Millardia Meltada Research Articles

Rodent communities in a neglected grassland landscape: Investigating species-specific responses of grassland rodents to habitat type and shrub presence

Arid grasslands worldwide are transitioning to scrublands due to shrub encroachment, resulting in habitats with varying shrub cover. Shrubs play a crucial role in grassland ecosystems, offering trade-offs to rodents in terms of visibility, shelter, and food availability, thereby affecting their occurrence and distribution. This study explores the link between habitat characteristics and rodent activity and density, focusing on shrub presence. In the Tirunelveli district of southern India, we measured rodent density and activity across three grassland types with increasing shrub presence. Our findings reveal species-specific responses to shrub density. The Soft-furred rat (Millardia meltada) dominated, showing adaptability to different shrub levels, while the black rat (Rattus Rattus) was least represented. Fine-scale analysis indicates a positive association between shrub presence and rodent captures. Grassland obligate species like the Indian gerbil (Tatera indica) exhibited reduced activity in densely shrubbed sites, whereas semi-arboreal species like the Indian palm squirrel (Funumbulus palmarum) showed increased activity. This study underscores the importance of considering habitat structure in grassland ecosystem management for the conservation of rodent diversity and ecosystem health.

Field efficacy of reduced active ingredient zinc phosphide formulation against rodents

A formulation of zinc phosphide with reduced active ingredient (40% concentrate) was evaluated for its rodenticidal activity in wheat, rice and sugarcane crops at farmer fields of Punjab, India. Comparison was made with the existing formulation (80% concentrate) and second generation anticoagulant bromadiolone (0.25% concentrate). Cereal based baits containing different doses of new (1.5, 2.0 and 2.5%) and existing zinc phosphide (2%) and bromadiolone (0.005%) were applied through burrow baiting where Bandicota bengalensis, Mus booduga, Millardia meltada and Tatera indica were the predominant rodents. The reduction in rodent activity was determined based on pre- and post-treatment bait census. Results revealed that 2% and 2.5% bait formulations of new zinc phosphide are as effective as the existing/ recommended zinc phosphide (2%) and bromadiolone (0.005%) bait formulations.

Differential Responses of Small Mammals to Woody Encroachment in a Semi-Arid Grassland

Encroachment by woody invasive plants is a major threat to grasslands and savannah ecosystems worldwide. Rodents, being primary consumers, are likely to be the first to respond to changes in the structure and composition of native vegetation. We examined the effect of an invasive shrub Prosopis juliflora (hereafter Prosopis) on the native rodent community of an arid grassland system of Western India. Our sampling plots were divided into five categories representing different stages of Prosopis invasion and other land cover types. These consisted of restored native grassland, agriculture fallow, open brushland, sparse-Prosopis plots, and Prosopis-dominated plots. We also examined the impact of woody invasion on the response of native rodents toward moonlight and temperature. As hypothesized, we found a significantly higher abundance of rodent species in the native grassland habitat compared to sparse-Prosopis habitats. However, there was no significant difference in rodent abundance and diversity between the grassland and Prosopis-dominated habitats. Thus, species richness and abundance of rodents were the highest in the restored grasslands and dense Prosopis thickets, and the lowest in the sparse Prosopis, potentially showing a “U” shaped response to Prosopis invasion. We observed a species-specific effect of Prosopis on the activity of Tatera indica, Bandicota bengalensis, and Millardia meltada. Habitat type mediated the effect of different environmental factors (moonlight and temperature) on the activity of the most commonly ocurring species T. indica while activity of M. meltada showed a weak association with environmental factors. B. bengalensis was the most generalist species showing similar activity across all habitat types. Thus, the impact of Prosopis invasion on the rodent community was uneven, and depended on species as well as on local environmental characteristics.

