Mycopesticides

Abstract

The present invention utilizes the non-sporulating mycelial stage of insect-specific parasitic fungi. The fungus can be present on grain, attracting the pest, and also infecting it through digestion. More than one fungus can be used in combination. The matrix of fungi can be dried or freeze-dried, packaged and reactivated for use as an effective bioinsecticide.

Description

[0001] This application is a divisional of U.S. application Ser. No. 09 / 678,141, filed Oct. 04, 2000, herein incorporated by reference.BACKGROUND OF THE INVENTION[0002] 1. Field of the Invention[0003] The present invention relates to the use of fungal mycelium as a biopesticide. More particularly, the invention relates to the control and destruction of insects, including carpenter ants, fire ants, termites, flies, beetles, cockroaches and other pests, using fungal mycelia as both attractant and infectious agent.[0004] 2. Description of the Related Art[0005] The use of chemical pesticides is the cause of many secondary environmental problems aside from the death of the targeted pest. Poisoning of soil and underlying aquifers may occur, along with pollution of surface waters as a result of runoff. Increases in cancer, allergies, immune disorders, neurological diseases and even death in agricultural workers and consumers have been attributable to the use of pesticides. Chemical pestici...

AI Technical Summary

Benefits of technology

[0015] The present invention offers an environmentally benign approach to insect control by attracting the insects who ingest latent preconidial mycelium (which may be fresh, dried or freeze-dried) which then infects the host. The preconidial mycelium is both the attractant and the pathogenic agent. The infected insects carrying the fungal hyphae become a vector back to the central colony, further dispersing the fungal pathogen. Mycelium is grown in pure culture using standard fermentation techniques for in vitro propagation. The fermented mycelia is diluted and transferred into a sterilized grain or a mixture of sterilized grains. Once inoculated, the fermented mycelia matures to a state prior to conidia formation. The preconidial mycelium may be utilized as is or may be arrested in its development through flash chilling (or by other means such as air-drying or refrigeration) and packaged in spoilage-proof or sealed packages. The end-user facilitates opening the package and placing the exposed mycelia-grain contents in the vicinity of recent pest activity.

[0016] The present invention thus provides improved products and methods wherein the fungal mycelium acts as bait and attractant and as an ingested or food insecticide, palatable enough that insects will readily consume it even in the presence of competing food sources, with high recruitment of other insects among social insects that exhibit such behavior. This results in multiple visits to a highly attractive pathogenic bait, thereby providing effective individual insect and / or colony inoculation.

[0017] The present invention further provides these and other advantages with improved control of insect pests using fungal insecticidal compositions (mycopesticides) having strong attractant properties and placing these attractant mycopesticides in or around an object or area to be protected. The present invention also provides insecticidal baits which use, as a toxicant, relatively innocuous, naturally occurring materials as the active agent, so as to control insects without undue effect on the ecology. Finally, by actively avoiding the use of conidia, the time and expense of raising conidial stage mycelium and / or separating conidia is avoided.

Problems solved by technology

The use of chemical pesticides is the cause of many secondary environmental problems aside from the death of the targeted pest.

Poisoning of soil and underlying aquifers may occur, along with pollution of surface waters as a result of runoff.

Compounding these problems, many pest type or vermin insects have developed a broad spectrum of resistance to chemical pesticides, resulting in few commercially available pesticides that are effective without thorough and repeated applications.

In addition to being largely ineffective and difficult and costly to apply, chemical pesticides present the further disadvantage of detrimental effects on non-target species, resulting in secondary pest outbreaks.

It is believed that widespread use of broad-spectrum insecticides often destroys or greatly hampers the natural enemies of pest species, and pest species reinfest the area faster than non-target species, thereby allowing and encouraging further pest outbreaks.

However, limited availability, cost and reliability have hampered the development of such fungal control agents.

One disadvantage to such approaches is that the fungal lifecycle may be particularly sensitive to and dependent upon conditions of humidity, moisture and free water, particularly during the stages of germination, penetration of the cuticle prior to growth, and hyphal reemergence and sporulation after death of the insect.

Another continuing problem with existing techniques has been inconsistent bait acceptance.

Such may be a particular problem with insects such as termites, as opposed to house ants and cockroaches, because it is usually not possible to remove competing food sources for termites.

Attractants and feeding stimulants have sometimes increased the consistency of bait acceptance, but such increases cost and complexity, and there remains a continuing need for improved baits with improved bait acceptance.

A particular disadvantage with conidial fungal insect preparations becomes apparent from U.S. Pat. No. 5,595,746 (1997) to Milner et al. for termite control.

The difficulties of utilizing conidia or conidia / mycelium as a bait and / or contact insecticide are readily apparent when considering that conidia are effective as an insect repellant to termites and are repellant in varying degrees to most or all targeted insect pests.

A repellant, of course, does not facilitate use as a bait or contact insecticide.

Such an approach has the disadvantage of utilizing toxic boron compounds.