Geffrey Whitney, A choice of emblemes (Leiden, 1586)
Fowlers lure duck into a net by using a decoy

Dolus in suosLatin
Treachery towards one's own
An outdoor landscape scene: at right a large tree grows beside a bank, where two or three men in hats crouch and kneel, holding ropes attached to a large net spread out across the foreground over water or ground. In the sky at upper left several ducks fly in formation, while one bird descends toward the net and another lies already fallen on the ground near the net's edge. Clouds appear at upper left, with low hills in the background. The whole image is set within a broad ornamental border of scrollwork.

WHILE nettes were sette, the simple fowles to take, Whoe kepte theire course alofte, and woulde not lighte, A tamed ducke, her hoame did straighte forsake, And flewe alofte, with other duckes in flighte, They dowtinge not, her traiterous harte at all, Did flie with her, and downe with her did fall. By this is mente, all suche as doe betraie, Theire kindred neare, that doe on them depende, And ofte doe make, the innocent a praie, By subtill sleighte, to them that seeke theire ende Yea vnto those, they shoulde moste frendship showe, They lie in waite, to worke theire ouerthrowe.
While nets were set to take the simple fowls, which kept their course aloft and would not alight, a tamed duck straightway forsook her home and flew aloft with other ducks in flight; they, not doubting her treacherous heart at all, flew with her and fell down with her. By this is meant all such as betray their near kindred, who depend on them, and often make the innocent a prey by subtle sleight to those that seek their end; yea, to those to whom they should show the most friendship, they lie in wait to work their overthrow.
Perfida cognato se sanguine polluit ales, Officiosa aliis, exitiosa suis.
The treacherous bird defiles herself with kindred blood, dutiful to others, destructive to her own.
And. Alciat. De Anate.
Andrea Alciato, On the Duck.
25F36(DUCK)(+441) water-birds: duck (+ herd, group of animals)25F36(DUCK)(+53) water-birds: duck (+ postures, positions of animal(s))25G3(+21) trees (+ stem, trunk)25H11 mountains25I12 prospect of city, town panorama, silhouette of city31A2331(+61) kneeling on both knees (+ forward)31A2512(+931) arm stretched forward (+ indicating, pointing at)31A2512(+933) arm stretched forward (+ holding something)31A25552 index finger forwards, pointing, indicating31D14(+72) adult man (+ two persons)41D211(+81) dress, gown (+ men's clothes)41D221(+81) head-gear (+ men's clothes)43C13(+415) fowling, fowler (+ net)43C132 duck decoy57AA6142(+4) Betrayal (+ emblematical representation of concept)57AA621(+4) Cheat, Deceit; 'Fraude', 'Inganno' (Ripa) (+ emblematical representation of concept)86(DOLUS IN SUOS) proverbs, sayings, etc. (DOLUS IN SUOS)Additional codes proposed for this emblem, not (yet) part of the indexing.
43C132 duck decoyhighThe correlate 'duck decoy' exactly matches the scene of fowlers with ropes and a spread net catching ducks lured down from the flock, which is the subject of Alciato's emblem 'On the Duck'.
25F36(DUCK) water-birds: duckhighThe correlate 'water-birds: duck' corresponds to the ducks flying in formation, the one descending into the net, and the one already fallen on the ground.
57AA6142 BetrayalmediumThe correlate 'Betrayal' captures the emblem's moral of the treacherous decoy bird that betrays its own kind, 'dutiful to others, destructive to her own'.
57AA621 Cheat, Deceit; 'Fraude', 'Inganno' (Ripa)lowThe correlate 'Cheat, Deceit' fits the fraudulent luring of the wild ducks into the net, though the emblem stresses betrayal of kin rather than deceit as a personified figure.
Suggested relationships between this emblem and adages in Erasmus’ Adagia.
Erasmus' essay explains παλεύτριαι as decoy doves which fowlers blind and set in their nets so that, fluttering about, they lure other birds to their destruction — precisely the decoy-duck luring her own kind into the fowler's net depicted and described in the emblem.
The adage is explicitly drawn from fowlers who lure birds into snares by bait, and is applied to those who entrap others by deceit; the emblem's picture of nets spread by crouching fowlers and birds falling into them embodies the same metaphor of 'luring into the snare'.
Erasmus applies it when someone is harmed by the very person on whom he depended and in whose loyalty he trusted — exactly Whitney's moral about those who betray 'theire kindred neare, that doe on them depende'.
Erasmus' adage describes those who feign friendship openly while secretly contriving another's ruin (the image of luring an animal with bread to strike it with a stone), matching the emblem's decoy who shows friendship to her fellows while leading them to the net.
The adage concerns one of the same kind, whose help was expected, turning against his fellows for a bribe — analogous to the tamed duck who serves the fowler and destroys her own species.
Record ID: embstma_1667_emblem027
This emblem on the Iconclass site: https://iconclass.org/view/embstma_1667_emblem027
Copy: University Library, Glasgow, Stirling Maxwell 1667