-9- 



This proceJure lets us see just how much of the crop of each variety was 

 harvested in the first, middle or last third of the season and thereby provides 

 data by which to classify a variety as early, midseason, or late. 



A. P. French 



I I I I I I I I I I I I I I I I 



CYCLAIIEN MITE - A P e st of Strawberries 



What is This Pest : It is a tiny mite, practically invisible to the naked eye, 

 much smaller than the common red spider or 2-spotted mite. It occurs on 



many different plants both in the greenhouse and outside. It sucks juices 

 from the plant tissues. 



S ymptoms of Injury : Heavy infestations result in severe dwarfing and stunting. 

 Early symptoms are a wrinkled, deformed appearance of the new leaves. The 

 plants appear dense or crowded and the leaflets are held vertical rather 

 than horizontal because of the shorter stems. Finally some of the inner 

 leaves are killed outright- Crops are greatly reduced, worthless or lost 

 altogether. 



Seasonal Development and Habits : Adult females overwinter in crevices between 



the bases of leaf stems. Become active in spring but all active stages avoid 

 light and require a high humidity. They remain in unopened leaves in plant 

 crovms or between parts o^f leave s or flowers . Eggs, nearly as large as the 

 females, are laid singly but as many as 3 each day for several days. Eggs 

 hatch into larvae which feed, enter a "pupal" stage and then become adults. 

 At 70° F. an entire generation requires only about 14 days. Just a few 

 females on a plant when it is set can result in a heavy infestation before 

 the season ends or before fruiting. Dr. Boulanger of Maine reported finding 

 1500 active mites on 20 leaflets on his unsprayed plants. 



How Introduced Into a Field : Cyclamen mites get into a field most commonly on 

 infested planting s tock . Some infestations can be traced to movement from 

 nearby infested plants or weeds. 



How Are They Spread : (1) By migration from mother to daughter plants or adja- 

 cent ones, (2) carried by birds and insects, (3) wind-borne, (4) carried 

 by workers in the fields. 



Some Points Related to Control of Cyclamen Mite 



Mites are in Protected Spots : Majority of the population remains within crown 

 in unfolded leaflets or other parts and inside sheaths at base of stems. 

 Hard to reach with a spray. Impossible to reach with dusts. Low-gallonage 

 and low pressure sprays probably will not be effective. 



Many Common Miticides do not Kill Cyclamen Mite : Allen and associates in Cal- 

 ifornia tested over 50 chemicals 1952-56. Found only 3 to be really effec- 

 tive: endrin (available but cannot be used during bearing year except after 

 harvest); isodrin (not on the market); Thiodan (available for testing only). 

 A 4th, Kelthane is only fair to good in single applications but may be used 

 during fruit bearing year. 