Histomorphological perspectives of preputial and clitoral glands of soft-furred field rat Millardia meltada

The present study was an attempt to understand the sexual dimor-phism of the integumentary scent glands of soft-furred field rat Millardia meltada from the perspectives of anatomy, morphology and histology with view to correlate with the sex-specific pheromones they produce. The scent gland of male is known as preputial gland, and female, the clitoral gland. The rats, that are agricultural pests were field caught, the glands of males and females of almost identical size were dissected out, and subjected to gravimetric, morphometric and histological analyses. Both glands are yellowish-brown, pear-shaped, and dorsoventrally compressed. The mean weight, length and width of preputial glands are significantly (p < 0.05) larger than that of the clitoral glands. The preputial gland is composed of sebaceous glandular lobules and apocrine glandular lobules whereas the clitoral gland is formed only of sebaceous glandular lobules. The sebaceous glandular lobules of both preputial and clitoral glands are filled with a wax-like material. Thus, the scent glands of the soft-furred male field rats exhibit sexual dimorphism in respect histoarchitecture of the glands and the nature of the secretory material. This sexual dimorphism of the scent glands may reflect control by male and female sex hormones impinging on specific roles as sex attractant pheromones.

Morphology, Histopathology and Hematology as Biomarkers of Cadmium Toxicity in Field Rats

Background: Cadmium is known as a unique heavy metal compared to others, due to its long half-life, low discharge from the body, toxicity at low concentrations and accumulation in tissues. Methods: The effects of chronic and acute Cadmium (Cd) exposure were investigated on the morphology and histopathology of 24 field rats (Millardia meltada). The rats were divided into two groups of 12 each, then sub-divided into: one control and two treatment sub-groups with Cd in the feed or water. The treatment subgroups received either 15mg/kg (low) or 30mg/kg (high) Cd concentration in the feed. Results: Hemorrhagic spots and fibrosis were observed in the liver of Cd treated rats compared to the controls. Also, necrosis, dilation, and calcinosis occurred in the renal tubules of the treatment groups compared to the controls. The levels of hemoglobin, red and white blood cells, hematocrit, and mean corpuscular hemoglobin were reduced, while mean corpuscular volume and hemoglobin concentrations were increased. Conclusion: This study reports the morphological, pathological and hematological abnormalities in the blood, liver and kidneys of rats due to Cd toxicity, which may be considered as the biomarkers of cadmium toxicity in other experimental mammals.

Assessing the status of critically endangered Kondana soft-furred rat (Millardia kondana) using integrative taxonomy: combining evidence from morphological, molecular and environmental niche modeling

Abstract Kondana soft-furred rat is a critically endangered (CR) species, known from a single locality – Sinhgad in the northern Western Ghats, India. However, the taxonomic status of this species is uncertain due to its close resemblance to the widely distributed soft-furred field rat Millardia meltada, which has serious implications on the conservation status of Millardia kondana. In this study, we assessed the current taxonomic status of M. kondana through an integrative approach combining morphological, molecular and environmental niche modeling analyses. We collected morphological data from the specimens around Sinhgad as well as preserved specimens in the museum. Both morphological and two-dimensional (2D) morphometrical analyses showed a significant difference between M. kondana and M. meltada. Molecular phylogeny based on cytochrome b gene revealed a sister relationship between M. kondana and M. meltada, and both species form distinct well-supported monophyletic clades. Niche modeling also predicted niche segregation between the two species: M. kondana preferred areas with a high elevation and precipitation seasonality while M. meltada favored regions with a low elevation and precipitation. We confirmed that M. kondana is taxonomically distinct from M. meltada, and based on our estimates of its occurrence and occupancy, M. kondana continues to be treated as CR until further detailed investigations.

Adoption of rodent pest management strategies by farmers of district Ludhiana, Punjab

