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<therevid.htm> [For educational purposes only] Glossary <Principal Natural Enemy Groups > <Citations> <Home> |
DIPTERA, Therevidae -- <Images>
& <Juveniles> Please refer also
to the following link for details on this group: Therevidae = Link 1 This is a small family, the adults of which are
predaceous mainly on other Diptera.
Larvae live in sandy soil where they feed on earthworms and various soft-bodied
insects. Larvae of Phycus brunneus Wied. occurring in bat dung in India feed on dermestid
larvae (Isaac 1925). However, Goetze
(1932) questioned the supposed predaceous habit of therevid larvae when he
noted that a rye field showed extensive root injury in which only therevid
larvae were present in large numbers.
However, laboratory tests failed to confirm this kind of damage. Immature stages of Therevidae are similar to
Asilidae. First instar larvae are
vermiform, with 20 apparent segments, due to "intersegments"
between the first 6 true abdominal segments.
Prothoracic and caudal spiracles are present. Mature larvae of Psilocephala sequa Wlk.
are also elongate and bear spiracles at the posterior margin of the first
thoracic segment and at the anterior margin of the 4th "segment"
from the abdomen's end. Pupae have
heavily sclerotized processes on the antennal sheaths and at the base of each
wing sheath. Abdominal segments each
have a ring of long spines at the posterior margin, and the final segment is
developed into a pair of large, heavily sclerotized processes (Clausen
1940/62). References: Please refer to <biology.ref.htm>, [Additional
references may be found at: MELVYL
Library ] |