Hi all:
Found some more info and am I seeing soft shelled insects again (not that
bees are soft exoskelton insects) listed looks like.
Regards,
Dee
_http://www.nysaes.cornell.edu/ent/biocontrol/pathogens/fungi.html_
(http://www.nysaes.cornell.edu/ent/biocontrol/pathogens/fungi.html)
Fungi
* Primary hosts: aphids, whiteflies, leafhoppers, flies, beetles,
caterpillars, thrips, and mites; some beetle larvae
* Key characters: reduced feeding, lethargy; dead insects swell, and
may be covered with fungi
* Crops: many
* Commercially available: several, including antagonists of fungal
disease and a product (Metarhizium anisopliae) which is used against household
cockroaches
Some insect species, including many pests, are particularly susceptible to
infection by naturally occurring, insect-pathogenic fungi. These fungi are
very specific to insects, often to particular species, and do not infect animals
or plants. Fungal growth is favored by moist conditions but fungi also have
resistant stages that maintain infection potential under dry conditions.
Fungi have considerable epizootic potential and can spread quickly through an
insect population and cause its collapse. Because fungi penetrate the insect
body, they can infect sucking insects such as aphids and whiteflies that are not
susceptible to bacteria and viruses.
Several fungal species have potential as microbial insecticides and, in some
countries, are commercially available in formulations that can be applied
using conventional spray equipment.
Habitat (Crops)
Most crops including soybeans, greenhouse crops, vegetables, cotton, citrus,
and ornamentals; also interior plantscapes and forests. An aquatic fungus
infects mosquito larvae of some genera.
Pests Attacked
Most insect pests are susceptible to fungal pathogens. Some fungi, such as
the Entomophthora and related species, are fairly specific with regard to the
groups of insects affected; others, such as Beauveria, have a wider host
range.
Mode of Action
Fungi invade insects by penetrating their cuticle or "skin." Once inside the
insect, the fungus rapidly multiplies throughout the body. Death is caused
by tissue destruction and, occasionally, by toxins produced by the fungus. The
fungus frequently emerges from the insect's body to produce spores that,
when spread by wind, rain, or contact with other insects, can spread infection.
Symptoms
Infected insects stop feeding and become lethargic. They may die relatively
rapidly, sometimes in an upright position still attached to a leaf or stem,
perhaps in an elevated location or concentrated near crop borders. The dead
insect's body may be firm and "cheese-like" or an empty shell, often but not
always with cream, green, red, or brown fungal growth, either enveloping the
body or emerging from joints and body segments. Infected aphids can be swollen
and discolored; infected root maggot flies may be clustered on shoot tips,
tall grasses, or other prominent features.
Relative Effectiveness
Insect-pathogenic fungi usually need moisture to enable infection, and
natural epizootics are most common during wet or humid conditions. The
effectiveness of these fungi against pest insects depends on having the correct fungal
species and strain with the susceptible insect life stage, at the appropriate
humidity, soil texture (to reach ground-dwelling pest species), and
temperature. The fungal spores, which can be carried by wind or water, must contact
the pest insect to cause infection. Naturally occurring fungal epizootics may
decimate aphid, root maggot fly, caterpillar, leafhopper, and thrips
populations. They can be an important natural control of aphids in potatoes and other
crops.
Many insect-pathogenic fungi occur in the soil. There is evidence that
application of some soil insecticides, fungicides, and herbicides can inhibit or
kill these fungi. For example, even quite low concentrations of some
herbicides can severely limit the germination and growth of Beauveria bassiana fungal
spores in soil samples.
Commercially Availability
Metarhizium anisopliae is registered in the U.S. for control of household
cockroaches. Beauveria bassiana Strain GHA (trade names Mycotrol GH-OF and
Mycotrol GH-ES) is registered to control grasshoppers, locusts, and Mormon
crickets on rangeland, improved pastures, alfalfa, corn cotton potatoes, rapeseed,
safflower, small grain crops, soybeans, sugarbeets, and sunflowers.
Paecilomyces fumosoroseus Apopka Strain 97 has been approved for use on ornamentals,
non-food crops in greenhouses, and interiorscapes to manage whiteflies,
aphids, thrips, and spider mites and is sold by Thermo Trilogy Corp. In addition,
there are fungal antagonists available to combat various fungal pests.
Some Common Insect-Pathogenic Fungi
Entomophthora muscae infects flies. Susceptible pest species include the
adults of the onion maggot, cabbage maggot, and seedcorn maggot. The fungus
multiplies within the body of the adult fly which becomes enlarged; yellowish
bands of fungal spores stripe the abdomen.
Related species include Pandora neoaphidis, a common, naturally occurring
pathogen of aphids that can be particularly effective during moist periods.
Zoophthora radicans is another common fungus, with a broad host range. Strains
have been isolated from several caterpillars, including diamondback moth,
leafhoppers, aphids, and some weevils. Other related species infect thrips.
Beauveria bassiana is an insect-pathogenic fungus found naturally on some
plants and in the soil. Epizootics are favored by warm, humid weather. It is
known as the white muscardine fungus because infected insect larvae eventually
turn white or gray. Beauveria is used as a fungal microbial insecticide in
some countries. It has an extensive host list that includes such important
pests as whiteflies, aphids, grasshoppers, termites, Colorado potato beetle,
Mexican bean beetle, Japanese beetle, boll weevil, cereal leaf beetle, bark
beetles, lygus bugs, chinch bug, fire ants, European corn borer, codling moth, and
Douglas fir tussock moth. It has even been found infecting the lungs of wild
rodents, and the nasal passages of humans. Unfortunately, natural enemies,
such as lady beetles, are susceptible too. One possible application method
that may avoid harming beneficial insects is the use of fungus-contaminated
insect baits that are attractive to pest species only. There are many different
strains of the fungus that exhibit considerable variation in virulence,
pathogenicity and host range. It occurs in the soil as a saprophyte.
Metarhizium spp. is being tested as a natural enemy of corn rootworm, white
grubs (scarabs), and some root weevils. It has a very broad host range and is
extensively used in Brazil against spittle bugs in sugar cane and alfalfa.
Other species of insect-pathogenic fungi have been tested as microbial
insecticides for the control of pests. Verticillium lecanii is used in Europe
against greenhouse whitefly and thrips and aphids, especially in greenhouse
crops. Neozygites floridana has been successfully tested against spider mites, and
Nomuraea rileyi has activity against green cloverworm, cabbage looper,
imported cabbageworm, armyworms, corn earworm, and tobacco budworm. Hirsutella
thompsonii infects mites and was previously registered for use in the United
States.
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