Response of Trichogramma egg parasitoids to colored sticky traps

The response of Trichogramma spp. egg parasitoids to colored sticky traps w as evaluated in the field during two seasons (1995/1996, 1996/1997). Traps consisted of a glass tube coated with Bird-Tanglefoot(R) into which colored paper was inserted or clear traps without paper. Colors tested were white, green, blue, yellow and red in the first season and white, green, yellow a nd black in the second season. The proportion of both female and male paras itoids caught on the sticky traps was significantly different among colors, indicating that the parasitoids actively move between plants and are not s olely carried along passively by wind. White was the color most preferred b y female parasitoids, followed by clear and green traps. Yellow was preferr ed over black but was less attractive than green. Visual cues may be used b y Trichogramma spp. during the habitat location process. The color preferen ce of male Trichogramma spp. differed significantly from females with yello w and green being more attractive than white. For all colors, more female T richogramma spp. were caught on the sticky traps (>85% of all wasps caught) , indicating a lower activity level and/or shorter lifespan for males. The use of white cylindrical sticky traps for monitoring Trichogramma spp. popu lations in the field is recommended.