WO2018019857A1

WO2018019857A1 - Method and device for measuring insect density

Info

Publication number: WO2018019857A1
Application number: PCT/EP2017/068809
Authority: WO
Inventors: Frédéric Villain; Patrick Pirim
Original assignee: Demand Side Instruments
Priority date: 2016-07-26
Filing date: 2017-07-25
Publication date: 2018-02-01
Also published as: EP3491365A1; FR3054662B1; FR3054662A1

Abstract

The invention relates to a method for measuring insect occupancy rates and an autonomous device for taking reliable and effective measurements. This method for measuring insect density comprises: a step of measuring a value of an electromagnetic radiation parameter A, in particular the luminance, of an analysis area (2) exposed to the insects, and a value of the electromagnetic radiation parameter B, in particular the luminance, of a control area (3) without insects; and a step of calculating a ratio R between measured value A and measured value B, the ratio being R=A/B or B/A. The invention also relates to a device (1) configured to carry out the method.

Description

The present invention relates to the field of detection and / or monitoring of insects. The present invention thus relates to a method and a device for measuring insect density.

In the agricultural sector, improving crop yields involves preventing pests by quantifying them daily. Different types of sensors are used for this purpose. Insect collectors are placed in cultivated areas and are raised in a very regular manner, hence the large manpower necessary for this purpose. Several camera-based methods have been proposed to reduce this manpower such as JP 2003 304788, JP 2008 099598, JP 2012 161269 and CN 10481 3993. All these methods consist in retaining the insects that have occurred. placed on a measuring element visualized by a camera and then to analyze the types of insects by a computer processing (image analysis) in order to deliver the desired quantitative information.

The analysis of images is a complex subject which requires an important computation mode, from where a slow and constraining treatment with a more important energetic need. It is therefore difficult to produce autonomous energy devices.

These data represent the state of a restricted culture area, the coverage of a field involves several systems of this type, the economy of labor is canceled by the cost of exploitation of this set of systems. These data are important for planning pesticide treatment of crop fields. Given the size of the application areas, these treatments are costly to the farmers and an optimization of these treatments is desirable. The pesticide treatment of a field crop is often done with a large amount of pesticides, to try to touch the greatest variety of insects. In addition, these treatments have repercussions on the cost of harvests but also on the quality of the crops themselves (pesticides absorbed), on the environment (pollution) and thus on public health. The object of the invention is to know and control more effectively the insect population present in a harvest field. The present invention aims to meet these needs by providing a simple device for use and low cost of use, using a method for efficient data processing and fast.

The object of the invention is achieved by a method of measuring insect density

comprising a step of measuring a value of a radiation parameter

electromagnetic A, in particular the luminance, of an analysis zone exposed to insects, and a value of the electromagnetic radiation parameter B, in particular the luminance, of a control zone without insect; and a step of calculating a ratio R between the measured value A and the measured value B, said ratio being R = A B or B / A. The luminance measured corresponds to the amount of light that is reflected by a particular surface, here the area of the analysis area and the area of the control area. By this method, a value representative of the insect density is obtained. This method is less expensive in data processing and can advantageously replace the image analysis known in the art.

According to an alternative of the invention, the value 1-R can be used instead of the value R. In the case where R = A B, the ratio can become very low when measuring high insect levels. It may therefore be better to speak of an increase in the measured value for a problem of understanding the measurement.

According to an alternative of the invention, a measurement of the temporal density of insects D can be obtained. This rate of change in insect density is equal to the ratio of [R (t1) -R (t0)] / (t1-t0), where R (t1) is the ratio calculated at time t1 and R (t0). ) being the ratio calculated at time t0, and t1-t0 being the time interval of the measurement. This rate of variation gives the temporal evolution of the representative parameter of the insect density.

According to another alternative of the invention, the radiation parameters

electromagnetic A and B can be optimized by the Albedo parameter corresponding to the overall light energy received on the analysis zone, in particular due to an adaptation of the integration time t of the measurement, inversely proportional to the energy received. The Albedo parameter, or coefficient of reflection, is the diffuse reflectivity or reflectivity of a surface. Its use here makes it possible to optimize the accuracy of the calculation of the associated report. According to a variant of the invention, the method may comprise a step of geo-location of the position P where the values A and B are measured by a locating means. Thus a measure of localized density, for example in a field of a farmer, is obtained.

