Diphyus KRIECHBAUMER, 1890

A. M, 2011, Illustrated key to the genera of the subtribe Amblytelina of Palaearctic (Hymenoptera, Ichneumonidae, Ichneumoninae, Ichneumonini), Linzer biologische Beiträge 43 (1), pp. 597-711 : 657-660

9. Diphyus KRIECHBAUMER

Diphyus KRIECHBAUMER 1890 - Entomol. Nachr. 16 (12): 184.

Type species: Diphyes (!) tricolor KRIECHBAUMER.

Pseudamblyteles: HEINRICH 1961 - Can. Ent., Suppl. 23: 307-401.

Pseudamblyteles: HEINRICH 1965 - Entomol. Ts. Agr. 86, 1-2: 92-94.

Diphyus: HEINRICH 1968 - Ichn. Stenop. of Africa 3: 648-651.

Diphyus: HEINRICH 1977 - Ichn. Florida and Neigb. States 9: 13-114.

Diphyus: RASNITSYN 1981 - Opr. Faun. SSSR 3 (3): 572, 612-618.

D i s t r i b u t i o n: Holarctic, Oriental and Ethiopian Regions.

I n t r o d u c t i o n:

Distinctive characters of Diphyus genus from relative genera Eutanyacra CAMERON , Spilichneumon THOMSON and Ctenichneumon THOMSON are based on characters of males predominately. From first two genera males are differed by absence of narrow

process at apex of hypopygium, and from latter one, by not ribbed practically from base as at Ctenichneumon flagellum. Females of genus are differed by rudimentary or almost rudimentary thyridia from Ctenichneumon (thyridia are absent) and Spilichneumon (thyridia are usually distinct). From many species of Spilichneumon , females are differed by normal, not broadened mandibles and by normal, not elongated propodeum. From Eutanyacra they are differed first of all, by absence of fascicle of long coarse bristles at apex of hypopygium.

M o r p h o l o g y:

F l a g e l l u m: Of females bristle-shaped, usually slender, behind middle only just widened and flattened in different degree. Flagellum of males not ribbed or only slightly ribbed, usually with closely merged segments and with moderate number of narrow bacilliform tyloides.

H e a d: Temples never strongly broadened and from above never considerably convex behind eyes; temples from above usually more or less, often rather strongly, narrowed behind eyes and from side often to base of mandible, or parallel to hind margin of an eye; mandibles usually rather narrow, upper tooth usually sharp, rarely blunted, lower tooth developed, sometimes rather small, as exception (some American species) reduced; clypeus only just convex.

T h o r a x: Mesonotum distinctly convex, usually densely punctured, rarely entirely dull (type species), usually more or less shining ; axillary tongue expressed, but slightly; scutellum from slightly to moderately convex, from lateral moderately elevated above postscutellum, laterally not carinated. Hind margin of metanotum with projections. Area superomedia of quadrangular type, usually almost square or rectangular, sometimes elongated and not limited from behind, in males usually transverse; areae dentiparae at apex always without apophysises, but sometimes with sharp apices (denticles).

L e g s: From slender to moderately stout. Hind coxae of females always without scopa.

W i n g s: Areolet always pentagonal, sometimes with narrow base; radius almost straight; nervulus usually distinctly postfurcal.

A b d o m e n:Offemalesamblypygous, elongate-oval in type species, usually shortlyoval, rarely narrow, elongated (raptorius L.). Middle field of postpetiolus distinctly expressed and usually regularly longitudinally striated, rarely indistinctly or irregularlywrinkled ( latebricola WESM. ). Gastrocoeli of both sexes small and only slightly impressed with rudimentary or almost rudimentary thyridia, rarely thyridia distinct ( latebricola WESM. ). Usually tergites 2-3, sometimes only 2nd tergite of females with fold. Hypopygium of females with uniform pubescence, without of fascile of coarse bristles at apex; hypopygium of males, as the general rule, short and blunted with tendency to extension at central part, to rather long prominence (e.g. ochromelas GMEL. ), but without median process.

C o l o r a t i o n: Very diversified. Main color of females abdomen black or rusty-red; in numerous of species abdomen with yellow bands or rusty-red with black bands; last tergites often with apical white or yellow spots.

S i z e: Palaearctic species 9-18 mm.

