Sorghum Midge Research Articles

Observations on the Seasonal Abundance of Sorghum Midge

Observations on the Seasonal Abundance of Sorghum Midge

Exploitation of Hybrid Vigor for Identification of Promising Sorghum F1 Hybrid for High Grain Yield and Resistance to Sorghum Midge

Sorghum is the second most grown cereal crop in Niger. However, sorghum production in the country is dominated by indigenous cultivars with low productivity. Productivity in grain sorghum has been achieved in developing countries around the world using hybrids. This study was conducted to evaluate heterosis in F1 sorghum hybrids for grain yield and resistance to midge. Fifty F1 sorghum hybrids were evaluated for grain yield and resistance to midge. Variation for grain yield, midge resistance, and flowering time was observed. The magnitude of better parent heterosis for grain yield and resistance to midge varied significantly among hybrids. Four hybrids combined high better parent heterosis for both grain yield and resistance to midge while eight hybrids were better than their better parent for resistance to midge. These hybrids performed well for grain yield and/or resistance to midge. Therefore, the parental lines involved in these hybrids can be advanced for commercial hybrids production or used in sorghum improvement programs.

Identification of stable genotypes and genotype by environment interaction for grain yield in sorghum (Sorghum bicolor L. Moench)

AbstractSorghum is a staple food crop in Niger and its production is constrained by sorghum midge and the use of low yielding, local sorghum varieties. To improve sorghum productivity, it is crucial to provide farmers with high yielding sorghum cultivars that are resistant to midge. We evaluated 282 genotypes in four environments of Niger Republic. Alpha (0.1) lattice with two replications was the experimental design. Genotype and genotype by environment (GGE) biplot analysis was used to study grain yield (GY) stability and G × E interactions. The results revealed that two distinct mega environments were present. Genotype L232 was the best genotype for GY in the first planting date at Konni and the first and second planting dates (PDs) at Maradi. Genotype L17 was the best for GY in the second PD at Konni. The second PD at Konni was the most discriminating environment while the first PD at Konni is suitable for selecting widely adapted genotypes for GY.

Principal component analysis of early generation sorghum lines for yield-contributing traits and resistance to midge

ABSTRACT Sorghum (Sorghum bicolor L. Moench) is a staple food crop in Niger. Its production is constrained by sorghum midge (Stenodiplosis sorghicola Coquillett 1898) and by the use of low-yielding, local sorghum varieties. To improve sorghum productivity, farmers need high-yielding and midge-resistant sorghum cultivars. The objective of this research is to evaluate genetic diversity among sorghum inbred lines for yield, yield-contributing traits, and resistance to midge. Two-hundred and eighty-two lines (280 recombinant inbred lines plus two checks) were evaluated at two experimental sites in Niger. An alpha (0.1) lattice design with two replications was used to conduct the trial. Principal component analysis was used to determine the relationship between grain yield and resistance to midge. The first three principal components (PC) accounted for 56.22% of the total genotypic variation. Based on the similarity of traits within and between members of clusters, genotypes were divided into 18 clusters. Genetic variability was present for the traits under study in the tested germplasm. Hybridization of midge-resistant genotypes from different clusters should be able to yield new genotypes combining high yield and other desirable yield-contributing traits.

Genetic Variability and Its Implications on Early Generation Sorghum Lines Selection for Yield, Yield Contributing Traits, and Resistance to Sorghum Midge

Sorghum is the second most important cereal crop in Niger. The crop is grown in a wide range of ecological environments in the country. However, sorghum grain yield in Niger is limited by both abiotic and biotic constraints. Recombinant inbred lines derived from the cross of a local variety with a midge resistant variety and two local checks were evaluated during the 2015 rainy season across two planting dates in two environments in Niger. The objective was to investigate genetic variability for yield, yield related traits, and resistance to sorghum midge. High phenotypic coefficient of variation (PCV) versus genotypic coefficient of variation (GCV) was observed in both sites and planting dates. Across planting dates at both Konni and Maradi, grain yield, plant height, panicle weight, and midge damage had high heritability coupled with high estimates of genetic advance. At Konni, high genetic advance coupled with high heritability was detected for grain yield, plant height, panicle weight, and resistance to midge. There were similar results at Maradi for grain yield, plant height, and panicle weight. Therefore, selection might be successful for the above characters in their respective environments.

