Insect exclusion screens: the size of the holes from a three-dimensional perspective

Álvarez, A.; Oliva, Rocío M.

doi:10.17660/actahortic.2017.1170.133

Cited by 4 publications

(5 citation statements)

References 4 publications

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“…Thus, for nets with square or hexagonal apertures, a smaller size is necessary to achieve a pest exclusion efficacy similar to that obtained with nets with rectangular, rhomboid or triangular shapes. Most exclusion nets on the market are indeed rectangular in shape, with an a/b ratio generally less than 0.5 (Àlvarez and Oliva 2015). In our laboratory tests, the greatest exclusion efficacy was actually obtained with the rectangle, which had the smallest a/b ratio (0.5) among tested shapes.…”

Section: Discussionmentioning

confidence: 60%

“…However, net use can sometimes be accompanied by increased population levels of specific leafrollers (i.e., Choristoneura rosaceana) and aphids of various species (e.g., Aphis pomi, Dysaphis plantaginea), possibly due to the exclusion of some of their natural enemies (Dib et al 2010;Capowiez et al 2013;Romet et al 2010;Beers 2021, 2022). Smaller-sized meshes have generally been identified as the culprit, but mesh shape can also affect the composition of the pest population (Bethke and Paine 1991;Bethke et al 1994;Àlvarez and Oliva 2015), and hence beneficial species (Hanafi et al 2007).…”

Section: Introductionmentioning

confidence: 99%

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Insect netting: effect of mesh size and shape on exclusion of some fruit pests and natural enemies under laboratory and orchard conditions

et al. 2022

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To improve exclusion systems for fruit trees, insect nets of various types were evaluated for their permeability to different beneficial and pest species, under laboratory and field conditions. Pests studied were the apple maggot, Rhagoletis pomonella (Diptera: Tephritidae) and the spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae). Beneficials were Aphidoletes aphidimyza (Diptera: Cecidomyiidae), Aphidius matricariae (Hymenoptera: Braconidae) and Aphelinus abdominalis (Hymenoptera: Aphelinidae). Mesh nets with five different apertures (square, rectangle, triangle, rhombus and hexagon) and six different sizes (from 0.4 to 2.8 mm) were 3D-printed from strands of polylactic acid and tested in the laboratory along with two commercially available nets made of polyethylene. The physical and behavioral characteristics of the six studied species affected their ability to cross the nets. For an equal size (open area), the intrusion rate was generally greater through the square- and/or hexagonal-shaped meshes. Rectangular-shaped apertures totally excluded the apple maggot in both laboratory and field trials, provided their shortest side did not exceed 1.9 mm. For the spotted wing drosophila, a maximum of 1.0 mm was similarly required for exclusion in the laboratory. The shape factor (length/width ratio) of the apertures appeared to affect net selectivity. Field trials confirmed that more aphid predators and leafroller parasitoids colonized trees covered with larger mesh nets (2.3 × 3.4 mm), while still excluding the apple maggot. Thus, for a similar aperture size (area), an elongated rectangular-shaped mesh appears to facilitate access for beneficials, while continuing to provide effective protection against apple pests.

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Section: Discussionmentioning

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Insect netting: effect of mesh size and shape on exclusion of some fruit pests and natural enemies under laboratory and orchard conditions

et al. 2022

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“…In order to find the reasons that contraindicate the prison effect as a design strategy, it is necessary to take into account that, in this approach, the woven structure of insect screens is considered to conform to a plane, that is, the woven structure can be explained in two dimensions from a macroscopic point of view. However, from an insect perspective, the region defined by the crossing of threads that make up a hole cannot be explained from the two-dimensional perspective, and it is necessary to resort to the third dimension to explain it [23,24,28] (Figure 3).…”

Section: Prison Effect Assessmentmentioning

confidence: 99%

Textile Physical Barriers: An Assessment of the Prison Effect as a Design Criterion to Increase the Porosity without Loss of Efficacy

