Interaction of trap colour attractiveness with morphological variability of the thripsFrankliniella occidentalis(Pergande 1895)

Abstract

In the latitude of Kiev, 80% of Frankliniella occidentalis (Pergande 1895) population was caught on the colour traps from 11 a.m. to 5 p.m. in summer and from 11 a.m. to 3 p.m. in winter. Meanwhile, 10% of the population did not react to the colour traps at all (''passive'' individuals), whereas for 20% of the population it was impossible to determine the clear colour with attractive properties. The thrips attracted with blue and yellow color traps, had more massive and variable body parts to be connected with their flight. Their antennae and segment sizes were significantly smaller than compared to the control variant, which could be explained by eyesight domination over other organs of sensory orientation. The indices of heterogeneity of morphological features can be used as evaluation criteria for the adaptive variability and stability of the thrips population.

Haze of glue determines preference of western flower thrips (Frankliniella occidentalis) for yellow or blue traps

“…In 100% of the winter/spring/autumn publications blue is more attractive than yellow in trapping western flower thrips 4 , 16 , 18 – 20 , 22 , 23 and no publications with yellow better than blue. In contrast tests performed in summer (6) show 50% yellow better than blue 24 , 25 , 28 and 33% have blue better 17 , 21 or equal (17%) to yellow 59 . The location of the trials may also influence the different results as the angle of the sun does not differ as much for both seasons near the equator.…”

“…Excluding all results with the known hazy Stikem and Pestick glue and lab experiments and only including literature in the field and greenhouse with blue and yellow leave 13 publications to judge colour preference. Of them 7 publications were performed in winter, spring or autumn 4 , 16 , 18 – 20 , 22 , 23 and 6 in summer 17 , 21 , 24 , 25 , 28 , 59 . In 100% of the winter/spring/autumn publications blue is more attractive than yellow in trapping western flower thrips 4 , 16 , 18 – 20 , 22 , 23 and no publications with yellow better than blue.…”

“…They found spectral efficiency peaks in the ultraviolet and the green range via electroretinogram recordings. However, most publications mention blue 4 , 16 – 23 , some yellow 24 , 25 and occasionally white/blue 26 , 28 as the most attractive colour in comparative field and greenhouse studies. The attraction to blue is different from what expected according to this study and has not been explained so far.…”