Insects and reagents

Since 2009, a colony of Bemisia tabaci MED has been maintained in an insect-proof cage (45 × 60 × 90 cm) and fed on suhgwang cultivar of tomato plants (Lycopersicon lycopersicum), grown in 1.5-L pots (one plant/pot) filled with potting mix. Growing conditions were 25 ± 1°C, 60 ± 10% relative humidity (RH), and a 16L:8D photoperiod. Our colony is a Mediterranean species (MED; Q biotype) of B. tabaci species complex. More specifically, our colony belongs to Q1 biotype (mt COI Genbank accession number {"type":"entrez-nucleotide","attrs":{"text":"HM488315","term_id":"301348674","term_text":"HM488315"}}HM488315) among at least five subgroups of Q biotype [35,36]. The genetic identity of the whitefly colony maintained in the laboratory is checked every six months according to a published protocol [37]. Prior to this experiment, we rechecked with mitochondrial COI gene for conformity.

Methyl benzoate (M29908-500G), Tween 20 (P1379-25ML), and Tween 80 (P1754-25ML) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Methyl benzoate solutions (0.1%, 0.25%, 0.5%, 1%, 2%) were prepared with distilled water containing 1% emulsifier (v/v) consisting of a 1:1 ratio of Tween 20 and Tween 80. For controls, distilled water containing 0.5% Tween 20 (v/v) and 0.5% Tween 80 (v/v) were used.