The present study was conducted to assess adoption of rodent pest management strategies by farmers in District Ludhiana, Punjab during the year 2017-18. Farmers belonging to three villages, namely Barewaal Dogra (maintenance area), Kutbewaal Gujran (neglected area) and Ladiyan Kalan (survey area) having land holding ranging from 2.0-32.0 acres were selected. The pre-dominant rodent pest species in area under study was Bandicota bengalensis followed by Tatera indica, Millardia meltada and Mus boodguga. Education and training was provided to farmers belonging to maintenance and neglected villages whereas free rodenticide baits were distributed among farmers of maintenance village only. In survey village, no such activity was performed and kept as reference area. KAP survey (Knowledge Aptitude and Practice) of farmers before imparting education during paddy crop period revealed similar rodent control practices being used by farmers in all the three selected villages. Subsequent KAP survey during wheat crop period for impact assessment revealed the sustainability of education and training already imparted during paddy crop period. About 41-92% increase in farmers observing recommended rodent control practices during crop production was noticed. So timely education and free rodenticide bait distribution are important factors responsible for adoption and sustainability of rodent control strategies by the farmers. Farmer can save food grains (33.09 kg paddy/acre and 36.39 kg wheat/acre) with an economic benefit (Rs. 500.09-575.66/acre) and cost: benefit ratio of 1: 36 to 1: 39 by using education, training and free rodenticides which will help in food security.

Food composition of Indian Eagle Owl Bubo bengalensis Franklin (Aves: Strigiformes: Strigidae) from Tiruchirappalli District, Tamil Nadu, India

The diet of the Indian Eagle Owl was studied from April to September 2017 in Tiruchirapalli District, Tamil Nadu, India. Analysis of 1082 regurgitated pellets yielded 2077 prey items; the mean prey items/ pellet was 1.91. The diet constituted 65.1% of rodent prey and the remaining 34.83% of other groups of both vertebrate and invertebrate animals. The mean percentage of prey composition was 31.15% Millardia meltada Soft-furred Field Rat, 12.95% Bandicota bengalensis Lesser Bandicoot Rat, 10.25% Mus booduga Indian Field Mouse, and 10.24% of other rodent species. Of the 34.83% of non-rodent prey, the owls ingested insects (Rhinoceros beetles, 9.58%), Arachnida (Solifugae or Sun spider, Galeodes sp., 9.58%), reptiles (Calotes sp., 3.7%), amphibians (3.56%), shrews (Suncus murinus, 2.84%), and others (5.57%). The Indian Eagle Owls consumed more than one prey per day and chiefly foraged in agricultural crop fields and consumed both small mammals and insects of agricultural importance under crop ecosystems.

Localization of α 2u-globulin in the acinar cells of preputial gland, and confirmation of its binding with farnesol, a putative pheromone, in field rat (Millardia meltada).

Pheromones, low molecular weight chemical entities that bind to pheromone carrier proteins, are chemical signals that play an important role in the communication system in animals. This has been rather fairly well-studied in the rodents. The preputial gland, a rich source of pheromones in many rodents, contains a low molecular mass protein (18–20 kDa) that acts as one such pheromone carrier. However, the presence of this protein in the notorious rodent pest Millardia meltada has not yet been proven. Therefore, we aimed at identifying this protein, and the pheromones that are bound to it, in this rodent so as to utilize the information in the control of this pest. Twenty volatile compounds were identified in the preputial gland using GC-MS. Total protein of the gland was fractioned by both one and two-dimensional electrophoresis when we identified a low molecular mass protein (19 kDa, pI-4.7). Adopting MALDI-TOF MS and LC-MS analyses, the protein was confirmed as α 2u-globulin. To identify the volatiles bound to this protein, we used column chromatography and GC-MS. We found that farnesol and 6-methyl-1-heptanol are the volatiles that would bind to the protein, which we propose to be putative pheromones. Immunohistochemical analysis confirmed localization of α 2u-globulin in the acinar cells of the preputial gland. Thus, we show that α 2u-globulin, a pheromone-carrier protein, is present in the preputial gland acinar cells of M. meltada and suggest farnesol and 6-methyl-1-heptanol to be the volatiles which would bind to it. The α 2u-globulin together with farnesol and 6-methyl-1-heptanol contribute to pheromonal communication of M. meltada.