Álvarez

Oliva

2023

Applied Sciences

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Insect-proof screens are a physical method of crop protection against pests whose use is widespread. The hole size must be optimized since too small holes give rise to poorly porous textiles that cause a significant reduction in the permeability of the textiles to air. A common design strategy is to use a rectangular-hole geometry with the aim of limiting the hole width to prevent insect entry and increasing the hole length to increase the hole surface. However, the validity of this approach has not been tested, and indications suggest that it may not be offering the expected results. The results obtained discredit this widely accepted design criterion since they show that, while the hole width is maintained, protective screens lose efficacy as the hole length increases at least in the range of values considered. It is not possible to find an explanation for these results by considering the hole geometry from a two-dimensional point of view. However, when considering the spatial arrangement of the threads, it is understood that the passage surface for the insects is larger than that considered in the orthogonal projection images and that as the hole length increases, the efficacy of the textiles decreases.

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“…Table 1 shows the average thorax width of "key insects" and the hole size and mesh number required for their effective exclusion from greenhouses. The hypothetical exclusion efficiency does not necessarily coincide with real effectiveness, achieving up to 90% control of a designated pest [33]; for example, due to the shape of thrips (F. occidentalis) bodies, they can penetrate through small holes of widespread commercial nets [34]. The reason that small holes do not ensure total exclusion is correlated to the 3D arrangement of the threads.…”

Section: Technical Aspects Of Anti-insect Netsmentioning

confidence: 99%

“…The reason that small holes do not ensure total exclusion is correlated to the 3D arrangement of the threads. Usually, nets are considered flat structures, but they are three-dimensional, and their effectiveness depends on several factors like the threads' thickness, width and length of the hole, and its geometry [34]. Warp threads are usually closer together than weft threads, forming a hole with a rectangular geometric structure; the overlapping of warp and weft threads alters the geometric structure of the hole, allowing easy access of the insect [34].…”

Section: Technical Aspects Of Anti-insect Netsmentioning

confidence: 99%

Biochemical, Physiological, and Productive Response of Greenhouse Vegetables to Suboptimal Growth Environment Induced by Insect Nets

Formisano

El‐Nakhel

Corrado

et al. 2020

Biology

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Environmental pressure poses a major challenge to the agricultural sector, which requires the development of cultivation techniques that can effectively reduce the impact of abiotic stress affecting crop yield and quality (e.g., thermal stress, wind, and hail) and of biotic factors, such as insect pests. The increased consumer interest in premium-quality vegetables requires the implementation of sustainable integrated pest management (IPM) strategies towards an ever-increasing insect pressure, also boosted by cultivation under protected structures. In this respect, insect nets represent an excellent, eco-friendly solution. This review aims to provide an integrative investigation of the effects of the insect screens in agriculture. Attention is dedicated to the impact on growth, yield, and quality of vegetables, focusing on the physiological and biochemical mechanisms of response to heat stress induced by insect screens. The performance of insect nets depends on many factors—foremost, on the screen mesh, with finer mesh being more effective as a barrier. However, finer mesh nets impose high-pressure drops and restrict airflow by reducing ventilation, which can result in a detrimental effect on crop growth and yield due to high temperatures. The predicted outcomes are wide ranging, because heat stress can impact (i) plant morpho-physiological attributes; (ii) biochemical and molecular properties through changes in the primary and secondary metabolisms; (iii) enzymatic activity, chloroplast proteins, and photosynthetic and respiratory processes; (iv) flowering and fruit settings; (v) the accumulation of reactive oxygen species (ROSs); and (vi) the biosynthesis of secondary biomolecules endowed with antioxidant capacity.

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Insect exclusion screens: the size of the holes from a three-dimensional perspective

Cited by 4 publications

References 4 publications

Insect netting: effect of mesh size and shape on exclusion of some fruit pests and natural enemies under laboratory and orchard conditions

Insect netting: effect of mesh size and shape on exclusion of some fruit pests and natural enemies under laboratory and orchard conditions

Textile Physical Barriers: An Assessment of the Prison Effect as a Design Criterion to Increase the Porosity without Loss of Efficacy

Biochemical, Physiological, and Productive Response of Greenhouse Vegetables to Suboptimal Growth Environment Induced by Insect Nets

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