Nature’s recourse: How plants and animals fight back when deals go sour. S. Milius. Science News, 2010, July 31, 22-26.
https://www.sciencenews.org/article/nature%E2%80%99s-recourse

Trees strike back when wasps’ efforts are fruitless, biologist finds. K. Ramanujan, Ezra magazine, 2010, 2: 14-15.
http://ezramagazine.cornell.edu/SPRING10/ResearchSpotlight.html

Armoured wasps chop off opponents’ heads in brutal fig wars. I. Twaddell, New Scientist, Sep 16, 2015.
https://www.newscientist.com/article/dn28177-armoured-wasps-chop-off-opponents-heads-in-brutal-fig-wars