According to a variant of the invention, the measurement data can be transmitted by a transmission unit to an external processing center, said measurement data comprising the measured values A and B and / or the positions P of the measured values and / or the calculated ratios R and / or D. The data transmission allows centralized data processing in particular for several devices for measuring insect density distributed in one or more fields to obtain an overview of the situation.

According to a variant of the invention, the method may comprise a step of establishing a map representing the density of insects by using at least a portion of the values R, P, D, A and B. Such a map gives the user an accurate and early diagnosis of areas to be treated with pesticides and allows an optimization of the dosage of pesticides. This optimization of the pesticide treatment of the harvesting areas results in a reduction of the associated costs and a less harmful treatment for the environment.

The object of the invention is also achieved by the insect density measuring device which comprises a measuring means and a calculating means for carrying out at least

partially the steps as described above. This device makes it possible to produce a method that is less expensive in data processing.

According to another variant of the invention, the measuring device for measuring the density of insects, in particular according to the method detailed above, can comprise a measuring means with a first substrate for carrying out measurement A in the analysis zone. a second substrate for measuring B in the control zone and means for measuring the electromagnetic radiation parameter A and B, in particular the luminance, in both zones, in particular an optical sensor. The device for measuring density is a simple device to achieve, and therefore low cost.

According to another variant of the invention, the first substrate may comprise a tacky layer serving as an insect trap. The insects will accumulate on the substrate allowing a reliable measurement of the insect population. According to another embodiment of the invention, the area between the means for measuring and the second substrate may be covered by a mosquito net. Thus the control zone remains devoid of insects. According to another embodiment of the invention, at least a part of the device, in particular at least one of the two substrates, may be impregnated with pheromones. In one embodiment, a blotter paper impregnated with pheromones may be used. It may be predetermined pheromones depending on the desired counted insect species. Such a pheromone trap is a bait loaded with odorous sex hormones to attract insects. Insect detection can therefore be targeted for a more accurate diagnosis, allowing a more focused and therefore more effective pesticide crop treatment.

According to another embodiment of the invention, the device may comprise an armature keeping the first substrate juxtaposed to the second substrate essentially on the same plane and substantially perpendicular to the optical axis of the means for measuring the parameters of electromagnetic radiation. This allows the optical sensor to perceive both areas at the same time with the same shooting characteristics and signal shaping, which allows for reliable and stable measurements over time. According to yet another embodiment of the invention, the device may comprise a light source of at least one predetermined wavelength, to attract insects. For some species, it is more advantageous to attract them by a light source having a specific wavelength, for example UV or yellow. In this way, insect detection can be targeted for more accurate diagnosis, allowing more effective pesticide crop treatment.

According to a variant of the invention, the light source can be installed on the hidden face of the first and / or second substrate relative to the optical sensor. This makes it possible to limit the amount of illumination coming from this light source sensed by the optical sensor, and to obtain a reliable measurement of the radiation parameter coming from the control and analysis zones.

According to another characteristic of the invention, one or more secondary sensors may be integrated in the device, in particular a temperature sensor, in particular air and soil, humidity, pH and a displacement sensor. They make it possible to obtain other interesting parameters for the treatment of the fields. For example, a measurement of pH, humidity and temperature of the earth, air temperature and / or a measurement of movement of the device. Temperature measurement is used to predict the number of insects. The measurement of displacement is done using an electronic sensor measuring the acceleration in 3D coordinates, in order to check the good positioning of the device in the time, an alarm can be sent in case of noticeable change of these data which normally remain stable, indicating for example a fall or a flight of the device. The use of all these measurement data allows anticipation of treatment and therefore better regulation of the culture ecosystem.

