Degree day-based model predicts pink bollworm phenology across geographical locations of subtropics and semi-arid tropics of India

Abstract

There is a global concern about the effects of climate change driven shifts in species phenology on crop pests. Using geographically and temporally extensive data set of moth trap catches and temperatures across the cotton growing states of India, we predicted the phenology of cotton pink bollworm Pectinophora gossypiella (Saunders). Our approach was centered on growing degree days (GDD), a measure of thermal accumulation that provides a mechanistic link between climate change and species’ phenology. The phenology change was predicted by calculating absolute error associated with DD and ordinal date, an alternative predictor of phenology, for peak moth abundance. Our results show that GDD outperformed the ordinal dates in predicting peak moth abundance in 6 out of 10 selected locations. Using established thresholds of 13.0/34.0 °C, mean DD accumulated between the consecutive moth peaks across different years were estimated at 504.05 ± 4.84. Seven generations were determined for pink bollworm in a cropping season, the length of which varied between 35 and 73 days in response to temperature. Pink bollworm population reached its peak during third generation which can be the target for management actions. The study provides essential information for developing pink bollworm management strategies under climate change.

Elementos del clima y su relación con la polilla guatemalteca Tecia solanivora (Povolný, 1973) (Lepidoptera: Gelechiidae) en cultivo de papa (Solanum tuberosum L.)

“…En el presente estudio se logró identificar que la croscorrelación de los grados día (1 -4,6 °Cd ±1 °Cd) de T. solanivora, presentó una respuesta positiva, representada en picos uniformes de población de adultos al transcurrir del tiempo, por tanto, esta variable tiene una relación directa con el aumento de las poblaciones de adultos del insecto. Lo que coincide con estudios en otras polillas como Pectinophora gossypiella (Saunders, 1844) (Lepidoptera: Gelechiidae) (Fand et al, 2021) y Phthorimaea operculella (Zeller, 1873) (Lepidoptera: Gelechiidae) (Skenderasi et al, 2021).…”

Timings of treatments determine the effectiveness of insecticides in controlling the cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)

“…The life cycle of PBW passes through four distinct developmental stages viz., egg, larva, pupa and adult, and requires accumulation of ~500 growing degree days (GDD) for completion of one generation (Beasley and Adams, 1996;Peddu et al, 2020;Fand et al, 2021). The length of life cycle of PBW varies with prevailing environmental conditions, especially the temperature during cotton growing season, being shortest (35-37 days) during relatively warmer months of July to October, and longest (59-73 days) during cooler winter months of November to January (Peddu et al, 2020;Fand, 2021;Fand et al, 2021). Generally, PBW is a late season pest of cotton crop and its infestation coincides with the onset of squaring, flowering and boll development (Fand, 2021;Fand et al, 2021); accounting for huge yield losses to the tune of 30% (Fand et al, 2019).…”

“…The length of life cycle of PBW varies with prevailing environmental conditions, especially the temperature during cotton growing season, being shortest (35-37 days) during relatively warmer months of July to October, and longest (59-73 days) during cooler winter months of November to January (Peddu et al, 2020;Fand, 2021;Fand et al, 2021). Generally, PBW is a late season pest of cotton crop and its infestation coincides with the onset of squaring, flowering and boll development (Fand, 2021;Fand et al, 2021); accounting for huge yield losses to the tune of 30% (Fand et al, 2019). The larvae of PBW feed on developing flower buds and seeds of green bolls of cotton plant, which causes rosetted flowers, premature opening of infested bolls, reduction in fibre length and poor quality of lint due to staining (Fand et al, 2019;Fand et al, 2020;Fand, 2021).…”

“…The probable origin of PBW is in Indo-Pakistan region (Saunders, 1843;Naranjo et al, 2001), and it is now present in tropical America, Africa, Asia, Australia, Egypt, USA and Mexico (CABI, 2022). The life cycle of PBW passes through four distinct developmental stages viz., egg, larva, pupa and adult, and requires accumulation of ~500 growing degree days (GDD) for completion of one generation (Beasley and Adams, 1996;Peddu et al, 2020;Fand et al, 2021). The length of life cycle of PBW varies with prevailing environmental conditions, especially the temperature during cotton growing season, being shortest (35-37 days) during relatively warmer months of July to October, and longest (59-73 days) during cooler winter months of November to January (Peddu et al, 2020;Fand, 2021;Fand et al, 2021).…”

“…The blanket application of periodical, calendar date-based insecticide sprays seems to be unwise in suppressing the PBW because of increased target site inaccessibility of the spray chemical once the larvae penetrate into the bolls. Therefore, for better control efficacy, the insecticide sprays should be applied well before the larvae enter the green bolls (Naranjo et al, 2001;Fand, 2021;Fand et al, 2021). In this context, we evaluated some chemical insecticides against PBW by laying out specific experiments under laboratory conditions.…”