Author

• ahmad dezianian

Shahrood (Semnan) Agricultural Research and Natural Resources and Education Center

Abstract

A study carried out on cherry weevil in Bastam and Zirstagh regions of Shahroud district during 1999-2000. Stone fruits production playing an important role in economy of region. Currently the cherry weevil is the most important insect pest of cherry, sour cherry and other allied species in Shahrood. Adult insects are metalic green or red in colour, having scattered hairs on elytra. Max., Min. and mean length of adult females was 10.4, 12 and 10.7 and those of males 10, 10.6 and 10.1mm respectively. Length of first instar larva was
1-1.5mm and the last instar measured 7.3-11mm with mean of 9.3mm. The insect showed to hibernate as last instar larvae in mud chambers at the depth of 5-10 mm in the siol. Adults appeared in mid April and their appearance coincided cherry tree bloosoming. They mated several times after feeding on fruit pulp and young leaves. Oviposition period lasted 28-39 days with mean of 32.3 days. The onset of oviposition coincided the completion of petals fall. Females layed only one egg on each fruits. No. of eggs were 29-193 per female with mean of 99.3. Eggs hatched after 3-5 days with mean of 4.2 days. Min., Max. and mean pupal period were 25, 35 and 29.4 days respectively. Longevity of adults males and females were between 35-60 days with mean of 44.3 days under lab. conditions (25 ±1 ºC, 40 –50%RH). Under field condition eggs hatched after nearly 10 days and 1^st instar larvae penetrated into fruits' stones after 24hrs. larval period lasted 18-20 months, thus each generation of this insect completed in two years. The main hosts of cherry weevil showed to be cherry and sour cherry and subcidiary hosts that tolerate only minor injuries are apricots, peaches, almonds and pulms.
 
 

Keywords

• Rhynchites auratus
• cherry weevil
• biology
• Shahrood