Neoseiulus =Amblyseius cucumeris, the thrips predatory mite, are useful for the prevention, control, and management of various thrips species. Like most of the Neoseiulus spp., N. cucumeris are tough, flexible predators. These happen to prefer thrips, mostly the immature thrips stages. N. cucumeris are shipped as adults, immatures and eggs (the latter are not part of the guaranteed count) in a loose bran-flake carrier. With this medium, these predators are supplied three different ways: a bulk product for fast distribution and consumption; a pre-punched packet product for slow preventive releases over an 8 week period; and a packet which is not pre-punched that must be torn open and immediately distributed. The latter is designed for small scale use. Some of the species they can devour include: the western flower thrips (Frankliniella occidentalis); the flower thrips or eastern flower thrips (F. tritici); the onion thrips (Thrips tabaci); the greenhouse thrips (Heliothrips haemorrhoidalis); and possibly the melon thrips (Thrips palmi), too. Other pests which can be impacted by these predators include cyclamen mites (Phtyodromus =Steneotarsonemus pallidus), broad mites (Polyphagotarsenomus =Hemitarsonemus latus) and, to a slight degree, tomato russet mite (Aculops lycopersici). And, as Neoseiulus spp., these predators may eat other pests as well.
The tiny 0.5 mm. clear-white adult female mites lay eggs amongst thrips concentrations. They can lay up to 35 eggs. The eggs hatch into super small larvae which develop into nymphal forms before reaching adulthood. These, too, are fierce predators, consuming many immature thrips. The life-span of these predators is about 10 days in their immature stages, then around 30 days as adults. The conditions for optimum performance will be between 66-80°F with a relative humidity of between 65-72%. But these are optimum conditions, and not necessarily a prerequisite of successful implementation. Please note, however, considerably cooler temperatures will hamper reproduction and development a certain degree.
N. cucumeris are very cost-effective. These predators enjoy snacking on available pollen. This helps them be an efficient long-term preventive agent as well as a curative one. And, when supplied in slow-release packets, they are even more outstanding. The packets, which normally last up to eight weeks, contain a food source for the predators: a bran mite or, more properly, the mold mite (Tyrophagus putrescentiae). This mold mite is merely a sustainable food source for the predatory mites while they’re in transit, and longer in the packet system. These mites are very, very economical. So economical, in fact, some growers are using N. cucumeris as they would a pesticide: the infamous repeated dousing technique. Speaking of pesticides, these predators are compatible with many; a real plus in an Integrated Pest Management (IPM) program. Lastly, commercially produced N. cucumeris is mostly nondiapausing strain. They can, therefore, be used year ’round.
You get a lot, but you have to use a lot. Good thing they’re inexpensive. The packets are great, though more expensive, they do the preventive job assigned to them. The problem is when growers want to use them for control in an environment where the loose material is impractical to apply: certain hydroponic systems, for example where the bran carrier may fall into a trough. The drawback is they’re not designed to work that way. Slow release in the case of these packets means that the resident generation usually doesn’t venture out of the bag. Their offspring, however, begin the process of prevention as they start exploring the world outside. Humid environments can sometimes be a drawback with the use of the packets (see Advisories).
Finding N. cucumeris on the plants is difficult. To the beginner I suggest simply monitoring the thrips levels. This is much easier than looking for predators all day. Monitoring thrips levels can be done two different ways:
- Use blue or yellow sticky traps to capture adults which can be counted weekly and/or;
- Use the “paper method” by gently shaking the plant over a white piece of paper on which they’ll show up nicely.
Try the latter on a corn plant this summer, tap out the tassels if you really want to see some thrips. Unless your scouting is really top-notch, you’ll probably miss most of the predators present on the leaves. However, if you see some agile-looking mites running a zigzag quickly across the leaf’s undersurface, they are probably predators.
Flowering, pollen producing plants are a big plus so certain crops may prove beneficial. Humidity: the packets can develop a growth of some sort about two weeks after they were put out in humid conditions (90% and up).
There may be a compatibility issue when used with Phytoseiulus persimilis. Used together, these pairs are under suspicion: the N. cucumeris may eat the other predators’ eggs. Before getting some loose bran product, determine how it’s going to be applied so that you can prepare. Beside shaking out the bulk bran onto the leaves, you may wish to apply it with a broadcast granule or whirlybird type spreader.
Another compatibility issue may exist with Dalotia coriaria. If used together, we strongly suggest using the N. cucumeris release packets instead of the bulk bran bottles.
Greenhouses/interiors are where these mites are most often used.
Release Rates for Neoseiulus cucumeris
|Comments||When using “slow-release packets” for prevention, repeated releases need to be made roughly monthly instead of bi-weekly. Please note that the slow release packets contain approximately 1,000 mites each.|
|Prevent||30-90/yd, bi-wkly, as needed (see comments).|
|Low||90-150/yd, weekly, 3-5 times.|
|Med||150-210/yd, weekly, 3-5 times.|
|High||150-210/yd, weekly, 3-5 times.|
|Maint||60-120/yd, tri-wkly, indef.|
|Garden||60-80% of rates listed.|
|Acre+||50-75% of rates listed.|
Amblyseius cucumeris – thrips predator (250,000 in 5liter bulk bag)
Buy 2 or more and pay $106.50 per bag!
Amblyseius cucumeris – thrips predator (50,000 in liter tube)
Buy 2 or more and pay $23.70 per bottle of 50,000!