An efficient treatment of Anarsia lineatella it must be carried out after the hatching of the eggs, when the majority of larvae have already left, but before they pierce the buds or shoots of fruit trees, as then insecticides no longer reach the pest.

Each pest has its most vulnerable moment, when they are most sensitive to treatments. However, it is difficult to know and predict those moments. That is the main than pest control treatments, chemical or biological, are usually carried out by calendar dates or by the evidence of the damage in crops. The problem is that generally in the first case these treatments were either not necessary or have no effect. Or, in the second case, if the treatments are performed when the damage to the crop is already evident, they are usually late and the pest is already difficult to control. Consequently, the reality of current agriculture is that most of the treatments are carried out even if not necessary, or an excessive quantity of chemical insecticides are being applied.

The indiscriminate and repeated use of insecticides for pest control has no effect: it means a waste of money and in most cases the problem of pests is aggravated.

If a producer intends to control the pest in its first generation larvae stage of the pest, but carry out an chemical treatment too soon, it will have decreased the effectiveness of the treatment due to the degradation of product. But, if the treatment is carried out too late, it will be ineffective because it will not make contact with the vulnerable phase of the pest. And the economic consequences of the decision are plain to see. If a tomato crop has a value of 0.42 euros / kg, and has a yield of 75,242 kg / Ha in outdoor irrigated crops, an inappropriate moment of insecticide spraying, supposing a damage increase of only, 0.4% , the inopportune treatment will result in a loss of 1,264 euros per hectare and pest generation.

In an economy of increasing competitiveness, certain crops with high production costs and slow harvesting are no longer profitable if added costs have to be considered. Even though, proportionally the costs of pesticides are the lowest in the agricultural production (because the costs of labor, machinery, etc. are not usually allocated to the tasks of pest control),  the risk of losing the harvest by a wrong pest control action is very high. For this reason, to minimize uncertainty and risk, agriculture has become dependent on the application of chemical insecticides, increasing their consumption, often unnecessarily.

There is a false belief that the use of chemical pesticides is a quick solution against pests. But the reality is that the effectiveness of chemical insecticides has diminished over time, because they have been used repeatedly and indiscriminately.

There is an obvious lack of training when facing pest control issues. It is not enough to carry out treatments,  but those have to be done with sufficient chance of success.

There are 2 very frequent errors in pest control: 

• Misidentification of the pest that causes crop damage. It is an important mistake, as each pest or disease requires a different product for its treatment.
• To carry out the treatments at a time that is not the appropriate. For example, if sprayed against the olive cochineal when it is under the shell, the insecticide can hardly have any effect.

MONITORING AND RATIONALIZATION OF TREATMENTS

Identifying the pest correctly is essential for the treatment to be efficient. By monitoring a crop, an expert entomologist can identify the pest, know and predict the moments of its greater vulnerability to treatments. But even an entomologist needs to control the crops and perform calculations to accurately predict those moments.

Plant Health public organism of many countries usually send farmers information in which they warn of risks and pest development forecasts. To obtain this information they use phenological models and a calculation technique known as the degree-day method. But these is generic information that in many cases arrive late to producers.

With the purpose of providing all agricultural producers with this information, but personalized and in real time, we have compiled the entomologist's knowledge on the aspects of the biological development, monitoring and treatment of 179 pests, automated the data collection and calculation processes. We have developed a computer-based information system that alerts and provides information for pest control decision making. Also there is no need to buy and install expensive equipment in the fields.

FuturCrop, the decision support software for pest control, sends warning notices for each specific pest, and also facilitates brief instructions on the appearance of the different phases of the pest, examples of crop damage, location, habits, etc. that help to differentiate very similar species (for example, Panonychus ulmi and Tetranychus urticae) 

The software helps determine if the monitoring data justifies a treatment action. For example, pheromone traps may indicate an increase in the number of adults of a pest, but the cumulative grade-days will indicate whether the increase is real or if it is a false peak. For a false peak, the treatment could be delayed until the actual beginning of the next generation of the pest, thus avoiding unnecessary pesticide applications. The software can also be used to determine when extensive scouting should be done, limiting monitoring to the pests the programa warned of.

FUTURCROP SCREENSHOTS

Each of the 179 pests has information on monitoring, according to their stage of development, the optimal phases and conditions for treatment, as well as their biological control organisms.

FuturCrop calculates the biological development stages of the pest 10 days in advance. The program generates the events calendar from 2016 to the present. This facilitates preventive actions and treatment planning.