A comparative study of the diet of the Indian Eagle Owl Bubo bengalensis (Franklin, 1831) from two distinct habitats in the Tamil Nadu - Puducherry area, southern India

A total of 166 prey items were identified from pellets, pellet remains and prey remains – 84 from Arunachala Hill and 82 from Pondicherry University campus. The total biomass encountered from pellet and prey remains was 22,620.17g – 11,240.59g from Arunachala and 11,379.58g from Pondicherry University. Out of the 166 prey items 102 were non-volant small mammals accounting for a biomass of 13,973.90g – 5,616.83g (49.94%) from Arunachala and 8,357.07g (73.42%) from Pondicherry University. Even among these murid rodents dominated – 44.99% in Arunachala and 70.13% in Pondy University. Milvus migrans were predated upon by Bubo bengalensis and 10 partly eaten carcasses were recovered – hence they could not be assigned a category as the quantity consumed could not be determined. It is a well known fact that Eagle Owls are intolerant to other avian predators, and territorial behaviour and intraguild aggression / predation could be responsible for this phenomenon. 3 other partly consumed remains of birds were also encountered and these too could not be assigned a category for the same reason that the quantity ingested could not be determined. Anurans occurred for a combined biomass of 12.87% in both areas. The rest, viz. Coleoptera, Orthoptera and Paratelphusa sp. accounted for a paltry biomass of 0.51%. The difference between murid rodents occurring in the two habitats was illuminating. In Arunachala the constant food of the owls were the field rodents Millardia meltada (15.47%), Bandicota bengalensis (8.74%) and Tatera indica (11.65%), and a single Bandicota indica (6.07%) which is a species found around rural habitations. The first two species were conspicuous by their absence in Pondicherry University and the Tatera indica was encountered in very small quantities (3.70%). Uniquely enough, the terrestrial and fossorial forms of urban rodents formed the basic food of Bubo bengalensis in Pondicherry University – Rattus rattus (20.64%) and Bandicota indica (43.94%). Both these species are human commensals and occur in pestilential proportions in urban habitats. The specific identity of Mus spp. could not be derived due to the complexity of identification, but as our specimens are housed in the repository of WILD molecular analysis could shed light on the species complex in the near future. We have compared non-volant small mammal prey of the regions we studied with those of Maharastra and the results are discussed.

Efficacy of Germinated Cereals as Bait Carrier for Zinc Phosphide and Bromadiolone against Field and Commensal Rodent Pests: A Laboratory Evaluation

Both sexes of rodent pests such as Bandicota bengalensis, Millardia meltada, Mus booduga, and Rattus rattus were subjected to toxicity tests (acute rodenticide: 1.5% and 2% zinc phosphide and chronic rodenticide: bromadiolone (0.005%), under no-choice and choice tests) by using their preferred germinated cereals, namely, paddy, pearl millet, and finger millet, as bait base, individually. The results indicated that the poison baits in the germinated cereals induced all the chosen four species of rodent pests to consume greater quantities of bait perhaps due to the bait carrier’s palatability and texture. Besides these, the chosen three germinated cereals proved themselves that they are also capable of acting as suitable bait base for both selected rodenticides in bringing maximum mortality among the tested rodent pests under both no-choice and choice tests. Therefore, these germinated cereals may be recommended as a bait carrier for both zinc phosphide (2%) and bromadiolone (0.005%) poisons for the control of all these four species of rodent pests under field conditions. However, this requires field based trials with rodenticides for making a final recommendation.

5-Azadeoxycytidine induced heteromorphic undercondensation in the C-blocks of X chromosomes of three mammalian species, Pipistrellus abramus, Millardia meltada, and Apodemus argenteus

5-Azadeoxycytidine induced heteromorphic undercondensation in the C-blocks of X chromosomes of three mammalian species, Pipistrellus abramus, Millardia meltada, and Apodemus argenteus

Efficacy of acute and anticoagulant rodenticide baiting in sugarcane fields of Punjab, India

