Bandicota Research Articles

Burrowing Pattern of Bandicoot Rats in Deep Water Rice Fields

Burrowing Pattern of Bandicoot Rats in Deep Water Rice Fields

Effect of DL-6-(N-alpha-pipecolinomethyl)-5-hydroxy-indane maleate (PMHI) on the reproductive system of a wild rat, Bandicota bengalensis.

The anti-testicular action of PMHI was investigated in a wild rodent, the bandicoot rat. Bandicoots were given a single subcutaneous injection of this compound at a dose of 150 mg/kg and were killed 2, 10, or 30 days later. PMHI induced marked and rapid testicular regression with complete arrest of spermatogenesis by day 10 such that the seminiferous tubules contained only a ring of Sertoli cells with few spermatogonia. This was also reflected by a severe depletion of the number of sperm in the cauda epididymis. However, by day 30 after PMHI injection, testicular histology indicated restoration of spermatogenesis in parallel with the time schedule of germ cell development. The results indicate that PHMI produces a reversible anti-spermatogenic effect in the bandicoot rat which appears to be time dependent.

Alternate Foods of Bandicoot Rats in Deep Water Rice Areas of Bangladesh

Alternate Foods of Bandicoot Rats in Deep Water Rice Areas of Bangladesh

Spermatogenesis in the bandicoot rat. I. Duration of the cycle of the seminiferous epithelium.

The duration of the cycle of the seminiferous epithelium was studied in a pest rodent, the bandicoot rat. Fourteen stages of the cycle were identified. The duration of the seminiferous epithelium cycle was determined to be 10.0 days.

Patterns of Bandicoot Rat Damage to Deepwater Rice in Bangladesh

Patterns of Bandicoot Rat Damage to Deepwater Rice in Bangladesh

Leucocyte responses to fighting in the adult male bandicoot rat.

The effect of fighting stress on blood leucocyte count was studied in the adult male bandicoot rat. Exposure to fighting stress for 3 h induced neutrophilia, eosinopenia, lymphopenia and monocytopenia. The changes were more significant in the subordinate rat than in the dominant animal. It is suggested that leucocyte responses to fighting are perhaps mediated by the adrenal gland in these animals.

Rodent Damage and Burrowing Characteristics in Bangladesh Wheat Fields

Rat damage to wheat was assessed in 303 fields (196 ha) in 4 districts of Bangladesh. In an appraisal of 315,000 wheat stems, only 0.5% were cut by rats before the booting growth stage. The countrywide rat-damage estimate in mature wheat was 12.1%, or 77,000 tons of grain destroyed before harvest. Wheat damage is attributable primarily to the lesser bandicoot rat (Bandicota bengalensis). Damage was highly correlated with stem density. Yield loss and percent rodent damage were also correlated. The average yield for 20 fields was 1,795.9 kg/ha. Seventeen percent of the damaged stems had only the panicle removed, whereas 83% were cut near ground level. Twenty lesser bandicoot rat burrow systems were excavated from the centers of wheat fields. The mean burrow length was 40.2 m, and storage chambers contained as much as 18 kg of cached wheat panicles. Rat damage was correlated with the number of active burrow systems within fields. J. WILDL. MANAGE. 46(1):139-147 Various vertebrate pest species cause serious crop losses throughout southern Asia, and rodent infestations are a major problem in most field crops. The principal pest rodents in Bangladesh wheat fields are burrowing Muridae, primarily the lesser bandicoot rat (pers. observ.). In addition to what it consumes during the growing season, the rodent digs elaborate underground burrow systems and caches large amounts of grain. Although many farmers complain of considerable loss of rice and wheat in their fields, the present study provides the first information on the magnitude and extent of the losses in Bangladesh. Wheat production in Bangladesh is becoming increasingly popular among farmers. Between the 1977-78 and 197879 crop seasons, the area under cultivation increased from 150,000 to 291,000 ha. The traditional dry-season Boro rice crop (Jan-May) is much more difficult to cultivate because it requires frequent irrigation, most of which is done by hand. Wheat requires little cultivation and watering after broadcasting. Yields over the last 4 years have increased from an average of 1.431 to 1.939 tons/ha, reflecting promotion of adaptable high-yielding varieties. The objectives of this study were to quantify the extent of rodent damage in wheat, identify which rodent species were causing most of the damage, and determine the effects of stem cutting on yield. The stem is defined as that portion of the plant that gives rise to a panicle (i.e., seed head). Existing methods for damage assessments in wheat are few; however, Bindra and Sagar (1968) examined wheat losses in India, and Khokhar et al. (unpubl. rep., FAO-Vertebr. Pest Centre Working Pap. PAK/71/554, 1979) conducted similar studies in Pakistan. Support for this study was provided by the Bangladesh Research Institute and the U.S. Agency for International Development project Agricultural Research, Vertebrate Pest Component, PASA ID/BNG-0003-1-78. A. Mannan I, A. Mannan II, D. Miah, and J. Libay assisted in various aspects of the fieldwork. M. Fall offered comments on earlier J. Wildl. Manage. 46(1):1982 139 This content downloaded from 157.55.39.253 on Sat, 11 Jun 2016 05:26:12 UTC All use subject to http://about.jstor.org/terms 140 RODENT DAMAGE IN BANGLADESH* Poche et al.

