Search

In search for botanicals as an alternative remedy to synthetic chemicals in the pest control of tea plantations, ferns such as Adiantum raddianum, Asplenium aethiopicum, Cyclosorus interruptus, Dicranopteris linearis, Diplazium polypodioides, and Pteridium aquilinum were evaluated against the two major pests of tea, red spider mite Oligonychus coffeae Nietner and tea mosquito bug Helopeltis theivora Waterhouse, which are the foremost seasonal pests in tea fields, causing severe crop loss. Apart from synthetic chemicals, only the neem kernel extract is recommended in tea fields. The aqueous extracts of ferns were screened at different concentrations against these pests under laboratory and field conditions. The extracts of P. aquilinum and D. linearis showed good contact toxicity at a 5% concentration to O. coffeae. The acaricidal activity was observed in the order P. aquilinum > D. linearis > C. interruptus > A. raddianum > D. polypodioides > A. aethiopicum. Under field conditions, the extract of D. linearis and P. aquilinum showed a 50% reduction in the population of red spider mite and caused no phytotoxic effect to tea leaves. But their insecticidal activity was less pronounced against H. theivora. They exhibit antifeedant activity, which was sustained only for 24 hours. The photochemical screening of extracts showed a qualitatively increased level of saponins in P. aquilinum, D. linearis, and C. interruptus. The study shows that the aqueous extracts of D. linearis and P. aquilinum can be incorporated in the mite control programme in tea.

Helopeltis theivora commonly called as tea mosquito bug (TMB) is considered as important pest of tea in South India. Extensive survey in tea plantations of Anamallais, recorded H. bradyi and Pachypeltis maesarum (Hemiptera: Miridae) causing considerable damage and were registered for the first time on tea. Their occurrence was seen in association with H. theivora. There was considerable variation among these species in size of the circular rings formed by rostral piercing, indicating that these three species can be easily demarcated based on the observation of feeding punctures even in field condition. As the dosage and recommendations of insecticides against TMB in tea in south India was pertaining only to H. theivora the addition of H. bradyi and P. maesarum will improve the future pest management strategies.

The incidence of peritonitis ranges from 1 episode every 24 patient treatment months to 1 episode every 60 patient treatment months [Keane WF, et al. ISPD Guidelines/Recommendations. Adult peritoneal dialysis-related peritonitis treatment recommendations: 2000 update. Perit Dial Int 2000; 20:396-411.]. Gram-positive organisms account for over 80% of continuous ambulatory peritoneal dialysis (PD)-associated peritonitis. Recent fear of vancomycin-resistant enterococci (VRE) has prompted suggestions of limiting vancomycin use. Fifty-one episodes of peritonitis in 30 patients studied over 2 years were evaluated. Cloudiness of the PD fluid and/or abdominal pain were considered suggestive of peritonitis and were confirmed by cell count and culture. Baseline cell count, Gram stain, and cultures were obtained, with periodic follow-up. Patients were randomized to receive either vancomycin 1 g/L intraperitoneally (IP) as loading dose, repeated on day 5 or day 8, depending on residual renal function, for 2 weeks, or cefazolin 1 g in the first PD bag and continued with 125 mg/L every exchange for 2 or 3 weeks, depending on culture results. All patients also received gentamicin 40 mg IP every day until the culture results were available. A similar randomized trial comparing vancomycin and cefazolin in the past used a lower concentration of cefazolin 50 mg/L [Flanigan MJ, Lim VS. Initial treatment of dialysis associated peritonitis: a controlled trial of vancomycin versus cefazolin. Perit Dial /nt 1991; 11:31-7.]. Peritoneal dialysate fluid cultures revealed 31(60.7%) gram-positive organisms, 7(13.7%) gram-negative organisms, and 2 (3.9%) cultured yeast; 11 (21.5%) cultures yielded no growth. The incidence of peritonitis at our center was 1 episode every 42 patient treatment months. No case of VRE was noted. There was no statistical difference in clinical response or relapse rate for the two protocols. It was the authors' and nurses' observation that patient compliance and satisfaction was better with vancomycin, and the cost per treatment was 23% less than cefazolin. Based on these data we believe vancomycin should still be considered for first-line treatment of PD-associated peritonitis.