Bhendi or okra Abelmoschus esculentus L. Moench is one of the most vital vegetable crops grown extensively in tropical and subtropical parts of the world. In India, okra occupies a significant place among vegetable crops owing to its short duration, adaptability and continuous market demand. The crop is nutritionally rich, containing appreciable amounts of dietary fibre, proteins, vitamins, minerals and carbohydrates and hence plays a significant part in human nutrition (Kumar et al., 2010; Omoniyi et al., 2020). Due to its wide adaptability and economic importance, okra is often referred to as the “queen of vegetables”. Asia contributes to major share of global okra production, with India being the largest producer. Despite the expansion of area under okra cultivation, productivity remains relatively low due to various biotic (pests and diseases) and abiotic (climatic and environmental) stresses (FAOSTAT, 2020). In Tamil Nadu, okra is grown throughout the year under irrigated conditions; however, yield stability is often affected by pest pressure and climatic variability (INDIASTAT, 2021). Amid the biological factors, insect pests are considered the most serious constraint in okra production. The crop is susceptible to pest infestation from the early seedling stage till harvest and more than seventy species of insects have been reported to infest okra at various growth stages (Srinivasa and Rajendran, 2003). Among these, sucking pests are of prime importance as they continuously extract plant sap, weaken the plants and reduce yield potential. The major sucking pests associated with okra include Aphids(Aphis gossypii Glover), Whiteflies (Bemesia tabaci Gennadius), Leafhoppers (Amrasca biguttula biguttula Ishida), Thrips (Thrips tabaci Lindeman) and Mealybugs(Phenacoccus solenopsis Tinsley) (Singh et al., 2018). Sucking pests cause direct damage by sap feeding and indirect damage through honeydew excretion, leading to sooty mould development and reduced photosynthetic activity. Whiteflies and aphids are known to act as vectors of viral diseases, thereby aggravating crop losses (Navas-Castillo et al., 2011). Several studies have reported notable yield reduction in okra due to sucking pest infestation, particularly during peak vegetative and fruiting stages (Kanwar and Ameta, 2007; Vikas et al., 2016). Seasonal variations in weather parameters often result in fluctuations in pest population dynamics, making weather-based pest forecasting an essential component of integrated pest management (Kumar et al., 2010). Although several studies have reported the influence of meteorological parameters on insect pests of okra, region-specific information on the seasonal abundance of sucking pests under coastal agro-climatic conditions is limited. Similar observations on the influence of abiotic factors on insect pest population dynamics have been reported in other crop ecosystems (Meena et al., 2026). Understanding the relationship between weather variables and pest incidence is therefore essential for developing timely and location-specific pest management strategies. In this context, this study was carried out to evaluate the seasonal occurrence of key sucking pests on Bhendi and their relationship to meteorological factors. 

The present study was executed at the experimental field of SRM College, Baburayanpettai, Tamil Nadu, India, situated at approximately 12.85° N latitude and 80.05° E longitude, representing the coastal agro-climatic conditions of the area. The investigation was carried out during the cropping period from October 2025 to January 2026, corresponding to Standard Meteorological Weeks (SMW) 40 to 3, with the objective of studying the seasonal incidence of major sucking pests on Bhendi (Abelmoschus esculentus L.). The Bhendi variety ‘Arka Anamika’ was raised following the recommended package of practices. The crop was planted at a spacing of 45 cm × 30 cm and all agronomic practices were uniformly adopted throughout the crop period, except for plant protection measures, which were deliberately avoided to allow natural pest buildup. Weekly observations were recorded on major sucking pests, viz., leafhoppers(Amrasca biguttula biguttula Ishida), mealybugs (Phenacoccus solenopsis Tinsley), whiteflies (Bemisia tabaci Gennadius), thrips (Thrips tabaci Lindeman) and aphids (Aphis gossypii Glover). Pest abundance was assessed by tallying the number of insects present on three leaves per plant (one each from the top, middle and bottom canopy) selected randomly from tagged plants. The mean population was expressed as the number of insects per three leaves. Daily meteorological data, viz., minimum temperature (°C), maximum temperature (°C), Relative humidity (%) and rainfall (mm), were obtained from the nearby meteorological observatory. These data were converted into weekly mean values and expressed according to Meteorological Standard Weeks (MSW). The correlation between meteorological parameters and sucking pest occurrence was analysed using Pearson’s correlation coefficient.
       