First record of Stenodiplosis sorghicola on sorghum in Greece

In October 2007, the sorghum midge Stenodiplosis sorghicola (Coquillett) (Diptera: Cecidomyiidae) was recorded for the first time in Greece. Its occurrence was noticed in an experimental sorghum cultivar at Aliartos, near Athens, in Viotia region. Information on its morphology, biology and distribution is given.

Population dynamics and bio-intensive management of sorghum midge, Contarinia sorghicola (Coquillett) in sorghum under southern Tamil Nadu

Surveys on distribution of sorghum midge at southern region of Tamil Nadu during 2011 to 2014 indicated that, midge observed in all areas of three districts. Effect of abiotic factors on sorghum midge revealed that maximum, minimum temperature, wind velocity and sunshine were positive while maximum, minimum relative humidity and rainfall showed negative correlation. Among bio-intensive management strategies, Neem oil 3 per cent showed maximum reduction (63.36), minimum midge incidence/5 panicle (17.5) and maximum grain yield (2498 kg/ha) when compared to control (244 kg/ha). The highest incremental cost benefit ratio (ICBR) obtained in Neem seed kernel extract (NSKE) 5 per cent (1:24.7) followed by Neem leaf extract 5 per cent (1:22.3) treated plots.

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 …

Evaluation of Indian Popular Varieties and Validation of Integrated Pest Management Strategies Against Major Pests of Sorghum

Sorghum shoot fly (Atherigona soccata Rondani), Stem borer (Chilo partellus Swinhoe), Head bug (Calocoris angustatus Lethiery) and midge (Contarinia sorghicola Coquillett) are the most important pests of sorghum in southern region of Tamil Nadu. The results on the field evaluation of popular varieties of sorghum over three years (post rainy or winter 2010–2012) revealed that DSV-4 and CSV-216R for shoot fly, DSV-4, Maulee, CSV-15, K-8, Phule Anuradha and M 35-1 for stem borer, Maulee and K-8 for midge were found to be more resistant and promising. In validation of IPM practices seed treatment with imidacloprid 70 WS @ 3 g/kg of seed + spray of metasystox @ 0.07 % or NSKE @ 5 % at 45 DAE, intercropping with cowpea (4:1)+ seed treatment with imidacloprid 70 WS @ 3 g/kg of seed were effective in reducing the attack of above pests. Intercropping with cowpea (4:1)+ imidacloprid 70 WS @ 3 g/kg of seed was the most effective and recorded the highest ICBR (1:25).

Cost-Benefit Analysis of Sorghum Midge,Stenodiplosis sorghicola1(Coquillett)-Resistant Sorghum Hybrid Research and Development in Texas

Sorghum, Sorghum bicolor (L.) Moench, is important to the economies of Texas and the U.S. Sorghum midge, Stenodiplosis sorghicola (Coquillett), attacks flowering sorghum, causing substantial loss of grain every year. Sorghum midge-resistant genotypes are available for use in breeding programs to develop agronomically superior sorghum hybrids. Estimated yield loss caused by sorghum midge varied between 94.2 and 890.8 and 12.9 and 188.8 kg/ha if sorghum midgesusceptible and resistant hybrids, respectively, were grown. Yield saved by using a resistant hybrid was 48.1 (45.3 kg/ha) to 96.7% (702.0 kg/ha). Benefits accrued during a 25-year period were 66.7, 99.9, and 319.8 million (in 1984 constant dollar) at 1, 5, and 15% compounding/discounting rates, respectively. The corresponding accruable costs were $4.3, 6.7, and 23.4 million. Net present value was positive and cost-benefit ratio was less than one, indicating investment in developing a sorghum midge-resistant hybrid was profitable. Depending on the interest rate, a dollar invested in research and development of a sorghum midge-resistant hybrid would generate $13.6 to 15.7.

