Vol. 118 (2005): Proceedings of the Florida State Horticultural Society
Citrus

Thrips (thysanoptera: thripidae) pests of Florida grapefruit: biology, seasonal and relative abundance, fruit damage and monitoring

Carl C. Childers
University of Florida
2005 Proceedings of the Florida State Horticultural Society

Published 2005-12-01

Keywords

  • chaetanaphothrips orchidii,
  • danothrips trifasciatus,
  • heliothrips haemorrhoidalis,
  • orchid thrips,
  • greenhouse thrips,
  • citrus
  • ...More
    Less

Abstract

The orchid thrips, Chaetanaphothrips orchidii (Moulton), Danothrips trifasciatus Sakimura, and the greenhouse thrips, Heliothrips haemorrhoidalis (Bouché) can cause rind blemish injuries to clustered grapefruit that are touching each other. Red grapefruit varieties in Florida tend to produce more interior clustered fruit that increase the protective micro-environment for these pest thrips compared to white grapefruit. Damaged fruit can be rejected for the fresh market depending on the extent of thrips-induced rind blemish. Any of the three thrips species are capable of causing rind blemish injury from onset of clustered fruit contact beginning in early May until harvest. Adults as well as first and second instar larvae are feeding stages. Only H. haemorrhoidalis completes its entire life cycle within the tree canopy, either between touching fruit or between leaves or twigs and touching fruit. All three thrips species have alternate hosts in Florida, including various weed species within citrus groves. Effective insecticidal control options currently labeled for citrus are limited to Danitol 2.4EC sprayed at concentrations of one pint per acre (1.403 liters per ha) or chlorpyrifos 4EC at five pints per acre (5.845 liters per ha). Sticky traps of 13 different colors or hues were tested at two citrus grove sites in Collier and Hendry County, Florida during 1994. No C. orchidi, D. trifasciatus, or H. haemorrhoidalis adults were collected from any of these traps. Scouting is essential to minimize both fruit damage and insecticidal applications due to the long period of potential vulnerability to thrips feeding. Three monitoring methods including destructive clustered fruit samples washed in 80% ethanol, visual inspection for adult thrips pests between clustered fruit and nascent fruit damage by the orchid thrips complex were compared. Advantages and disadvantages for each method are discussed.