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Gold nanoparticles (AuNPs) are by far the most studied nanomaterials by the scientific fraternity, possibly due to their immense potential in medical applications. Nevertheless, there is a disparity of opinion that prevailed concerning the toxicity of AuNPs. This study, therefore, presents a systematic review concerning toxicity related to AuNPs with the help of recently published databases. The disparity is due to the fact that the adoption of various protocols in the assessment of toxicity over the years that led to divergent views about the actual safety of AuNPs. This paper has considered a few recent research works and their databases to assess the toxicity of AuNPs in vivo and in vitro. Further, this paper also discussed the possible approaches that could effectively minimize the lethal effects of AuNPs and elaborated on the future scope of this interesting and highly useful research. For time being, it is concluded here that nanomaterial safety data are scarce, and it is not even an exaggeration to say that that is even scarcer than reported. [ABSTRACT FROM AUTHOR]

Mannose-specific Allium sativum leaf agglutinin encoding gene (ASAL) and herbicide tolerance gene (BAR) were introduced into an elite cotton inbred line (NC-601) employing Agrobacterium-mediated genetic transformation. Cotton transformants were produced from the phosphinothricin (PPT)-resistant shoots obtained after co-cultivation of mature embryos with the Agrobacterium strain EHA105 harbouring recombinant binary vector pCAMBIA3300-ASAL-BAR. PCR and Southern blot analysis confirmed the presence and stable integration of ASAL and BAR genes in various transformants of cotton. Basta leaf-dip assay, northern blot, western blot and ELISA analyses disclosed variable expression of BAR and ASAL transgenes in different transformants. Transgenes, ASAL and BAR, were stably inherited and showed co-segregation in T1 generation in a Mendelian fashion for both PPT tolerance and insect resistance. In planta insect bioassays on T2 and T3 homozygous ASAL-transgenic lines revealed potent entomotoxic effects of ASAL on jassid and whitefly insects, as evidenced by significant decreases in the survival, development and fecundity of the insects when compared to the untransformed controls. Furthermore, the transgenic cotton lines conferred higher levels of resistance (1-2 score) with minimal plant damage against these major sucking pests when bioassays were carried out employing standard screening techniques. The developed transgenics could serve as a potential genetic resource in recombination breeding aimed at improving the pest resistance of cotton. This study represents the first report of its kind dealing with the development of transgenic cotton resistant to two major sap-sucking insects.

The entire world is now agog with the novel coronavirus disease-2019 (COVID-19) chaos, as it has caused unexpected devastation in almost every country. As the resurgence of the COVID-19 is most certain in the coming two years (most probably during the winter season), extremely stringent methods have to be practiced to lower its spreading. The appropriate measures to be followed by wearing a mask (both infected as well as healthy population), adopting social distancing methods, regular medical checkups, and lowering of the grim emissions of toxins from heavy industries around the world, and other effective methods. This study has presented databases of COVID-19 (as of 25 May 2020), which revealed that most of the western countries are showing decreasing trends after being attained the maximum peak of the 'Gaussian shape'. In contrast, Asian countries (India, Indonesia, and Pakistan) show, alarmingly, increasing trends that imply great care has to be taken to fight against COVID-19. It is well known that nanomaterials have unique physical and chemical properties (ultra-small size, large surface-area-to-mass ratio, and high reactivity) that are different from bulk materials of the same composition. Therefore, this paper discusses the role of nanomaterials in identifying and offering protection against the virus. Also, it gives an insight into their use in the treatment to treat COVID infected patients. Furthermore, this paper also elaborated the challenges being faced while dealing with coronaviruses with a few feasible solutions to eradicate this untoward danger of the pandemic. A meaningful schematic on 'flattening of the curve' is included in this paper by considering several factors into account that may help to lessen or eradicate the present pandemic. [ABSTRACT FROM AUTHOR]

Field experiment on effectiveness of different biorational insecticides against mealybug (Maconellicoccus hirsutus Green) and spiralling whitefly (Aleurodicus disperses Russel) and their safety to natural enemies in guava were carried out at Experimental Farm, Division of Entomology and Nematology, IIHR, Bangalore, India during 2015-16. All the treatments were significantly superior over untreated check. Results indicated that the maximum reduction of mealybug population was recorded in the treatment of organic salt 30 WS @ 5 ml/l (2.32 mealy bugs/three shoots) followed by spinosad 45 SC @ 0.2 ml/l (2.45 mealy bugs/three shoots) after first and second spray respectively. Whereas less population of spiralling whitefly was recorded in spinosad treated plot (2.06 spiralling whiteflies/three leaves). Safety of natural enemy's concern dimethoate 30 EC @1.6 ml/l, azadirachtin 10000 ppm @1 ml/l and Neem soap @ 10 g/l were found to be more harmful to coccinellid beetles and recorded very less beetle population, while Organic salt 30 WS @ 4 ml/l, L. lecanii @ 2 g/l and spinosad 45 SC @ 0.2 ml/l were the safest chemicals. [ABSTRACT FROM AUTHOR]

