Pests In India Research Articles

Seasonal Patterns and Abiotic Influences on Fall Armyworm Dynamics in Chhattisgarh's Maize Agroecology

The fall armyworm Spodoptera frugiperda (J. E. Smith), an invasive pest in India, exhibits variations in population dynamics and incidence levels compared to its native regions. Understanding these variations is crucial for developing effective management strategies. Given India's diverse agroecosystems and climatic conditions, continuous watch on pest dynamics is essential. In this context a fixed plot experiment for comprehensive analysis of fall armyworm population dynamics, incidence patterns across seasons, and damage potentials in the maize crop ecosystem of the Chhattisgarh plains, India was conducted across three seasons of the year 2022-23. The year-round activity of the pest and its potential to cause huge losses in the early stages of maize was reported. Specifically, the study provided insights into the comparative incidence of fall armyworm in the different maize growing seasons of the area with a maximum incidence in the rainy season (0.58 larvae/plant) followed by winter (0.56 larvae/plant) and summer (0.53 larvae/plant) seasons. Moreover, the incidence trends of fall armyworm in different growing stages of maize were analysed by considering egg laying pattern, leaf damage, larval incidence and plant damage parameters, which highlighted the plant age-dependent response of fall armyworm. The impact of various weather parameters in shaping the damage and population fluctuations was analysed, where the influence of temperature was significant. Results obtained in this study are crucial in devising ETL levels and developing integrated pest management strategies against fall armyworm.

Decoding defenses: Biochemical insights into insecticide resistance in tea mosquito bug, Helopeltis theivora Waterhouse (Hemiptera: Miridae) from tea plantations of Eastern India

Helopeltis theivora is one of the major tea pests in India and the strategies of management largely depend on application of different insecticides. Resistance in ten field populations of H. theivora collected from different tea growing regions of Eastern India to three insecticides was evaluated by leaf dip method in the laboratory. The results showed varied levels of susceptibility in nine populations to thiamethoxam and deltamethrin with a resistance coefficient (RC) ranging from 2.04 to 30.95 and 1.56–59.81-fold, respectively. Upper Assam and Central Dooars populations showed high resistance to thiamethoxam and deltamethrin. A high resistance to deltamethrin was also recorded in the Eastern Dooars (RC = 52.74) and Western Dooars (RC = 53.07) populations. There was no resistance to quinalphos in any of the populations (RC = 0.11–0.60). The Darjeeling population was relatively susceptible to the insecticides. Biochemical enzyme assays suggested that glutathione S-transferases (GST), general esterase (GE) and cytochrome P450 (CYP) activities were high in most of the field populations as compared to the susceptible population. However, the expression of CYP was statistically at par between the Cachar, Tripura, Darjeeling and susceptible population. GST and GE activity displayed a strong significant correlation with LC50 values of thiamethoxam and deltamethrin while a moderate to strong linear relationship was recorded between CYP and the LC50s of thiamethoxam and deltamethrin, respectively. A weak positive correlation was established between LC50 of quinalphos and the enzymes. Synergistic assays reveal that the addition of synergists’ piperonyl butoxide and diethyl maleate with thiamethoxam and deltamethrin enhanced the toxicity of these insecticides. The results of this study will contribute to the insecticide resistance management and integrated management of H. theivora.

Management of Fruit and Shoot Borer, Leucinodes orbonalis (Guenee) in Brinjal through Sequential Application of Selected Insecticides and Biorationals

Leucinodes orbonalis Guenee (Lepidoptera: Crambidae), commonly known as brinjal shoot and fruit borer is a dreaded pest in India. The bio efficacy of insecticides and biorationals has been test verified in managing fruit and shoot borer through logical sequential schedules. The results of the present field experiment conducted during Summer 2023 in Agricultural and Horticultural research Station (AHRS), Bavikere revealed the most effective insecticidal schedule among the tested sequences. The sequence containing Chlorantraniliprole 18.5 SC @ 0.3 ml/L - Spinosad 45 SC @ 0.4 ml/L - Lufenuron 5 EC @ 1.0 ml/L - Bacillus thuringiensis var. kurstaki @ 2.0 g/L demonstrated remarkable success in reducing the damage caused by L. orbonalis along with economic viability and high cost-benefit ratio.

