Potential for the Postharvest Biological Control of Phthorimaea operculella (Lepidoptera, Gelechiidae) by Blattisocius tarsalis (Mesostigmata, Blattisociidae)

Jorge Gavara,Tomas Cabello,Ana Piedra-Buena,Estrella Hernandez-Suarez,Manuel Gamez,Juan R Gallego

doi:10.3390/agronomy11020288

Jorge Gavara, Tomas Cabello + Show 4 more

Open Access

https://doi.org/10.3390/agronomy11020288

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Abstract

Phthorimaea operculella is one of the most important pests causing damage to stored potatoes. In this work, the effect of temperature (at 10, 20 and 30 °C) on the predation of pest eggs by Blattisocius tarsalis was studied in the laboratory. In addition, the effect of three predatory release rates on two pest densities was studied under microcosm conditions. The results showed that B. tarsalis maintains its predatory capacity at low temperatures (10 °C), obtaining an efficiency of 49.66 ± 5.06% compared to the control. In turn, at 20 °C, a maximum efficacy of 78.17 ± 4.77% was achieved, very similar to that presented at 30 °C (75.57 ± 4.34%). Under microcosm conditions and at low pest density (10 eggs/container), the mortality due to the mite was 96.97 ± 3.03%, 81.82 ± 8.84%, and 84.85 ± 8.30%, respectively, for the three predatory release rates (5, 10 or 20 mites/container). At the high infestation level, the pest control ranged from 61.54 ± 9.21% to 92.31 ± 2.74%, depending on the predatory release rate. The results obtained show that B. tarsalis could be a relevant control agent against P. operculella under non-refrigerated potato storage conditions, as well as in the first stages of their storage under refrigerated conditions.

Highlights

The importance of the potato as a key food source in the global diet is evident both by the quantity produced and by its nutritional value [1,2]
The predatory mite B. tarsalis can be an important tool for the biological control of storehouse pests
It has been verified that B. tarsalis can maintain predatory activity on pest eggs in the 10 to 30 ◦ C range

Summary

Introduction

The importance of the potato as a key food source in the global diet is evident both by the quantity produced and by its nutritional value [1,2]. There is only one growing cycle per year and fresh tubers are only available for 2 to 3 months, making storage necessary [4]. Storage requirements vary depending on how the potatoes are used. Potatoes are vegetatively propagated through the tubers; for this reason, the “seed potatoes” (tubers) are stored at low temperatures (2–4 ◦ C) for the year prior to planting. Potatoes stored and processed for consumption are in demand throughout the year, which means that both short and long-term storage is required. In short-term storage (3–4 months), nonrefrigerated storage methods in the growing areas themselves are inexpensive and a common alternative, especially in tropical and subtropical countries, for potato crops [4,5]

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