Insect and Pest Management for Sustaining Crop Production Under Changing Climatic Patterns of Drylands

Climate change is alarming, particularly for agriculturists as it severely impacts the development, distribution, and survival of insects and pests, affecting crop production globally. Over time, climate change is drastically tumbling the crop productivity in all the cropping systems, whereas the dryland agriculture with existing low productivity is immensely hit. While all the existing species in drylands, including humans, are coping with extreme climate variations for millennia, future climate change predictions put dryland agriculture in a threat zone. Drylands support 38% of the world’s population; therefore, climate change coupled with population growth and global food security draws the attention of scientists towards sustainable crop production under changing trends. The intermingling and intermixing of various biological, hydrological, and geographical systems plus the anthropogenic factors continuously amplify the changes in the dryland systems. All of this brings us to one challenge: developing pest management strategies suitable for changing climatic patterns. In this complex agrology framework, integrated pest management (IPM) strategies, especially those involving early monitoring of pests using prediction models, are a way to save the show. In this chapter, we will summarize the direct and indirect effects of climate change on crop production, the biology of insect pests, the changing pest scenarios, the efficacy of current pest management tactics, and the development of next-generation crop protection products. Finally, we will provide a perspective on the integration of best agronomic practices and crop protection measures to achieve the goal of sustainable crop production under changing climatic trends of drylands

Rapid brain development and reduced neuromodulator titres correlate with host shifts in Rhagoletis pomonella

Host shifts are considered a key generator of insect biodiversity. For insects, adaptation to new host plants often requires changes in larval/pupal development and adult behavioural preference toward new hosts. Neurochemicals play key roles in both development and behaviour and therefore provide a potential source for such synchronization. Here, we correlated life-history timing, brain development and corresponding levels of 14 neurochemicals in Rhagoletis pomonella (Diptera: Tephritidae), a species undergoing ecological speciation through an ongoing host shift from hawthorn to apple fruit. These races exhibit differences in pupal diapause timing as well as adult behavioural preference with respect to their hosts. This difference in behavioural preference is coupled with differences in neurophysiological response to host volatiles. We found that apple race pupae exhibited adult brain morphogenesis three weeks faster after an identical simulated winter than the hawthorn race, which correlated with significantly lower titres of several neurochemicals. In some cases, particularly biogenic amines, differences in titres were reflected in the mature adult stage, when host preference is exhibited. In summary, life-history timing, neurochemical titre and brain development can be coupled in this speciating system, providing new hypotheses for the origins of new species through host shifts