B i o l o g y a n d e c o l o g y:

H o s t s: For 14 species of a genus from the literature the following data about hosts

are known: D. amatorius (MÜLL.) – Semiothisa liturata CL. (Geometridae) , Actinotia polydon CL., Epilecta linogrisea DEN.ET SCHIFF. , Phlogophora meticulosa L., Polyphaenis sericata Esp., Triphaena pronuba L. ( Noctuidae ); D. castanopyga (STEPH.) – Trachea atriplicis L. ( Noctuidae ); D. fossorius (L.) – Graphiphora augur F. ( Noctuidae ), Vanessa io L. ( Nymphalidae ); D. gradatorius (THUNB.) – Eurois occulta L. ( Noctuidae ); D. luctatorius (L.) – Agrotis clavis HUFN. (Noctuidae) ; D. mercatorius (F.) – Mamestra brassicae L., M. pisi L. ( Noctuidae ); D. monitorius (PANZ.) – Smerinthus populi L. ( Sphingidae ), Perigrapha cincta F. ( Noctuidae ); D. ochromelas (GMEL.) – Agrotis segetum DEN.ET SCHIFF. , Diarsia brunnea DEN. et SCHIFF. , Mamestra brassicae L., M. persicariae L. ( Noctuidae ); D. palliatorius (GRAV.) – Smerinthus populi L. ( Sphingidae ), Cirrhia lutea STROM, Perigrapha l-cinctum DEN.ET SCHIFF., Plusia gamma L. ( Noctuidae ); D. quadripunctorius (MÜLL.) – Graphiphora augur F., Mamestra brassicae L., Noctua comes HBN. , N. interjecta HBN. , N. orbona HUFN. , Polymixis polymita L., Triphaena pronuba L. ( Noctuidae ); D. raptorius (L.) – Cirrhia togata ESP., Mythimna vitellina HBN. ( Noctuidae ); D. trifasciatus (GRAV.) – Eurois occulta L. ( Noctuidae ); D. fossorius (L.) – Apamea anceps DEN.ET SCHIFF. , A. crenata HUFN. , A. obscura HW. , A. unanimis HBN. , Mormo maura L. ( Noctuidae ) ( HERTING 1976; RASNITSYN 1981). G. HEINRICH (1977) gives authentic data about of breeding by ROLF HINZ species of latebricola, trifasciatus, palliatorius, gradatorius, and (?) longigena from species of Agrotis (Noctuidae) .

S p e c i e s c o m p o s i t i o n a n d a b u n d a n c e: Genus Diphyus is presented in the region of researches by ten rare or not numerous species. Abundance of this genus in the nature (quantity of the collected individuals / quantity of revealed species of a genus) leads it to the 10th place according to indicator of abundance among Amblytelina and only on 60th place among genera of Ichneumoninae St. in the region. (4,2 individuals / 1 species of genus). According to abundance in collections in decreasing order they are distributed as follows: D. raptorius (L.) – 24 %, D. amatorius (MÜLL.) – 20 %, D. indocilis (WESM.) –17 %, D. ochromelas (GMEL.) (9 %), D. palliatorius (GRAV.) – 7 %, D. latebricola (WESM.) – 7 %, D. restitutor (WESM.) – 6 %, D. septemguttatus (GRAV.) – 6 %, D. luctatorius (L.).

B i o t o p i c a l d i s t r i b u t i o n: The genusis presented in the majority of the open and forest ecosystems. 83 % from total number of collected specimens are focused on forest (10 species) and 17 % on open ecosystems (meadows and personal plots) (3 species). Most mass species, D. raptorius is presented in the greatest quantity in the forest ecosystems. The species, registered in open ecosystems – D. armatorius , D. ochromelas , D. septemguttatus – met also in forest ecosystems. From them only the first species prefers open ecosystems (personal plots). Among forest ecosystems, species of the genus are presented in the greatest quantity in pine forests (33 % and 8 species). The most ordinary species, D. raptorius , prefers polytric pine forests (Pinetum pleurozosum) and wood sorrel spruce forests (Piceetum oxalidosum).

S e a s o n a l a c t i v i t y a n d h i b e r n a t i o n: Representatives of the genus are being met in the nature from the end of April till November. Low abundance of representatives of the genus does not allow with sufficient confidence to estimate number of generations of separate species. At the same time, regular, during many years collectings, allow to draw some conclusions on a basis of aggregate data. In females two periods of activity, in the spring from the end of April to the beginning of June and from July till November are observed. Males are active since June to the beginning of October. From the species, revealed in the region, females D. raptorius and D. indocilis begin activity the first in the early spring, and they also finish activity of these species in the late autumn. Based on the data about of the periods of activity of the species collected by us, with the high degree of confidence it is possible to say that the majority of them has two generations and females hibernate as adult.

Only three species of hibernating females are found by us – D. raptorius , D. indocilis and D. restitutor . Hibernating females were found under a bark and mostly in a wet dust of a rotten wood of laying trunks. G. HEINRICH found females of D. restitutor in the early spring and assumed their hibernating on imaginal stages ( HEINRICH 1977). The females are found by us on hibernation under a bark of the fallen spruce in the wood sorrel spruce forests (Piceetum oxalidosum).

From the literature the hibernation of following species of the genus is known: amatorius (MÜLL.) , fossorius (L.), salicatorius (GRAV.) (= indocilis WESM. ), raptorius (L.), latebricola (WESM.) , ochromelas (GMEL.) , septemguttatus (GRAV.) , catagraphus (KOK.) [ palliatorius (GRAV.) ?(quinquecinctus (KRIECHB.))] (RASNITSYN 1964).