Metrocoris Mayr (Insecta: Hemiptera: Gerridae) of India with descriptions of five new species.

The Metrocoris fauna of India is reviewed and five new species are described from India: M. murtiensis Basu, Polhemus and Subramanian sp. nov. belonging to the nigrofasciatus species group, M. dinendrai Basu, Polhemus and Subramanian sp. nov. and M. darjeelingensis Basu, Polhemus and Subramanian sp. nov. of the compar species group, M. deceptor Basu, Polhemus and Subramanian sp. nov. (previously treated as M. quynhi Tran & Zettel in Basu et al., 2015) of the anderseni species group, and M. lavitra Basu, Polhemus, Subramanian and Saha sp. nov., which does not fit well into any currently established species group. The new species proposed are compared to all other known species, and a key to all the species of Indian Metrocoris is provided, accompanied by a table for comparison of key morphological characters, and a map and table of distributional details.

Intraguild Predation in Heteroptera: Effects of Density and Predator Identity on Dipteran Prey.

In tropical freshwaters, different species of water bugs (Heteroptera) constitute a guild sharing similar prey resources including chironomid and mosquito larvae. Assuming possibilities of intraguild predation (IGP) among the constituent members, an attempt was made to evaluate the effects of prey and predator density on the mortality of mosquito and chironomid larvae (shared prey), using Laccotrephes griseus Guérin-Méneville (Hemiptera: Nepidae) and Ranatra filiformis Fabricius (Hemiptera: Nepidae) as IG predators and Anisops bouvieri Kirkaldy (Hemiptera: Notonectidae) as IG prey. The predation on mosquito and chironomid larvae varied with the density and combinations of the predators. When present as conspecific IG predators, L. griseus exhibited greater effect on the prey mortality than R. filiformis. The effects on shared prey suggest that the two predators are not substitutable in terms of the effect on the shared prey mortality. The mortality of A. bouvieri (IG prey) at low shared prey density was significantly different (p < 0.05) from high shared prey density. In view of predatory effect of the heteropteran predators on the dipteran larvae, the results suggest possible interference by the presence of A. bouvieri as an intermediate predator. It seems that the presence of heteropteran predators including A. bouvieri as IG prey may benefit the dipteran prey under situations when the density is low in tropical waters. The intensity of the predatory effect may differ based on the species composition at IG predator level. For mosquito biological control, the interactions between the predators may not be substitutable and are independent in their effects.

A new species of Aulacogenia Stål (Hemiptera: Heteroptera: Reduviidae: Stenopodainae) from India.

A new stenopodaine reduviid, Aulacogenia darjeelingensis sp. nov. belonging to the "corniculata species group" from India is described and illustrated. A key to the Indian species of the genus Aulacogenia Stål is provided. 

A new genus, Neoschidium (Hemiptera: Reduviidae: Emesinae), with a redescription of the type genus, Neoschidium phasma (Distant) [Ghilianella phasma Distant and Schidium phasma (Distant)], recorded for the first time from India.

A new genus, Neoschidium was erected with the type genus, Neoschidium phasma (Distant). It was earlier described under Ghilianella Spinola 1850 as G. phasma Distant and later under Schidium Bergroth 1916 as Schidium phasma (Distant) by Bergroth (1916). Because it exhibits characters not only of Ghilianella and Schidium but also intermediate specific characters that are not found in both the genera, the type genus Neoschidium phasma (Distant) is redescribed with additional taxonomic details, morphometrics, and illustrations. It is also recorded for the first time from India.

Prey preferences of aquatic insects: potential implications for the regulation of wetland mosquitoes.

