Potential impact of pests of sugarcane in the major growing districts of Tamil Nadu under varied climatic conditions

Introduction

Sugarcane is an important cash crop grown in India since ancient times and it is one of the most important cash crops and industrial crops after textiles. Sugarcane is grown in various states in subtropical and tropical regions of the country. Sugarcane provides raw material for the second largest agro-based industry after textile. The sugar industry is an instrumental in generating the sizable employment in the rural sector directly and through its ancillary units. In Tamil Nadu sugarcane is cultivated at an average area of 1.59 lakh ha with an average yield of 111 MT/ha. In Tamil Nadu 65 to 75 per cent of sugarcane produced is used as raw material for sugar mills (Anonymous, 2023) [1] . Sugarcane is a long-duration crop of 10-18 months and normally crop is followed by one or two ratoon crops, grown over large areas for higher production of sugarcane per unit area. This provides a sort of mono-cropping stable agro ecosystem for the multiplication of insect pests. Though the sugarcane agro-ecosystem is a stable one periodically it is affected by different abiotic and biotic changes in the environment. These changes along with difficulties in the application of chemicals in the closed canopy and limited control provided by various insect pest control tactics (viz. cultural, mechanical and biological).

Early shoot borer, Chilo infuscatellus Snellen (Crambidae:Lepidoptera) is the major pests of sugarcane, infesting the crop during its early growth stages (i.e. prior to internode formation) (David and Nandagopal 1986) [2]. Based on the feeding habit, the insect pests are broadly classified as borers, sucking pests, subterranean pests, defoliators and noninsect pests. Among these, nine lepidopteran borers are considered as most detrimental in both tropical and sub-tropical sugarcane fields. The larvae of borers may reduce yield upto 80 per cent (Goebel et al., 2011 ) [5]. ; Kalra and Sidha 1955) [4]. Amongst the borers, Chilo sacchariphagus indicus (Kapur) (Lepidoptera: Pyralidae), commonly known as internode borer, has remained a major pest in peninsular India (Gupta, 1957) [6]. . There is a necessity to monitor and assess the population dynamics of the major borer pests and sucking pests of sugarcane to early warn the farmers and take appropriate management steps to avoid yield loss.

Materials and Methods

Roving survey was carried out in sugarcane crop at monthly intervals in Cuddalore, Villupuram, Kallakurichi,Trichy, Thiruvannamalai,Chengalpet and Ariyalur districts of Tamil Nadu, India to assess the damage level of major borer and sucking pests of sugarcane during 2024-25 and 2025-2026. In each field, the early shoot borer was assessed based on the per cent deadhearts, for internode borer the per cent damaged canes, sucking pests viz., white fly, woolly aphid,mite damage was assessed based on per cent damaged leaves and for crown mealybug and pokkah boeng disease grading was used to assess the damage.In the survey besides to damage assessment, the details on the variety, stage of the crop, plant or ratoon crop were also collected.

Results and Discussion

The results of the roving survey during 2024-2025 revealed that the damage level of early shoot borer in sugarcane ranged from 5.60% (Velliyakudi, Cuddalore dist.) to 9.27% (Varakkalpattu, Cuddalore Dist.). Damage level of inter node borer ranged from 3.69% (Sitarasurr) to 34.67% (Mokur, Kallakurichi Dist). The incidence of Crown mealybug and Pokkoh boeng disease with mean damage grade ranged from 1.40 (Solainayakkanpalayam-Cuddalore Dist.) to 3.20(Kizhapalur-Ariyalur Dist.) During September 2024, white grub damage was recorded at Melmalaiyanur block of Villupuram District. The incidence of white grub ranged from 1.8 grub/clump(Karadikuppam) to 3.2 grub/clump (Ethapattu).The incidence of whitefly ranged from 8.0 -22.82% leaf damage at Semmandalam. The incidence of sugarcane woolly aphid was recorded as 5.5% leaf damage at S.K.Palayam of Cuddalore Dist (Table 1). During 2025-2026, the damage level early shoot borer in sugarcane ranged from 4.65% (Thirukandeeswaram,Cuddalore dist.) to 10.80% (Semmandalam, Cuddalore Dist.). Damage level of inter node borer ranged from 6.50% (Vilangalpet, Cuddalore Dist.) to 18.60% (Semmandalam, Cuddalore Dist). The incidence of Crown mealybug and Pokkoh boeng disease with mean damage grade ranged from 0.90(Sirumadurai, Villupuram Dist.) to 2.50(Thellar, Thiruvannamalai Dist.) During July 2025, white grub damage was recorded at Chinnasalem block of Kallakurichi District. The incidence of white grub ranged from 0.9 grub/clump(Kizhpathi) to 1.2 grub/clump (Oothuvodai).The incidence of mite ranged from 5.50% to 6.50%leaf damage at Semmandalam. The incidence of sugarcane woolly aphid was recorded as 3.5% leaf damage at S.K.Palayam of Cuddalore Dist. During March 2026(Table 2). Early shoot borer, Chilo infuscatellus Snellen (Crambidae: Lepidoptera) is the major pests of sugarcane, infesting the crop during its early growth stages (i.e. prior to internode formation) (David and Nandagopal 1986) [2] . Economic loss caused by this particular pests is due to a 16-65% reduction in sugarcane setts and mother shoots, resulting in 22-33% losses in cane yield (Singh and Tomar 2003) [3] . Usually, C. infuscatellus infestations are high during the tillering phase, but decrease appreciably during the south-west monsoons that often begin in July (David and Nandgopal 1986) [2] . The early shoot borer incidence Kharif during 2019 was first reported at 17thstandard week (last week of April) with 3.38 percent per ten plants when mean maximum andtemperature 34.36 °C and 28.84 °C, relative humidity at morning and evening 90.29 and 64.29 per cent and rainfall were ranged from 0.00 to 0.00 mm, respectively(Pankaj Batham et.al 2023) [7]. The internode borer is distributed in the states of Tamil Nadu, Kerala, Andra Pradesh, Karnataka, Maharashtra, Bihar, Uttar Pradesh and Haryana (Siddiqi and Agarwal, 1957) [8] . Internode borer generally attacks the crop from internode formation to harvest, causing estimated crop losses of 10-35 Per cent. When the borer injury extends to three or more internodes per cane, or more than 10% of the total length of the cane, canes suffer significant deterioration in juice quality. The threshold for the internode borer was found to be 13 -15 per cent bored internodes (Yalawar et al., 2010) [9] .

References

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