MSc

A study entitled “Management of the rhinoceros beetle (Oryctes rhinoceros L.) using new generation insecticides and botanicals” was conducted in four panchayats of Neyyattinkara taluk during 2012 to 2013. The objectives were to assess the intensity of damage caused by the rhinoceros beetle in coconut and evolve management measures using new generation insecticides and botanicals to control the beetle.
The survey was conducted in 40 coconut farmers’ gardens. The most salient findings of the survey were 1) WCT variety of palm was predominant in the area (87.50 %). 2) 55 per cent of the palms were above 40 years. 3) 82.50 percent of palms gave less than 40 nuts per year. 4) the recommended dose of manures and fertilizers were applied by only 20 percent of the farmers. 5) only 12.50 percent of the farmers irrigated the palms. 6) about 30.00 of the farmers conducted only field sanitation and crown cleaning and 7) no farmer undertook pest management measures in an integrated manner against the rhinoceros beetle.
In the four panchayats, the mean percentage of palms infested, fresh infestation on palms, leaves infested, central spindles infested, fresh spathes infested, dried spathes infested by the rhinoceros beetle were 77.50, 25.89, 45.33, 35.50, 14.43 and 7.55, respectively.
Apart from the rhinoceros beetle infestation, the percentage of palms infested by coreid bug and eriophyid mite was 34.00 and 35.00 per cent respectively. Thirty two per cent of the palms exhibited symptoms of leaf rot disease.The rhinoceros beetle did not infest any crop other than coconut.
The rhinoceros beetle population and its damage to leaves, spathes and central spindles of the coconut palms were positively correlated to minimum temperature and number of rainy days.
The mean population of male and female rhinoceros beetles caught per fortnight in aggregation pheromone traps ranged from 6.33 to 7.00 and 5.66 to 6.00 respectively during May 2012 to July 2012.
The most important constraint in adoption of recommended practices in coconut cultivation was high cost of labour followed by low cost of produce, uneconomical holding size and lack of proper guidance.
Four field experiments were conducted in farmers’ fields to evaluate the effect of selected new generation chemical insecticides and botanicals for the control of rhinoceros beetle in coconut. The results indicated that the best treatments included the chemical insecticide, cartap hydrochloride followed by crushed neem seed kernel.
The present investigations brought to focus the crop husbandry practices including plant protection adopted by coconut farmers, constraints, incidence of rhinoceros beetle and its extent of infestation. Based on the study, the following recommendations can be included as part of an Integrated Pest Management strategy against the rhinoceros beetle.
“Crown cleaning followed by three applications of either cartap hydrochloride 4 G (25 g) plus (200 g) sand mixture or crushed neem seed kernel (100 g) plus (200 g) sand mixture in the innermost three leaf axils during April-May, September – October and December-January.”