How to Manage Pests
UC Pest Management Guidelines
Dichondra Flea Beetle
Scientific Name: Chaetocnema repens
(Reviewed 9/09, updated 9/09, pesticides updated 12/16)
In this Guideline:
DESCRIPTION OF THE PEST
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 longand 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.
UC IPM Pest Management Guidelines:
Insects and Mites
A. M. Sutherland, UC Statewide IPM Program, Alameda County
Acknowledgment for contributions to Insect and Mites:H. K. Kaya, Nematology, UC Davis
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