The Striped Flea Beetle <i>Phyllotreta striolata</i> (Illiger) (Coleoptera: Chrysomelidae) Invades South India

The striped flea beetle Phyllotreta striolata (Illiger) (Coleoptera, Chrysomelidae, Galerucinae, Alticini) has been reported for the first time from south India. Heavy incidence of P. striolata on Raphanus sativus, causing 84.6 – 92.6% and 74 – 96.6% root damage in Krishnagiri (Tamil Nadu) and Kolar (Karnataka) respectively, was observed. Information on the distribution of the pest in India is provided. New state records in India include Tamil Nadu, Karnataka, Odisha, Madhya Pradesh and Uttar Pradesh.

Effect of Different Host Plants on Biology of Tobacco Caterpillar, Spodoptera litura (Fabricius)

The tobacco caterpillar, Spodoptera litura (Fabricius) is present as an economically important and regular polyphagous pests in India and other countries. The knowledge of biology and ecology of an insect pests is a prerequisite for its management. An experiment was conducted on biology of Spodoptera litura (Fabricius) on different host plants in laboratory of the Department of Entomology, Rajasthan College of Agriculture, Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan. The results revealed that the minimum and maximum incubation period of S. litura was 2.98 and 3.30 days recorded on castor and cauliflower, respectively. The minimum larval and pre pupal period was 12.96 and 1.00 days recorded on castor. The minimum and maximum pupal period were recorded on cotton (8.27 days) and cauliflower (6.44 days), respectively. The adult male and female moth survival maximum larvae reared on cauliflower 5.00 and 6.90 days whereas minimum on castor 3.95 and 6.00 days, respectively. The maximum percent adult emergence was recorded larvae reared on castor (87.50%) followed by cauliflower (85.00%) whereas minimum on cotton (67.50%). The maximum fecundity was recorded on castor (886.25) followed by soybean (870.00). The entire minimum life cycle was recorded on castor (29.05 days) whereas maximum on cotton (36.50days) followed by soybean (34.24 days). It was concluded that castor is best host plant for S. litura.

Scenario of climate change impact on insect pests in India

The climate change has been intensified the risk of climate dependent crop production. Increase in temperature can reduce crop duration, increase crop respiration rates, alter photosynthesis process and affect the survival and proliferation of pest populations. The importance of climate and weather events to the distribution of insects and their population dynamics has long been recognized. Insects are poikilothermic in nature and are directly under the control of temperature for their growth. The duration of insect life cycle is altered under increased temperature and elevated carbon dioxide concentrations resulting in variable number of generations per year. The elevated carbon dioxide concentrations are mediated through enhanced photosynthesis in plants for phytophagous insects’ growth and development. Several insect pests, that were important in the past or the minor pests are likely to become more devastating with global warming and climate change. Insect pests cause an estimated annual loss of 13.6% globally and 23.3% in India. Losses due to insect pests are likely to increase as a result of change in crop diversity and climate change. An increase of 0.4ºC average surface temperature over past century in India has led to crop insect pests losses increase from 3.0% during the pre-green revolution period to 50% during the post-green revolution period. The changes of insect pests losses has been increased up to 32%. Considerable knowledge is available on the effects of weather and climatic events on insect pests in India. But concerned to the impact of climate change on insect pests studies are in lag phase. A major portion of the cultivated areas of India covered under rainfed. The rainfed agriculture is directly reciprocal to the climate. So, any changes in the state of climate may cause crop failure due to biotic and abiotic stresses of climatic vagaries. Therefore, detailed study of the climate change scenario, its impact on insect pest management and formulation of coping strategies are of paramount importance to reduce the risk of crop failure. This paper attempt to analyse the review of reported studies on the scenario of climate change impact on insect pests in India to reduce the risk of strategy for effective insect pest management.