Zeugodacus cucurbitae (Coquillett), is an important pest of several vegetable crops. Detection and monitoring of this pestiferous species rely heavily upon male lure or parapheromone cue lure. Consuming natural male lure compounds by males of tephritid fruit flies enables them to mate more successfully within their female choice mating systems. Here, we studied the olfactory behavioural response of mature male and female melon flies to body volatiles of cue lure fed and unfed mature male melon flies and protein fed immature male and female, protein unfed mature male and female melon flies body volatile. Olfactometer assay results revealed that female melon flies were highly attracted towards the cue lure fed male flies body volatile and male melon flies towards the cue lure unfed male flies body volatile. Our study also revealed the chemical composition of body volatiles collected from the aforesaid treatments and N-(3-Methylbutyl) acetamide was found to be abundant in the body volatile samples. [ABSTRACT FROM AUTHOR]

The study was conducted to identify the genetic marker for prolactin gene related to milk yield in pedigreed Sahiwal population. PCR-RFLP was carried out by using Rsa1 restriction endonuclease and revealed three genotypes GG, GA and AA in Sahiwal population. The frequency of G and A allele of Prolactin gene (exon 3) was estimated as 0.575 and 0.425, whereas the frequencies of GG, GA and AA genotypes for Prolactin gene (exon 3) were estimated as 0.45, 0.25 and 0.30, respectively. Regression analysis inferred that, SNP (G55A) of prolactin gene (exon 3) contributed to an increase in the average test day milk yield by 321.5g which was 3.92% of the average test day milk yield. Forty Sahiwal animals (20 families) under Daughter-Dam Design were screened and it was observed that one SNP (G55A) was found in all the nine families (45%) having heterozygous (GA) genotype. Thus, it could be considered as a potential genetic marker for high milk production in Sahiwal population. [ABSTRACT FROM AUTHOR]

Melon fruit flies are economically important pests of cucurbit vegetables. The development and survival of melon fly was compared at six constant temperatures ranging from 16 to 36 °C and two carbon dioxide levels (380 and 570 ppm) under laboratory conditions. Temperature below 20 °C and above 32 °C proved less favourable for growth and development of melon fruit fly. It exhibited normal growth and development at 24 °C. Temperatures above 24 °C caused mortality of 19.07 % and up to 100 % at 36 °C. But, levels of elevated carbon dioxide did not elicit varied response to growth and development in four generations studied and confirmed. [ABSTRACT FROM AUTHOR]

The impact of eight IPM modules on whitefly Bemisia tabaci and its natural enemies were recorded during kharif 2016 and 2017, rabi-summer 2016-17 and 2017-18. There was a significant difference among the modules in the number of natural enemies per plant. In general, it was found that during rabi-summer the population of B. tabaci was higher than the kharif season on bitter gourd. When modules were compared for the population of B. tabaci, module 1 to 4 (sowing maize as a barrier crop, removal of infested leaves and residues from the appearance of pests, erection of solar light trap with yellow pan @ 5 traps/ha for trapping, tying yellow sticky trap to attract whiteflies, spraying neem oil @ 1% and pongam oil @1%) and module 6 (spraying of Metarhizium anisopliae (2 x 109), Beauveria bassiana (2 x 108), Neem oil 1% and Pongam oil 1%) which do not include frequent insecticidal applications recorded higher number of coccinellids, syrphids, hymenopterans and spiders than the IPM modules where frequent applications of chemical insecticides were included as a treatment. [ABSTRACT FROM AUTHOR]