Wetlands are potential sites for mosquito breeding and are thus important in the context of public health. The use of chemical and microbial controls is constrained in wetlands in view of their potential impact on the diverse biota. Biological control using generalist aquatic insects can be effective, provided a preference for mosquito larvae is exhibited. The mosquito prey preferences of water bugs and larvae of odonate species were evaluated using chironomid larvae, fish fingerlings and tadpoles as alternative prey. Manly's selectivity (αi ) values with 95% confidence intervals (CIs) were estimated to judge prey preference patterns. Multivariate analysis of variance (manova) and standardized canonical coefficients were used to test the effects of density on prey selectivity. The αi values indicated a significant preference (P < 0.05) in all of the insect predators tested for mosquito larvae over the alternative prey as a density-dependent function. On a comparative scale, chironomid larvae had the highest impact as alternative prey. In a multiple-prey experiment, predators showed a similar pattern of preference for mosquito larvae over alternative prey, reflecting a significant (P < 0.05) niche overlap. The results suggest that, in a laboratory setting, these insect predators can effectively reduce mosquito density in the presence of multiple alternative prey.

Frequency-dependent prey-selection of predacious water bugs on Armigeres subalbatus immatures.

BACKGROUND & OBJECTIVES: The predatory behaviour with reference to the frequency-dependent prey-selection of the water bugs Sphaerodema annulatum Fabricius and S. rusticum Fabricius was studied in the laboratory using the IV instar larvae and pupae of Armigeres subalbatus as prey to ascertain their efficacy as predator of mosquito immatures. METHODS: Field collected adult morphs of the water bugs were allowed to predate on larvae and pupae provided in different ratios and densities as per the model of Greenwood and Elton' for a fixed time period. The data obtained on their predation rate were analysed with respect to the model parameters, lnV--the frequency independent component and b--the frequency dependent component of selection. RESULTS: It was found that the prey-selection was dependent on the relative numbers of prey available, favouring apostatic selection. The b values and lnV values for S. annulatum were 0.54 +/- 0.01 and 0.92 +/- 1.04 respectively whereas the corresponding values for S. rusticum were 0.71 +/- 0.03 and 0.17 +/- 1.57 respectively. INTERPRETATION & CONCLUSION: The selection of preys by the water bugs was dependent on the relative number of the prey forms and thus they are expected to predate on the form more abundant in a heterogeneous prey population and adversely affect the adult emergence.

Predatory efficiency of the water bug Sphaerodema annulatum on mosquito larvae (Culex quinquefasciatus) and its effect on the adult emergence.

The daily number of IV instar larva of Culex quinquefasciatus killed, rate of pupation and adult emergence was noted in presence of the predatory water bug Sphaerodema annulatum for a period of seven consecutive days, experimentally, in the laboratory. The rate of IV instar larva killed by the water bugs on an average was 65.17 per day. The rate of pupation ranged between 7.6 and 48 in control while in presence of water bugs it ranged between 6 and 35. The rate of adult emergence in control experiments varied between 1.4 and 4.8 per day, which was reduced to only 0.4-28.8 per day in case of the water bugs. The results clearly indicate that the water bugs on its way of predation reduces the rate of pupation and adult emergence of Cx. quinquefasciatus significantly which calls for an extensive field trials.

Disregulated expression of the Th2 cytokine gene in patients with intraoral squamous cell carcinoma.

It has been seen that advanced stage oral squamous cell carcinoma is associated with impaired T-cell function and higher antibody response. In order to find out if such immune disregulation is associated with alteration of T-helper (Th) type CD4+ T-cell phenotype leading to altered cytokine production, we studied the Th-like cytokine profile in 35 oral squamous cell carcinoma patients and 21 normal controls. Concomitant expression of both Th1 and Th2 cytokine genes was studied by reverse transcription and Polymerase Chain Reaction (PCR) based amplification (RT-PCR) of mRNA extracted from freshly isolated peripheral blood mononuclear cells (PBMC) using specific primers for Interferon (IFN)-gamma, Interleukin (IL)-2, IL-4 and IL-10. Almost 63% of oral cancer patients showed polarization of a Th-like cytokine response as compared to 33% of the normal controls while 66.6% of normal controls showed a predominantly non-polarized Th0 response. Expression of IFN-gamma and IL-2 genes was more commonly seen in the early stage of the disease (p < 0.02) whereas majority of advanced stage tumours was associated with enhanced expression of IL-4 and IL-10 but not IFN-gamma and IL-2 genes. Patients with lymphnode metastases and poorly differentiated tumours expressed IL-4 and IL-10 more frequently with concomitant suppression of IFN-gamma and IL-2 genes. It seems therefore, that the development of oral squamous cell carcinoma leads to polarization of cytokine gene expression that is skewed towards the Th1-like response in the early stage. However, increasing tumour load and lymphnode invasion suppresses Th1 cytokine genes, thus skewing it toward a Th2-like cytokine response.