Thermal integral represents the rate of biological development of an specific pest as a function of temperature, per unit of time. The annual evolution and the annual comparatives are used to monitor the pest and to determine the appropriate time for treatment.

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Generally, for efficient treatments it is recommended to control the immature stages of the second generation; but this is because it is very difficult to monitor the first generation, since the population density of the pest is low and there is still not enough visible damage  done to the plant. But the reality is that according to FAO 30% of the pest control treatments are late. Thanks to FuturCrop it is possible to plan the treatment for the first generation of the pest, at the most vulnerable stage of its life cycle, be efficient and save costs.

Pest treatments done at the time of its greatest vulnerability can save up to 40% of the costs.

GREATER EFFICIENCY OF CHEMICAL TREATMENTS

The advantage of using an information system for pest control decision-making is that it rationalizes treatments, and therefore allows the number of insecticide applications to be reduced, thus avoiding the development of pesticide resistance and allowing the auxiliary fauna to carry out its natural control activity.

Controlando el desarrollo de la plaga podemos optimizar

el momento del tratamiento, el tipo y el producto

Diptera

A pest control decision taking support software such as Futurcrop can inform us that the specific pest is in its pupation phase, then we can determine if it is useful to sweep the soil between crops, apply  insecticides to the soil or deep carving when the soil is sanded, so we can eliminate a large number of the pupae from the plague. Or, knowing that a certain plague of lepidoptera that affects our crops will be in larval phase in 7 days, we can plan a treatment for its control using ciromazine, which applied at another time would mean wasting money, because this chemical substance has no effect later stages of development.

Knowing the stage of development of the olive fly (Bactrocera oleae), it is possible to control its populations through treatments specifically directed against adults (for example by baits), or against larvae (by spraying).

Every pest has a phase in which it is vulnerable to a specific treatment. For example, in order to effectively treat the olive scale (Saissetia oleae), it is best to treat when 100% hatching of eggs, when the larvae have already left the protection of the female shell, but before the appearance of the third stage larval (In the table olive grove it is recommended to treat from 90% of hatched eggs). Treatments to control adults do not have a efficient results, as adult females are very resistant to treatments. The tabby knot-horn moth (Euzophera pingues) is another pest that should be treated when first larvae appear, as they are the most sensitive and vulnerable to insecticide control.

Generally, it is convenient to carry out pest treatments during its immature stages and its first generations. But it is not always the case. For example, for the European cherry fruit fly (Rhagoletis cerasi) treatments are more efficient in its adult phase, and itshould be aimed to control females, as they cause the damage by depositing the eggs inside the fruits.

Lepidoptera

Forecast and accuracy to be efficient allows to reduce pest control costs and eliminate risks.

Usually, it is necessary to be very precise in the determination of the moment of treatment, which must be carried out between the hatching of the egg and before the action of the larvae within the leaf, stems or fruit.

The fall armyworm (Spodoptera frugiperda) causes significant crop losses, despite the fact that farmers make numerous insecticide applications. But generally such applications are early or late, with very little effect on the pest. To be efficient, treatments must be performed before the larva is protected inside the plant or fruit, which usually happens in the third larval stage. But how do you know when exactly that moment occurs? Until now, only an expert entomologist could estimate it, constantly monitoring the crops and making calculations of the incidence of the weather on the development of the pest. FuturCrop calculates the development of the pest, specifying the time of the 6 larval instants, pupa, adult, oviposition and hatching of the eggs.

Another pest of difficult treatment is the codling moth (Cydia pomonella), whose treatment has to be done at the time of maximum hatching of eggs and before the larvae penetrate the fruits. The treatment should be repeated a few days later to cover as many larvae as possible. FuturCrop also calculates the moment of the adult flight peak, so that it is possible to perform that second treatment with accuracy.

The choice of the pesticide to be used  depends on the pest stage of development, its habits, whether it is the winter generation, its reproductive cycle, the generation, its population density, etc.

A computational support system for pest control decision-making not only helps to establish the appropriate time of treatment, but also which treatment is appropriate according to the pest stage of development. For example, in the case of the cotton leafworm (Spodoptera littoralis) knowing the larval development stage serves to decide the convenience of one treatment or another. Because, when the cotton leafworm larva is small, it is best controlled using Bacillus, Etofenprox, Pyrethrins or Trichlorfon. But when the larva is large, it is best controlled by disinfecting the soil with Foxin in pre-planting, Chlorpyrifos or Diazinon in planting, spraying, or by using baits  (poisoned with these last two products).