Field evaluation of eight IPM modules was done against whiteflies, Bemisia tabaci Genn. in bitter gourd during, kharif and rabi -summer 2016-17 and 2017-18 at ICAR-Indian Institute of Horticultural Research, Bengaluru, Karnataka. During kharif 2016-17, spraying diafenthiuron 50 WP @ 1g/L, triazophos 40 EC @1.5ml/l, buprofezin 25SC @ 0.25ml/l and imidacloprid 17.8 SL @ 0.5ml/lat 15days intervals proved effective with 78.09% control followed by module consisting of application of Neem oil @ 1%, Pongam oil @ 1%, M. anisopliae (2x109) @ 2ml/l and B. bassiana (2x108) @ 2ml/l at weekly intervals and spraying Neem oil @ 1%, Pongam oil @ 1% at weekly intervals. Spraying subsequently diafenthiuron 50 WP @ 1g/l and triazophos 40 EC @1.5ml/l both 15 days intervals, respectively. Sowing maize (barrier crop) + removal of infested leaves and residues from the field +erection of solar light traps @ 5 traps/ha for mass trapping +tying yellow sticky trap to attract whiteflies) were able to suppress 15.5% whiteflies. When the same IPM modules were evaluated during rabi-summer 2017-18, same trend prevailed. The above mentioned first module alone had a control of 80.69% whiteflies followed by other modules. Application of M. anisopliae (2x109), B. bassiana (2x108), Neem oil 1% and Pongam oil 1% at 10 days intervals gave the highest yield of 10.50 and followed by 10.39, 10.24 and 10.09 t/ha in other modules. The above module recorded higher benefit cost ratio (2.82). [ABSTRACT FROM AUTHOR]

Field experiments were conducted to evaluate the nine different Integrated Pest Management (IPM) modules including standard check and control against South American tomato moth, Tuta absoluta on cv. 'NS-501' of tomato. Module 7 (Pheromone traps @20/ha, Metarhizium anisopliae @3ml/L, Spinosad (45% SC) @0.2ml/L and Azadirachtin (1% EC) @ 2ml/L) followed standard check (Indoxacarb (14.5SC)@0.75ml/L, Flubendiamide (480SC) @0.2ml/L, Cyantraniliprole (10.26 OD)@0.3ml/L, Spinetoram (11.7 SC)@0.75ml/L) and Module 6 (Pheromone traps @20/ha, M. anisopliae @3ml/L, Azadirachtin (1% EC) @ 2ml/L and Spinosad (45% SC) @0.2ml/L) were found effective in reducing T. absoluta population. The highest yield (59.31 t) was obtained from Module 7 compared to farmer's practice i.e., standard check (52.92 t) and control (20.61 t). Highest Cost-Benefit ratio were obtained from Module 7 (1:3.25) compared to standard check (1:2.72) and control (1:1.47). [ABSTRACT FROM AUTHOR]

The genetics of fitness traits, viz. replacement rate (RR) and selective value (SV) were studied in the flock of Malpura Sheep along the production parameters of the animals. The study was carried out on 10 years records for 2307 lambing sired by 187 sires. Sire wise incidence of replacement traits was as follows: abnormal birth (0.30%), sex ratio (49.98%), mortality (17.26%), culling (15.37%), RR on total lamb basis (33.98%) and RR on female lamb basis (68.44%). The selective value or adaptive value for the flock was 1.37. Sire did not affect abnormal birth, mortality, culling and SV significantly, whereas sire significantly affected sex ratio, and RR on total female lambs born basis. Ranking of the sires for selective value was incoherent with the ranking for production parameters such as age at first service, age at first lambing, weight at first service, productive flock life and longevity. Study indicated that the selection of sires for SV would not bring desired correlated change on any of the production parameter of the animals. [ABSTRACT FROM AUTHOR]

Larvae of coconut moth, Batrachedra arenosella Walker (Lepidoptera: Batrachedridae) were found damaging premature nuts of coconut for the first time in India. The feeding resulted on an average of 20% loss of nuts in Mysore and Mandya districts of Karnataka, South India. The mean egg incubation period was 2.95 ± 0.55 days. Larval stage comprised four instars and the mean duration of first, second, third and fourth instar larvae were 2.55 ±2.50, 2.75 ± 0.35, 3.40 ± 0.57 and 4.10 ± 0.61 days, respectively. Total larval period varied from 11 to 14 days, with an average of 12.80 ± 1.01 days. Mean pupal period was 7.20 ± 0.86 days. The total developmental period occupied 22.95 ±1.17 days. Adult females lived longer (6.50 ± 1.20 days) than males (5.50 ± 0.78 days). The study indicated that B. arenosella has more than one generation a year. Short life cycle, presence of adults and larvae throughout the year in an overlapping manner and a perennial host characterizes B. arenosella to be an economically important pest. [ABSTRACT FROM AUTHOR]

