Flower thrips.

Development of Problem -

Thrips invade strawberry fields from blooming citrus, clover and wild flowers.  Although thrips are not strong fliers, winds aid their movement into flowering strawberry fields.  Thrips rasp the portions of the strawberry flower that develop into fruit, causing it to develop poorly.  Damaged green fruits may become bronze or grayish and very fine shallow cracks may develop in their surfaces.  As these fruits ripen, they remain dull in appearance.  Thrips damage can easily be mistaken for damage caused by powdery mildew or by spray burn.  This insect occurs on every farm in every year and may require control measures.

Control -

1. Scout fields at least once a week when strawberries are in bloom.  This is particularly important in the late winter and early spring when thrips activity is at its peak.  Thrips may be detected by thumbing opened flowers onto the observer's hand or by blowing lightly into the flowers.  A magnifying lens may be required to see the insect.
2. Apply recommended pesticides when populations warrant.

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