The population density of sucking pests was calculated from the following formula:

Seasonal incidence of sucking pests on bhendi
 
Leafhoppers (Amrasca biguttula biguttula Ishida)
 
The incidence of Leafhopper was not observed during the initial stage of the crop 40^th and 41^st Meteorological Standard Week (MSW). The population appeared during 42^nd MSW (third week of October) with a mean density of 0.5 Leafhoppers per three leaves and increased gradually thereafter. A steady buildup was noticed from 43^rd MSW to 48^th MSW. The peak population was observed during 48^th MSW (fifth week of November) with 17.1 Leafhoppers per three leaves. Subsequently, the population declined gradually from 49^th MSW onwards and reached a low level by 3^rd MSW (third week of January). The leafhopper population remained active mainly during the mid-season of the crop. Leafhoppers population reflected a negative correlation with maximum temperature (r = -0.404) and minimum temperature (r = -0.303), while positive correlation was observed with relative humidity (r = 0.244). Rainfall demonstrated a negative association with Leafhopper population (r = -0.158) (Table 1). The population of Leafhoppers on Bhendi showed a gradual increase from the early stage of the crop and attained its peak during the mid-season, corresponding with moderate maximum temperature, relatively lower minimum temperature and higher relative humidity. The progressive buildup of Leafhoppers during MSW 45^th to 48^th may be attributed to favourable climatic conditions that support rapid multiplication and feeding activity. A population decline was noted during the later weeks of the crop, which could be due to fluctuations in temperature and the occurrence of intermittent rainfall, adversely affecting leafhopper survival and activity. Similar seasonal trends of leafhopper incidence on okra in relation to weather parameters have been reported earlier (Gupta et al., 2024). The present findings clearly indicate that weather variables play a major role in controlling leafhopper population dynamics on Bhendi.  Similar trends were reported by Singh et al., (2013), who found a negative association between the leafhopper population and mean, maximum and minimum temperatures as well as relative humidity. On the other hand, Jadhav et al. (2015) found a strong positive association between the leafhopper population and evaporation (r =0.586), minimum temperature (r =0.772) and maximum temperature (r =0.667) (Fig 1). Leafhopper infestation began when the okra crop was 21 days old, peaked when it was roughly 63 days old and after that, its population declined (Kumari et al., 2009).




 
Whiteflies (Bemisia tabaci gennadius)
 
Whitefly infestation commenced during 41^st MSW (second week of October) with a population of 2.1 whiteflies per three leaves. The population increased steadily from 42^nd MSW onwards and attained its peak during 48^th MSW (fifth week of November) with a maximum of 16.2 whiteflies per three leaves. Following that, a gradual population decline was noted from 49^th MSW to 3^rd MSW. Whiteflies remained active for a prolonged period and showed higher abundance during the mid-season of the crop. Similarly, whitefly population exhibited a negative correlation with maximum temperature (r = -0.444) and minimum temperature (r = -0.343). Relative humidity showed a positive correlation (r = 0.255), whereas rainfall had a weak negative correlation with whitefly incidence (r = -0.053) (Table 2). Whitefly population remained active throughout the crop growth period, with a gradual increase from the early stage and peak incidence during the mid-season. The highest population noted during favourable weather conditions suggests that moderate temperature and high relative humidity promote whitefly reproduction and feeding activity. Similar findings have been reported by Kumar et al., (2010); Venkanna et al., (2016), described that the peak whitefly population during last week of March, third week of January, last week of December in okra. The findings were similar to Kumawat et al., (2000) who demonstrated a significant positive correlation between whitefly population and highest temperature. According to Pun et al., (2005), whitefly population was positively correlated with maximum and minimum temperature and daylight hours, whereas it was negatively correlated with morning relative humidity, wind speed and total rainfall. As per Dhandge et al., (2018), Whitefly population was significantly positively correlated with the highest temperature and significantly negatively correlated with the lowest temperature and morning relative humidity. Singh and Thakur (2018) reported that the population of whiteflies had a positive association with relative humidity and a negative correlation with both the highest and lowest temperatures. Whitefly populations progressively grew as humidity and temperature increased and declined with the age of the plant (Latif et al., 2013). Similar observations on weather-mediated fluctuation of sucking pests in vegetable crops were reported by Mawtham et al., (2023).


