Effect of weather factors on populations of Helicoverpa armigera moths at cotton-based agro-ecological sites

Pheromone trapping was used to monitor populations of the moth Helicoverpa armigera at five cotton‐based agro‐ecological sites – river, vegetable, orchard, forest and clean cultivation (areas under only cotton cultivation) – in the Bahawalpur district, Pakistan. Three locations at each site were chosen and three pheromone traps at each location were installed in cotton fields. Moth catches were recorded at 15–20 day intervals from 24 October 2004 to 19 December 2006. In 2004, the river sites showed the maximum trapped population of H. armigera (0.22/trap) followed by 0.165 per trap at the vegetable sites. Orchard, clean cultivation and forest sites had zero moth catches. In 2005, the river sites again showed the highest trapped population (0.57/trap), followed by clean cultivation (0.45/trap), vegetable (0.44/trap), orchard (0.40/trap) and forest (0.29/trap). The moths appeared during July to December and March to May. In 2006, sites showed non‐significant difference, with a population range of 0.47 to 0.97 moths per trap. On average, river sites peaked at 0.49 per trap, followed by vegetable (0.38), clean cultivation (0.47), orchard (0.35) and forest (0.25) sites. The peak was observed on 3 April 2006, and moths appeared during February to July and October to December. The minimum temperature in river, forest and clean cultivation sites; the maximum temperature in orchard sites; and the average temperature in river, orchard, forest and clean cultivation sites showed significant positive correlations with trapped moth populations. Relative humidity showed significant negative correlation with population at the orchard sites in 2005. All weather factors during 2004 and 2006 showed non‐significant correlations with the moth populations. No model was found to be best fit by multiple linear regression analysis; however, relative humidity, minimum temperature, maximum temperature, minimum temperature and maximum temperature contributed 8.40, 10.23, 2.43, 4.53 and 2.53% to the population fluctuation of the moth at river, vegetable, orchard, forest and clean cultivation sites, respectively.     

Silkworm Growth and Silk Yield on Selected Supplemented/ Un-supplemented Mulberry Varieties

ABSTRACT Sericulture has been on developing foot hills till today in Pakistan. It is for the past few years that this industry has received recognition through greater research on the nutritional aspects. Various experiments i.e., nutritional supplementation and searching alternate food plants have been on way with varying degree of success. The present approach includes the very much neglected aspect of trying mulberry varieties and working out their impact on the silkworm growth/ development and silk yield. In Pakistan three varieties of mulberry Morus alba, M. nigra and M. indica are commonly found, these were selected for the present studies and the already established mineral dose 0.2 %N +0.1%P+0.3%K+0.1%Ca+0.15%Mg+0.15%Mn was supplemented to them through dipping method. Amongst the so designed nine treatments those in which the silkworm larvae were fed on M. nigra leaves in any form /combinati-yielded best results, as the larvae in these treatments consumed more food (73.71 gm/10 larvae) and converted maximum (77.22%) of it into body matter. This improved silkworm growth, a primary parameter for increasing the over all production and resulted in better cocoon size which weighed heavier (2.43 gm/cocoon and 1.10 gm/shell) as compared to rest of the test treatments (0.67 and 0.70 gm/shell on M. alba and M. indica , respectively).     

Comparison of Groundnut bud necrosis virus isolates based on movement protein (NSm) gene sequences

The nucleotide and amino acid sequences of the movement protein (NSm) genes of five isolates of Groundnut bud necrosis virus (GBNV) originating from different hosts and parts of India such as cowpea and tomato from Kerala, groundnut from Tamil Nadu, and potato from Madhya Pradesh and Rajasthan were determined and compared to the known NSm sequences. Sequence analysis revealed that the NSm genes of GBNV isolates were identical in length (924 bp encoding 307 amino acids). GBNV isolates shared maximum identity (98–100%) at amino acid levels with GBNV‐Type isolate, while 82–83% and 34–65% amino acid sequence identities were observed with Watermelon silver mottle virus and other Tospoviruses respectively. The NSm genes among GBNV isolates originating from different hosts and locations appeared highly conserved (93–100%), suggesting their common origin.     

Molecular Identification and Prevalence of Entamoeba histolytica,Entamoeba dispar and Entamoeba moshkovskii in Erbil City,Northern Iraq

The present study was conducted to evaluate the infection rates of Entamoeba histolytica, Entamoeba dispar, and Entamoeba moshkovskii among asymptomatic individuals in Erbil City, northern Iraq. The research intent was to discover whether pathogenic or nonpathogenic species cause a high rate of symptomless Entamoeba infections. Stool samples were microscopically examined, and the 18S-rRNA gene was targeted utilizing the nested PCR technique in the positive specimens. Initial results based on morphological features showed that the Entamoeba prevalence rate was 7.4%. Significantly higher rates of infections were seen in females than in males and in low-income people than in moderate-income people. The incidence rates among the asymptomatic individuals, as determined by molecular analysis, were as follows: E. histolytica – 6%, E. dispar – 4.3%, and E. moshkovskii – 0.3%. Of all the Entamoeba positive samples, a single infection with E. histolytica was identified in 41.4% samples; the single infection with E. dispar in 18.6% samples, 35.7% samples had mixed infections with two Entamoeba species, and 4.3% had mixed infections with three species. The current study concluded that 7.4% of healthy people, who live in the endemic area under investigation, carry Entamoeba species asymptomatically. Additionally, the majority of asymptomatic Entamoeba infections were caused by the pathogenic E. histolytica (81.4%) compared to E. dispar (58.6%), and E. moshkovskii with the lowest rate of infection. Single and co-infections with E. histolytica and E. dispar were noted. E. moshkovskii, which was identified for the first time in the region, was only seen in mixed infections.Key words: Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, epidemiology, asymptomatic infections