HISTORICAL PERSPECTIVE ON DRUG-PLACEBO DIFFERENCES: IMPLICATIONS FOR GENERALIZABILITY OF RESULTS AND FUTURE TRIAL DESIGN

Studies on tritrophic interactions involving sorghum genotypes, midge (Stenodiplosis sorghicola) and the predominant parasitoids (Aprostocetus spp.) at ICRISAT Asia Center were conducted using three midge resistant (ICSV 745, ICSV 89058 and IS 10712) and three susceptible (Swarna, CSH 9 and ICSV 112) genotypes during the post-rainy (1992/93) and rainy (1993) seasons. A. coimhatorensis, the predominant parasitoid during post-rainy season, preferred mid-late midge larvae for parasitization, while A. gala, which was predominant during the rainy season, preferred early-mid larval stages. Variations in the preference of A. coimbatorensis and A. gala for the developmental stage of their host larvae indicate good prospects for the biological control of sorghum midge populations. There were significant differences in parasitization level of midge by Aprostocetus spp. between resistant and susceptible sorghum genotypes, and season. Higher parasitization was observed on susceptible genotypes than on resistant ones during both post-rainy and rainy seasons. However, the level of parasitization was greater in post-rainy than in rainy seasons. There was also evidence of higher midge infestation in rainy than in post-rainy seasons. Susceptible genotypes attracted more parasitoids because of high levels of midge infestations. Low parasitoid density in midge resistant sorghum under glasshouse and field conditions was associated with low midge infestations in these genotypes. However, parasitoids were always associated with their host in spite of low midge densities in resistant genotypes. The present study revealed that the interaction between host plant resistance and parasitoids of sorghum midge would thus be synergistic and complementary and could result in successful integration of these two important pest management tactics.

Host-plant resistance and biopesticides: ingredients for successful integrated pest management (IPM) in Australian sorghum production

There are two major pests of sorghum in Australia, the sorghum midge, Stenodiplosis sorghicola (Coquillett), and the corn earworm, Helicoverpa armigera (Hübner). During the past 10 years the management of these pests has undergone a revolution, due principally to the development of sorghum hybrids with resistance to sorghum midge. Also contributing has been the adoption of a nucleopolyhedrovirus for the management of corn earworm. The practical application of these developments has led to a massive reduction in the use of synthetic insecticides for the management of major pests of sorghum in Australia. These changes have produced immediate economic, environmental and social benefits. Other flow-on benefits include providing flexibility in planting times, the maintenance of beneficial arthropods and utilisation of sorghum as a beneficial arthropod nursery, a reduction in midge populations and a reduction in insecticide resistance development in corn earworm. Future developments in sorghum pest management are discussed.

Host plant resistance in grain crops and prospects for invertebrate pest management in Australia: an overview

An integrated pest management (IPM) approach that relies on an array of tactics is adopted commonly in response to problems with pesticide-based production in many agricultural systems. Host plant resistance is often used as a fundamental component of an IPM system because of the generally compatible, complementary role that pest-resistant crops play with other tactics. Recent research and development in the resistance of legumes and cereals to aphids, sorghum midge resistance, and the resistance of canola varieties to mite and insect pests have shown the prospects of host plant resistance for developing IPM strategies against invertebrate pests in Australian grain crops. Furthermore, continuing advances in biotechnology provide the opportunity of using transgenic plants to enhance host plant resistance in grains.

Economic Injury Levels for Sorghum Midge, Stenodiplosis sorghicola1,and Corn Earworm, Helicoverpa zea2, Feeding on Panicles of Sorghum, Sorghum bicolor

Abstract Sorghum midge, Stenodiplosis sorghicola (Coquillett), and corn earworm, Helicoverpa zea (Boddie) are important insect pests of sorghum, Sorghum bicolor (L) Moench. Both pests feed on the developing kernel and directly reduce grain yield. Economic injury levels (EIL) that respond to pest management costs, commodity values and pest density are developed for each pest based upon published reports on grain loss per insect stage and stage-specific mortality. The economic injury level for sorghum midge is M = C 33,256 / V F where M = mean number of adult sorghum midge per flowering panicle, C = cost of management to control sorghum midge per unit area ($/acre), V = market value per unit of production ($ per 100 lbs of sorghum grain), and F = number of flowering panicles per acre. The EIL for sorghum midge is expressed as the number of adult sorghum midge per flowering panicle because only flowering panicles are susceptible to oviposition by sorghum midge females. Corn earworm larval stage must be consi...