Toxicity and resistance levels of phosphine against Tribolium castaneum (Herbst) and Sitophilus oryzae (L.) populations

The most destructive stored grain pests in India are the rust red flour beetle and the rice weevil. The most common method for controlling these two pests in storage is phosphine fumigation. However, frequent and acute or chronic doses of exposure than the recommended doses lead to the development of genetic and morphological resistance by changing their traits towards phosphine.Our recent study aimed to detect phosphine resistance degreesin T. castaneum and S. oryzae populations from twelve locations in Odisha. According to bioassay analysis, for S. oryzae after 24 hrs exposure period forphosphine gas to all the assessed populations, the LC50 value varied from 0.004 mg/l to 0.038 mg/l and the population of one location i.e., Chhata (Kendrapara) was found to have strong resistance to phosphine with 9.50 fold more resistant in comparison with the laboratory population. The phosphine toxicity levels for T. castaneum ranged from the LC50 values of 0.130 mg/l (Kendupali, Barghar) to 0.011 mg/l (Durgapali, Sambalpur), i.e., they were 13.00 and 1.10 times more resistant than the laboratory-susceptible population. It is possible that increasing resistance levels is due to storage structures are not tightly sealed during fumigation leading to sub-lethal phosphine concentration and lack of knowledge about fumigation procedures.

Studies on the relationship of weather on Fall armyworm damage in maize (Zea mays L.) under different growing environments

Fall armyworm is a recently occurring invasive pest in India, the most important defoliator causing drastic damage to maize production. Hence, the present study aimed to understand the temporal infestation level of Fall armyworms on maize (Zea mays L.) with weather patterns. Field experiments were conducted during Summer (February-May) and Rainy seasons, 2022 (August-December) at Agro Climate Research Centre, Tamil Nadu Agricultural University, Coimbatore. Three different growing environments (GE1, GE2 and GE3) were created by providing staggered sowing. Regression models were developed for per cent leaf damage against three-days lagged (LT3) and seven-day lagged (LT7) weather variables. Results showed that irrespective of growing environments, weather variables showed negative correlation (Tmax: r = -0.57, -0.81*, -0.31; SSH: -0.30, -0.48, -0.39; Tmean: -0.49, -0.23, -0.30; and SR: -0.48, -0.94*, -0.40) during summer season whereas same variables (i.e Tmax =0.62*, 0.41, 0.33; SSH = 0.09, 0.68*, 0.24; Tmean = 0.29, 0.32, 0.44; and SR=0.13, 0 .67*, 0.26 ) showed a positive correlation with PLD. Rainfall exhibits positive relation (0.06, 0.54, 0.53) and negative correlation (-0.64*, -0.10, -0.02) during summer and rainy season, respectively. Among the regression models, LT7 model had higher R2 (0.65 and 0.76) than LT3 (0.57 and 0.68) during summer and rainy seasons, respectively. These models had good regression values of 0.56 and 0.70 during Rainy and Summer, respectively. It was concluded that Tmax (32.9 °C), Tmin (23.7 °C), Tmean (28.3 °C), RH-I (85.6%), RH-II (56.4%), SSH (4.1), SR (274.6 cal cm-2 m-2), afternoon cloud cover (4.8 okta) and weekly total rainfall (10.2 mm) were very conducive for the greater leaf damage.

Predicting the potential geographical distribution of onion thrips, Thrips tabaci in India based on climate change projections using MaxEnt

Onion thrips, Thrips tabaci Lindeman, an economically important onion pest in India, poses a severe threat to the domestic and export supply of onions. Therefore, it is important to study the distribution of this pest in order to assess the possible crop loss, which it may inflict if not managed in time. In this study, MaxEnt was used to analyze the potential distribution of T. tabaci in India and predict the changes in the suitable areas for onion thrips under two scenarios, SSP126 and SSP585. The area under the receiver operating characteristic curve values of 0.993 and 0.989 for training and testing demonstrated excellent model accuracy. The true skill statistic value of 0.944 and 0.921, and the continuous Boyce index of 0.964 and 0.889 for training and testing, also showed higher model accuracy. Annual Mean Temperature (bio1), Annual Precipitation (bio12) and Precipitation Seasonality (bio15) are the main variables that determined the potential distribution of T. tabaci, with the suitable range of 22–28 °C; 300–1000 mm and 70–160, respectively. T. tabaci is distributed mainly in India's central and southern states, with 1.17 × 106 km2, covering 36.4% of land area under the current scenario. Multimodal ensembles show that under a low emission scenario (SSP126), low, moderate and optimum suitable areas of T. tabaci is likely to increase, while highly suitable areas would decrease by 17.4% in 2050 20.9% in 2070. Whereas, under the high emission scenario (SSP585), the high suitability is likely to contract by 24.2% and 51.7% for 2050 and 2070, respectively. According to the prediction of the BCC-CSM2-MR, CanESM5, CNRM-CM6-1 and MIROC6 model, the highly suitable area for T. tabaci would likely contract under both SSP126 and SSP585. This study detailed the potential future habitable area for T. tabaci in India, which could help monitor and devise efficient management strategies for this destructive pest.