According to a variant of the invention, the optical sensor may comprise an array of multi-spectral sensors. An example of multi spectral sensor can be the AMS TCS3490x sensor, which has a red, green, blue color perception,

panchromatic and near infra-red. It is therefore possible to make a measurement

panchromatic, on the whole spectrum, or for a precise wavelength (color) which makes it possible to differentiate certain types of sought-after insects and to extract a report of measurement. We obtain a targeted detection system. According to one variant, the optical sensor comprises two groups of sensors, one dedicated to the analysis zone and the other to the control zone. CCD or CMOS sensors can also be used.

According to a variation of the invention, the optical sensor may comprise a lens in front of the sensor array, in particular an aspherical lens, even more particularly in a diameter / focal length ratio of less than 0.6, preferably of approximately 0. 5 and positioned defocused with respect to the image plane. This has the advantage of a limited mosaic of multi spectral sensors: each measurement point integrates a large perceived area, and allows reliable detection of the luminance values of the test areas.

According to a complementary feature of the invention, the device may comprise a measurement system configured to perform a panchromatic measurement and / or at a single wavelength. This makes it possible to obtain a global insect density or to differentiate certain types of desired insects and to extract a specific insect density, one obtains a polyvalent detection system allowing global and / or targeted analysis.

According to a complementary feature of the invention, the device may comprise an autonomous power supply device, in particular a photovoltaic sensor. The autonomous power supply device makes it possible to obtain a measurement device essentially autonomous in energy. This allows the installation of the measuring device in several places of a field without the need for installation of power lines.

According to another complementary feature of the invention, the insect density measuring device may comprise a location device, in particular a GPS unit. This makes it possible to know the position of the device when taking measurements. This makes it possible to use several devices over a large area and thus to obtain information on the density of insects for the entire surveillance zone. According to another embodiment of the invention may include a data transmission unit to an external processing center thus allowing centralized data processing. Preferably it is a wireless transmission, type Sigfox, Lora, sms or other standards of wireless communications. Alternatively, the measuring device may comprise an insect trap to trigger an action from the moment a certain Rnmite threshold is observed.

The subject matter of the invention is also achieved by an insect mapping system which comprises an insect measuring device as described above and an external treatment center for establishing an insect density map. from at least a portion of the values A, B, R, P and D. With such a map we obtain an overview of the situation with respect to the presence of insects. In addition, the map can group not only a field but an entire region to handle large scale issues. The large amount of information ensures a reliable statistical measurement and a more accurate prediction.

The invention may be understood by reference to the following description taken in conjunction with the appended figures, in which numerical references identify the elements of the invention. Figure 1 shows schematically the measuring device according to a first embodiment of the invention.

FIG. 2 diagrammatically represents the optical sensor forming part of the first embodiment of the invention.

FIG. 3 schematically represents the optical subset of said optical sensor. Figure 4 shows a case of using the results of the measuring device.

Figure 5 shows a block diagram of the density measurement method according to the invention.

The insect density measuring device 1, also called insectometer thereafter, illustrated in FIG. 1 comprises a first substrate as analysis zone 2 and a second substrate as control zone 3 and a means for measuring the luminance of the two zones. , here an optical sensor 4. In this embodiment, the first substrate 2 and the second substrate 3 are juxtaposed and arranged in the same plane which is essentially perpendicular to the optical axis 5 of the optical sensor 4. The juxtaposition of the measurement zones is horizontal as shown. in Figure 1 but may also be different, for example vertical. The analysis zone 2 and the control zone 3 correspond to two zones of the same dimension, of clear hue and of the same nature, for example a transparent PVC sheet. The volume defined by the control zone 3 and the optical sensor 4 is protected from any insect intrusion by a screen 6. The analysis zone 2 serving as an insect trap that is rather dark, includes a sticky layer to catch 7. The analysis zone 2 in this embodiment is coated with an adhesive product, in particular glue, to catch the insects 7. At least a part of the insectometer, in particular at least one of the two substrates of the analysis zone 2 or the control zone 3, is coated with one or more types of pheromones to attract insects. Pheromones are chemical substances comparable to hormones, emitted by most animals and acting as messengers between individuals of the same species, transmitting to other individuals information that plays a role, for example, in sexual attraction.