Seasonal incidence of Stenodiplosis sorghicola (Coquillett) (Diptera: Cecidomyiidae) and its parasitoids on Sorghum halepense (L.) Pers. in south‐eastern Queensland, Australia

Abstract To quantify the role of Johnson grass, Sorghum halepense, in the population dynamics of the sorghum midge, Stenodiplosis sorghicola, patterns of flowering of Johnson grass and infestation by sorghum midge were studied in two different climatic environments in the Lockyer Valley and on the Darling Downs in south‐eastern Queensland for 3 years. Parasitism levels of S. sorghicola were also recorded. In the Lockyer Valley, Johnson grass panicles were produced throughout the year but on the Darling Downs none were produced between June and September. In both areas, most panicle production occurred between November and March and infestation by S. sorghicola was the greatest during this period. The parasitism levels were between 20% and 50%. After emergence from winter diapause, one to two generations of S. sorghicola developed on S. halepense before commercial grain sorghum crops were available for infestation. Parasitoids recorded were: Aprostocetus diplosidis, Eupelmus australiensis and two species of Tetrastichus. Relationships between sorghum midge population growth rate and various environmental and population variables were investigated. Population size had a significant negative effect (P < 0.0001) on population growth rate. Mortality due to parasitism showed a significant positive density response (P < 0.0001). Temperature, rainfall, open pan evaporation, degree‐days and host availability showed no significant effect on population growth rate. Given the phenology of sorghum production in south‐eastern Queensland, Johnson grass provides an important bridging host, sustaining one to two generations of sorghum midge. Critical studies relating population change and build‐up in sorghum to sorghum midge populations in Johnson grass are yet to be performed.

Effect of soil burial depth and wetting on mortality of diapausing larvae and patterns of post‐diapause adult emergence of sorghum midge, Stenodiplosis sorghicola (Coquillett) (Diptera: Cecidomyiidae)

Abstract In south‐eastern Queensland, Australia, sorghum planted in early spring usually escapes sorghum midge, Stenodiplosis sorghicola, attack. Experiments were conducted to better understand the role of winter diapause in the population dynamics of this pest. Emergence patterns of adult midge from diapausing larvae on the soil surface and at various depths were investigated during spring to autumn of 1987/88–1989/90. From 1987/88 to 1989/90, 89%, 65% and 98% of adult emergence, respectively, occurred during November and December. Adult emergence from larvae diapausing on the soil surface was severely reduced due to high mortality attributed to surface soil temperatures in excess of 40°C, with much of this mortality occurring between mid‐September and mid‐October. Emergence of adults from the soil surface was considerably delayed in the 1988/89 season compared with larvae buried at 5 or 10 cm which had similar emergence patterns for all three seasons. In 1989/90, when a 1‐cm‐deep treatment was included, there was a 392% increase in adult emergence from this treatment compared with deeper treatments. Some diapausing larvae on the surface did not emerge at the end of summer in only 1 year (1989/90), when 28.0% of the larvae on the surface remained in diapause, whereas only 0.8% of the buried larvae remained in diapause. We conclude that the pattern of emergence explains why spring plantings of sorghum in south‐eastern Queensland usually escape sorghum midge attack.

Impact of Phenolic Compounds and Related Enzymes in Sorghum Varieties for Resistance and Susceptibility to Biotic and Abiotic Stresses

Contents of phenolic compounds and related enzymes before and after sorghum grain germination were compared between varieties either resistant or susceptible to biotic (sooty stripe, sorghum midge, leaf anthracnose, striga, and grain molds) and abiotic (lodging, drought resistance, and photoperiod sensitivity) stresses. Independent of grain germination, sorghum varieties resistant to biotic and abiotic stresses had on average higher contents of proanthocyanidins (PAs), 3-deoxyanthocyanidins (3-DAs), and flavan-4-ols than susceptible varieties. Results show that content of 3-DAs is a good marker for sorghum resistance to both biotic and abiotic stresses because it correlates with resistance to all stresses except for photoperiod sensitivity. The second good marker for stress resistance is content of PAs. Total phenolic compounds and the activities of related enzymes are not good markers for stress resistance in sorghum grains.