Evolutionary trends in the hemoglobins of murine animals

The evolutionary origin of murine line based on a phylogenetic tree made on sequence data of ∞-and β-hemoglobin chains, followed by the diversity spectrum of hemoglobin genes in two wild species of murine rodents:Rattus rattus rufescens (house rat) andBandicota indica (bandicoot rat) has been reported. Each house rat contains six hemoglobin types involving two ∞-and three β-chains, which suggests a probable gene duplication at the oc chain locus and a gene triplication at the β-chain locus. Each bandicoot rat contains one ∞-and two β-chains suggesting a probable gene duplication at the β-chain locus. Peptide pattern analysis of the polypeptide chains of these murine hemoglobins further indicates that intraspecies differences among duplicated chains of the same kind are less than interspecies differences among corresponding ∞-and β-chains.

Laboratory evaluation of scilliroside used as a rodenticide against the lesser bandicoot rat, Bandicota bengalensis.

The toxicity and efficacy of the acute rodenticide scilliroside was evaluated in the laboratory against the lesser bandicoot rat, Bandicota bengalensis. The acute oral LD50 and LD95 doses for males were 0 . 8 mg/kg and 2 . 5 mg/kg respectively, and for females were 0 . 5 mg/kg and 1 . 6 mg/kg, respectively. When caged bandicoots were given a choice between plain and poison baits, the optimum concentration of scilliroside was found to be 0 . 05%. Symptoms of poisoning appear from 22 to 34 min after feeding starts and the latency pattern indicated an abrupt ceasing to feed at these points. Death occurred from 2 h to as long as 6 days after poisoning, following prolonged convulsive seizures. There appears to be aversion to scilliroside at all concentrations in food baits. Maximum mortality attained on free-choice feeding on scilliroside was 90%. Despite these disadvantages, the material may have merit as an alternative rodenticide to zinc phosphide where acute toxicants are to be used.

Laboratory Evaluation of Zinc Phosphide as a Rodenticide againstBandicota bengalensis

Abstract The toxicity and efficacy of the acute rodenticide zinc phosphide (Zn3P2) was evaluated in the laboratory against the lesser bandicoot rat (Bandicota bengalensis), from Rangoon, Burma. The acute LD50 and LD95 doses of orally-administered zinc phosphide for B. bengalensis were found to be 25.0 mg/kg and 113.0 mg/kg of body weight respectively. When caged bandicoots were given a choice between plain and poison baits, the optimum rodenticidal concentrations in the bait was found to be 2.5%. Symptoms of poisoning appear from 32 minutes to 3 hours after feeding starts, giving individual animals time to consume from 10 to over 27 LD50 doses of 25% zinc phosphide before feeding stops. Death occurred in a minimum of 4 to 5 hours following either oral dosing or free choice feeding. There appears to be aversion to the poison at higher concentrations in food baits. The relative merits of zinc phosphide and pyriminyl as rodenticides against the lesser bandicoot in Rangoon will have to be determined in a seri...

Wenyonella baghdadensis sp. n. from the bandicoot rat Nesokia indica in the Baghdad area.

