Answer for garden grub problem
The most probable
identification of the gardener's grubs are either June Beetle larve or
Chafer beetle larve that
belong to the white grub complex
of turfgrass insect pests.
These websites offer more information
on the identification and biology of these critters.
(http://ag.arizona.edu/pubs/garden/mg/entomology/turf.html)
(http://ag.arizona.edu/turf/publications/TurfgrassInsectPestsIPM.pdf)
(http://fireflyforest.net/firefly/2005/12/05/june-beetles-and-a-white-grub/)
(http://ag.arizona.edu/maricopa/garden/html/t-tips/bugs/maskedchaferbeetle.htm)
Organic control can be obtained with a couple
choices. See below. The gardener who sent in the problem
actually told us she talked to Tony Sarah, of Magic Garden Nursery, in
Tucson, and he had a nice organic solution that she used. Tony
provided her with a box of "Beneficial Nematodes" that he had on
hand at his store. The product is produced by Orcon of Los Angeles
CA. A few applications at specific times of the year will take care
of the white grub problem.
Grub control
options:
Option 1: Biological white grub control:
Bacterial Milky Disease problem.problem.
The bacterial milky diseases,
Bacillus popilliae Dutky, has been quite effective at controlling the
grubs in certain areas of the eastern United States. The spore count must
build up for 2 -3 years to be effective and during this time you should
not use an insecticide against the grubs that are needed to complete the
bacterium cycle. In Ohio and Kentucky, test trials have not produced
satisfactory results. Additional experiments are needed to determine the
lack of efficacy of milky disease in these soils
Option 2:
Biological white grub control: Entomopathogenic Nematodes
Parasitic
nematodes have recently become commercially available. Products containing
strains of Steinernema carpocapsae (Biosafe, Biovector, Exhibit, Scanmask)
have been marginally effective against white grubs. Preparations
containing Heterorhabditis spp. seem to be more effective. Apply the
nematodes when the white grubs are small. Irrigate before and after
applying the nematodes
Control
information provided from the American-lawns web site:
http://www.american-lawns.com/insects/grubs.html
More information on biological control can
be found on these web links:
http://www.arbico-organics.com/category/grub-beetle-control-products
http://www.buglogical.com/beneficialNematodes_control_soilDwellingPests/beneficialNematodes.asp
(Aug.
2010)