The optical sensor 4 may be an AMS TCS3490x sensor or a CCD or CMOS sensor. The insectometer comprises a light source 8 of a specific wavelength or range of wavelength, in particular UV and / or yellow, in order to attract certain species. Normally, light traps are selective, that is, they project a light of a wavelength that does not attract auxiliary insects that are useful. In an exemplary embodiment, a range of wavelengths for which a large majority of the insects are sensitive is between 380 nm and 315 nm, with a maximum efficiency reached around 365 nm, and / or for blue with a peak around 450 nm and / or for green around 550 nm. The light source 8 is installed behind the analysis zone 2 and / or the control zone 3 with respect to the optical sensor 4. The insectometer 1 comprises an armature 9 which carries the first substrate with the analysis zone 2 and the second substrate with the control zone 3 in a plane. The insectometer also comprises four reinforcing bars 10a, 10b, 10c, 10d which position the optical sensor 4 in order to maintain its optical axis perpendicular to the plane of the analysis zone 2 and the control zone 3. Moreover, the optical sensor 4 is positioned in such a way that its optical axis 5 is at the center of said plane, ie at the centered limit of the junction of the analysis zone 2 and the control zone 3. The armature 9 is held by a global support 12 which is generally planted in a field 13.

According to variants, the overall support 12 may also include one or more secondary sensors 14, 15. These secondary sensors may be positioned in the planted portion, sensor 14 and / or in the non-planted portion, sensor 15. The sensor or sensors 14 allow, for example, a measurement of the pH and / or the humidity and / or the temperature of the earth of the field 13. The sensor or sensors 15 allow, for example, a measurement of the air temperature, the humidity, wind and / or movement of the insectometer 1. Alternatively, one or more of the sensors may be arranged in or on the frame 9.

The insectometer 1 also has a roof 16 which serves as a rain shelter. The roof 16, in a variant, can be covered by an autonomous energy supply device, here a solar collector unit 17, preferably a photovoltaic film. Figure 1 also shows an antenna 18 forming part of a data transmission system. The solar collector unit 17 supplies the energy necessary to power the optical sensor 5 through an electrical connection located on a support bar 19, the secondary sensors 14, 15 if present, as well as for the data processing and for the processing of the data. data transmission. The insectometer can alternatively be connected to an insect trap to be able to trigger a treatment if R exceeds a certain threshold Rumite-

Alternatively, the insectometer can also be deposited directly on the ground 13, without overall support 12. In this way, an insect density measurement can be made to obtain an analysis of the insect population on the ground. The system works as follows. An insect 7, attracted by the pheromone or pheromones or by the light of the light source 8, lands on the analysis zone 2. The insect 7 remains stuck there and is trapped. A measurement of a value of an electromagnetic radiation parameter, in particular the luminance A, of this analysis zone 2 is collected together with the value of the electromagnetic radiation parameter, in particular the luminance B, of the zone. witness 3 which is devoid of insects, by the optical sensor 4.

Additional data can be collected by the secondary sensors 14 and 15 located on the overall support 12, such as a measurement of the pH and / or the humidity and / or the temperature of the earth, or else a measurement of the air temperature, humidity or wind for example. The measured data are transmitted by an electrical connection in the overall support 12 via one or more of the reinforcements 10a, 10b, 10c, 10d to a data processing unit, for example in the optical sensor 4. Then the transmission of the measured data is done by a transmission unit via the antenna 18 to an external processing center. The data transmission can be done for all the measured data or only for a part of the measured data, depending on the desired application and the subsequent data processing required. It is also possible to transmit none of the measured data and to store them on data storage means or they can be downloaded later. When the analysis zone 2 reaches an insect coverage rate higher than a predefined threshold, a new transparent and glue-coated PVC sheet covering said analysis zone 2 can be automatically deployed and a corresponding signal is transmitted by the transmission unit to inform an external processing center.

Thus we obtain a targeted measure of the rate of insects. The optical sensor 4 shown in FIG. 1 is illustrated in greater detail in FIG. 2. For elements bearing the same reference as elements already described, reference is made to the description in FIG. 1.

The optical sensor 4 comprises a lens 20 in front of a sensor unit 21 which is connected to a data multiplexer 22. The sensor unit 21 corresponds to a matrix of two groups of multi-spectral sensors 21a and 21b. The data multiplexer 22 transmits the data to a computing unit 23.

