Biological information:

• Common name: Flea Beetle
• Scientific name: Alticini spp., Phyllotreta spp., Podagrica spp.   
• Family or class: Chrysomelidae

Symptoms and/or signs to watch out for:

• Presence of adult beetles on leaves
• Flea Beetles damage plants by chewing small holes in the foliage
• Watch for sudden burst of jumping black spots among leaves

Life cycle:

• Overwinter in the adult stage
• Become active during warm days in mid-spring
• Seek out host plants by locating chemical sues that some plant produce
• Adults feed for several weeks
• Soon females intersperse feeding with egg laying
• Lay eggs in soil cracks around the base of the plants
• Worm-like larvae move to feed on small roots and root hairs
• Larval stage is completed in a month
• Pupate in the soil for 2-3 weeks and emerge as adults
• May be more than one generation per year

Mode of reproduction:

• The flea beetle reproduces by sexual reproduction

Vectors for the pest:

• Potato flea beetle spreads spindle tuber blight, brown rot, and potato scab
• Corn Flea Beetle spreads Stewart’s bacterial wilt of corn

Overwintering habit:

• Adult flea beetles overwinter in the leaves or fallen foliage that they use as protection

Alternate hosts:

• May have been seen at UNH on mesclun mix
• Brassica foliage
• Potato tubers and foliage
• Solanaceous crops

Horticultural production information:

Preventative strategies:

• Crop rotation – avoid planting crops prone to flea beetles in the same area over different seasons and in consecutive years
• Soil disruption in late fall

Threshold levels:

• Economic threshold level is when greater than 25% of the foliage is affected

Control options:

Physical controls:

• Plant earlier or later in the season to avoid peak larvae feeding times
• A good option for Brassica crops is to plant in mid to late July, reducing areas where overwintered flea beetles can feed and reproduce
• Use trap crops to lure flea beetles away from cash crops (ex: Chinese Southern Giant Mustard)

Biological controls:

• Entomopathogenic Nematodes- soil-dwelling parasitic worms that kill insects
• Steinernematidae and Heterorhabditidae families can attack larval stage of flea beetles

Chemical controls:

Kaolin (Surround WPOG):

• 12.5 to 50 lbs/A or 0.125 to 0.5 lbs/gal (0 dh, REI 4h, Bee:L)

• This is for suppression and repellence only
• May be applied to transplants prior to setting in field
• Use on seedlings and young plants
• Product residue may need to be washed off if applied after fruit set
• White residue may be minimized if applications stop when fruit is 25% of its expected harvest size
• Generally compatible as a tank mix with other insecticides

Petroleum Oil (Suffoil XOG):

• 1 to 2 gal/100 gal water (0 dh, REI 4h, Bee:L)
• Apply as needed
• Beetle larvae only

Pyrethrin (PyGanic EC5.0OG):

• 4.5 to 18 oz/A or 0.25 to 0.50 oz/gal (0 dh, REI 4h, Bee:L)
• For field and greenhouse use

 

Historical notes from Farm to YoU NH:

Date/circumstances observed (Pictures)

Control method used, efficacy of control method

 

References:

http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/insects/beetles/flea-beetle.aspx

https://www.uvm.edu/pss/ppp/pubs/el71.htm