Pest management of postharvest potatoes: lethal, sublethal and transgenerational effects of the ectoparasitic mite Pyemotes zhonghuajia on the potato worm Phthorimaea operculella.

BACKGROUND: Potato, Solanum tuberosum, is one of the most important food crops in the world, playing a significant role in global food security. However, many potato industries and farms may suffer losses of tuber yield and quality in storage due to lepidopteran pests. Here, we evaluated the effectiveness of an ectoparasitic idiobiont mite Pyemotes zhonghuajia in the biological control of the potato tuber moth (PTM) Phthorimaea operculella by determining the lethal, sublethal (nonconsumptive) and transgenerational effects of P. zhonghuajia of various population densities and exposure durations on PTM survival, development and reproduction. RESULTS: Pyemotes zhonghuajia females were capable of killing all instar stages of PTM, while resistance to mite parasitism increased with the development of PTM life stage. The mortality of mature larvae (i.e., fourth instar) and pupae increased with increasing mite density and exposure duration. P. zhonghuajia imposed significant negative sublethal impacts on PTM pupation rate, female fecundity and adult longevity but not on immature development. The sublethal stress was transgenerational, resulting in lower reproduction in the offspring generation. CONCLUSION: P. zhonghuajia induces lethal, sublethal and transgenerational effects and significantly decreases PTM survival and reproductive out, demonstrating its high efficiency in the biological control of PTM. Our study provides insight into the mechanisms underlying the nonconsumptive effects of parasitism in an ectoparasite-host system and delivers critical information for the design and implementation of augmentative releases of P. zhonghuajia in the biological control of PTM in potato storage. © 2023 Society of Chemical Industry.

Establishment of Beauveria bassiana as a fungal endophyte in potato plants and its virulence against potato tuber moth, Phthorimaea operculella (Lepidoptera: Gelechiidae).

The potato tuber moth, Phthorimaea operculella, is the most damaging potato pest in the world and is difficult to control as the larvae are internal feeders in the foliage and tubers. Entomopathogenic fungi that colonize plants as endophytes have lethal and sublethal pathological effects on insect pests. We show that Beauveria bassiana colonizes the aerial parts of potato plants endophytically after inoculation through soil drenching. Endophytic B. bassiana persisted in potato foliage for more than 50 days postinoculation. Bioassays indicated that foliage of B. bassiana-inoculated potato plants were pathogenic against larvae of P. operculella. Sublethal experiments indicated that B. bassiana negatively affected the growth, development, and reproduction of P. operculella. Development experiments showed that the weight of P. operculella pupae reared on B. bassiana-colonized potato plants (4.25 mg) was significantly less than that of those reared on uninoculated control plants (8.89 mg). Compared with newly eclosed larvae fed on control plants, those fed on B. bassiana-inoculated plants had significantly lower survivorship, with only 17.8% developing to the adult stage. Oviposition of P. operculella females reared on B. bassiana endophytically colonized plants was significantly lower (35 eggs/female) than of those reared on uninoculated plants (115 eggs/female). This study demonstrates that endophytic B. bassiana can be a potential biological control agent for the control and management of P. operculella. Comparing pupal weights of P. operculella reared on potato plants inoculated with the B. bassiana strain GZGY-1-3 and on untreated control plants, pupae from the control plants were significantly heavier than those from treated plants.

A randomized, controlled comparison of different intensive lipid-lowering therapies in Chinese patients with non-ST-elevation acute coronary syndrome (NSTE-ACS): Ezetimibe and rosuvastatin versus high-dose rosuvastatin.

BACKGROUND: Statin combined with ezetimibe demonstrates significant benefit in lowering low density lipid cholesterol (LDL-C) and cardiovascular events abroad, but whether intermediate intensity statins combined with ezetimibe is superior to high-intensity statin monotherapy in Chinese people is unknown. METHODS: A total of 125 patients were randomly assigned to a intermediate intensity rosuvastatin group (rosuvastatin 10mg/d, n=42), high-dose rosuvastatin group (rosuvastatin 20mg/d, n=41) or combination therapy group (ezetimibe 10mg/d and rosuvastatin 10mg/d, n=42) with a 12-week follow-up. The primary end point was the proportion of patients who achieved the 2011 ESC/EAS LDL-C goal <70mg/dL (1.8mmol/L) at week 12. Secondary end points included changes from baseline in lipids, the occurrence of all cardiovascular events, high-sensitivity C-reactive protein and safety markers. RESULTS: The combination therapy group in the primary end point was significantly higher than rosuvastatin (20mg) and rosuvastatin (10mg) at week 12 (81.0% vs 68.3% vs 33.3%, P<0.001). And the similar change was observed in reducing LDL-C levels at week 12 (67.28% vs 52.80% vs 43.89%, P<0.001). The incidence of drug-related adverse events was much higher in the rosuvastatin 20mg group than the rosuvastatin 10mg group and the combination therapy group (17.0% vs 2.4% vs 4.8%, P<0.05). CONCLUSIONS: The combination of rosuvastatin 10mg/ezetimibe 10mg was an effectively alternative therapy superior to rosuvastatin 20mg or 10mg with a greater effect on lowering LDL-C and a lower incidence of drug-related adverse events in Chinese patients.