Selective detection of bed bugs

A adduct of the formula IV

• or a tautomer thereof, wherein
• X is S or O;
• Z1 and Z2 are each independently O or S;
• R1 is selected from the group consisting of hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C6-C10 aryl, 5- to 7-membered heteroaryl, —OR5, —SR5, —(OC1-C4 alkylene)xR5, —(SC1-C4 alkylene)yR5—(OC1-C4 alkylene)x(SC1-C4 alkylene)yR5, —(SC1-C4 alkylene)y(OC1-C4 alkylene)xR5, C1-C3 alkylene(OC1-C4 alkylene)xR5, C1-C3 alkylene(SC1-C4 alkylene)yR5, C1-C3 alkylene(OC1-C4 alkylene)x(SC1-C4 alkylene)yR5, and C1-C3 alkylene(SC1-C4 alkylene)y(OC1-C4 alkylene)xR5;
• R2 is selected from the group consisting of hydrogen, C1-C12 alkyl, C2-C12 alkenyl, C6-C10 aryl, 5- to 7-membered heteroaryl, —OR5, —SR5, —(OC1-C4 alkylene)xR5, —(SC1-C4 alkylene)yR5—(OC1-C4 alkylene)(SC1-C4 alkylene)yR5, —(SC1-C4 alkylene)y(OC1-C4 alkylene)xR5, C1-C3 alkylene(OC1-C4 alkylene)xR5, C1-C3 alkylene(SC1-C4 alkylene)yR5, C1-C3 alkylene(OC1-C4 alkylene)x(SC1-C4 alkylene)yR5, and C1-C3 alkylene(SC1-C4 alkylene)y(OC1-C4 alkylene)xR5;
• R5 is selected from the group consisting of hydrogen, C1-C8 alkyl, C2-C8 alkenyl, C6-C10 aryl, and a polymeric bulking group;
• R6 is C1-C12 alkyl or oxo substituted C1-C12 alkyl;
• a is 0 or 1;
• and
• x and y are each independently an integer from 1 to 10.