. Insecticide treatments were applied on 31 Jul after sampling two leaves per plant from 25 randomly selected plants in each block revealed that sugarcane aphid densities had reached 112 aphids per leaf on 30 Jul. A high-clearance self-propelled sprayer with a compressed-air …

Sugarcane Aphid (Hemiptera: Aphididae): A New Pest on Sorghum in North America.

In 2013, the sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), a new invasive pest of sorghum species in North America, was confirmed on sorghum in 4 states and 38 counties in the United States. In 2015, the aphid was reported on sorghum in 17 states and over 400 counties as well as all sorghum-producing regions in Mexico. Ability to overwinter on living annual and perennial hosts in southern sorghum-producing areas and wind-aided movement of alate aphids appear to be the main factors in its impressive geographic spread in North America. Morphological characteristics of the sugarcane aphid include dark tarsi, cornicles, and antennae, allowing easy differentiation from other aphids on the crop. Sugarcane aphid damages sorghum by removing sap and covering plants with honeydew, causing general plant decline and yield loss. Honeydew and sooty mold can disrupt harvesting. The aphid’s high reproductive rate on susceptible sorghum hybrids has resulted in reports of yield loss ranging from 10% to greater than 50%. In response, a combination of research-based data and field observations has supported development of state extension identification, scouting, and treatment guides that aid in initiating insecticide applications to prevent yield losses. Highly efficacious insecticides have been identified and when complemented by weekly scouting and use of thresholds, economic loss by sugarcane aphid can be minimized. Some commercial sorghum hybrids are partially resistant to the aphid, and plant breeders have identified other lines with sugarcane aphid resistance. A very diverse community of predators and parasitoids of sugarcane aphid has been identified, and their value to limit sugarcane aphid population growth is under investigation.

Evaluation of Selected Insecticides for Control of Sugarcane Aphid in Grain Sorghum, 2015: Table 1.

Selected insecticide treatments were evaluated for control of sugarcane aphid in grain sorghum at the Research and Education Center at Milan (Milan, TN). Grain sorghum was planted on 17 June. The test was arranged in an RCB design with four replicates. Individual plots were 12.5 by 30 ft. Treatments were applied with a high clearance sprayer calibrated to deliver 9.4 GPA at 40 PSI with 8,001 flat fan nozzles. Foliar application was made 21 Aug. Plots were sampled by visually counting the number of aphids …

Insecticide Control of Sugarcane Aphid on Grain Sorghum, 2014

Sugarcane aphid is a new invasive pest of sorghum that can cause severe plant injury if not controlled. It first arrived in Georgia in August 2014 and quickly spread across the state. Three insecticide trials were conducted to evaluate the efficacy of various insecticides. Trials were conducted in Marion County, GA (Trial 1), the Agricultural Expo in Moultrie (Colquitt County), GA (Trial 2), and in a grower field near McDonough (Henry County), GA (Trial 3). Sorghum was planted in early June in 30- or 36-inch rows. Plot size was 4 rows by 20–40-ft long. Treatments in each trial were arranged in a RCB design with four replications. Insecticide treatments were applied at milk/early dough stage. Insecticides in …

Insecticidal Control of Sugarcane Aphid, 2015: Table 1

Sugarcane aphid, Melanaphis sacchari (Zehtner), was first observed as pest of sorghum in the United States in 2013 in Texas. It has since spread throughout the Southeastern United States. Sorghum ( Sorghum bicolor (L.) Moench) ‘RV 9782’ (Terral Seed, Rayville, LA) was planted 31 Jul 2015 at the University of Florida’s Everglades Research and Education Center in Belle Glade, FL, atop raised beds on 30-inch centers in a Lauderhill Muck soil using a John Deere Max Emerge vacuum planter at 2.5 in spacing using sorghum plates. Four, 4-row blocks were planted 20 ft apart to reduce potential spray drift. Liquid starter fertilizer (300 lb/ac 11-37-0, N-P-K) was applied at planting in the seed furrow. Atrazine (2 qt/ac) was applied at-plant for pre-emerge weed control. Tecmangam (4 lb/ac) was applied …

