| NEW
SEARCH |
Saw-tooth grain beetle |
|
Oryzaephilus surinamensis
|
| 
Adult saw-tooth grain beetle (Oryzaephilus surinamensis)
Courtesy of Degesch Inc.
|
|
Description
The saw-tooth grain beetle (Oryzaephilus surinamensis) is dark brown in colour and about 2.5-3.5 mm in length. They are slender and flattened in appearance making them well adapted for crawling into cracks and crevices. The margins of the thorax are saw-like and posses six projections on each side. In addition, there are three longitudinal ridges on the top surface of the thorax. A tooth on the femur of the hind leg separates the male from the female. Wings are well developed but there is no record of this insect flying. Sawtoothed grain beetle larvae are a yellowish white except for their head, which is brown. Full - grown larvae are less than 3mm long.
|
| 
Developmental stages in saw-tooth grain beetles
Courtesy of Degesch Inc.
|
|
Life cycle
Eggs are deposited singly or in small masses in the food. They may either be laid in crevices or freely. The number of eggs averages 375 per female. Eggs hatch in three to five days. Within a few hours of hatching, larvae begin to feed. There are 2 - 5 (usually 3) larval instars. The average larval period lasts 12 - 15 days, and the pupation time is 4 - 5 days. In preparation for pupation, the larva attaches itself to a fixed object. The pupa is formed in a crude cell made of food particles. The larval exoskeleton is shed but remains attached in the pupal cell. The pupa has the same six projections on each side of the thorax. Development time from egg to adult under optimum conditions can occur in about 25 days. Adults and larvae are somewhat resistant to cold temperatures, withstanding 3 week exposure to 0?C. Average adult lifespan of mated females ranges from 4-19 weeks; however some females have been known to live for more than 7 months. Oviposition usually begins during the first week of adult life and reaches a maximum during the second or third week. After 10 weeks, the oviposition rate declines rapidly. |
| 
Damage caused by saw-tooth grain beetles
Courtesy of Degesch Inc.
|
|
Damage
This beetle can be found feeding on cereals, dried fruit, bran, rolled oats, brown rice walnuts, breakfast foods, macaroni, sugar, drugs, fried meats, chocolate and tobacco. It cannot attack perfectly sound grain, but can feed on slightly damaged grain. Thus, it is often found in whole grain in association with other insects. It has also been observed feeding on eggs and dead adults of stored-product moths. |
| 
Saw-toothed grain beetle
? Agriculture Western Australia
|
|
Control
Grain insects are declared under the Agriculture and Related Resources Protection Act. Limited chemical controls are available to farmers and emphasis is placed on clean hygienic storage and cleaning of machinery. Farmers are encouraged to purchase and maintain sealed farm silos to increase the effectiveness of fumigation.
|
MPEG of Oryzaephilus surinamensis (approx 4.5 Mb)
|
|
|
|
|
|
|