In addition, the data multiplexer 22 can be linked to other elements, such as a location unit 24, for example a GPS unit, an Albedo sensor 25, the secondary sensors 14 and / or 15 present on the global support 12, a temperature measuring unit 26 and a unit of measurement of the displacement of the device 27.

The optical sensor 4 further comprises a data transmission unit 28 receiving the results of the computing unit 23 to transmit them via the antenna 18. The transmission unit 28 can use a standard wireless transmission protocol, for example example of type LORA, Sigfox, sms, etc. The optical sensor 4 also comprises a power supply management unit 29 connected to the solar collector unit 17 by an electrical connection in a support bar 19 and which distributes the energy through the various units integrated in the sensor 4 and more general in the insectometer 1 to ensure its power supply. All or at least some of these components of the optical sensor 4 can be arranged on an electronic card 30.

The optical sensor 4 operates in the following manner. It measures an electromagnetic radiation parameter A of the analysis surface 2 including the insects and an electromagnetic radiation parameter B of the reference surface 3, this parameter being in particular the median of the luminance histogram. These two values A and B are entered by the two groups of sensors 21a and 21b through the lens 20 and are then transmitted to the calculation unit 23, through the data multiplexer 22, which calculates a ratio R of density, defines as R = AB or B / A. The 1-R value can also be used. The calculation unit can also be configured to calculate other parameters, such as a rate of change. The rate of variation over a time interval t = t1 -t0, or still referred to as the time density D, is an indication of the evolution of the presence of the insect. D is equal to the ratio (R1-R0) / (t1-t0), R1 being the ratio calculated at time t1 and R0 the ratio calculated at time t1, where t1 -t0 is the time interval between measurement at time t0 and at time t1.

The Albedo sensor 25 measures the total energy of the overall illumination of the environment and transmits the data to the computing unit 23 through the data multiplexer 22, in order to ensure the optimization of the energy measurement. by an adaptation of the integration time t of the measurement inversely proportional to the energy received. This optimizes the precision of the R ratio calculation.

The locating system 24 makes it possible to reference the measured values A and B with respect to the location Pi of the insect density measuring device 1. We will then speak of Ai and Bi in position Pi.

The calculation results Ri (t) as well as the data referenced Pi are transmitted to the transmission unit 28 for sending the data to the external processing center 40. The transmitted data can correspond to all the data Ai, Bi, Ri , Di and Pi as a function of time or only part of the data, ie Ai and / or Bi and / or Ri and / or Di and / or Pi. Moreover, a part of the calculations or the totality of the calculations can be done at the treatment center external 40. The external processing center 40 may be a farmer's computer, a smartphone or a tablet, as well as a specialized computing center of a third party.

The measured data and / or the calculation results can also be stored in a storage unit in the optical sensor 4, for further use of the data. Since the device is compact, it can be transported to the external processing center 40 and thus be able to access the data at that time. Alternatively the data can be recovered by any means of data transfer, for example using a USB or WIFI connection to transfer the data. In this case, the antenna of

Transmission 18 is not required in Insectometer 1 and can be removed. The data collected by the secondary sensors 14 and 15 located on the overall support 12 are transmitted by an electrical connection in the overall support 12 and one of the reinforcing bars 10a, 10b, 10c or 10d to the calculation unit 23 also via the Data multiplexer 22. These data can also be processed first in the temperature measurement unit 26 and / or in the unit for measuring the displacement of the insectometer 27. The measurement of the temperature 26 serves as the prediction for measuring the number of insects. When installing multiple sensors in a field, insects being more attracted to a hot zone, the temperature measurement corroborates the measurement of the insect level. The displacement measurement 27 can be done using an electronic sensor measuring the acceleration in 3D coordinates, in order to verify the correct positioning of the device 1 in time, an alarm can be sent in case of a variation beyond a predetermined threshold of placement. A significant variation may be related to a fall or theft of the device 1.

