84a (83b). Mandibles not heavily sclerotized and not brush-like; spiracles usually present on

thorax and most abdominal segments, the posterior pair not enlarged; larvae occur in plant tissues

as phytophagous parasites, or in cells constructed by adults [Apocrita]…...Hymenoptera..... 118

84b. Mandibles usually brush-like; spiracles usually not as previously described-- if present on

several abdominal segments, the posterior pair is much larger than the rest; occur in wet

places, in plant tissues, or as internal parasites (Fig.A) [fly larvae, mainly Nematocera]

..................................................................................................................................................…....... Diptera

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A