Striped flea beetle
Encyclopedia
The striped flea beetle (Phyllotreta striolata) is a small flea beetle
, shiny black with a greenish tinge, 1.5 to 2.5 mm long, having a wavy yellow line running the length of each elytron (wing cover). It is a pest of cabbage
and other brassica
s. The hind legs are thickened, enabling the beetle to jump like a flea when disturbed.
The minute, oval to elongate white eggs are laid in the soil close to the host plant. The white, brown-headed larva
, when fully grown, is 3.2 to 5.0 mm long. It has three pairs of tiny legs near its head. The white pupa
is approximately the same size and shape as the adult.
Eurasia
n in origin, the striped flea beetle is common throughout the eastern and Pacific areas of the United States (though not in much of the Rocky Mountain region
), as well as in South Africa
.
Although the larvae live in the soil, feeding on the roots of host plants, they are not significant pests. Rather, the primary damage is caused by adult beetles feeding on the foliage. With their chewing mouthparts, beetles make small round pits in the cotyledon
s and leaves of young plants. As the plants grow, the remaining thin layers of tissue eventually dry up and fall away, leaving small "shot holes" in the foliage. This type of injury is capable of killing young plants. The seedlings may be killed if severe damage occurs. In addition, beetles may act as vectors of plant disease.
Striped flea beetles overwinter among debris in and around fields. Emerging early in spring, they attack seedlings and young plants. Eggs are deposited in tiny crevices gnawed out of the base of host plant stems. About ten days later, the grubs hatch from the eggs and move into the soil to attack roots. After feeding for three or four weeks, the larvae pupate for seven to ten days. A new generation of beetles then emerges. Generations can be continual in warmer climates, recurring at least twice a year.
Cultivation practices and the use of resistant crop varieties help prevent severe flea beetle infestations. Seedbeds are covered with strips of a thin transparent gauze
to protect seedlings from adult feeding before transplanting. Good weed control and the destruction of crop residue
in and around fields reduce overwintering populations. After harvest, fields are plowed to expose larvae. For quick control of large populations attacking young seedlings, insecticide sprays are the only alternatives.
Biological pest control
can be introduced to fight the beetle. Many other beetle species act as parasitoids, attacking the pest beetle. These parasitoids include the braconid wasps Microtonus epitricis, M. punctulatae, M. vittatae and Townesilitus psylliodis. Among biological insecticides, the nematode
species Steinernema feltiae and S. carpocapsae show promise.
The use of resistant plant varieties may reduce injury by existing beetles. Resistant cabbage varieties include 'Stein's Early Flat Dutch', 'Mammoth Red Rock', 'Savoy Perfection Drumhead', and 'Ferry's Round Dutch'. 'Vates and Georgia' is a resistant collard variety. 'Florida Broadleaf' is a resistant mustard plant
, and 'American Purple Top' is a resistant rutabaga
. Resistant cauliflower
varieties include 'Snowball A' and 'Early Snowball X'. Varieties of broccoli
resistant to the beetle include 'DeCicco', 'Coastal', 'Italian Green Sprouting' and 'Atlantic' and resistant kale
varieties include 'Dwarf Siberian', 'Dwarf Green Curled Scotch', and 'Early Siberian'.
Flea beetle
Flea beetles is a general name applied to the small, jumping beetles of the leaf beetle family . They make up the tribe Alticini, which is a part of the subfamily Galerucinae, though they were historically classified as a subfamily in their own right...
, shiny black with a greenish tinge, 1.5 to 2.5 mm long, having a wavy yellow line running the length of each elytron (wing cover). It is a pest of cabbage
Cabbage
Cabbage is a popular cultivar of the species Brassica oleracea Linne of the Family Brassicaceae and is a leafy green vegetable...
and other brassica
Brassica
Brassica is a genus of plants in the mustard family . The members of the genus may be collectively known either as cabbages, or as mustards...
s. The hind legs are thickened, enabling the beetle to jump like a flea when disturbed.
The minute, oval to elongate white eggs are laid in the soil close to the host plant. The white, brown-headed larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
, when fully grown, is 3.2 to 5.0 mm long. It has three pairs of tiny legs near its head. The white pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
is approximately the same size and shape as the adult.
Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
n in origin, the striped flea beetle is common throughout the eastern and Pacific areas of the United States (though not in much of the Rocky Mountain region
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
), as well as in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.