In order to carry out effective treatments, it is not only necessary to take into account the stage of development of the pest, but also its generation. For example, in order to make an effective treatment of the European grapevine moth (Lobesia botrana), FuturCrop warns users of 12 events of the pest development, so that the producer's reaction capacity is increased. The most efficient moment for the treatment of the moth is that of the “Start of flight of adults of the 1st generation”, since it ensures the hatching of 5% of adults of the first generation, for the beginning of sexual disruption.

Pest habits are also important when determining the right time for treatment. For example, in the case of the potato tuber moth (Phthorimaea opercullela) the second generation is more problematic, and to which treatments are usually applied, directed to the adults to diminish the possibility of the laying of eggs. But according to the habits of this pest, the high mobility of adults and their ability to hide, makes them difficult to reach by sprying. Therefore, more intensive use of insecticides is usually made, which makes it easier for the pest to acquire resistance to them. It is better to control the pest at its most vulnerable stage, which in this case is the larval stage.

Obviously the data provided by monitoring sampling are decisive when determining the need to perform treatments. For example, the efficient treatment for controlling the European corn borer (Pyrausta / Ostrinia nubilalis), should be done it with 75% of hatched eggs. But monitoring is required to establish the need for the treatment, if a damage of 5 to 25% is observed. If damage exceeds 25%, a second application should be carried out when advised by the software. In the case of the American cotton bollworm (Helicoverpa zea) FuturCrop calculates and warns the exact moment of egg hatching, in order to do treatments that affect the larvae of first and second stages. And the same control strategy is suitable for the corn earworm (Helicoverpa armigera) or the rice armyworm (Mithimna unipunctata).

In those pests in which generations overlap, FuturCrop provides information on various events of their life cycle, in order to adapt the treatment to the state of development. For example, FuturCrop controls 35 events of the biological development of the European maize borer (Ostrinia nubialis) and also the pink stalk borer (Sesamia nonagrioides). In both cases, the highest treatment efficiency is obtained by controlling wintering adults or larvae of all generations. Even to carry out pest Biological Control, the program allows to know the moment of the 5 larval stages of the first 2 generations, so that the release of parasitoid wasps of the genus Trichogramma are more successful in controlling the pest.

Coleoptera

FuturCrop controls the development of several Coleoptera pests (attacking crop, forest and ornamental species), such as  the peach capnodis (Capnodis tenebronis), the lined click beetle (Agriotes lineatus), the false potato beetle (Leptinotarsa decemlineata), the elm leaf beetle (Xanthogaleruca luteola), cotton boll weevil (Anthonomus grandis), palm weevil (Rhynchophorus ferrugineus), etc. In general, in the pests of this Order, larvae cause the greatest damage, and treatments should control this stage of development. For example, for the treatment of the false potato beetle (Leptinotarsa decemlineata) treatment is recommended when observing the first larvae. FuturCrop sends a warning message to the user when its  calculations predict that such an event may occur.

But not always treatments are recomended when the beetle pest is in its larval stage. Sometimes it is also advisable to carry out the treatment for controlling adults. For example, to control the elm leaf beetle  (Xanthogaleruca luteola), a first treament can be done when adults have left their shelters, and a second one at the larval peak.

Hemiptera/Homoptera

The control of Hemiptera/Homoptera, such a as the green peach aphid, tobacco whitefly, citrus mealybug, San José scale, black bean aphid, etc.) has become very complicated. The indiscriminate application of chemical insecticides eliminated their natural predators, which previously performed a natural control over these pests. And because of their short life cycle and the ability of their females to lay large quantities of eggs, it is very common that demographic explosions of these pests occur, even when the pest was considered controlled. FuturCrop facilitates that the treatments can be carried out in their younger stages. In addition, through the software it is possible to predict its development, for example for the maximum of sensitive forms of successive generations, thus allowing the planning of treatments.

Thysanoptera

Thrips (Thrips tabaci, Frankliniella occidentalis, Scirtothrips dorsalis, Thrips palmi, etc.) are difficult to control, due to their short llife cycle and high reproductive rate, which quickly causes high population densities and easily develops resistance to chemical insecticides. Actual effectiveness of insecticides may vary. In general it is very important to control the pest at its first generations. The choice of products to apply and the form of application should be made considering the habits in the different stages of development. As a nymph or as an adult, insects are located in different parts of the plant. And pupae, for example, are very resistant to many of the insecticides usually applied to the control of nymphs and adults.