Resistance Evaluation for Native Potato Accessions against Late Blight Disease and Potato Cyst Nematodes by Molecular Markers and Phenotypic Screening in India.

The potato originated in southern Peru and north-western Bolivia (South America). However, native accessions have also been cultivated in India for many years. Late blight, caused by the fungus Phytophthora infestans, is the most devastating potato disease, while potato cyst nematode (Globodera spp.) (PCN) is another economically significant quarantine-requiring pest in India. In this study, we have generated a new Indian native collection of 94 potato accessions collected from different parts India. These accessions were screened against late blight and potato cyst nematode resistance by using gene-based molecular markers and phenotypic screening methods. Marker assisted selection using R1 gene-specific marker CosA210 revealed a late blight resistance gene in 11 accessions. PCN resistance bands were found in 3 accessions with marker TG689141, 5 accessions with marker 57R452, and 1 accession having Gro1-4-1602 marker for G. rostochiensis (Ro1,4), while 64 accessions amplified marker HC276 indicating G. pallida (Pa2,3) resistance gene (GpaVvrn QTL). On the other hand, phenotypic screening against late blight resistance under natural epiphytic conditions (hot-spot) revealed three accessions with high resistance, while others were resistant (1 accession), moderately resistant (5 accessions), susceptible (29 accessions), and highly susceptible (56 accessions). For G. rostochiensis (golden cyst nematode) and G. pallida (white cyst nematode) resistance, accessions were grouped into highly resistant (3, 3), resistant (0, 2), moderately resistant (6, 29), susceptible (32, 30), and highly susceptible (53, 30), respectively, for the two PCN species. Collectively, we identified promising accessions with high resistance to late blight (JG-1, Kanpuria Safed, and Rangpuria), and also highly resistant to both Globodera species (Garlentic, Jeevan Jyoti, and JG-1). Our findings suggested that these accessions would be useful for late blight and PCN resistance breeding, as well as future molecular studies in potatoes.

A peculiar case of parasitisation with two new species of wasps parasitizing the rice leaf-roller Pelopidas mathias (Fabricius, 1798) (Lepidoptera: Hesperiidae) from southern India.

Paddy, Oryza sativa L. (Poales: Poaecea) is infested by a series of lepidopteran, coleopteran, hemipteran, and acarine pests in India. Of the long list, the species Rice Leaf-Roller Pelopidas mathias (Fabricius, 1798) (Lepidoptera: Hesperiidae) is one of most encountered defoliators on paddy. Here we record and describe with illustrations, a new parasitic complex comprising of two new species of parasitic wasps, viz. Brachymeria eastwoodi Binoy, sp. nov. and Sympiesis eastwoodi James & Santhosh, sp. nov. on the pupae of P. mathias from southern India. The parasitoid complexes on P. mathias are also augmented.

Unfolding the mitochondrial genome structure of green semilooper (Chrysodeixis acuta Walker): An emerging pest of onion (Allium cepa L.).

Onion is the most important crop challenged by a diverse group of insect pests in the agricultural ecosystem. The green semilooper (Chrysodeixis acuta Walker), a widespread tomato and soybean pest, has lately been described as an emergent onion crop pest in India. C. acuta whole mitochondrial genome was sequenced in this work. The circular genome of C. acuta measured 15,743 base pairs (bp) in length. Thirteen protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and one control region were found in the 37 sequence elements. With an average 395 bp gene length, the maximum and minimum gene length observed was 1749 bp and 63 bp of nad5 and trnR, respectively. Nine of the thirteen PCGs have (ATN) as a stop codon, while the other four have a single (T) as a stop codon. Except for trnS1, all of the tRNAs were capable of producing a conventional clover leaf structure. Conserved ATAGA motif sequences and poly-T stretch were identified at the start of the control region. Six overlapping areas and 18 intergenic spacer regions were found, with sizes ranged from 1 to 20 bp and 1 to 111 bp correspondingly. Phylogenetically, C. acuta belongs to the Plusiinae subfamily of the Noctuidae superfamily, and is closely linked to Trichoplusia ni species from the same subfamily. In the present study, the emerging onion pest C. acuta has its complete mitochondrial genome sequenced for the first time.

