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Parasitoid larvae and caterpillar host
Alvesgaspar	#1 Posted on 22-04-2010 00:12
Member Location: Lisbon, Portugal Posts: 573 Joined: 24.08.07	What is this? Is the caterpillar going to be eaten alive by the larvae or is it some form of commensalism? Taken today, in Lisbon. There were several, in vaious stages, going up the walls, in the outside. Joaquim Alvesgaspar attached the following image: [105.3Kb] Edited by Alvesgaspar on 23-04-2010 22:49


Alvesgaspar	#2 Posted on 22-04-2010 00:13
Member Location: Lisbon, Portugal Posts: 573 Joined: 24.08.07	next photo... Alvesgaspar attached the following image: [144.84Kb]


Tony Irwin	#3 Posted on 22-04-2010 00:19
Member Location: Norwich, England Posts: 7306 Joined: 19.11.04	They are parasitoids - Apanteles glomeratus (Braconidae) Tony ---------- Tony Irwin


Alvesgaspar	#4 Posted on 22-04-2010 00:32
Member Location: Lisbon, Portugal Posts: 573 Joined: 24.08.07	Thanks, Tony. If I understand well, the eggs were laid inside the cocoon by the wasp. But why is the caterpiller staying with its predators? Is it really going to be eaten?


Tony Irwin	#5 Posted on 22-04-2010 23:55
Member Location: Norwich, England Posts: 7306 Joined: 19.11.04	The eggs were laid in the caterpillar, so the wasp larvae have been eating it from inside. When ready, they emerge and spin cocoons under the caterpillar. Both the caterpillars you photographed are already mostly eaten inside. Tony ---------- Tony Irwin


Alvesgaspar	#6 Posted on 23-04-2010 22:45
Member Location: Lisbon, Portugal Posts: 573 Joined: 24.08.07	Impressing, Nature is cruel! If I understaood well, the caterpillars will die. And why do them stay in the place even after the larvae formed the cocoons?


Tony Irwin	#7 Posted on 24-04-2010 08:41
Member Location: Norwich, England Posts: 7306 Joined: 19.11.04	When the larvae emerge and form cocoons, the caterpillars are more or less dead already. And it's just as well the braconids do this, otherwise we would never have any cabbage to eat! Tony ---------- Tony Irwin


Alvesgaspar	#8 Posted on 24-04-2010 13:34
Member Location: Lisbon, Portugal Posts: 573 Joined: 24.08.07	Thanks again, Tony, now I understand. Yes, Pieris brassicae is a serious pest of cultivated brassicas!