Although the larvae live in the soil, feeding on the roots of host plants, they are not significant pests. Rather, the primary damage is caused by adult beetles feeding on the foliage. With their chewing mouthparts, beetles make small round pits in the cotyledon
Cotyledon
A cotyledon , is a significant part of the embryo within the seed of a plant. Upon germination, the cotyledon may become the embryonic first leaves of a seedling. The number of cotyledons present is one characteristic used by botanists to classify the flowering plants...
s and leaves of young plants. As the plants grow, the remaining thin layers of tissue eventually dry up and fall away, leaving small "shot holes" in the foliage. This type of injury is capable of killing young plants. The seedlings may be killed if severe damage occurs. In addition, beetles may act as vectors of plant disease.
Striped flea beetles overwinter among debris in and around fields. Emerging early in spring, they attack seedlings and young plants. Eggs are deposited in tiny crevices gnawed out of the base of host plant stems. About ten days later, the grubs hatch from the eggs and move into the soil to attack roots. After feeding for three or four weeks, the larvae pupate for seven to ten days. A new generation of beetles then emerges. Generations can be continual in warmer climates, recurring at least twice a year.
Cultivation practices and the use of resistant crop varieties help prevent severe flea beetle infestations. Seedbeds are covered with strips of a thin transparent gauze
Gauze
Gauze is a thin, translucent fabric with a loose open weave.-Uses and types:Gauze was originally made of silk and was used for clothing. It is now used for many different things, including gauze sponges for medical purposes. When used as a medical dressing, gauze is generally made of cotton...
to protect seedlings from adult feeding before transplanting. Good weed control and the destruction of crop residue
Crop residue
There are two types of agricultural crop residues:Field residues are materials left in an agricultural field or orchard after the crop has been harvested. These residues include stalks and stubble , leaves, and seed pods...
in and around fields reduce overwintering populations. After harvest, fields are plowed to expose larvae. For quick control of large populations attacking young seedlings, insecticide sprays are the only alternatives.
Biological pest control
Biological pest control
Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...
can be introduced to fight the beetle. Many other beetle species act as parasitoids, attacking the pest beetle. These parasitoids include the braconid wasps Microtonus epitricis, M. punctulatae, M. vittatae and Townesilitus psylliodis. Among biological insecticides, the nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
species Steinernema feltiae and S. carpocapsae show promise.
The use of resistant plant varieties may reduce injury by existing beetles. Resistant cabbage varieties include 'Stein's Early Flat Dutch', 'Mammoth Red Rock', 'Savoy Perfection Drumhead', and 'Ferry's Round Dutch'. 'Vates and Georgia' is a resistant collard variety. 'Florida Broadleaf' is a resistant mustard plant
Mustard plant
Mustards are several plant species in the genera Brassica and Sinapis whose small mustard seeds are used as a spice and, by grinding and mixing them with water, vinegar or other liquids, are turned into the condiment known as mustard or prepared mustard...
, and 'American Purple Top' is a resistant rutabaga
Rutabaga
The rutabaga, swede , turnip or yellow turnip is a root vegetable that originated as a cross between the cabbage and the turnip; see Triangle of U...
. Resistant cauliflower
Cauliflower
Cauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. It is an annual plant that reproduces by seed...
varieties include 'Snowball A' and 'Early Snowball X'. Varieties of broccoli
Broccoli
Broccoli is a plant in the cabbage family, whose large flower head is used as a vegetable.-General:The word broccoli, from the Italian plural of , refers to "the flowering top of a cabbage"....
resistant to the beetle include 'DeCicco', 'Coastal', 'Italian Green Sprouting' and 'Atlantic' and resistant kale
Kale
Kale is very high in beta carotene, vitamin K, vitamin C, lutein, zeaxanthin, and reasonably rich in calcium. Kale, as with broccoli and other brassicas, contains sulforaphane , a chemical with potent anti-cancer properties. Boiling decreases the level of sulforaphane; however, steaming,...
varieties include 'Dwarf Siberian', 'Dwarf Green Curled Scotch', and 'Early Siberian'.
External links
- Striped flea beetle. AVRDC - The World Vegetable Center (formerly Asian Vegetable Research and Development Center). Information from: Field Guide: Insect Pests of Selected Vegetables in Tropical and Subtropical Asia (1995). B.L. Parker, N.S. Talekar and M. Skinner. Publication 94-427.
- Striped Flea Beetle. North Carolina Cooperative Extension.