Table 1 Outcome of 120 encounters (30 per instar) between Polistes dominula and sentinel monarch butterfly larvae feeding on swamp milkweed (Asclepias incarnata) plants in urban pollinator gardens.

From: Invasive paper wasp turns urban pollinator gardens into ecological traps for monarch butterfly larvae

Instar

Outcome

Totalc

Wasp kill behaviors

(in sequence)a

Larval escape behaviorsb

S,Cd

S,G,C

S,G,P

S,W,G,P

D

DSk

T

2nd

Killed

23

21

2

     
 

Escaped

7

    

5

2

 

3rd

Killed

24

2

20

2

    
 

Escaped

6

    

5

1

 

4th

Killed

20

 

4

13

3

   
 

Escaped

10

    

5

 

5

5th

Killed

2

   

2

   
 

Escaped

28

    

8

 

20

  1. aWasp behaviors resulting in kill: S = strike, G = gut, C = carry off, W = wait, P = process (cut into pieces, then carry off in multiple trips).
  2. bLarval behaviors leading to escape: D = drop, DSk = drop on silk, T = thrash.
  3. cProportion of larvae killed or escaped differs significantly between instars (χ2 = 43.5, df = 3, P ≤ 0.001).
  4. dIncludes one 2nd and one 3rd instar that dropped on silk, then was found by the wasp and carried off intact.
Back to article page