Tylenchida Thorne, 1949, is an order of nematodes that includes plant-parasitic nematodes with economically importance, and it forms parasitize insect's haemocoels
which must be considered as biological control agents (Siddiqi 2000).
The transverse musculature of the haemocoel
is much more developed in B.
Then, it is ingested by a copepod and, in the haemocoel
of this invertebrate, attains its third stage.
The lepidopteran NPV first invades the host at the midgut and then enters the haemocoel
after proliferation, thereby infecting other sensitive tissues.
The infective juvenile nematodes penetrate into the insect host to inhabit inside the insect haemocoel
(Forst and Clarke, 2002).