The aim of this study was to recommend locality-specific rodent pest management techniques for sugarcane using acute and anticoagulant rodenticides during the months when maximum damage is inflicted on the crop in Punjab, India. Sugarcane crops were found to be infested with four rodent species namely: Bandicota bengalensis (Gray and Hardwicke); Mus booduga (Gray); Millardia meltada (Gray) and Golunda ellioti (Gray), with B. bengalensis being the most prevalent species (accounting for 69.45–83.36% of the total catch). Surveys in 11 villages of three districts of Punjab (India) revealed 19.12 ± 12.22% rodent damage to the sugarcane crop during the months of December–January. Rodenticide treatments were conducted in farmer's fields in two districts of Punjab from December 2003 to January 2007. The results revealed that, to protect the sugarcane crop from rodent damage during the months of December–January, the rodenticide treatment may be applied either: (1) by double-baiting with 2% zinc phosphide followed by 0.005% bromadiolone after 15d at 1 kg/ha each, or (2) by single-baiting with 0.005% bromadiolone at 2 kg/ha. The impact of rodenticide treatment in canefields was also evident in the adjoining wheat crop fields where the incidence of rodent damage was less (0.97–3.24%) than in the fields surrounding untreated canefields (3.53–6.22%).

Prey selection by the Barn Owl Tyto alba (Scopoli, 1769) in captivity

We investigated prey selection of the Barn Owl Tyto alba under captive conditions where birds were allowed to choose among individuals of varying size from four field rodent species: Bandicota bengalensis, Millardia meltada, Tatera indica and Mus booduga. Owls showed little species preference and a tendency to favour the medium weight class in all prey species except M. booduga. Preference for body parts consumed varied according to prey size, ranging from the head alone in the large weight class to the entire body in the small weight class. Biochemical measurements showed that protein, carbohydrate and lipid levels were higher respectively in the brain, liver and muscles of all three species and weight classes studied. The preference for medium weight prey despite a lower nutrient content compared to large weight prey is attributed to a greater ease of capture.

Morphological and histochemical observations on the prenatal and postnatal testes of the field rat (Millardia meltada).

The foetal testis of the field rat (Millardia meltada) shows seminiferous tubules and interstitium consisting of mesenchymal cells and differentiated Leydig cells associated with blood vessels. The tubules during the prenatal period show gonocytes and Sertoli cells. After birth, their diameter decreases but again increases progressively after postnatal days 9 and 10. Spermatogonia appear among the gonocytes on postnatal day 1 and primary spermatocytes on day 8. Secondary spermatocytes and spermatids are not seen up-to-day 23. Several hypertrophied Leydig cells are seen in the foetal testis on day 17 but are greatly increased in number on days 18 and 19. A few hours after birth the Leydig cells show a rapid decrease in their number. These fluctuations in the Leydig cells of prenatal and neonatal testes have been correlated to the rise and fall in testosterone production during these periods. The Leydig cells show the histochemical characteristics of actively steroid-secreting cells, which consist of the presence of diffuse lipoproteins and a few lipid granules consisting of phospholipids; no cholesterol and/or its esters could be demonstrated. Such lipids are not present in the cytoplasm of undifferentiated mesenchymal cells. The seminiferous tubules do not show any appreciable development of lipid changes.

Epididymal resorption of spermatozoa in the field rat (Millardia meltada).

A study has been made of epididymal resorption of spermatozoa in the field rat (Millardia meltada). At the height of its reproductive activity, many spermatozoa penetrate the epididymal epithelium and intertubular tissue where they undergo fragmentation and resorption. Sperm disposal is maximum in the cauda epididymidis.

Chromosome homology between mouse and three Muridae species, Millardia meltada, Acomys dimidiatus and Micromys minutus, and conserved chromosome segments in murid karyotypes

Comparative chromosome painting with mouse (Mus musculus, MMU) chromosome-specific DNA probes was performed for three Muridae species, the Indian soft-furred field rat (Millardia meltada), the spiny mouse (Acomys dimidiatus) and the harvest mouse (Micromys minutus). All probes except for the Y probe were successfully hybridized to the chromosomes of all species, and homologous chromosome segments between mouse and the three species were identified at the molecular level. Comparison of our data with the published data of six other genera (Mus, Rattus, Apodemus, Otomys, Rhabdomys and Cricetulus) of the Muridae suggested that the associations MMU1b/17a, 2b/13a, 5b/11a, 7/19, 10b/17b, 10c/17c, 11b/16a, 12/17d and 13b/15, and the single painted chromosomes and chromosome segments MMU3, 4, 5a, 8a, 8b, 16b, 18 and X were probably contained by the ancestral karyotype of the Muridae, and have been strongly conserved throughout murid evolution.

