Tuta absoluta, Whitefly & other pests
Nesidiocoris tenuis, is a predatory mirid bug. It is a highly mobile predator used to prevent Tuta absoluta and whitefly populations building up in tomato and aubergine crops.
It is found in nature in the Mediterranean region and on the Canary Islands. This predator attacks Bemisia sp. as well as Trialeurodes sp. whitefly. All mobile stages eat whitefly, and it should be released early for good establishment. The packaging is designed to maintain optimum conditions during transport by providing humidity, food and shelter for the 250 or 500 insects inside. It also allows quick visual assessments of quality by the end user.
Nesidiocoris tenuis has five larvae and nymph stages before becoming an adult. As an adult it has a large appetite and feeds on several species of insects and mites. The larvae of whitefly are its primary prey but as a generalist predator it will feed on other prey such as leafminers and Lepidopteran eggs and larval stages. It is recommended for use in tomatoes and aubergines. It is a key predator of the South American Leafminer Moth (Tuta absoluta).
Mirid bugs are known to feed on plants and in the absence of prey and at high levels there is a risk of plant and fruit damage. It is therefore critical that timing and introduction rates are matched to the crop situation.
Nesidiocoris is classed as a plant pest in some countries and cannot be used as a bio-control agent
Use at the rate of 0.5-3.0 Nesidiocoris per m² as a single introduction or as a split introduction. Introductions at low rates can also be made at the plant propagation stage of production where early establishment is required.
Close greenhouse doors and vents. Apply in the cool morning or evening. Avoid application in bright sunlight. Distribute the contents onto the leaves evenly throughout the crop in clusters of 15 – 25 bugs, by gently shaking and rotating the bottle. Leave the containers in the crop for several hours, allowing any remaining insects to escape.
This predator may cause damage to small-fruited tomato varieties at low pest populations.
Nesiline t is a proprietary product containing the predatory bug Nesidiocoris tenuis (Reuter, 1895) (Heteroptera: Miridae).
It is usually found in the area of the Mediterranean and the Canary Islands. It is a generalist predator that is commonly found on solanaceous plants including tomatoes and aubergines. The product is supplied as young adults packed into bottles with moistened carrier material.
Some larvae may be present in the product.
All mobile stages of Nesidiocoris tenuis are voracious predators, from the first instar to the adult.. They prey on many small invertebrates, such as whitefly and mites. Nesidiocoris also thrives on eggs of Lepidoptera, such as Tuta absoluta, and will take some nutrients from plants.
Nesidiocoris females insert eggs singly into the stems and thicker leaf-veins of plants. These eggs are extremely difficult to see, even with a microscope. Under optimal conditions it will go from egg to adult in 3 to 4 weeks. This is much quicker than Macrolophus, a similar mirid bug that takes 6 to 8 weeks to develop from egg to adult. Optimal development conditions are around 23ºC with some humidity.
When compared to predatory mites the development and population increase of predatory mirid bugs is relatively slow. This means that timing of introductions can be important to ensure that bugs are on the crop in sufficient numbers to control the pests as they occur. However the fact that Nesidiocoris tenuis will feed on the plant may result in plant damage if the population is high with no pests to eat. If the target pest is Tuta absoluta the preferred introduction strategy is to introduce low numbers early in the crop cycle. Where whitefly is the target pest later introductions may be better.
When established on the crop Nesidiocoris makes a significant contribution to the control of other pests such as spider mite and leaf-miner, but is not recommended specifically for control of these pests. Spider mite in particular is a poor quality diet and results in slow growth and low fecundity. It is important to note that Nesidiocoris tenuis and other generalist predators may have prey preferences and ignore one potential pest in favour of another that they prefer. Control of these less favoured dietary items will always be unpredictable.
Nesiline t was developed originally the for control of whitefly on tomatoes but in more recent years it has been targeted more at the South American Tomato Moth Leafminer (Tuta absoluta). It is recommended for use on tomatoes and aubergines only. All tomato varieties can suffer damage from Nesidiocoris tenuis if high populations build up. As pest populations decline, the Nesidiocoris become more phytophagous and this feeding can result in necrotic rings on stems, leaves and flower trusses, causing fruit drop and a potential loss in yield.
On tomatoes and aubergines, early release gives the best result. Release rates of 0.25-2/m² are recommended, depending on previous season experience of pest problems. Initial releases can be accompanied by use of sterilised eggs of the stored product moth Ephestia, which may help initial establishment of Nesidiocoris in the absence of prey.
Release Nesidiocoris as uniformly as possible throughout the crop, preferably in subdued light early or late in the day to avoid adults flying directly to the vents.
Open the pack where it is needed and walk along the plant rows, gently shaking the container to distribute the adults. Alternatively, pour small amounts of products onto leaves or into a release box (URB). Leave the packaging at the base of a plant to allow any remaining adults to leave.
Nesiline t has been reported to cause leaf damage and fruit loss in some tomato crops Cherry and vine ripened tomatoes are most at risk, and Nesidiocoris should only be used on these crops when there is a serious risk of damage from Tuta absoluta, other methods of control are not available, for example on organic crops. In conventional crops use of recently introduced chemical controls would be a preferred approach.
It should not be used on ornamental crops without a trial treatment of a small number of isolated plants.
Nesiline t will help prevent the build-up of high populations of Tuta absoluta and whitefly in round tomato and aubergine crops when used as recommended. It will also contribute to control of other pests once it has established.
Nesiline t will not quickly reduce high existing whitefly or Tuta absoluta populations unless used at very high rates.
It is not recommended for use to control other pests such as spider mite, although once established in the crop it will contribute to their control.
It is not recommended for control of whitefly on cucumber or pepper crops.
A number of chemical insecticides can be integrated with the use of Nesidiocoris tenuis. Some will result in a reduction of the population as a result of direct toxicity to certain stages, or as an indirect result of prey removal.