Evaluation of Insecticides for Sugarcane Aphid Control in Grain Sorghum, 2014

In 2013, the sugarcane aphid was first found in a sorghum field in Bryan County, OK, and became a serious pest of sorghum in Texas, Louisiana, and Mississippi. This aphid has proven difficult to control with currently registered insecticides. A field trial was conducted at the Wes Watkins Research and Extension Center in Lane, OK, in 2014 to evaluate the efficacy of registered and unregistered insecticides for control of sugarcane aphid in grain sorghum. ‘KS 585’ sorghum was planted 7 May in 36-inch rows. Plots measuring 4 rows by 25 ft were arranged in an RCB design with 4 replications and 14 treatments. An additional set of untreated plots was established outside of …

Efficacy of Neonicotinoid Seed Treatments Against Sugarcane Aphid in Grain Sorghum, 2014: Table 1

An insecticide efficacy trial of neonicotinoid seed treatments against sugarcane aphids in grain sorghum was conducted at the Macon Ridge Research Station (MRRS) in Franklin Parish near Winnsboro, LA, in 2014. Grain sorghum was planted on 2 Jul and emerged on 6 Jul in a Gigger fine silty loam soil with minimum tillage. The test was an RCB design with four replications. Individual plots were four rows (centered on 40 inches) …

Effects of Adjuvants on Transform Efficacy Towards Sugarcane Aphid in Grain Sorghum, 2014: Table 1

An insecticide efficacy trial was conducted to determine the effects of adjuvants on the activity of Transform against sugarcane aphids in grain sorghum. The trial was conducted at the Macon Ridge Research Station (MRRS) in Franklin Parish near Winnsboro, Louisiana in 2014. Grain sorghum was planted on 4 Jun and emerged on 9 Jun in a Gigger fine silty loam soil with minimum tillage. The test was an RCB design with four replications. Individual plots …

Evaluation of Insecticides for Control of the Sugarcane Aphid in Grain Sorghum, 2014: Table 1

A study was conducted at the LSU AgCenter Dean Lee Research Station in Alexandria, LA, to evaluate insecticides for management of the SA. Six insecticide treatments, in addition to an untreated check, were assessed in an RCB design with four blocks and one replicate per block. Grain sorghum (Dyna-Gro GX13355) was planted on 5 May on 38-inch centers at a density of 83,100 seeds/acre. Plots were four rows wide and 35 ft long. Insecticides were applied on 1 Jul. A CO2-pressurized bicycle sprayer calibrated to deliver 10 gpa at 40 psi was used with a four-row boom equipped with eight TeeJet TX …

Effects of Insecticides on Blooming Grain Sorghum on Sorghum Midge and Sugarcane Aphid Control, 2014

Two insecticide efficacy trials were conducted to determine impact insecticides targeting SM have on SM and SCA. The trials were conducted at the Macon Ridge Research Station (MRRS) in Franklin Parish near Winnsboro, Louisiana in 2014. Grain sorghum was planted on 4 Jun and 8 Jul in a Gigger fine silty loam soil with minimum tillage. Both tests were RCB designs with four replications. Individual plots were four rows (centered on 40-in.) × 50 ft. Insecticide treatments were applied with a four-row plot sprayer calibrated to deliver 10 GPA at 3.25 mph with eight TeeJet TX-8 hollow cone nozzles …

Registration of Sorghum Germplasm Tx3408 and Tx3409 with Tolerance to Sugarcane Aphid [Melanaphis sacchari (Zehntner)

The sorghum [Sorghum bicolor (L.) Moench] germplasm lines Tx3408 (ATx3408, Reg. No. GP‐838, PI 675360; BTx3408, Reg. No. GP‐839, PI 675361) and Tx3409 (ATx3409, Reg. No. GP‐840, PI 675362; BTx3409, Reg. No. GP‐841, PI 675363) were developed and released from Texas A&amp;M Agrilife Research in 2015 because they possess high levels of tolerance to the sugarcane aphid [Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae)]. Both of these lines were developed from intentional crosses using the pedigree method of plant breeding. The breeding crosses for these lines were made in College Station, TX, with selection and advancement made in multiple locations across Texas. Screening for sugarcane aphid (SCA) resistance/tolerance was completed in field and greenhouse environments where SCA pressure varied among environments. All of these lines express consistently high levels of tolerance to sugarcane aphid infestation; they are not immune when SCA is present, but they do not accumulate high numbers of SCA and exhibit fewer phenotypic effects typically associated with SCA infestation. They provide the sorghum industry with sources of tolerance to the SCA in an elite and diverse genetic background.

Quantification of sugarcane yellow leaf virus in sugarcane following transmission through aphid vector, Melanaphis sacchari.