Acari

FuturCrop computes different events in the life cycle of each pest. For example, regarding the European red mite (Panonychus ulmi), the program calculates the specific dates for each stage or event, such as eggs, larvae, male protonymphs, female protonymphs, male adults, female adults and oviposition. With this information, it is possible to carry out efficient treatments. For example, for the treatment of Panonychus ulmi it is convenient to do it when hatching the wintering generation, which coincides with the appearance of the first summer sprouts. Applying paraffin oil at that time has an efficiency of 76.2%.

In order to control the greenhouse red spider mite (Tetranychus urticae), FuturCrop warns the user when the different generations become adults and the laying of eggs. That way monitoring is more accurate (as the software informs, adults are located in the tender sprouts of the higher parts of the citrus, on the underside of the leaves) and it is easier to choose the appropriate product, according to the generation stage of development (such as ovicides, larvicides, adulticides). Generally, given that the greenhouse red spider mite live in colonies on the underside of the leaves, and produce silk threads in large quantities which serve as a refuge from predators and acaricides, treatments are more efficient when there are majority of eggs or early stages.

GREATER EFFICIENCY IN PEST BIOLOGICAL CONTROL

The success pest biological control techniques requires knowledge of the biology of the organisms involved, both of pest and the control agent. To achieve greater efficiency using predators, parasites and parasitoids it is important to know the state of biological development of pests, in order to release the predators when they have greater abundance of prey, or parasites and parasitoids when hosts are more abundant.

The mos effective is to synchronize the life cycle of the biological control agent with the life cycle of the pest. Parasitoids have specific requirements of the host development stage for the parasitic effect to occur. In addition to the percentage of parasitism, the reproduction capacity of the pest must also be considered. For example, a parasitism rate of 90% on a pest with a reproductive capacity of 20 eggs per female, assumes that the pest density will remain stable. But the same rate of parasitism acting on a pest with a reproductive capacity of 100 eggs per female means that the population will quintuple in each generation.

In 1970 it has been calculated that the success of pest biological control techniques was 54% (DeBach, P. 1977). In later researches the percentage of successes was evaluated as 40% (Waage, J.K, and D.J. Greathead, 1988). But in recent decades there has been an increase, probably due to a greater knowledge of the mechanisms that determine the success of pest biological control. In economic terms the benefits of biological control are evident, since it has been calculated an approximate return for each dollar invested of 30 to 1, while for the chemical control the ratio has been 5 to 1. Therefore, pest biological control is an appropriate measure, realistic and economically profitable, when applied correctly. But a support system for decision-making (moment of release, number of individuals that need to be released, etc.) is essential for its success.

For example, to control the American serpentine leaf miner (Liriomyza trifolii), it is used Diglyfus diasea, an ectoparasite of the pest larvae in its second and third stage, or instar. To accurate release the ectoparasite at the best moment, FuturCrop computes the eggs hatching moment, and the the moment in which 50% larvae are in the third stage. Also each species of predator has its preferences on the development stage of its prey. Thus, for example, Amblyseius californicus, acts on all stages of the red spider mite (Tetranychus urticae), but prefers eggs and immature stages, thereby increasing the chances of success if the release is done at those times.

If using bacteria for pest controlling, information on the right time to carry out the treatment also largely determines its success. For example, bacteria of the eenus Bacillus sp. are among the best-known bacteria used for the biological control of the Egyptian cotton leafworm (Spodoptera litoralis), specially Bacillus thuringiensis (used to control dipterans and beetles -such as the Colorado potato beetle). The appropriate time for its use, when larvae can become infected, that is when the larva bites the leaf to enter into it. If the leaf has the bacteria then it could kill the larva. Once the larva manages to enter the leaf, the infection will be very difficult. For this reason, pest control treatments using B. thuringiensis are more effective if applied during the first larval stages of the pest. 

FuturCrop not only can be used to establish and predict the right time for the release of predators, parasitoids and bacteria, but it can also be useful to decide if the pest control done by its natural enemies is sufficient. For example, counting the eggs and larvae of the American cotton bollworm (Heliothis zea) it is possible to estimate what result the biological control is having, knowing through the software the generation the pest is in, and then evaluating its future population density. When the percentage of eggs is similar to the percentage of larvae in their early stages, we have evidence that there is a low rate of biological control done by its natural enemies,

References

DeBach, P. 1977. Lucha biológica contra los enemigos de las plantas. Ed. Mundi-Prensa, Madrid, 399 P.

Hokkanen, H.M.T, 1985. Success in classical biological control. CRC Critical Reviews in Plant Sciences 3: 35-72

Waage, J.K, and D.J. Greathead, 1988. Biological control: Challenges and opportunities. Philosophical Transactions of the Royal Society of London, Series B, 318: 111-128

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