Otiorhynchus ovatus
Encyclopedia
Otiorhynchus ovatus, also called the Strawberry Root Weevil, is one of the many species in the weevil
family (Curculionidae
). Its name comes from its affinity for strawberry
plants, which form a large part of its diet. They are, however, known to feed on other plants as well. It is known to be one of the major pests threatening sub-tropical strawberry farming.
The larvae can be up to thirteen millimeters long when fully grown and they are found near the roots of the plants they are infesting. The larvae are white, legless, with a darker colored head and are often C-shaped.
The larvae feed on the roots of the plant and remain there until adulthood, when they begin to feed on foliage instead.
Adults feed nocturnally on leaves and stems, leaving notches and causing slight damage, while the larvae cause significantly more damage by feeding on the roots and crowns of the plant, even as they overwinter
, if the temperatures are mild.
The plants that are fed upon by the larvae are stunted and have reddish leaves that curl exposing the underside, and the plant wilts as the fruits form, especially in dry weather.
The fine roots and sometimes even the hard fibrous roots are destroyed, allowing for the plants to be easily pulled from the soil. These plants have significantly shortened lives, poor yields that result in losses in revenue.
Fields with significant damage can be up to 0.2ha. Since adults do not fly, plants bordering older plantings show damage the first season, with damage spreading each year the planting is kept.
Controlling the strawberry root weevil includes a wide variety of methods such as the use of insecticides, plowing under old crops and crop rotation
, cleaning farm equipment before moving to a new field, and fall plowing infested beds or fields. Another control method is the use of entomopathogenic nematode
s, though results have varied.
Weevil
A weevil is any beetle from the Curculionoidea superfamily. They are usually small, less than , and herbivorous. There are over 60,000 species in several families, mostly in the family Curculionidae...
family (Curculionidae
Curculionidae
Curculionidae is the family of the "true" weevils . It was formerly recognized in 1998 as the largest of any animal family, with over 40,000 species described worldwide at that time...
). Its name comes from its affinity for strawberry
Strawberry
Fragaria is a genus of flowering plants in the rose family, Rosaceae, commonly known as strawberries for their edible fruits. Although it is commonly thought that strawberries get their name from straw being used as a mulch in cultivating the plants, the etymology of the word is uncertain. There...
plants, which form a large part of its diet. They are, however, known to feed on other plants as well. It is known to be one of the major pests threatening sub-tropical strawberry farming.
Identification
The adult strawberry root weevil is about six millimeters long, and is dark brown/black in color. They are often found in the leaves and foliage of the plants they feed on. The adult weevil's elytra are fused together, which means they are unable to fly.The larvae can be up to thirteen millimeters long when fully grown and they are found near the roots of the plants they are infesting. The larvae are white, legless, with a darker colored head and are often C-shaped.
Natural history
Strawberry root weevils reproduce through a process called parthenogensis. This means that female adults can reproduce without the need for a male. In fact, no male specimen has ever been observed in this species.The larvae feed on the roots of the plant and remain there until adulthood, when they begin to feed on foliage instead.
Human Impact
The plants that the strawberry root weevil feeds on include strawberry, raspberry, rhododendron, grape, and peppermint and they have also been known to feed on grasses.Adults feed nocturnally on leaves and stems, leaving notches and causing slight damage, while the larvae cause significantly more damage by feeding on the roots and crowns of the plant, even as they overwinter
Overwinter
To overwinter is to pass through or wait out the winter season, or to pass through that period of the year when “winter” conditions make normal activity or even survival difficult or near impossible...
, if the temperatures are mild.
The plants that are fed upon by the larvae are stunted and have reddish leaves that curl exposing the underside, and the plant wilts as the fruits form, especially in dry weather.
The fine roots and sometimes even the hard fibrous roots are destroyed, allowing for the plants to be easily pulled from the soil. These plants have significantly shortened lives, poor yields that result in losses in revenue.
Fields with significant damage can be up to 0.2ha. Since adults do not fly, plants bordering older plantings show damage the first season, with damage spreading each year the planting is kept.
Controlling the strawberry root weevil includes a wide variety of methods such as the use of insecticides, plowing under old crops and crop rotation
Crop rotation
Crop rotation is the practice of growing a series of dissimilar types of crops in the same area in sequential seasons.Crop rotation confers various benefits to the soil. A traditional element of crop rotation is the replenishment of nitrogen through the use of green manure in sequence with cereals...
, cleaning farm equipment before moving to a new field, and fall plowing infested beds or fields. Another control method is the use of entomopathogenic nematode
Entomopathogenic nematode
Entomopathogenic nematodes are soil-inhabiting, lethal insect parasitoids that belong to the phylum Nematoda, commonly called roundworms. The term entomopathogenic comes from the Greek word entomon, meaning insect, and pathogenic, which means causing disease...
s, though results have varied.