Yellow leaf caused by Sugarcane yellow leaf virus (SCYLV) is a serious constraint to sugarcane production in India and currently the disease epidemics occur on many of the susceptible varieties under field conditions. Studies were conducted on the virus transmission by sugarcane aphid Melanaphis sacchari in sugarcane by inoculating virus-free meristem derived from micro- propagated plants of sugarcane cv Co 86032 with viruliferous aphids. Virus transmission was confirmed through RT-PCR assays and subsequently SCYLV population was established through RT-qPCR. A maximum of 22.3×10(3), 3.16×10(6) and 4.78×10(6) copies of SCYLV-RNA targets were recorded in the plants after 7, 180 and 300days, respectively. This study showed that the aphid species M. sacchari acts as an effective vector of SCYLV. The relative standard curve method in RT-qPCR efficiently detected the increment in SCYLV copy numbers in sugarcane following transmission through M. sacchari.

Indigenous Aphid Predators Show High Levels of Preadaptation to a Novel Prey, Melanaphis sacchari (Hemiptera: Aphididae).

The performance of four aphid predators, Hippodamia convergens Guerin-Meneville, Coleomegilla maculata DeGeer, Chrysoperla carnea Stephens and Orius insidiosus Say was compared on three prey species: Schizaphis graminum Rondani, Melanaphis sacchari (Zehntner), and Ephestia kuehniella Zeller eggs. Species predatory in both life stages (all except Ch. carnea) were reared on E. kuehniella eggs and switched to aphid prey for assessment of reproduction. Differences were greater between the E. kuehniella and aphid diets than between the two aphid species. Juvenile survival was high for all predators on all prey, except for O. insidiosus, which had survival on E. kuehniella > S. graminum > M. sacchari. The fastest development of Ch. carnea and O. insidiosus was obtained on E. kuehniella, whereas H. convergens developed fastest on S. graminum, and C. maculata did not differ among diets. S. graminum also yielded the largest H. convergens adults, whereas the largest adults of other predators were obtained on E. kuehniella. Female fecundity and egg viability were similarly high on both aphid diets for H. convergens and C. maculata, whereas, on E. kuehniella, 50% of the former entered reproductive diapause and the latter species had reduced fecundity. Reproductive success of Ch. carnea was S. graminum = M. sacchari > E. kuehniella, but it was similar among treatments for O. insidiosus, although female infertility ranged from 25 to 37.5%. We concluded that all the predators studied are preadapted to utilize sugarcane aphid as prey and have excellent potential to provide sustainable biological control of this newly invasive pest.

NDVI to Detect Sugarcane Aphid Injury to Grain Sorghum.

Multispectral remote sensing has potential to provide quick and inexpensive information on sugarcane aphid, Melanaphis sacchari (Zehntner), pest status in sorghum fields. We describe a study conducted to determine if injury caused by sugarcane aphid to sorghum plants in fields of grain sorghum could be detected using multispectral remote sensing from a fixed wing aircraft. A study was conducted in commercial grain sorghum fields in the Texas Gulf Coast region in June 2014. Twenty-six commercial grain sorghum fields were selected and rated for the level of injury to sorghum plants in the field caused by sugarcane aphid. Plant growth stage ranged from 5.0 (watery ripe) to 7.0 (hard dough) among fields; and plant injury rating from sugarcane aphid ranged from 1.0 (little or no injury) to 4.0 (>40% of plants displaying injury) among fields. The normalized differenced vegetation index (NDVI) is calculated from light reflectance in the red and near-infrared wavelength bands in multispectral imagery and is a common index of plant stress. High NDVI indicates low levels of stress and low NDVI indicates high stress. NDVI ranged from -0.07 to 0.26 among fields. The correlation between NDVI and plant injury rating was negative and significant, as was the correlation between NDVI and plant growth stage. The negative correlation of NDVI with injury rating indicated that plant stress increased with increasing plant injury. Reduced NDVI with increasing plant growth probably resulted from reduced photosynthetic activity in more mature plants. The correlation between plant injury rating and plant growth stage was positive and significant indicating that plant injury from sugarcane aphid increased as plants matured. The partial correlation of NDVI with plant injury rating was negative and significant indicating that NDVI decreased with increasing plant injury after adjusting for its association with plant growth stage. We demonstrated that remotely sensed imagery acquired from grain sorghum fields using an airborne multi-spectral imaging system was sensitive to injury to sorghum plants caused by sugarcane aphid.