Phylogeny and reclassification of Distictus Townes (Hymenoptera, Ichneumonidae, Cryptinae), with description of a new species
Author
Santos, Bernardo F.
Author
Aguiar, Alexandre P.
text
Zootaxa
2008
1934
30
39
journal article
10.5281/zenodo.184917
b17808e2-9c19-48ba-957f-977478ce0222
1175-5326
184917
Distictus
Townes
Distictus
Townes, 1966
:325
. Description, figure.
Type
species:
Mesostenus tibialis
Brullé 1846
Fenixia
Aguiar, 2005:126
–127,
n. syn.
FIGURES 1–5.
Summary of clades containing the species of
Distictus
and closely related taxa, according to results obtained with unweighted and implied weigthing searches. 1, Unweighted searches. 2, Consensus of two trees obtained with
K
=1 (character 36 does not support basal clade for one of such trees). 3, Single tree obtained with
K
=2. 4,
K
=3-5 (all trees identical, except for synapomorphy 15:1, not recovered with
K
=3). 5,
K
=6. Black circles represent non-homplasious synapomorphies.
Redefinition.
Head
. Supra-antennal area with short median carina developed near anterior ocellus, sometimes reaching almost full length of supra-clypeal area; mandible 1.0–1.5 as long as basal width; both gena and temple swollen, giving head spherical shape.
Mesosoma
. Epomia short and weak, sometimes indistinct from rugulosities of collar; mesoscutum ovoid, distinctly longer than wide; notauli moderately to strongly impressed, parallel or subparallel; sternaulus sinuous, strongly to weakly impressed, reaching mid coxa.
Propodeum
. Area in front of anterior transverse carina varying from alutaceus punctures to very strong rugulosities; spiracle weakly oval; anterior transverse carina complete, low, centrally weakly to moderately curved forward, placed approximately on mid-length of propodeum.
Wings
. Fore wing cell 1+2Rs 0.8–1.3 as long as width of pterostigma, same height or a little higher than its own width; crossveins 2r-m and 3r-m weakly to distinctly convergent.
Hind
wing vein 1-Cu 1.2–1.5 length of crossvein cu-a.
Metasoma
. First tegite basally with or without lateral tooth; dorsolateral carina suggested only as blunt ridge in basal or apical portions.
Comments.
In the couplet of the key to Neotropical
Gabuniina
that leads to
Nesolinoceras
Ashmead, Aguiar (2005)
mentions “fore wings hyaline or infuscate but never with dark bands”. Although
D. aurantium
has a weak dark band on the apex of the fore wing, it could hardly be mistaken with the pattern of three dark bands exhibited by
Nesolinoceras
; in the following couplet, however, the distinction between
D. aurantium
(=
Fenixia
) and some species of
Agonocryptus
Cushman
can be misleading, because of the features “fore wing crossveins 2r-m and 3r-m distinctly convergent towards anterior margin of wing” and “hind wing vein 1-Cu about twice as long as crossvein cu-a”; in this case, the correct determination of
Distictus
must consider the generic redefinition provided above.
Relationships.
The relationships recovered here are basically similar to that proposed by Aguiar (2005), in which
Distictus
(
Fenixia curta
) appears most related to
Lagarosoma assitum
Gupta. Current
results also show that
Prosthoporus
always formed a clade with both species of
Lagarosoma
, while
Trypha atriceps
frequently appears as the sister group, or close to
Lagarosoma
+
Prosthoporus
. All of these are Neotropical groups predominantly known from the Brazilian Atlantic Forest; only
Prosthoporus
is recorded from other parts of South
America
. These groups also appear to be rare or uncommon. The relationships of
Prosthoporus
were not discussed by Aguiar (
op. cit.
), but it is relevant to mention that for the present work five specimens of
P. t e r a n i
could be studied, allowing the codification of 20 characters which could not be examined by that author, as well as all the additional 14 characters used here to expand the original matrix. The relationships of
Prostophorus
and
Lagarosoma
will be further discussed elsewhere.