Incidence and prognostic significance of right bundle branch block complicating acute myocardial infarction.

The incidence and hospital courseofacute myocardial infarction wereobserved among randomly selected 560 patients. The mean age of the patients was 53 +/- 6.67 years with male-female ratio 2.6:1. The incidence of right bundle branch block (RBBB) was 15% (84 out of 560 patients). New RBBB, old RBBB and RBBB of indeterminate age were observed in 33 (39.25%), 23 (27.40%) and 28 (33.25%) cases respectively. RBBB was isolated in 50 (60%) cases and bi-fascicular in remaining 34 (40%) cases. The rate of use of thrombolytic was greater in RBBB group than non-RBBB group (52% vs 30.67%, P < 0.05). The complications were more frequently observed in patients with RBBB: in-hospital mortality, 27.40% vs 10.90% (P < 0.01); use of temporary pacemaker, 15% vs 9% (P < 0.05); and heart failure, 50% vs 35% (P < 0.05). In sub-group analysis, in-hospital mortality rate was higher among bi-fascicular group than isolated RBBB group (P < 0.05). Thus it appeared from the results that the incidence of RBBB is relatively common i.e. 15% over all (84 out of 560) and 5.90% new (33 out of 560) and despite greater use of thrombolytics, some specific in-hospital complications were significantly higher in patients with RBBB than without, RBBB.

Incidence of spontaneous echocontrast in left atrium in mitral stenosis detected by transoesophageal echo cardiography and related factors.

The incidence of left atrial (LA) spontaneous echo contrast (SEC) and the clinical and echocardiographic variables related to it were prospectively evaluated in a series of 60 patients with mitral stenosis (MS) undergoing transoesophageal echocardiography (TEE) with a 5 MHz multiplane transducer. LA-SEC was found in 39 patients (65%) employing TEE. Statistical analysis showed a significant relationship between the presence of SEC and MS without mitral regurgitation (MR) (P < 0.05), MS with < or = MR grade II (P < 0.05), atrial fibrillation (P < 0.001) and increased left atrial dimension (P < 0.05). Age, sex, mitral valve area and ejection fraction did not show any positive association (P > 0.05). Thus, it is concluded that LA-SEC is a common finding observed in approximately 65% of MS patients undergoing TEE and associated with conditions favouring stasis of left atrial blood.

Anophelines of Siliguri-Naxalbari block, Darjeeling, West Bengal.

A systematic survey has been carried out during 1993-94 to study the occurrence and distribution of anopheline mosquitoes in Siliguri-Naxalbari block of Darjeeling district. The anopheline fauna of this region consists of 13 species, namely, An. vagus, An. culicifacies, An. annularis, An. barbirostris, An. subpictus, An. maculatus, An. tessellatus, An. jamesii, An. aconitus, An. "hyrcanus" group, An. karwari, An. fluviatilis and An. jeyporiensis among which the first five species forms the major bulk (92%). All the species showed preference to cattlesheds than human-habitation for resting. The ratio between morning and evening collection was 1:0.87.

Indoor resting anophelines of north Bengal.

A systematic survey was carried out between April 1993 and March 1994 to study the distribution and prevalence of anopheline mosquito species in two malaria-prone areas situated in the foothills of Darjeeling district. Ten different species of Anopheles viz. An. aconitus, An. annularis, An. barbirostris, An. culicifacies, An. fluviatilis, An. hyrcanus group, An. maculatus, An. subpictus, An. vagus and An. varuna were collected. Per man hour density of mosquitoes collected was 4.5 and the most prevalent species was An. vagus, comprising 63% of the total catch. An. fluviatilis, an efficient vector of malaria in the foothill regions of India, was reported for the first time from this area. However, the classical vector of this region viz. An. minimus was altogether absent during the course of the present survey. All the ten species were found in cowsheds while, human habitation harboured higher population density (56.5%) of the total catch.

