| WFT adult surrounded by S. feltiae.
PHOTOS COURTESY BECKER UNDERWOOD
NEMATODES CAN BE USED ALONE OR IN COMBINATION WITH OTHER BCAs
Insect parasitic nematodes are commonly used BCAs that can be incorporated into many pest management programs. Nematodes can be used as a stand-alone program or in conjunction with other BCAs, such as predatory mites and beetles, parasitic wasps and beneficial fungi. The combination broadens the pest control spectrum, and helps effectively manage all life stages in a pest population. Nematodes can also be used in a rotational program with conventional insecticides to reduce the number of chemical applications needed for effective pest control, reducing the likelihood that pests will develop pesticide resistance.
|Untreated plant on the left with fungus gnat damage, and an S. feltiae-treated plant on the right
For pests like WFT, it’s best to apply S. feltiae as foliar and drench applications. Begin applications with a drench early in the growth cycle and follow with weekly foliar applications. Drench applications target soil-dwelling pupae, whereas foliar applications target foliar-dwelling adult and pupal stages. By applying both drench and foliar applications, more stages of the thrips’ life cycle will be targeted, providing more complete pest control. Other BCAs that can be used with nematodes for control of WFTs include Orius spp., Amblyseius swirskii, A. cucumeris, Hypoaspis aculeifer, H. miles and Beauveria bassiana.
Many growers often utilize S. feltiae in a rotational program with conventional pesticides.
CONVENTIONAL PESTICIDES HAVE A KEY ROLE TO PLAY
Under ideal environmental conditions for pest growth and development, populations may exceed the ability of BCAs to quickly decrease the pest population. In this instance, the quick knockdown often associated with conventional insecticides is desirable. Adding the insect parasitic nematode to a WFT spray program can significantly reduce the number of chemical applications needed for commercially acceptable levels of control.
|Electric air pump and bubbler used to prevent settling of nematode solutions. Go to www.beckerunderwood.com to find out how to make a nematode bubbler.
Fungus gnats can also be targeted using BCAs. Begin using drench applications of S.feltiae, applying every two to six weeks to the soil/media. Applications of H. aculeifer, H. miles and Atheta coriaria will also reduce fungus gnat populations.
In addition to using S. feltiae, some growers use Steinernema carpocapsae for shore fly control. S. carpocapsae and S. feltiae can be tank-mixed and sprayed at the same time to target a wider range of pest organisms. Like WFT, the key to successful control of shore fly larvae is frequent applications.
THE IMPORTANCE OF AN EARLY START
For all BCAs listed, always apply early in the growth cycle when pest populations are low and follow all manufacturers’ product label directions to maximize control of target pests.
| Sticky cards are used for scouting.
| Nematode specialist Julie Graesch. PHOTOS COURTESY BECKER UNDERWOOD
WHY THE GROWING INTEREST IN BIOCONTROLS?
Growers have adopted BCAs because of the growing concern with insect resistance associated with conventional pesticide programs, pesticide residue, inconvenience of personal protective equipment and re-entry intervals that reduce worker productivity. BCAs are an excellent solution to these concerns because, when integrated properly, they are safe to use on plants, can be used confidently around employees and customers to break the life cycle of pests, and finally, can prevent resistance issues while providing a similar level of control to conventional pesticides.
To learn more about insect parasitic nematodes and their compatibility within a comprehensive pest control program, visit www.beckerunderwood.com or call 515-232-5907.