Abiotic factors such as temperature and carbon dioxide (C2) influence the growth of crops and phytophagous insects, however, the effect of elevated temperature and C2 on Tuta absoluta is not well understood till date. T. absoluta have potential to cause 100% damage to the crop, if proper management practices are not followed. In the present study effect of elevated C2 (eC2) levels and temperature on T. absoluta revealed that temperature and eC2 (550 ppm) had a significant effect on the life stages. The incubation period of eggs was found significantly reduced with the increase in temperatures both in ambient (aC2) and elevated (eC2) conditions. The eC2 had a significant effect on the life table parameters up to 30°C. The duration of all larval stages of T. absoluta were decreased significantly with the increased temperatures. The pupal period decreased significantly with the increase in temperatures in both aC2 and eC2 conditions. An eC2 delayed the pupal period significantly compared to the aC2. The total pre-adult period was significantly longer in eC2 than the aC2 conditions and also, the pre-adult period decreased significantly with increase in temperatures. As eC2 increase the larval duration compared to aC2 condition, the larva will get more time to feed on foliage resulting in greater damage to the potato foliage. [ABSTRACT FROM AUTHOR]

Elucidation of genetic variation in geographical populations is an important aspect to study the pest populations and their management. Within an ecosystem, the extent of genetic variation between geographical populations depends on several factors, including gene flow between populations, host range, climatic factors etc. The genomic DNA was extracted from male flies of Bactrocera dorsalis (Hendel) collected fromdifferent agro ecological regions of Karnataka using modified 2% Cetyltrimethylammonium bromide (CTAB) method. 170 decamer primers, randomly selected from OPA - OPZ, OPAA - OPAX, OPBA-OPBD and OPYO series were screened and 51 primers which produced reproducible bands and were tested across the DNA samples. The RAPD-PCR of 31 DNA samples of B. dorsalis populations yielded 169 scorable bands. The per cent polymorphism varied from 33.33% to 100% and an average of 71.66 %. The Jaccard s similarity coefficients ranged from zero to 0.91. UPGMAdendrogram generated byRAPD data indicated the segregation of populations into three clusters. Genetic diversity plays an important role in the survival and adaptability of a species therefore B. dorsalis populations of different agro ecological regions have undergone changes probably to survive or the changes are consequent to interplay between genes and the environment in which they have adapted. [ABSTRACT FROM AUTHOR]

Elastomer blends based on fluorosilicone and silicone rubber have been investigated as a seal for aeronautical fuel system. Fluorosilicone seals are widely used as a prospective candidate in the aeronautical fuel system due to its notable resistance to aircraft turbine fuel (ATF) as well as its service in wide temperature applications. However, the FVMQ is relatively inferior in strength and high in cost compared to other ATF resistant elastomers. The drawbacks of FVMQ can be improved by blending with a High Consistent Rubber (HCR) such as vinyl methyl silicone (VMQ), which enhances the strength and reduces the cost. In the present work, an attempt has been made to study the properties and optimization of FVMQ-VMQ blend ratio by varying VMQ content. Blends were prepared in two-roll rubber mixing mill, cured and characterized for rheological, mechanical, physical, ageing and low temperature brittleness resistance. Furthermore, the effects of various aeronautical fluids such as ATF, lubricating and hydraulic oil on blends were also analysed. This paper reports the preface analysis of the properties of FVMQ-VMQ blend as a futuristic seal for the aeronautical fuel system. [ABSTRACT FROM AUTHOR]

Four bacterial and one yeast species, cultured and identified asStenotrophomonas maltophilia,Acinetobactersp.,Pseudomonassp. andOchrobactrumsp. and the yeast asMetschnikowia reukaufii, were isolated from the internal organs of four collections of field-sourced egg parasitoid,Trichogramma chilonis, obtained as parasitisedHelicoverpa armigeraeggs. Bacteria were identified through 16 rRNA amplification and sequencing. The single species of yeast was identified through internal transcribed spacer sequences. A single bacterial species could be isolated from each of the fourT. chiloniscollections; however, all fourT. chiloniscollections yielded the yeast,M. reukaufii. In order to study the influence of the association of each of the bacterial species and the yeast, microbe-free laboratory-bred populations ofT. chiloniswere fed with the individual cultures and fitness parameters as parasitisation vigour and female bias were studied inT. chilonisover 10 generations.T. chilonisfed with eitherS. maltophiliaorAcinetobactersp. andPseudomonassp. showed a mean percent increase in female ratio of 26.2%, 30% and 30.3% and mean percent parasitisation ofH. armigeraeggs significantly increased by 38%, 32.2% and 31.3%, respectively. However,T. chilonisfed withAcinetobactersp. did not positively influence the twoT. chilonisfitness factors. The ubiquitous yeast,M. reukaufii, which could be isolated from all four collections ofT. chilonis, could significantly increase both female count and percent parasitism ratio by 22% and 65%, respectively. This study has opened the possibility of modulating the parasitisation fitness of laboratory-bredT. chilonis, prior to field release, using microbes associated with them in the wild. [ABSTRACT FROM AUTHOR]

