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Department of Entomology, S.V. Agricultural College, ANGRAU, Tirupati-517 502.
A roving survey was carried out in castor cultivating areas of Ananthapuramu district during kharif, 2023 to know the
incidence of sucking pests. From the selected district, different mandals, viz., Kanekal, Belguppa, Atmakur, Narpala, Uravakonda, Ananthapuramu, Bukkarayasamudram and Kalyandurgam were surveyed randomly for the incidence of sucking pests at two stages of crop growth period during kharif, 2023 at vegetative stage and at spike formation stage of the castor. Results revealed that at vegetative stage leafhopper and whitefly population were more compared to thrips, and thrips population was more during spike formation stage. The highest mean leafhopper population was recorded in Atmakur (28.6) followed by Bukkarayasamudram (27.5), Belguppa (26.72), Narpala (24.52), Kanekal (24.50), Ananthapuramu (23.06), Kalyandurgam (21.7) and Uravakonda (21.00) respectively. Highest mean thrips population was observed in Belguppa (9.72) followed by Narpala (8.20), Atmaku (8.00), Ananthapuramu (7.06), Uravakonda (7.20), Kanekal (7.40), Bukkarayasamudram (7.2) and Kalyandurgam (5.9). Highest white fly mean population was recorded in Bukkarayasamudram (38.5) followed by Atmakur (38.6), Kalyandurgam (33.00), Kanekal (31.00), Narpala (29.5), Uravakonda (27.06), Belguppa (26.72) and Ananthapuramu (22.06).
KEYWORDS: Castor, Leafhopper, Sucking pest, Thrips, Whitefly.
Castor (Ricinus communis L.) is a significant oil seed crop from the spurge (Euphorbiaceae) family, believed to have originated in Abyssinia. It is extensively grown in tropical and subtropical regions due to its minimal soil fertility requirements, moderate water needs, and lack of competition with food crops and food-grade oils. The plant is also well-suited to temperate climates. Castor is known for its high yield potential, with varieties and hybrids tailored for various agro-ecological conditions, producing approximately 800-1000 kg/ha under rainfed conditions and 1600-2000 kg/ha under irrigated conditions.
The production of castor in India is about 20.54 lakh tonnes with mean productivity of 2,044 kg ha-1 in 2023- 2024 (www. Statista.com). Gujarat is the major castor producing state accounting for 77 per cent area and 86 per cent production in the country followed by Rajasthan and Andhra Pradesh. Total area of castor in Andhra Pradesh during 2023-2024 was 0.33 lakh hectares and the total production was 0.33 lakh tonnes with a productivity of 575 kg ha-1 (www.agricoop.nic.in).
Among various pests, the leafhopper is a significant threat to castor plants, particularly during the summer and rabi seasons. The adult leafhopper species (Cicadellidae: Hemiptera), were greenish yellow small, slender wedge shaped insects of various forms, colours, sizes and distinguished from other Auchennorrhyncha by having one or more rows of spines on hind tibia and found on almost any type of plant, but each species is specific to only a few plants. Nymphs were pale greenish almost translucent and walk diagonally (6-10 days) and most prevalent in southern India, with peak infestations occurring from September to December in Andhra Pradesh and from November to January in Tamil Nadu (Sujatha et al., 2014). In Northeast India, leafhoppers are commonly found during the rabi and summer months wherever castor is grown. Extreme temperatures, whether hot or cold, and humid weather conditions increase pest activity and reproduction. Both nymphs and adults suck the sap causing hopper burn symptoms.
The castor whitefly, Trialeuro desricini is broadly polyphagous but is most commonly associated with castor bean (Ricinus communis Linnaeus) and plant species belonging to the former Leguminasae (now Caesalpiniaceae, Papilionaceae and Mimosaceae). It persists throughout the year on castor crop the peak activity is reported to be January to July. Adult is delicate with milky white coating on the body. Nymphs are pale yellowish they are ovalin shape, translucent with waxy projections all round. They remain adhere to the lower surface of the leaves. Both nymphs and adults suck the sap causing yellowing and drying of the affected leaves. If the infestation is severe, the vitality of the plant is reduced and its vegetative growth is arrested resulting in shedding of damaged leaves. Hence, survey for the sucking insect pests in castor would help in formulating the suitable management practices and timely management of the pests.