Figure 3 schematically shows the optical subassembly 50 of said optical sensor 4 shown in Figures 1 and 2, reference is made to the detailed description above. FIG. 3 illustrates the simplicity of the device for shooting the optical sensor 4.

The aspherical lens 20 is placed at the entrance of the receptacle 52 of the optical sensor 4, inside which the multi spectral sensors 21a and 21b are located. The aspheric lens 20 has a small diameter / focal ratio, that is to say a value smaller than 0.6, preferably about 0.5, in order to limit the distance d between the plane of the analysis zone 2 and the optical sensor 4 (see FIG. 1).

In particular, the lens 20 has a diameter greater than the diagonal of the mosaic of the set of multi spectral sensors. The small diameter / focal ratio of the lens allows to locate the multi spectral sensors 21a and 21b at a distance 54 slightly different from the focal length of the image plane 56, which causes a blur of the perceived image.

This presents an advantage for a perception by a restricted mosaic of multi spectral sensors 21a and 21b: each measurement point integrates a large perceived area, and allows reliable detection of the luminance values of the test areas. The receptacle 52 of the optical sensor 4 ensures the retention of the electronic card 30 and the lens 20 and also allows a concealment of the ambient light to the sensors 21a and 21b.

Looking at FIGS. 1 to 3, it can be seen that the optical sensor 4 completely sees the analysis zone 2 and the control zone 3. The sensor is positioned in a symmetrical manner, the optical axis 5 converging at the center of the junction of the two zones 2 and 3, on an image plane consisting of the two groups of multi spectral sensors 21a and 21b. Thus, these two groups of multi spectral sensors 21a and 21b, perceive the value A of the light energy reflected by the analysis zone 2 for the one and the value B of the light energy reflected by the control zone. 3 for the other, or said the luminance value or more generally the radiation parameter.

These two groups of multi-spectral sensors 21a and 21b are arranged to be juxtaposed vertically or horizontally, depending on the positioning of the analysis zone 2 with respect to the control zone 3.

Another embodiment of the invention comprises the use of a single group of sensors, in particular multi spectral sensors, placed in the center of the optical axis, to read the measured values A and B. The use of two groups of sensors , as described above, is also possible with another type of sensor, in particular CCD, CMOS type sensors, or color detection, in particular for cases of detection at a predetermined wavelength. Figure 4 shows a case of using the results of the one or more measuring devices 1 in an extended area, such as one or more fields of a region, to establish a reasoned control based on monitoring trapping and treatment. at the right dosage.

The external processing center 40 receives the geo-localized insect rate data Ri, Pi for all measurement devices (i) from 0 to n, where n is the number of devices installed in the area to be monitored.

From these data an insect density map 62 is established by a computer program operating in the external processing center 40. In the map 62 a symbol is drawn on a plane for each of the n insectometers or measuring devices 1 for the positions Pi, with in combination the associated value Ri.

This same computer program draws zones grouping the same class of values Ri, lower than Ra in zone 64, of Ra to Rb in zone 65, of Rb to Rc in zone 66 and greater than Rc in zone 67. In this example, the zone 67 is considered to be infected and therefore to be treated by the farmer. For zone 66 anticipatory treatment may be provided.

The invention allows treatment at the fairest assay by threshold evaluation to trigger treatments above a critical threshold, and a localized treatment, or only the infected areas, such as 67, are treated.

The variation of this index Ri can be visualized as zones of different classes and represents the risk of destruction of the crop. Alternatively, an insect trap can be connected to the insectometer which triggers an instant localized treatment campaign.

Figure 5 shows a block diagram of one embodiment of the density measurement method according to the invention using a measuring device 1 as described above.

Step 71 corresponds to taking measurement of the values A and B by the optical sensor 4 at a time t. According to one variant, the overall energy determined by the Albedo sensor 25 is used to determine the integration time of the measured signal.

Step 72 corresponds to the determination of the position P using the locating unit 24. The position P corresponds to the location of the device 1 in the area to be monitored.

In step 73 the computing unit 23 determines the ratio R (t) and / or D (t).

In step 74 the data and / or results of step 3 are transmitted by the transmission unit 28 to the external processing center 40.

During step 75, an insect density map as shown in FIG. 4 is established in the external treatment center 40.

