Evaluating larval performance of the South American tomato pinworm (Tuta absoluta) on wild tomato accessions

Originally from South America, the tomato pinworm (Tuta absoluta) is a highly invasive pest posing a significant threat to global tomato production. While T. absoluta has not yet been detected in North America, the development of proactive Integrated Pest Management (IPM) strategies for its potential introduction is essential, especially in regions with high tomato production like California. IPM approaches, including host plant resistance, represent a key strategy against T. absoluta. Considering that tomatoes were first cultivated in Peru, the native habitat of T. absoluta, our objective was to assess the susceptibility of T. absoluta when reared on wild tomato hosts. To achieve this, we conducted a series of no-choice tests using eight wild Solanum habrochaites accessions and a control group of cultivated tomato (S. lycopersicum). Second instar larvae were exposed to a single accession for 25 days, during which we measured larval development, survival rate, and percentage of herbivory. Compared to the cultivated tomato control, our findings revealed delayed development, reduced herbivory, and lower survival rates when larvae were exposed to several wild accessions. Notably, LA-2204 and LA-1928 consistently exhibited the most significant effects across all performance metrics. Overall, our results identified two wild accessions with promising resistance to T. absoluta. These findings hold potential for developing breeding programs aimed at producing more resistant commercial tomato varieties, particularly in anticipation of a potential T. absoluta invasion in California and other regions of the United States.