An Overview of Vertebrate Pests in India

Author(s): Sridhara, Shakunthala | Abstract: A billion-plus human population, agriculture, and development are shrinking and degrading the habitat of many of the 1,200 bird and 500 mammal species of India. With humans and herbivores competing for the same resources, many of them are becoming pests on crops. The granivorous birds depredate on selected cereals, sunflower, groundnut, and oil palm. Guava, grape, apple, sapota, pecan, pomegranate, and pineapple are damaged significantly by frugivore birds. Amongst vertebrate pests, rodents are the most destructive. A dozen species, viz. Rattus rattus, Bandicota bengalensis, B. indica, Millardia meltada, Mus booduga, M. platythrix, Mus musculus, Tatera indica, Meriones hurrianae, Funambulus pennanti, F. palmarum, F. tristriatus, and Hystrix indica are serious pests. Cereals, pulses, oil seeds, vegetables, fruits, and plantation crops are damaged considerably. Sown seeds, seedlings of maize, sorghum, sunflower, groundnut, red gram, tender coconut, oil palm, cardamom, and cocoa are depredated much more. Other vertebrate pests of significance are Pteropus giganteus, Cynopterus sphinx, Rousettus leschenaulti (bats), Boselaphus tragocamelus (Nilgai), Elephas maximus (elephant), Macaca mulatto, and Semnopithecus entellus (monkeys). Sporadically, other langurs, sloth bear, wild boar, hare, golden jackal, and peacock become pests. This paper reviews the lethal and non-lethal methods of managing this wide of array of vertebrate pests.

Syphacia (Syphacia) millardiae n. sp. (Nematoda: Oxyurida: Syphaciinae) from the Soft-Furred Field Rat, Millardia meltada, in India

Syphacia (Syphacia) millardiae n. sp. (Nematoda: Oxyuridae: Syphaciinae) is described based on specimens collected from a soft-furred field rat, Millardia meltada. This species is closely related to several other members of the genus Syphacia, also murid parasites. This species closely resembles Syphacia (Syphacia) obvelata, a cosmopolitan parasite of Mus musculus. Syphacia (Syphacia) millardiae n. sp. differs from S. obvelata in that females exhibit a cuticular ornamentation with varicose cuticular elevations between the cephalic nervous endings, smaller body width, smaller eggs, and a longer esophagus. Males exhibit a shorter body length, a longer tail with a shorter tail tip, a longer esophagus, and a longer gubernaculum than do males of S. obvelata.

Resistance of Cotton Rats, Sigmodon hispidus, to Primary Infection by Nippostrongylus brasiliensis.

The resistance of cotton rats, Sigmodon hispidus to Nippostrongylus brasiliensis infection was examined and compared the response to that of the susceptible Indian soft-furred rat, Millardia meltada. After a primary infection with infective third-stage N. brasiliensis larvae (L3), the number of eggs in feces and adult worm recovery rates from the small intestine of cotton rats were significantly lower than in the controls. To determine whether cotton rat resistance was observed during the migratory phase or the intestinal phase, cotton rats and control animals were challenged subcutaneously with L3 or intraduodenally with adult worms, and larval recovery from lungs and adult worm burden were evaluated. The recovery rate of larvae from the lungs of cotton rats was about five-fold lower than from controls. Adult worm recovery from the small intestine of cotton rats was also lower than that from the controls, but the difference (two-fold lower) was smaller than that observed for lung recovery. Carbon treatment at a dose of 250-500 mg/kg effectively increased larval worm recovery from the lungs of cotton rats. However, this treatment had no effect on worm recovery from the intestine after intraduodenal implantation of adult N. brasiliensis. These results suggest that macrophage function have important role in the expression of strong resistance during the migratory phase of N. brasiliensis infection in cotton rats.