The evaluation of skin prick test in house dust mite allergy in Calcutta, India.

Immediate type allergy towards house dust and house dust mites was measured in 188 dust-sensitive asthmatic patients in and around Calcutta by using the skin prick test. Of the 131 positive patients, 82% reacted to Dermatophagoides mites, 80% to D. farinae, 46% to D. pteronyssinus, and 43% to both species of mites. Sixty-two per cent of the positive patients showed strong skin reaction to D. farinae as compared to 32% to D. pteronyssinus. Skin reaction (positive/strong) was highest in D. farinae as compared to other allergens tested in the present study. Skin test results were also analysed in relation to patients' age, sex and duration of disease.

Relationship between Dermatophagoides mite density and specific immune response in asthmatic patients.

Dermatophagoides mites were abundant in the beds of asthmatic patients of Calcutta, India, comprising more than 60% of the total mites isolated in the present study. The patients' bed dust harbored significantly more dense (P < .02) mite populations as compared with bed dust samples of control subjects. The patients' sera contained significantly higher (P << .001) IgE concentrations than the sera of the controls and the sera of 92% patients were found to have elevated IgE levels of more than 300 U/mL. Eighty-five and 82% of patients responded positively to Dermatophagoides mite allergen by radioallergosorbent test (RAST) and skin prick test respectively, highlighting the importance of these mites in producing house dust allergy in Calcutta and its surrounding areas. The results indicate that with a tenfold increase in mite density in the patients' bed dust, the group mean serum IgE level increased considerably (P < .05). The increase in the total serum IgE and in the frequency of positive RASTs and prick tests to Dermatophagoides for allergic asthmatic patients correlated quite well with the increase in the specific mite density in their beds.

House dust mite allergy in Calcutta, India: evaluation by RAST.

A significantly elevated (above 300 U/mL) serum IgE level was found in 97 of 105 dust-sensitive asthmatic patients of Calcutta and the mean value (1002 +/- 614 U/mL) was significantly higher (P << .001) than the control sera. RAST results indicate a higher sensitivity (84.76%) to house dust and house dust mites (Dermatophagoides supp) either alone or in combination with each other. Among positive samples, 79.77%, 71.91%, and 88.76% showed the presence of allergen specific IgE antibodies against house dust (HD), D. pteronyssinus (DP), and D. farinae (DF) mite antigens, respectively. The study highlighted the superiority of D. farinae antigen as a potent allergen in house dust of Calcutta over others and the mites and house dust possibly had a common allergen. The present investigation indicates that RAST sensitivity was independent of age and sex of patients (P > .05). The frequency of RAST sensitivity was observed to be greater in patients suffering for longer durations.

Role of cockroaches in allergy to house dust in Calcutta, India.

Prick skin tests on 200 patients with a history of sensitivity to dust were done against house dust, cockroach, D. pteronyssinus, and D. farinae antigenic extracts. The frequency of positive reaction was 35% to cockroach, 59% to house dust, 84.7% to D. farinae, and 54% to D. pteronyssinus. Distinctively different prevalence of the three antigens, cockroach, house dust, and mites suggest that cockroach antigen is a specific antigen independent from house dust and mite antigens.

Clinical significance of IgE in bronchial asthma.

Total mean serum IgE levels of 63 patients (aged 16-49 years) suffering from bronchial asthma and 64 control subjects (aged 19-40 years) were estimated by RIA method. Mean serum IgE level of patients and control subjects was 1132 +/- 643 units/ml and 43 +/- 26 units/ml respectively. The difference between the two values was statistically significant (p less than 0.001). Four per cent of the patients had serum IgE levels within normal limits. No significant correlation was found between mean serum IgE level of the patients and the duration of the disease. Differences in mean serum IgE level of male and female patients and control subjects was not statistically significant. The mean serum IgE level of patients in the age group of 21-40 years was highest (F = 1.33, p less than 0.05). Significantly elevated levels of serum IgE were observed in patients with both personal and family history of atopic disease in comparison to patients with only personal or family history only (p less than 0.05). As such the estimated raised level of IgE was significant in view of the severity of atopic asthma.