Insect screens installed on doors, windows, and other openings act as a mechanical barrier that prevents insects from entering warehouses and manufacturing facilities. They are available in different mesh sizes. There is a tradeoff between air permeability and insect proofing when selecting a screen mesh - the exclusion of smaller insects requires the installation of finer mesh screens, which inevitably obstructs air flow. To maintain good ventilation through windows, there is a necessity to keep the screen resistance to airflow as low as possible. In the food industry, a 16 mesh for the exclusion of stored product insects (1) or a 14×18 or 16×16 mesh screen for flies (2) is recommended.
For the cigarette beetle,
The studies were conducted to confirm the relationship between mesh sizes and the sizes of the cigarette beetles that can pass through the screen and to elucidate the size distribution of beetles from natural populations. Based on the results, the proper/maximum mesh size will be suggested for the exclusion of this important tobacco pest.
The cigarette beetles used in this study came from our laboratory culture which has been maintained on tobacco for more than 30 years. They were reared under conditions of 27 °C, 60% relative humidity and 14 h (light phase): 10 h (dark phase) in photoperiod. The adult insects were collected from rearing containers within one week after emergence and supplied for the test.
Four cylindrical polystyrene containers (12 cm i.d. at the bottom and 8 cm in height; sides slightly tapered), three of which had a 10 cm
Adult cigarette beetles from natural populations were captured by using pheromone traps (Serrico®, Fuji Flavor Co. Ltd., Tokyo, Japan) in the area around three tobacco factories located in Japan during July and August, 2017. During these collection periods, 169 adults were captured, and the width of their prothoraxes was measured in the same manner as described above.
The prothorax widths of the beetles that passed through the screens and remained in the compartments ranged from 806–984 μm (
The widths of prothoraxes of the adults captured in the pheromone traps around tobacco factories, most of which were considered to be males, ranged from 727–1070 μm (899.6 ± 73.8, mean ± SD;
These screens are generally defined by mesh sizes, which only indicates the number of threads per linear inch in each direction, and in addition to differences between different commercial brands, the effective opening (aperture) of the mesh varies with the width of the threads. Tyler standard #20 mesh (= US standard #20 mesh: 0.85 mm opening/sieve size) is insufficient to protect against the cigarette beetle, and Tyler standard #24 mesh (= US standard #25 mesh: 0.71 mm opening/sieve size) or an equivalent-sized mesh, is recommended as an insect screen for tobacco facilities.
Thermal De-Oxygenation to Form Condensable Aerosol From Reconstituted Tobacco without Auto-Ignition Nondestructive Detection of Stem Content in Tobacco Strips Using X-Ray Imaging Analysis A Comprehensive Study of Biodegradation of Cigarette Filters and Bidi Butts Aerosol Formation and Transfer in Open- and Closed-Ended Heated Tobacco Products Qualitative and Quantitative Analysis of Nicotine, Nicotine Derivatives, and Nicotine-Related Alkaloid Optical Isomers: A Review Dr. William M. Coleman III, Recipient of the 2022 Tobacco Science Research Conference Lifetime Achievement Award