Crop diseases often occur as mixtures of different organisms which can be difficult to identify without lengthy laboratory tests. In addition, many diseases have long symptomless phases when an organism grows within the plant without damage being visible. In each case, rapid and specific diagnosis is necessary to enable effective and timely management actions to be taken. “Isothermal PCR” is a molecular technology where highlyspecific assays can be carried out at a constant temperature, without the need for laboratory conditions. All aspects of the test can be carried out using simple steps with pre-prepared assay tubes. Small, compact, commercially available machines (the Genie® platform, available from Optigene Ltd) produce a diagnostic outcome in as little as 30 minutes. A number of tests have now been developed for problematic diseases in arable crops, including the Alternaria species complex on potatoes, tan spot and Septoria on wheat, and light leaf spot on oilseed rape, which has a long symptomless phase. Using such assays, growers and agronomists could obtain rapid and definitive answers on which diseasesare present in crops, aiding fungicide selection and timing.

Crop diseases often occur as mixtures of different organisms which can be difficult to identify without lengthy laboratory tests. In addition, many diseases have long symptomless phases when an organism grows within the plant without damage being visible. In each case, rapid and specific diagnosis is necessary to enable effective and timely management actions to be taken. “Isothermal PCR” is a molecular technology where highlyspecific assays can be carried out at a constant temperature, without the need for laboratory conditions. All aspects of the test can be carried out using simple steps with pre-prepared assay tubes. Small, compact, commercially available machines (the Genie® platform, available from Optigene Ltd) produce a diagnostic outcome in as little as 30 minutes. A number of tests have now been developed for problematic diseases in arable crops, including the Alternaria species complex on potatoes, tan spot and Septoria on wheat, and light leaf spot on oilseed rape, which has a long symptomless phase. Using such assays, growers and agronomists could obtain rapid and definitive answers on which diseasesare present in crops, aiding fungicide selection and timing.

Bemisia tabaciis an obligate phloem-feeding pest, which is globally distributed. In total, at least 120 plant viruses are transmitted by B. tabaci, causing diseases of vegetable and fibre crops worldwide. Tomato (Lycopersicon esculentum) crops are particularly susceptible to more than 50 different species of the Begomovirus genus, including Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Sardinia virus (TYLCSV) both of which reduce yields and can cause large economic losses in tomatoes (Bedford et al., 1994). TLYCV and TYLCSV have been recorded in countries all around the Mediterranean Basin.Because B. tabaci is acquiring resistance to pesticides and because of the retrieval of pesticides from the European market, the development of novel control methods for this pest based on biological control agents will benefit European agriculture.Currently two predatory species are being used in the Mediterranean greenhouses: Macrolophus pygmaeus (commercially called Macrolophus caliginosus) and Nesidiocoris tenuis. The two species belong to the heteropteran family of Miridae and are omnivorous, that is, they can feed on both animal prey and plant materials. First species is very slow for establishing on the crop when it is released in the greenhouse whereas the second is quite fast but may strongly damage plant causing flower abortion, decrease of cosmetic value of fruit and reduced yield. For these reasons, new alternatives are needed.EMPHASIS project aimed to provide greenhouse growers with new generalist predators that overcome the constraints of the two commercially available species, that is, M. pygmaeus (commercially called M. caliginosus) and N. tenuis.Four main specific objectives were:1.To implement a commercial mass rearing of the twonew generalist predators2.To define the weather conditions under which the two predatory species belonging to the genusDicyhpuscan be used for biological control of the whiteflyB. tabaci.3.To know the prey consumption capacity of the two species.4.To determine whitefly control capacity in semi-field and field trials.TwoDicyphusspecies have been tested,Dicyphus bolivariandDicyphus errans. However, the protocol that follows refers only toD. bolivari, the one on which most applied results have beenobtained in the EMPHASIS project.Specific recommendations on biological control must be adapted to specific local conditions of the greenhouse, tomato variety, production area and crop season, among others. We recommend to consult the predator provider for adaptations of the following protocol to each tomato greenhouse.

How to proceed with seedlingsIn order to improve the early establishment of the predator on the crop, it is recommended to inoculate an initial population of the predator in the plant seedlings. A rate of 1 to 2 adult predators per plant are released in the nursery between 11-13 days before transplanting; Autumn season tomato should release closer to 2 adults/plant whereas for spring tomatoes about 1 adult/plant may be enough. With thisschedule, most of individuals in the seedlings are at the egg stage when plants are transplanted into the greenhouse, and loss of mobile nymphs in the transplanting process is prevented. Two successive releases of alternative food, f.i.Ephestia kuehniellaeggs (dose of 0.01-0.02 g/plant) are performed in the nursery in order to favour the establishment of the predators on the plants.How to proceed in the greenhouseOnce young plants have been transplanted into the greenhouse, it is required to monitor whitefly and predator populations. The number of whitefly adults and predator individuals on the 7 upper fully developed leaves will be scouted every 7-15 days (in warmer season/area –cooler season/area respectively). If the whitefly control exerted by the predator is not effective enough, an extra release of the predator should be done at a rate of 0.5-1 adult/plant. To maintain the predator on the plant, complementary predator food (Ephestiaeggs) may be added to the crop at a rate of 10 grams per 1.000 individuals ofD.bolivarireleased. A common procedure is the mixture of the eggs ofEphestiainside the bottles ofD. bolivari, just before the release of the predators, so that the alternative food is provided together with the predatory populations.Dicyphusbolivariwill offer the same biological control protection when the greenhouse whitefly,T. vaporariorum, is infesting the crop, instead of or together withB. tabaci.It can also be expected a certain suppressing action ofD.bolivarion other insect pests other than whiteflies, butD.bolivarican fail to suppress them at densities below economic threshold in case of high infestations. Then, other measures, including application of chemicals, are needed. In order to minimize chemical side effects on the predator in these situations, including the application of chemicals to control diseases, it is advisable to consult the predator provider about which active ingredients can be used and how can they be applied. Also, cultural practices have to be adapted to enhance predator action. For instance, plant deleafing must consider thatD.bolivariadults and nymphs may be foraging on leaves below flower trust and their removal can affect predator abundance.Dicyphusspp. are omnivorous predators, that is, under certain circumstances they can feed on the plants, including fruit and so they can cause some injuries on plants. In the case ofD.bolivari, plant damage only occurs when there are high populations and the ratio predator/prey is too high. This is tosay, when the action of the predator is ‘too good’ and the prey has been effectively suppressed. This situation, too many predators for low prey density, must be avoided and data of whitefly and predator monitoring can alert us about risks of plant damage. In such cases, a chemical spray to lower predator density is required. Consult the predator supplier (usually their webpages contain the information needed) in such cases,

Cabbage stem flea beetle has become a serious threat to oilseed rape establishment following the loss of neonicotinoid seed treatments. Using a “companion” species sown with oilseed rape has proved to be an effective means of reducing crop damage. In particular, white mustard appears to attract the beetle preferentially, and allow the oilseed rape to establish successfully. The technique is suitable for high risk situations, and the companion should be removed after a few weeks, using either a non-selective herbicide if the oilseed rape variety is herbicide resistant, or a conventional selective herbicide in the autumn. Relying on frost to kill the companions is not recommended for much of norther Europe as temperatures may not be low enough. Growers should consider constructing their own white mustard and oilseed rape mixture, or buying “co-packs” which may be marketed commercially. Small testareas are advised initially so the technique can be explored in different farm situations. Other companion crop species have not proved effective for flea beetle control.