Population phenology of insect pests in vegetable French bean, Phaseolus vulgaris L. and environmental forecast modeling for major pests using ARIMAX analysis

Nineteen insect species from four major insect orders viz., Hemiptera, Lepidoptera, Coleoptera, and Orthoptera, were found belong to sixteen families damaging common bean, which is also known as French bean cultivation in subtropical climates. Among the insect pests, sucking insects occupies maximum incidence; aphid, Aphis craccivora Koch incidence was peak in both seasons 2018 (77.4 aphids/plant) and 2019 (77.6 aphids/plant) during 8(th) SMW followed by Leafhoppers, Empoasca kerri Pruthi (6.4 Nos/plant). The impact of weather factors on the insect populations showed that minimum temperature negatively correlated with aphids (r =-0.189), leafhopper (r = -0.315) populations and positively correlated with whitefly, Bemisia tabaci Gennadius (r = 0.118) and thrips, Thrips palmi Karny population (r = 0.052). Relative humidity and rainfall were negatively correlated with French bean sucking pests. In defoliators, serpentine leaf miner, Liriomyza trifolii Burgess larvae incidence was high in both seasons (18.4 larva/plant) and (20.6 larva/plant) followed by hairy caterpillar, Euproctis fraterna Moore (1.4 larva/plant) and leaf folder, Nacoleia spp (1.15 larvae/plant). Among the pod borers, spotted pod borer, Maruca vitrata incidence was higher than others and influenced by both maximum (r = 0. 791) and minimum temperature (r = 0.714). Relative humidity and wind speed parameters were negatively correlated with pod borers viz., M. vitrata Fabricius and Helicoverpa armigera Hubner respectively. The model ARIMAX (3, 0, 0) of aphids showed that the incidence of the pest depended on the weather parameters such as minimum temperature, relative humidity, and rainfall significantly. The ARIMAX (2, 0, 0) model of M. vitrata showed that the weather parameters such as maximum temperature, minimum temperature and relative humidity played a significant role in the incidence of the M. vitrata.

Automated summary

A total of 19 insect species from four major insect orders were identified as pests damaging common bean cultivation. The incidence of sucking insects was the highest, with aphids being the most prevalent. Weather factors such as temperature, relative humidity, and rainfall influenced the population dynamics of these pests. Different models were used to analyze the relationship between weather parameters and pest incidence.