The occurrence of the South American tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is being reported for first time as an invasive pest on tomato and potato in India. T. absoluta was observed during regular surveillance on tomato at Indian Institute of Horticultural Research (IIHR) and adjoining farmers' fields in Bengaluru, Karnataka during November 2014 as a part of Real Time Pest Surveillance of Tomato (RTPST) of National Initiative on Climate Resilient Agriculture (NICRA) Project. Subsequent surveys revealed the presence of the pest in six districts of Karnataka State viz., Bengaluru Rural & Urban, Kolar, Chikkaballapur, Ramanagar and Tumkur. Incidence of the T. absoluta has also been recorded on potato. Larvae were generally found to feed on leaves, creating blotch-like mines visible from both sides of the leaf and several mines were observed on a single leaf. The larvae were also observed feeding on apical buds, stalks and boring the fruits. The affected fruits carried distinct holes mainly in the upper half towards fruit stalk and usually covered with faecal mass. The infestation of T. absoluta ranged from low to high (up to 15 mines/plant) in different tomato fields surveyed. In some of the fields up to 87% of the tomato plants were infested by T. abosoluta. A zoophytophagous mirid bug, Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) was recorded as predator on eggs and early larval stages of T. absoluta under field conditions. Hence, there is an urgent need to deploy suitable management practices to contain further spread of this potential pest. [ABSTRACT FROM AUTHOR]

Mannose-specific Allium sativum leaf agglutinin encoding gene (ASAL) and herbicide tolerance gene (BAR) were introduced into an elite cotton inbred line (NC-601) employing Agrobacterium-mediated genetic transformation. Cotton transformants were produced from the phosphinothricin (PPT)-resistant shoots obtained after co-cultivation of mature embryos with the Agrobacterium strain EHA105 harbouring recombinant binary vector pCAMBIA3300-ASAL-BAR. PCR and Southern blot analysis confirmed the presence and stable integration of ASAL and BAR genes in various transformants of cotton. Basta leaf-dip assay, northern blot, western blot and ELISA analyses disclosed variable expression of BAR and ASAL transgenes in different transformants. Transgenes, ASAL and BAR, were stably inherited and showed co-segregation in T1 generation in a Mendelian fashion for both PPT tolerance and insect resistance. In planta insect bioassays on T2 and T3 homozygous ASAL-transgenic lines revealed potent entomotoxic effects of ASAL on jassid and whitefly insects, as evidenced by significant decreases in the survival, development and fecundity of the insects when compared to the untransformed controls. Furthermore, the transgenic cotton lines conferred higher levels of resistance (1–2 score) with minimal plant damage against these major sucking pests when bioassays were carried out employing standard screening techniques. The developed transgenics could serve as a potential genetic resource in recombination breeding aimed at improving the pest resistance of cotton. This study represents the first report of its kind dealing with the development of transgenic cotton resistant to two major sap-sucking insects. [ABSTRACT FROM AUTHOR]

To evaluate the stain removal efficacy of a novel dentifrice containing papain and bromelain extracts (Glodent) in comparison with a control dentifrice (Colgate regular). This was a randomized, positive-controlled, doubleblinded, clinical study. Subjects were randomly divided into one of the two study groups. Pre-treatment and post treatment photographs of the 4 anterior teeth were recorded under standardized conditions and analyzed for lightness or luminosity values using Adobe Photoshop. The difference between the mean pre-treatment luminosity of test and control groups was not statistically significant. In both test and control groups, the post-treatment luminosity was significantly higher than pre- treatment luminosity (P < 0.001 and P = 0.003 respectively). The mean post-treatment luminosity for test group was found to be significantly higher than control group. The mean percentage removal of stains for test group was significantly higher than control group. The test dentifrice showed significant stain removal when compared to control which could be attributed to the role of proteolytic enzymes in the test dentifrice. [ABSTRACT FROM AUTHOR]

