Fly, cabbage root

Wilting, followed by general collapse and death of the plant, is a sign that the larvae of the cabbage root fly have eaten through the roots of the plant. By this stage the plants may be lost. 

Many Insects have become specialists on crucifers and a few related plant families. These Include flea beetles, leaf beetles, cabbage root fly, aphids, cabbage butterflies and the dlamondback moth. At the same time, several polyphagous Insects such as the cabbage looper, armyworms and aphids are major pests of crucifers. Comparative studies on these specialists and generalists have provided valuable Information on host recognition and possible resistance mechanisms. 

FINCH, S., Volatile plant chemicals and their effect on host plant finding by the cabbage root fly. Entomol. Exp. Appl., 1978,24, 150-159. 

Figure 5 Oviposition stimulants for the cabbage root fly (Delia radicum) and the Hessian fly (Mayetiola destructor).

Bright yellow pans or basins full of water with a few drops of liquid soap added are attractive to winged aphids and cabbage root flies. Adding soap breaks the surface tension of the water, so insects sink to the bottom. The yellow color attracts the pests, who try to alight and are drowned. 

Protection Offered Water traps are useful for monitoring winged aphids and cabbage root flies in the home garden. 

Cabbage root flies. See also Cabbage maggots... 

Diazinon, an organophosphoras compound with an anticholinesterase mode of action, was released for experimental evaluation in the early 1950s. Diazinon is now used extensively hy commercial and home applicators in a variety of formulations to control flies, cockroaches, lice on sheep, insect pests of ornamental plants and food crops (especially com, rice, onions, and sweet potatoes), forage crops such as alfalfa, and nematodes and soil insects in turf, lawns, and croplands. Diazinon is the most widely used organophosphorus pesticide in Pakistan to control cabbage root fly and carrot fly. In 1992, more than 612,000 kg of diazinon were used in California on alfalfa, nuts, stone fmits, vegetables, and other crops. 

Fig. 1.3 Tip recordings from a tarsal D-hair of Delia brassicae (cabbage root fly) in response to stimulation with the glucosinolate sinigrin and its aglycon allylisothiocyanate which is not stimulatory.

Hawkes, C. (1974) Dispersal of adult cabbage root fly (Erioischia brassicae (Bouche)) in relation to a brassica crop. J. appl. EcoL, 11, 83-93. 

Hawkes, C. and Coaker, T. H. (1979) Factors affecting the behavioral responses of the adult cabbage root fly, Delia brassicae, to host plant odour. Ent. exp. appl., 25, 45-58. 

Ellis, P. R., Cole, R., Crisp, P. and Hardman, J. A. (1980) The relationship between cabbage root fly egg-laying and volatile hydrolysis products of radish. Ann. appl. Biol., 95, 283-9. 

Finch, S. and Skinner, G. (1982) Trapping cabbage root flies in traps baited with plant extracts and with natural synthetic isothiocyanates. Ent. exp. appl., 31, 133-9. 

Usually pale colour e.g. frit fly or cabbage root fly... 

Fleece or net crop covers will stop egg laying of some pests such as carrot fly. On a field scale it is expensive although a very effective optiom hr swedes this is the only method available to growers to control cabbage root fly as there are cmrently no suitable recommended chemicals. 

On a Umited scale, crop covers are used over susceptible crops when there is likely to be damage. These crop covers form veiy effective barriers against pests such as carrot and cabbage root fly and caterpillars. Other than cost the problem with crop covers is that they have to be removed before weeding can be carried out. 

Cabbage root fly can be a problem and treatments will be required from April onwards. Aphids, caterpillars, cutworms, pollen beetle, cabbage stem weevil and slugs all attack broccoli. Damping off and wirestem can be a problem at the seedling stage. Club root, downy mildew, dark leaf spot, ring spot, white bhster and spear rot can all be a problem in the field. 

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