Panel traps have also been developed for fruit flies with no
known male lure. These traps are based on visual, or visual
plus odour, attraction. They are coated in sticky material. Traps
are usually flat-surfaced and coloured fluorescent yellow to
elicit a supernormal foliage response, or spherical and darkcoloured
to represent a fruit. The odour comes from protein
hydrolysate or other substances emitting ammonia, such as
ammonium acetate. Ammonium acetate and ammonium
carbonate, when used for capture of Rhagoletis spp, are used
with red sphere traps or yellow panel traps coated. (IAEA 2003)