Oocysts of Wenyonella baghdadensis sp. n. were found in the feces of 2 of 12 bandicoot rats Nesokia indica Gray & Harwicke from the Baghdad area. Sporulated oocysts were subspherical to broadly ellipsoidal, 25.4 (18-22) x 20.8 (15-28) micrometer, with a 2-layered wall, the outer wall being mammillated, without micropyle, micropylar cap, residuum, or polar granule. Sporozoites were ovoid, 11.8 (9-15) x 8.4 (6-10) micrometer, with Stieda body and residuum. Two sporozoites in each sporocyst were elongate, with granular cytoplasm and a refractile globule, the other 2 were bean-shaped, without granules or refractile globule. Sporulation time equalled 3 days at 22-24 C. Entamoeba coli and Giardia sp. cysts were also found in 3 rats each.

Influence of early nutritional experience on adult diet choice in the lesser bandicoot rat, Bandicota bengalensis

Evidence for food imprinting in Norway rats is conflicting. Postweaned litters of the lesser bandicoot rat, Bandicota bengalensis , were condition-fed on different foods for fixed periods. Later, as adults, they were tested for food imprinting. Rats exposed to rice, ragi, and standard feed during their infancy preferred these foods to others. A preference for rice developed early in life did not wane. The duration of infant exposure did not affect the formation and retention of preferences. It is suggested that food imprinting may occur after weaning.

Estrous cycle of the bandicoot rat-a rodent pest

Estrous cycle was studied in a rodent pest from behavioural and physiological standpoints. The bandicoot rat showed four stages of the cycle. The duration of proestrus was significantly lower, and that of estrus and metestrus were higher in this species. Total length of the cycle was also higher. Variation in the duration of stages or cycle observed in the bandicoot rat is suggested to be species specific.

Laboratory evaluation of pyriminyl used as a rodenticide against the lesser bandicoot rat, Bandicota bengalensis.

The properties of pyriminyl (N-3-pyridylmethyl-N'-p-nitrophenyl urea) as a rodenticide against the lesser bandicoot rat (Bandicota bengalensis) in Rangoon, Burma, were investigated in the laboratory. The acute LD 50 and LD 95 dose of orally administered pyriminyl for B. bengalensis were found to be 6.7 mg/kg and 23.0 mg/kg of body weight respectively. When caged bandicoots were given a choice between plain and poisoned baits, the optimum rodenticidal concentration in the bait was found to be 0.25-0.5%. Symptoms of pyriminyl poisoning appear from 1 to 4 h after feeding starts, giving individual animals time to consume from 2 to over 30 LD 50 doses of 0.5% pyriminyl before feeding stops. Deaths occurred from 4 to 96 h after either oral dosing or free-choice feeding. There appeared to be no significant aversion to the poison at 0.25% or 0.5% concentration in foods. The potential hazards and use of pyriminyl as a field bait against populations of B. bengalensis are discussed.

Piroplasms from Taiwanese rodents.

Piroplasms from naturally infected bandicoot rats, Bandicota indica (Hodgson), and spiny rats, Rattus coxinga (Swinhoe), from Taiwan caused parasitemias in a wide range of laboratory animals after syringe passage in laboratory rats. Bandicoot and spiny rats could be infected with heterologous piroplasms, but neither species was susceptible to infection with the Gray strain of Babesia microti (França). Nevertheless, the Taiwan piroplasms are probably a geographic strain of B. microti.

Is late replication of the inactive X chromosome irreversible in all cells of mammals?

The X chromosomes of the female bandicoot rat (Nesokia indica) were 3H-thymidine labeled during two consecutive cell divisions to determine if all of the same segments of the "triplicate-type" X chromosome of these animals always replicated late. In 87% of metaphases examined the findings were as expected. One entire X chromosome (X1) and the long arm of the other X (X2) synthesized DNA late in the S phase in both divisions. However, in the other 13% of the metaphases, the late-replicating and presumably genetically inactive short-arm segments of the X1 chromosome had completed DNA synthesis by the time it entered the late-S phase of the second cycle. Thus, in this species, some cells appear to have an X chromosome of which the facultative heteropycnotic segment condenses in one cell cycle but becomes euchromatic in the subsequent cell cycle. Although this appears at first to be inconsistent with the generally accepted pattern of X-chromosome condensation and genetic inactivation, it may represent an instance of evolutionary specialization for an as yet unexplained reason. It is also possible that closer analysis of other mammalian species with composite sex chromosomes or methods equally suitable for this type of analysis will reveal other instances where a minority of the somatic cells of females do not follow the predictions of the Lyons hypothesis completely.

