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How to Manage Pests
UC Pest Management Guidelines
Turfgrass
Dichondra Flea Beetle
Scientific Name: Chaetocnema repens
(Reviewed 9/09,
updated 9/09)
In this Guideline:
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Eggs are laid near the soil surface and require 3 days to hatch.
The soil-dwelling larvae are white, with fine bristles and a light brown head
capsule. Last (fourth) instar larvae are about 0.17 to 0.25 inch long. The
white pupae are 0.05 inch long and are found in the same depths (up to 4
inches) in the soil as the larvae. Larvae require 22 to 25 days to complete
development; pupation takes about 5 days. Adults are ovoid, about 0.06 inch
long, and have greatly thickened hind femora for jumping. Newly emerged adults
are white for 1 day, then turn a characteristic black color with a metallic
reddish bronze tinge. The antennae, front, and middle legs are reddish yellow.
Adults can be observed by passing a hand over affected dichondra. The disturbed
adults will jump, some of them onto your hand or arm. Dichondra flea beetle
overwinters as an adult.
Dichondra and bermudagrass.
Dichondra flea beetles seriously damage dichondra, causing many
dichondra lawns to be replaced with grass turf. Larvae feed between May and
October on small roots and the outsides of larger roots. This injury causes
dichondra to wilt and die; often, large patches are affected. Adults feed on
dichondra leaves, producing distinctive crescent marks on the upper surface.
Severely skeletonized plants may wither; however, this symptom is most likely
caused by larval root feeding. Larval populations can be assessed by placing
turf soil cores in a Berlese funnel and extracting the larvae.
The dichondra flea beetle has also
been found damaging common and hybrid bermudagrass in California. Symptoms
include overall appearance of lack of water or fertilizer burn. First signs of
damage appear in March and decrease in September as temperatures drop.
Individual leaf blades have white linear banding along the length of the leaf
blade. Occasionally the turf becomes bleached out in appearance.
Treat for dichondra flea beetle if
populations are high enough that damage may occur.
| Common name |
Amount/1000 sq ft** |
Ag Use R.E.I.+ |
NonAg Use R.E.I.+ |
| (trade name) |
|
(hours) |
(hours) |
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| The following
materials are listed in approximate order of usefulness in an IPM program,
taking into account efficacy and impact on natural enemies and the environment.
Not all registered materials are listed. Not all registered pesticides are listed. Always read label of product being used. |
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| A. |
ACEPHATE |
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(Orthene Turf, Tree, and |
1–1.9 oz |
24 |
until dry |
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Ornamental Spray) |
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MODE OF ACTION GROUP NUMBER1: 1B |
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COMMENTS: For use on golf courses and
sod farms only. Odorous. Up to 2.4 oz material/1000 sq. ft. can be used for black cutworm on turfgrass. |
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| B. |
DELTAMETHRIN |
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(DeltaGard T & O) G |
2 lb |
— |
until dry |
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MODE OF ACTION GROUP NUMBER1: 3 |
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COMMENTS: Not for use on sod farms or
in commercial seed production. For best results, irrigate with an adequate
quantity of water to thoroughly moisten grass and thatch and to dissolve the granules. |
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UC IPM Pest Management Guidelines: Turfgrass
UC ANR Publication 3365-T
Insects and Mites
M. L. Flint, UC IPM Program, UC Davis
M. A. Harivandi, UC Cooperative Extension, Alameda County
H. K. Kaya, Nematology, UC Davis
Acknowledgment for contributions to Insect and Mites:
J. Hartin, UC Cooperative Extension, San Bernardino County
R. S. Cowles, Connecticut Agricultural Experiment Station, Windsor, CT
K. Kido, Entomology, UC Riverside
H. S. Costa, Entomology, UC Riverside
D. D. Giraud, UC Cooperative Extension, Humboldt/Del Norte counties
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