Population dynamics and management of diamondback moth (Plutella xylostella) in China: the relative contributions of climate, natural enemies and cropping patterns

Abstract

Diamondback moth or DBM is the major pest of Brassica vegetable production worldwide. Control has relied on insecticides, and DBM resistance to these compounds has evolved rapidly. We review and summarize data on DBM population dynamics across a large latitudinal gradient from southwest to northeast China: DBM is, on average, more common in southern locations than in northern locations. The species' phenology is consistent: in southern and central locations there is a decline during hot summer months, while in the north, the species can only exist in the summer following migrations from the south. A cohort-based discrete-time model, driven by daily maximum and minimum temperatures and rainfall, which was built using the DYMEX modelling software, captures the age-structured population dynamics of DBM at representative locations, with year round cropping and threshold-based insecticide applications. The scale of the simulated pest problem varies with cropping practices. Local production breaks and strict post-harvest crop hygiene are associated with lower DBM populations. Biological control appears to improve the management of DBM. Of the management strategies explored, non-threshold based applications of insecticides with reduced spray efficacy (due to poor application or resistance) appear the least effective. The model simulates the phenology and abundance patterns in the population dynamics across the climatic gradient in China reasonably well. With planned improvements, and backed by a system of field sampling and weather inputs, it should serve well as a platform for a local pest forecast system, spanning the range of DBM in China, and perhaps elsewhere.

Temperature-dependent phenology of Plutella xylostella (Lepidoptera: Plutellidae): Simulation and visualization of current and future distributions along the Eastern Afromontane

“…This modeling approach was applied to predict a decrease in the development times of eggs of Busseola fusca from 19.1 to 6.5 days between 15 and 30°C, respectively [24–26]. Phenology models are process-oriented mathematical expressions that link climate variability with lesser levels of abstraction to physiological pattern of the insect species growth to mimic and predict the dynamics of their population within a given point location or region [14,27–32]. …”

Constraints to Vegetable Production Resulting from Pest and Diseases Induced by Climate Change and Globalization: A Review

“…However it has been recorded that most of these farmers are doing this without any guidance from the manufacturer and therefore it becomes harmful to the environment (Ngowi et al, 2007). Diamondback moth has also been reported to be resistance to many insecticides in China (Li et al, 2016). Integrated Pest Management has been proved to be effective in reducing diamondback moth in China.…”

“…China country has made more efforts to support implementation of Integrated Pest Management and this has been adopted by many farmers. However, these practices need to be supported continuously to prevent more insecticide reliance by farmers (Li et al, 2016).…”

“…Southern African countries will continue to be vulnerable to climate change (IPCC, 2014), and this will be problematic to brassica production because diamondback moth is exacerbated by climatic changes and variability (Furlong et al, 2013). In countries such as China, diamondback moth has costed the Chinese economy about US$0.77 billion annually (Li et al, 2016).…”

Isolation, characterization and toxicity of native Bacillus thuringiensis isolates from different hosts and habitats in Iran

“…Diamondback moth, Plutella xylostella (L.) (Lepidoptera, Plutellidae), is a serious and important pest of cruciferous plants worldwide (Talekar and Shelton 1993;Sarfraz et al 2006;Li et al 2016). Plutella xylostella occurs annually throughout different regions of Iran wherever cruciferous crops are grown and can cause substantial crop losses during outbreak years (Keyhanian et al 2005).…”