Genome Organization and Comparative Evolutionary Mitochondriomics of Brown Planthopper, Nilaparvata lugens Biotype 4 Using Next Generation Sequencing (NGS).

Nilaparvata lugens is the main rice pest in India. Until now, the Indian N. lugens mitochondrial genome has not been sequenced, which is a very important basis for population genetics and phylogenetic evolution studies. An attempt was made to sequence two examples of the whole mitochondrial genome of N. lugens biotype 4 from the Indian population for the first time. The mitogenomes of N. lugens are 16,072 and 16,081 bp long with 77.50% and 77.45% A + T contents, respectively, for both of the samples. The mitochondrial genome of N. lugens contains 37 genes, including 13 protein-coding genes (PCGs) (cox1-3, atp6, atp8, nad1-6, nad4l, and cob), 22 transfer RNA genes, and two ribosomal RNA (rrnS and rrnL) subunits genes, which are typical of metazoan mitogenomes. However, both samples of N. lugens mitogenome in the present study retained one extra copy of the trnC gene. Additionally, we also found 93 bp lengths for the atp8 gene in both of the samples, which were 60–70 bp less than that of the other sequenced mitogenomes of hemipteran insects. The phylogenetic analysis of the 19 delphacids mitogenome dataset yielded two identical topologies when rooted with Ugyops sp. in one clade, and the remaining species formed another clade with P. maidis and M. muiri being sisters to the remaining species. Further, the genus Nilaparvata formed a separate subclade with the other genera (Sogatella, Laodelphax, Changeondelphax, and Unkanodes) of Delphacidae. Additionally, the relationship among the biotypes of N. lugens was recovered as the present study samples (biotype-4) were separated from the three biotypes reported earlier. The present study provides the reference mitogenome for N. lugens biotype 4 that may be utilized for biotype differentiation and molecular-aspect-based future studies of N. lugens.

Bionomics of Fall Army Worm Spodoptera frugiperda (J. E. Smith) on Maize

The fall army worm Spodoptera frugiperda (J E Smith) is an invasive pest in India on maize crop, andnoticed to be polyphagous. Its biology was studied under laboratory conditions at the Department ofAgricultural Entomology, College of Agriculture, GKVK, Bengaluru, Karnataka, India. The incubation,total larval and pupal period were observed to be of 2.80, 15.70 and 10.04 days, respectively. The totallifecycle of male and female took 35.05 and 38.30 days, respectively. Preoviposition, oviposition and postoviposition period were 2.95, 3.10 and 4.50 days, respectively.

Foldscope: Increasing Science Accessibility Worldwide

Abstract:Foldscope Instruments, Inc. creates and distributes low-cost, high-quality scientific tools to communities around the world to help advance education, research, and medical diagnostics. The Foldscope—a high-quality microscope created for less than a dollar in parts—was created in 2015. To date, the Foldscope has reached 1.6 million people worldwide in over 160 countries. A few notable uses for the Foldscope include identification of microscopic eggs of agricultural pests in India, creation of a catalog of the biodiversity of soil arthropods in the Amazon, detection of fake currency and medicine, following toxic blooms, detection of bacteria in water samples, and mapping of pollen diversity in a city landscape.

Mapping potential geographical distribution of Acria meyricki (Lepidoptera: Depressariidae), an emerging oil palm defoliator in India

Ecological niche modelling study was attempted to identify climate suitable locations for Acria meyricki Shashank and Ramamurthy spread in India as area under oil palm cultivation is expanding. Geographical coordinates of 31 pest presence sites, world climate grid files, nineteen bioclimatic variables, MaxEnt software, DIVA-GIS were used for the construction of ecological niche model of A. meyricki. The model indicated potential geographical locations (districts) in six states viz., Andhra Pradesh, Gujarat, Karnataka, Maharashtra, Odisha, Tamil Nadu for the spread of pest in India. The predictions of potential distribution of the pest arrived at in this study should help in developing strategies for monitoring and managing this defoliator of oil palm.