This method of measuring the occupancy rate of insects of a surface relative to the same control surface is extremely simple and accurate enough for an evaluation treatments to perform. It makes it possible to develop an autonomous measuring device that can be applied in a universal way.

A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications and improvements can be made without departing from the following claims.

Claims

claims

A method of measuring insect density comprising:

a step of measuring a value of an electromagnetic radiation parameter A, in particular the luminance, of an analysis zone exposed to the insects, and a value of the electromagnetic radiation parameter B, in particular the luminance, an insect-free control area; and

a step of calculating a ratio R between the measured value A and the measured value B, said ratio being R = A B or B / A.

A method according to claim 1, comprising a step of calculating an insect time density (D) which is equal to the ratio of [R (t1) -R (t0)] / (t1-t0), R ( t1) being the ratio calculated at time t1 and R (t0) being the ratio calculated at time t0, and t1-t0 being the time interval of the measurement.

Method according to claim 1 or 2, characterized in that the parameters of electromagnetic radiation A and B are optimized by the albedo parameter, in particular due to an adaptation of the integration time t of the measurement, inversely proportional to the received energy.

Method according to at least one of claims 1 to 3, comprising a step of geolocation of the position P where the values A and B are measured by a locating means.

Method according to at least one of claims 1 to 4, characterized in that the measurement data are transmitted by a transmission unit to an external processing center, said measurement data comprising the measured values A and B and / or the P-positions. measured values and / or calculated ratios R and / or D.

Method according to at least one of claims 1 to 5, comprising a step of establishing a map representing the density of insects using at least a portion of the R, P, D, A and B values.

An insect density measuring device comprising measuring means and calculating means for carrying out the steps of at least one of claims 1 to 6.

Measuring device for measuring the density of insects, in particular according to claim 7, the measuring means comprising:

a first substrate (2) for performing measurement A in the analysis zone;

a second substrate (3) for measuring B in the control zone and

means (4) for measuring the electromagnetic radiation parameter A and B, in particular the luminance, in both zones, in particular an optical sensor.

Measuring device according to claim 8, wherein at least the first substrate (2) comprises a tacky layer.

Measuring device according to at least one of claims 7 to 9, wherein at least a part of the device, in particular at least one of the two substrates (2, 3), is impregnated with pheromones.

Measuring device according to at least one of claims 7 to 10, comprising an armature (12) holding the first substrate (2) juxtaposed to the second substrate (3) essentially on the same plane and substantially perpendicular to the optical axis (5) of the means (4) for measuring electromagnetic radiation parameters.

12. Measuring device according to at least one of claims 7 to 11, further comprising a light source (8) of at least one predetermined wavelength.

13. Measuring device according to claim 12, wherein the light source (8) is positioned on the hidden face of the first substrate (2) or the second substrate (3) relative to the optical sensor (4).

Measuring device according to at least one of claims 7 to 13, comprising one or more secondary sensors (14, 15), in particular a temperature sensor, in particular air and soil, humidity, pH and a sensor of displacement.

15. Device according to at least one of claims 7 to 14, characterized in that the optical sensor (4) comprises an array of multi-spectral sensors (21, 21a, 21b).

16. Device according to claim 15, comprising a lens (20) in front of the sensor array (21, 21 a, 21 b), in particular an aspherical lens, and even more particularly with a diameter / focal ratio of less than 0. , 6, placed defocused with respect to the image plane.

17. Device according to at least one of claims 7 to 16, comprising a measurement system configured to perform a panchromatic measurement and / or at a single wavelength.

18. Device according to at least one of claims 7 to 17, comprising an autonomous device (17) for supplying energy, in particular a photovoltaic sensor.

19. Device according to at least one of claims 7 to 18, comprising a location device (24), in particular a GPS unit.

20. Device according to at least one of claims 7 to 19, comprising a data transmission unit (28).

21. Device according to at least one of claims 7 to 20, comprising an insect trap.

22. An insect card establishment system comprising:

a device (1) according to at least one of claims 6 to 21,

an external processing center (40) for establishing an insect density map from at least a portion of the A, B, R, P and D values.