Palm squirrels, Funambulus palmarum, were believed and reported to inflict nut damage resulting in economic losses to coconut, Cocos nucifera, growers in South India. However, the current study, using field observations, pollination studies, gut content analyses, laboratory feeding tests, and exclusion experiments, established that Funambulus squirrels in cultivated coconut patches do not feed on nuts and hence do not generate economic losses. Squirrels cause male flower drop and feed on few male flowers without any negative impact on palm productivity or other aspects of the plantation ecosystem. Instead, squirrels pollinate (therophily) flowers, feed on insect pests, regulate vegetation at the microhabitat level as seed consumers and dispersers, and thus are an ecologically important component of cultivated coconut patches. Squirrels were found to be the most effective pollinators (85.70% nut formation in Arsikere and 94% at Madenur, Hassan). Fruit set was reduced by 19% when squirrels were prevented from pollinating coconut palms. Palm squirrel may also have myriad important roles to play in wild and cultivated patches in South India. Hence, the beneficial activities of F. palmarum must be sustained in cultivated coconut patches. [ABSTRACT FROM AUTHOR]

This paper presents results from gasoline- and diesel-powered hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs) that account for the interaction of drive cycle transients and engine start–stop events with after-treatment devices and their associated fuel penalties. These simulations were conducted using the Powertrain Systems Analysis Toolkit software combined with after-treatment component models developed at Oak Ridge National Laboratory. The present authors employed a three-way catalyst model for gasoline emissions control and a lean nitrogen oxide (NOx) trap model to simulate diesel exhaust NOx reduction. A previously reported methodology based on experimentally calibrated corrections to steady state maps was used to simulate engine-out emissions and thermal variations. As expected, the simulations indicate a higher baseline fuel efficiency for diesel-powered hybrid vehicles, but this advantage is reduced by about a third for both HEVs and PHEVs when the fuel penalty for the lean NOx trap is included. These preliminary studies demonstrate that existing engine and exhaust systems models can capture important features of the highly transient engine operation in hybrid vehicles and can provide useful comparisons between advanced hybrid vehicle engine options. [ABSTRACT FROM AUTHOR]

Many vehicle systems simulations utilize engine maps constructed from steady-state dynamometer measurements to estimate exhaust temperature and emissions as functions of engine speed and load. Unfortunately, steady-state engine behaviour is often significantly different from actual behaviour under transient driving conditions. This is particularly true for vehicles that undergo repeated engine shutdown and restart (e.g. electric hybrids). The authors propose a methodology for estimating transient engine exhaust properties and fuel economy based on corrections to steady-state maps. The suggested methodology has been implemented in the Powertrain Systems Analysis Toolkit (PSAT) and this implementation is used to demonstrate good agreement with experimental measurements for both a light-duty diesel and a flex-fuel gasoline/ethanol engine. Specific procedures are also recommended for setting key parameters required by the proposed methodology and possible directions for further improvements are suggested. [ABSTRACT FROM AUTHOR]

The midge Orseolia oryzae (Wood-Mason) (Diptera: Cecidomyiidae) is a major and endemic pest throughout Asia. The pest is difficult to manage in view of a mixture of biotypes co-occurring in the same location and showing variable response to cultivated rice, Oryza sativa L., varieties and differentials. To develop an understanding of the resistance mechanism(s), studies were initiated during wet 2005 and 2006 in Coastal Karnataka. Antibiosis was the predominant resistance category. The maggots survived but as first instar only on all the resistant genotypes. On susceptible genotypes, larvae reached second instar at 7 d after release, third instar at 14 d after release, and pupal stage at 18 d after adult release. However, in certain resistant genotypes, maggot mortality was evident in the absence of the susceptible plant silver shoot condition. In all resistant genotypes, distinct antibiosis was observed at 14 d after adult release. Antixenosis was evident in few genotypes. So, the midge resistance in rice is manifested as a mixture of antixenosis and antibiosis. Estimation of biochemical constituents in rice shoot apices of selected resistant genotypes revealed higher levels of total phenols and total free amino acids compared with susceptible genotypes. But, the amount of total sugars, reducing sugars, crude proteins, and amino acids were not related to resistance. Biochemical profiles in relation to midge infestation showed increased phenol and decreased proline and indole acetic acid content in the growing apical meristem of resistant genotypes compared with susceptible genotypes. [ABSTRACT FROM AUTHOR]