Roving survey on sucking insect pests of cast or was carried out in major cast or growing districts of Ananthapuram during August and September month, at two stages of crop growth period viz., vegetative and spike formation stages during kharif, 2023. From each mandal ten farmers’ fields were selected. The details of locations for field study are represented in Table 1. The farmer’s fields were surveyed following roving survey method and sucking pest status was evaluated by taking observations on ten plants from each field and expressed on per plant basis at vegetative and spike formation stages. For recording observations, the methodology as given in NCIP M manual for surveillance was followed. In case of sucking pests, population counts on leafhoppers was taken by counting the number of leafhoppers present on top (excluding two top most leaves), middle (medium matured leaves) and bottom (leaving two bottom most leaves) on the main shoot and the mean number of leafhoppers per plant was worked out. Population counts on thrips was carried out by counting the number of thrips per spike on each of the ten randomly selected plants and mean number per plant was worked out and in case of whiteflies adult population was recorded from fully developed top leaf on each of the ten randomly selected plants from each field. Simple statistical tools like mean was used to analyze the data. The mean of various sucking insect pests at two different crop growth period is presented in Table 2.
Leafhoppers: The results of the survey conducted during 2023-24, revealed that the mean population leafhopper in different mandals was ranged between 13.00 to 28.60 nymphs/ 3 leaves/ plant at vegetative stage at spike initiation stage mean population was ranged between 7.69 to 19.68 nymphs/ 3 leaves/ (Table 2 & Figure1). The results are in accordance with the findings of Akashe et al. (2015) who reported that leafhopper in castor was ranged from July to December
in the scarcity zone with a peak activity during August to September. The current studies were similar with Subash et al. (2014) who reported that leafhoppers were more prevalent in groundnut crop in August and September and also leafhoppers showed a negative relationship with rainfall. Leafhoppers exhibited a negative association with minimum temperature but a positive correlation with maximum temperature.
Thrips: The mean population of thrips in different mandals was ranged between 4.72 to 5.90 thrips/plant at vegetative stage at spike initiation stage mean population was ranged between 20.64 to 12.72 thrips/ spike (Table 2& Figure 2). The results are in confirmity with the findings of Ahir et al. (2017) reported that thrips (3.80 thrips) attained peak in the 2nd week of September. The results are similar with findings of Navya et al. (2024) reported that thrips infestation was started during the 52nd SMW with a population of 1.2 thrips /spike, with a peak population of 32 thrips/spike in the 8th SMW.
Whiteflies: The mean population of white flies in different mandals was ranged between 18.64 to 33.00 white flies/plant at vegetative stage at spike initiation stage mean population was ranged between 14.40 to
24.89 whiteflies/plant (Table 2 & Figure 3). The results are similar with the findings of Navya et al. (2024) reported that white fly infestation was first observed in the 4th SMW with a population of 10.8 whiteflies/top leaf/plant, with a peak population of 68.6 whiteflies / top leaf/plant in the 13th SMW. Overall survey studies revealed that sucking pests population and its incidence
depends on various climatic factors, it’s geographic allocation, genotypes and farmer’s cultivation practices. The present information on the status and diversity of the sucking insect pests of castor crop eco systems in Ananthapuramu district will help to formulate the priority research strategies by researchers. The knowledge on sucking insect pests scenario in castor crop ecosystems will also help the extension workers and farmers in deciding the judicious use of insecticides.
Ahir, K.C., Saini, A., Rana, B.S and Dangi, N.L. 2017. Population dynamics of sucking pests inrelation to weather Parameters in groundnut (Arachis hypogaea L.). Journal of Entomology and Zoology Studies. 5(2): 960-963.
Akashe, V.B., Indi, D.V., Patil S.R., Jadhav, J.D and Pawar, P.B. 2015. Incidence of insect pest damage in castor in relation to meteorological parameters in the scarcity zone of Maharashtra. Journal of Agrometeorology. 17(1): 139-141.
Directorate of Economics and Statistics. 2023. https:// des.ap.gov.in
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Navya, E., Aruna Sri, I., Duraimurugan, P and Srinivasa Chary, D. 2024. “Seasonal Incidence of Castor Sucking Pests in Southern Telangana Zone, India”. International Journal of Environment and Climate Change. 14(7): 789-95.
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Vijaya Lakshmi, P and Satyanarayana, J. 2003. Morphological characters of castor genotypes in relation to incidence of leafhopper and shoot capsule borer. M.Sc. Thesis. Acharya N.G. Ranga Agricultural University Rajendranagar, Hyderabad-500 030.