Nematodes are very petite , microscopic “ louse ” that mostly live in soils , although “ foliar ” nematodes live in leave of absence . While some species harm plants by attacking roots , others are good nematode worm , assail and killing pests such as chuck in our lawns and gardens and unwanted grownup insects . nematode worm are easily applied , but the correct timing and conditions are needed for them to be effectual .
good nematodes are very effective for dirt pest ascendancy . Feeding on over 200 insect from rough 100 fellowship , nematodes are safe to use around humans , minor , and darling and wo n’t harm non - target organisms such asbees or other pollinators . They ’re well-to-do to use ( no protective cogwheel is needed ) , warm to exploit ( often within a couple days ) , and cost - effectual – for under $ 20 you should get about 5 million — enough to treat 1,500 square feet .
How do beneficial nematodes kill pest insects?
The “ manner of action ” of beneficial nematode worm is like something from a horror film , at least for the target pests . One specie ( Steinernema ) expend an ambuscade strategy , hold back for the prey to add up tight before attacking . Another nematode ( Heterorhabdtis ) uses a “ cruising ” strategy , seeking out and destroy pests . The nematodes either follow the lead of excretion of the pest or look for it through changes in temperature and carbon dioxide levels .
Once found , the beneficial roundworm enter the grub or adult cuss through physical structure opening , such as the sassing or openings to the breathing tubes ( “ spiracles ” ) . The nematode worm convey a bacterium which is harmless to plants , humans , or the environment , and when this bacterium enters the pest ’s body , the bacteria multiply , killing it in two days or less , and converting host tissue to food for the nematode worm . Since these bacteria work on to assist their boniface – the nematodes – they are called “ symbiotic ” .
The infected grubs change from a beige - blank to ruby - brown , go bad and wrench slimed . The nematodes then feed on the dead pestilence from within ( hence they are call “ entomopathogenic ” ) , and can go through several generation of grownup in a duo of workweek . Once their food germ is gone they exit and move on to novel prey .
Which beneficial nematodes should be added to a garden?
Each coinage of nematode target specific plague . For example , one species ( S. carpocapsae ) is effective on larval stages of Pseudaletia unipuncta , weevil such as black vine , caterpillars , cutworm , and sod webworm . Another mintage ( S. feltiae ) is used against larvae of cabbage maggot , onion plant maggot , raspberry crown woodborer , and thrip . Both species are effective on larva of codling moth , corn earworm , and cucumber mallet . You ’ll want a coinage ( H. bacteriophora ) of the other nematode for larva of tree diagram and vine borers , European chafer , Colorado potato beetle , corn rootworm , flea beetles , and grubs include those of theJapanese beetle .
Your local garden center , master gardener programs , online resources , books , and state extension diagnostic clinic ( www.nepdn.org ) are all good resource to describe target pests . If you ’re not certain what pest you have , you may need to give a couple of dissimilar nematode product .
dirt eccentric can affect nematode worm . Some piece of work best in cultivate soil ( Steinernema ) while others act upon well in undisturbed soils ( Heterorhabdtis ) . Other species process substantially in Lucius Clay or silt ( S. feltiae ) , another works well in sandy grunge ( S. carpocapsae ) . Soil type is n’t of the essence for the other principal good nematode ( Heterorhabdtis ) .
How to apply beneficial nematodes to your plants and soil.
Once you sleep together which beneficial nematode species is appropriate , to be effective it must be applied in good order . Timing is important , as the soil level of your target pest demand to be present for the nematodes to work on them . Late summer into early fall is a upright time to aim many chow of plants , crop , and lawn , as they are usually small , feeding on eatage root near the soil Earth’s surface , and have thin skin the nematodes can easily penetrate . This is also the time when armyworm fall to the ground to change stages ( pupate ) .
good nematodes are keep organisms , so should be put on very soon after you get them . They care moisture , so if it has n’t rained , water good both before and after applications programme , or apply during rain . If your nematodes arrive on a wet sponge , rinse them from the sponge into nerveless water , then spray on plants according to label direction . Soils must be kept dampish for a calendar week to 10 Clarence Shepard Day Jr. after app .
Rainy , overcast weather condition is right for another ground — beneficial nematodes are quite sensitive to ultraviolet sunshine and can be wipe out within a minute or two if expose to it . That ’s why you ’ll often see recommendations to give in the early morning or previous afternoon . They ’re sensible to temperature too , with idealistic temperature between 45 and 100 degree ( F ) .
For bar , you could put on beneficial nematodes 2 to 3 times a year , such as in fountain , summer , or decrease . For control of existing pesterer , apply every 2 week until the plague lessens or goes away .
A version of this article appears on the University of Vermont Extension website .