Pear production trends and characteristics of important pests in India

Pear is one of the most important commercial crops of India. It is grown in northwestern states and hills of the country. India is the 9th largest pear producer in the world. Its cultivation area increased from about 19000 ha in 1991 to 42000 ha in 2019, with 2.2 times of increase over 28 years. In India, pears cultivated from foothills to high hills experience about five hundred to thousand five hundred chilling hours throughout the year. In India, pear occupies the third place for temperate fruits by area of cultivation and production quantity. The area with pear cultivated is steadily increasing in India. It is mainly grown in northern states of Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Punjab, and in south India (Tamilnadu state). The region of north-eastern hills, comprising of states of Arunachal Pradesh, Nagaland, Mizoram, Meghalaya, and Sikkim, also grows pear on a limited scale. Although northwestern and eastern hills of India provide a favorable climatic condition for growing a wide range of pears, cultivation and production of pears remain challenging due to pests and diseases. In this article, we discussed the current status of pear production and major common insects and pests in pear-growing regions of India.

Mushroom Phorid Flies—A Review

Diptera are among the most serious arthropod pests affecting mushroom crops. Phorid flies, especially Megaselia halterata, have traditionally been globally considered as a minor pest, although they are a very important problem on Spanish mushroom farms. The concerns with respect to the phorid fly populations have recently increased, notably jumping from being a minor to major pest in India, UK and the USA, where yield losses ranging between 10% and 40% were reported. This review updates and summarizes the available literature regarding mushroom phorid populations, stressing the natural distribution of phorids and their seasonal distribution, their biology within the growing substrates and the initial sources of infestation on mushroom farms. Moreover, the review also highlights the scarce available tools for their control and the current alternatives to chemical products.

Two new species of wasps parasitizing the rare gelechid defoliator Coconympha iriarcha Meyrick (Lepidoptera: Gelechiidae) on Cocos nucifera Linnaeus from India

The coconut palm, Cocos nucifera L. (Arecales: Arecaceae), is infested by a series of lepidopteran, coleopteran, hemipteran, and acarine pests in India. Of the long list, the species Coconympha iriarcha Meyrick 1931 (Lepidoptera: Gelechiidae) is one of the least encountered defoliators on coconut. Here we record and describe with illustrations, two new species of parasitic wasps, viz. Pediobius coconymphagus Binoy & Sureshan, sp. nov. and Goniozus coconymphagus Santhosh sp. nov., attacking the pupae and larvae of C. iriarcha from India.

Involvement of small heat shock proteins (sHsps) in developmental stages of fall armyworm, Spodoptera frugiperda and its expression pattern under abiotic stress condition

Fall armyworm (FAW), Spodoptera frugiperda a recent invasive pest in India is reported to cause significant damage by feeding voraciously on maize and other economic crops from tropical to temperate provinces. It is becoming an arduous challenge to control the pest as it can survive in a wide range of temperature conditions and is already said to develop resistance towards certain insecticides. The small Heat shock proteins (hereafter, sHsps) are known to play an important role in adaptation of insects under such stress conditions. Our present study involved characterization of the three sHsps genes (sHsp19.74, sHsp20.7 and sHsp19.07) which encoded proteins of about 175, 176 and 165 amino acids with a conserved α-crystalline domain. Phylogenetic analysis of deduced amino acid sequences of the three genes showed strong similarity with the other lepidopteran sHsps. The effect of different growth stages on the expression profile of these stress proteins has also been studied and the Quantitative real time PCR (qRT-PCR) analysis revealed that the transcript level of sHsp19.07 and sHsp20.7 were significantly upregulated under extreme heat (44 °C) and cold (5 °C) stress. However, sHsp19.74 responded only to heat treatment but not to the cold treatment. In addition, the expression profile of all three sHsps was significantly lower in the larval stage (5th instar). Chlorantraniliprole treatment resulted in maximum expression of sHsp19.07 and sHsp20.7 after 12hr of exposure to the insecticide. Meanwhile, the same expression was observed after 8hr of exposure in case of sHsp19.74. These results proved that the sHsp genes of S. frugiperda were induced and modulated in response to abiotic stress, thus influencing the physiological function leading to survival of FAW in diversified climate in India.