1250. Zirconium in our environment

Present day rodent management technology mostly relies on use of rodenticides, which is unsafe for human beings and other non-targets. Denatonium benzoate (DB) is an intensely bitter and non-toxic substance which is detectable by humans at a concentration of 10 ppb. Denatonium benzoate added wax block formulation of bromadiolone (0.005%) (an anticoagulant rodenticide) was evaluated against commensal rodents (house rat, Rattus rattus and lesser bandicoot rat, Bandicota bengalensis), which are always found in the proximity of pets, domestic animals and human beings. Single day exposure to bromadiolone (0.005%) formulation with DB and without DB in no-choice tests yielded 100% mortality in both the test rodent species in 2–11 days. The amount of poison bait ingested by R. rattus and B. bengalensis for both the formulations did not differ significantly, ranging between 5.87 - 7.30 and 6.51–6.71 g/100 g body weight, respectively. In choice tests in the presence of alternate plain food (broken wheat grain), consumption of both the formulations of bromadiolone (0.005%) (with and without DB) was similar to plain food at both the exposure periods (1 and 2 days), indicating a good acceptability of test rodenticide. However, mortality with a single day exposure to bromadiolone (0.005%) formulation with DB was 70% and without DB was 60–80% in both test rodent species within 3–14 days. With a two days exposure period, mortality was 100% in both the species of test rodents in 3–13 days. Single day choice test between the formulations revealed that intake of baits of both formulations by both the test rodents was similar i.e., in the range of 8.16–8.94 g/100 g b wt (bromadiolone with DB) and 8.20–9.5 g/100 g b wt (bromadiolone without DB) indicating that incorporation of a bittering agent (DB) with bromadiolone did not alter the consumption of poison in both the test species. In field trials the mean control success as assessed by census baiting and trapping methods with the application of bromadiolone (0.005%) with DB ranged between 54.0% (houses and shops) to 68.4% (poultry farms) and was 55.6% (houses and shops) to 68.4% (poultry farms) in treatments with bromadiolone (0.005%) without DB. It can be concluded that denatonium benzoate could be a best additive in rodenticidal formulations as the acceptability, palatability and toxicity in the laboratory and also its performance in field in managing the pest rodents were not altered.

Southeast Asian Haemaphysalis Ticks (Ixodoidea, Ixodidae). H. bandicota sp. n. from Bandicoot Rats in Taiwan, Thailand, and Burma

Both sexes and nymphs and larvae of Haemaphysalis bandicota sp. n. are described from the bandicoot rat, Bandicota spp., in Burma, Thailand, and Taiwan. This species is related to the H. doenitzi and H. erinacei groups of Asian, African, and southern European ticks that parasitize birds and small mammals, and should be an interesting subject for epidemiological investigations. The Haemaphysalis species described herein is a component of a complex that is probably common in humid tropical and temperate Asia and outlying islands, as well as in Africa and southern Europe, but is infrequently collected. Host-relationship, distributional, ecological, and epidemiological studies of species in this group, which characteristically parasitizes certain birds and small mammals, should be especially interesting. We are grateful to Captain Robert E. Kuntz, USN, formerly of the United States Naval Medical Research Unit Number Two, Taipei, Taiwan, and to Major John E. Scanlon, USA, of the SEATO Medical Research Laboratory, Bangkok, Thailand, for much of the material reported in this study. Colonel Robert Traub, USA, kindly furnished specimens collected by Mr. R. E. Elbel in Thailand. Received for publication 28 November 1964. * From Research Project MR005.09-1402.3, Bureau of Medicine and Surgery, Navy Department, Washington 25, D. C. The opinions and assertions contained herein are the private ones of the authors and are not to be construed as official or reflecting the views of the Navy Department or the naval service at large. t Head, Department of Medical Zoology, United States Naval Medical Research Unit Number Three, Cairo, Egypt, U. A. R. + Sanitarian Director, United States Department of Health, Education and Welfare, Public Health Service, National Institutes of Health, National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratory, Hamilton, Montana. Haemaphysalis bandicota sp. n. The Bandicoot Rat Haemaphysalid