Xyloryctidae Overview
Hodges (1998) defined this family
by three apomorphies of the larva: segments A1-8 with a pinaculum ring around
SD1; presence of a pore posterior or ventroposterior of SD1, and segments A3-7
with secondary SV setae. Xyloryctidae is worldwide in distribution with more
than 1200 species in 86 genera (Hodges, 1998). The family includes two subfamilies:
Xyloryctinae and Scythridinae.
Xyloryctinae
This subfamily
can be defined by the autapomorphy of the abdomen having a band of spiniform
setae on the posterior areas of terga 2-6. In addition, the antenna lacks a
pecten and in males, is ciliate or pectinate, a frenulum is absent, the gnathos
is fused with the tegumen laterally, the juxta is present, and the forewing
has CuP present. The pupa has abdominal terga with a crenulate ridge near the
anterior margins, becoming spined in some species. Two species of Thyrocopa,
endemic to Hawaii, are wingless and have a jumping behavior (Medeiros, 2008).
Xyloryctinae includes
more than 500 species in 60+ genera, with the highest diversity in the Indo-Australian
Region, but with species also occurring in sub-saharan Africa and Polynesia
(Scoble, 1992; Hodges, 1998).
Larvae feed on hosts in 21 plant families, including lichens, but almost half
of the known hosts are species in Proteaceae and Myrtaceae (Hodges, 1998). Larvae
live in concealed shelters or galleries made of silk and debris or soil. Larvae
of some species tie leaves or bore into bark or wood of branches, and others
drag leaves into their burrows (Scoble, 1992).
References: Common
(1990), Duckworth (1973), Hodges (1978), Medeiros (2008), Moriuti (1982), Powell
(1980), Zimmerman (1978).
Scythridinae
This subfamily
has an ankylosed aedeagus, antennal pecten present and ocellus (when present)
separate from the eye. In addition, Scythridinae lacks a transtilla (in contrast
to Chimabachidae), the juxta is present, the abdomen sternum 2 has paired apodemes
but lacks paired venulae, and the abdominal terga lacks spiniform setae. The
male genitalia are highly modified by reduction and fusion of structures in
some species. The female genitalia have the ductus seminalis arising broadly
from the posterior part of the corpus bursae (Hodges, 1998). The wings are narrow
and some species are brachypterous (Landry, 1991). The larvae have secondary
setae, especially at the bases of the prolegs.
Scythridinae occurs
worldwide and includes more than 700 species in 26 genera (Hodges, 1998), but
a large number of new species remain undescribed (Landry, 1991).
Adults of many
species are diurnal and can be found in flowers of hosts or on substrates near
the host (Landry, 1991). Larvae feed externally on buds and leaves within weak
webs on more than 20 families, and some species are leafminers on grasses (Scoble,
1992).
References: Bengtsson
(1984), Clarke (1965), Falkovitsch (1981), Hodges (1998), Landry (1991), Powell (1976a, 1980), Stehr (1987).