 
Aphids (Aphis gossypii glover)
 
Aphid incidence was first recorded during 41^st MSW (second week of October) with a mean population of 1.3 aphids per three leaves. The population increased progressively from 42^nd MSW to 48^th MSW. The peak aphid population was observed during 48^th MSW, registering 14.5 aphids per three leaves. After reaching the peak, a gradual reduction in aphids population was noticed from 49^th MSW onwards and the population declined to a minimum by 3^rd MSW. Aphids were predominantly active from the early vegetative stage to the mid-fruiting stage. In case of aphids, maximum temperature showed a negative correlation (r = -0.369), while minimum temperature also exhibited a weak negative association (r = -0.160). Relative humidity was positively correlated with aphid population (r = 0.130). Rainfall showed a weak positive correlation (r = 0.077). Venkanna et al., (2016), examined the incidence of sucking pests in okra and reported that the maximum aphid population (5.4 aphids/3 leaves) during 1^st week of January. The appearance of aphid started during 3^rd SMW and attained its peak (139 aphids/leaf) in 9^th SMW of February (Nihal and Sarkar, 2019). The findings were similar that the population of A. gossypii had a significant negative correlation with minimum temperature (r = -0.65), maximum temperature (r = -0.60) and relative humidity (r = -0.76) (Kaushal et al., 2019). In contrast, the aphid population has a substantial positive association with maximum temperature, morning, evening and average relative humidity (Meena et al., 2020) and aphids indicated a non-significant connection with meteorological parameters (Suman et al., 2022). The association between aphid incidence and abiotic factors observed in the present study is in agreement with findings reported by Pal et al., (2023).
 
Thrips (Thrips tabaci lindeman)
 
Thrips population was first observed during 41^st MSW with an average density of 0.8 thrips for every three leaves. A continuous increase in population was recorded from 42^nd MSW onwards. The maximum population was recorded during 48^th MSW with 12.1 thrips per three leaves. Following the peak, the thrips population showed a gradual decline from 49^th MSW to 3^rd MSW. Thrips infestation was comparatively higher during the mid-season period of the crop. Similarly, thrips population exhibited a negative correlation with maximum temperature (r = -0.410) and minimum temperature (r = -0.273). Relative humidity showed a positive correlation (r = 0.191), while rainfall manifested a weak positive association (r = 0.017). Thrips infestation followed a seasonal trend similar to other sucking pests, with population buildup during the crop’s mid-season. The peak population recorded under moderate temperature and high relative humidity suggests that these conditions favour thrips activity and reproduction. Vennila et al., (2007) reported that the severity of sucking pests is exacerbated by high temperatures and little rainfall and further reported that the Thrips population peaks during dry spells with high temperatures, which are ideal for population growth.
 
Mealybugs (Phenacoccus solenopsis tinsley)
 
Mealybug incidence commenced during 41^st MSW with a population of 1.0 mealybugs per three leaves. The population increased steadily from 42^nd and reached its peak during 48^th MSW with a maximum of 13.2 mealybugs per three leaves. Following that, a gradual population reduction was noted from 49^th onwards and the infestation persisted at a lower level until 3^rd MSW. Mealybugs remained active throughout the crop period, with severe infestation observed during the mid-season. The incidence of Mealybugs showed a negative correlation with maximum temperature (r = -0.413) and minimum temperature (r = -0.276). Relative humidity exhibited a positive association with leafhopper population (r = 0.183), while rainfall showed a negligible positive correlation (r = 0.021). These findings are consistent with those of Mani and Thontadarya (1987), who found a substantial positive association between the mealybug population and maximum temperature. The population of mealybugs and rainfall did not significantly correlate. The current results are identical to those of Patel et al., (1997), who stated that the mealy bug population did not reach its peak during periods of significant rainfall. The influence of abiotic factors on the population dynamics of sucking pests has also been documented in other cropping systems (Kalkal et al., 2026).

The present study demonstrated that major sucking pests of Bhendi, namely Leafhoppers, whiteflies, aphids, thrips and mealybugs, occurred all across the crop growth phase with peak incidence during the mid-season, particularly around the 48th Standard Meteorological Week under coastal agro-climatic conditions. The population buildup of all sucking pests showed a negative correlation with minimum and maximum temperatures. At the same time, relative humidity exerted a positive influence on their abundance, indicating its key role in pest proliferation. Rainfall had only a marginal effect on pest incidence during the cropping period. The synchronized peak action of sucking pests during periods of moderate temperature and higher relative humidity highlights the importance of weather-based monitoring for predicting pest outbreaks. The findings of this study provide valuable baseline information for developing location-specific, weather-based integrated pest management strategies to minimize crop losses and ensure sustainable Bhendi production.

The authors declare that there is no conflict of interest regarding the publication of this manuscript.