A Sorghum bicolor × S. macrospermum hybrid recovered by embryo rescue and culture

Although exotic germplasm is extensively used in sorghum improvement programs, Sorghum species classified in sections other than Eu-sorghum have not been utilised as germplasm because of strong reproductive barriers involving pollen–pistil incompatibilities. S. macrospermum is of particular interest to sorghum breeders because of its close phylogenetic relationship and cytogenetic similarities to S. bicolor and its resistance to important sorghum pests and pathogens, such as sorghum midge and sorghum downy mildew. A vegetatively vigorous interspecific hybrid was obtained from a cross between a cytoplasmic male-sterile S. bicolor plant and S. macrospermum by using embryo rescue and in vitro culture techniques. The hybrid was morphologically intermediate to S. bicolor and S. macrospermum in leaf width, leaf pubescence, plant height, inflorescence morphology, chromosome number and nuclear DNA content. It was male-sterile like its ATx623 parent. The hybrid produced no offspring when used as the female parent in a backcross with S. bicolor. This is the first confirmed hybrid between S. bicolor and S. macrospermum, and to our knowledge, it is the first reported hybrid between S. bicolor and any Sorghum species outside the Eu-sorghum section.

Variation in inheritance of resistance to sorghum midge, Stenodiplosis sorghicola across locations in India and Kenya

Sorghum midge [Stenodiplosis sorghicola (Coquillett)] is an important pest of grain sorghum, and host plant resistance is one of the important components for the management of this pest. We studied the inheritance of resistance to this insect involving a diverse array of midge-resistant and midge-susceptible genotypes in India and Kenya. Testers IS 15107, TAM 2566, and DJ 6514, which were highly resistant to sorghum midge in India, showed a greater susceptibility to this insect in Kenya. The maintainer lines ICSB 88019 and ICSB 88020 were highly resistant to sorghum midge in India, but showed a susceptible reaction in Kenya; while ICSB 42 was susceptible at both the locations. General combining ability (GCA) effects for susceptibility to sorghum midge for ICSA 88019 and ICSA 88020 were significant and negative in India, but such effects were non-significant in Kenya. The GCA effects of ICSB 42 for susceptibility to sorghum midge were significant and positive at both the locations. The GCA effects were significant and positive for Swarna, and such effects for IS 15107 and TAM 2566 were negative at both the locations. GCA effect of DJ 6514 were significant and negative in India, but non-significant and positive in Kenya; while those of AF 28 were significant and positive during the 1994 season in India, but significant and negative in Kenya. Inheritance of resistance to sorghum midge is largely governed by additive type of gene action. Testers showing resistance to sorghum midge in India and/or Kenya did not combine with ICSA 88019 and ICSA 88020 to produce midge-resistant hybrids in Kenya. Therefore, it is essential to transfer location specific resistance into both parents to produce midge-resistant hybrids.

Identifications of two different mechanisms for sorghum midge resistance through QTL mapping.

Sorghum midge is the one of the most damaging insect pests of grain sorghum production worldwide. At least three different mechanisms are involved in midge resistance. The genetic bases of these mechanisms, however, are poorly understood. In this study, for the first time, quantitative trait loci associated with two of the mechanisms of midge resistance, antixenosis and antibiosis, were identified in an RI (recombinant inbred) population from the cross of sorghum lines ICSV745 x 90562. Two genetic regions located on separate linkage groups were found to be associated with antixenosis and explained 12% and 15%, respectively, of the total variation in egg numbers/spikelet laid in a cage experiment. One region was significantly associated with antibiosis and explained 34.5% of the variation of the difference of egg and pupal counts in the RI population. The identification of genes for different mechanisms of midge resistance will be particularly useful for exploring new sources of midge resistance and for gene pyramiding of different mechanisms for increased security in sorghum breeding through marker-assisted selection.