A review of the genus Aphidius Nees in Greece (Hymenoptera: Braconidae: Aphidiinae) with the description of a new species

A review of Aphidius species occurring in Greece is presented. Fourteen species are keyed and illustrated. In addition, a new Aphidius species: Aphidius apolloni sp. nov. from Macrosiphum daphnidis Börner on Daphne oleoides, is described. The new species was collected from Mt Tymphi (western Greece). The aphidiines presented in this work have been identified from 60 aphid taxa occurring on 136 plant taxa from a total of 57 sampling sites. Furthermore, 90 original parasitoid–host aphid associations are presented.


Introduction
Southeastern Europe represents a significant centre of biodiversity in Europe because historical events are combined with compound ecological characteristics of the area. According to Turrill (1929) about 27% of the floras in southeastern Europe are endemic. High mountain endemism of the flora in southeastern Europe is very common. It is influenced by geographical, genetic, and ecological isolation of plant populations which led to great diversity and endemism of aphid-aphid parasitoid associations here. Over the period 1998-2003 we found a large number of parasitoid-aphid-plant associations (Kavallieratos et al. 2004a(Kavallieratos et al. , 2004b and species new to science (Starý et al. 1998;Tomanović and Starý 2001;Tomanović and Kavallieratos 2002;Tomanović et al. , 2003Tomanović et al. , 2004 in the high mountainous areas of southeastern Europe. With over 70 species described worldwide, the genus Aphidius is the largest in the Aphidiinae, including many of the subfamily's most beneficial species (Mescheloff and Rosen 1990). In this paper we review 14 Aphidius species found in Greece and provide an original key for the identification of the species. In addition, a new species from Mt Tymphi in western Greece infesting Macrosiphum daphnidis Bö rner on Daphne oleoides, is described.
The key and the description include SEM, microscope, and line drawings. The species presented in this work have been identified from 60 aphid taxa occurring on 136 plant taxa from a total of 57 sampling sites. We report 90 original parasitoid-host aphid associations.
The plant genus Daphne includes several species which are valuable in landscape architecture (rock gardens, alpine gardens, front of shrub borders) (Hay 1988). The host plant D. oleoides is a calcilode evergreen dwarf shrub which is distributed in the mountains of southern and central Europe, in northern Africa, Asia Minor, Afghanistan, and Himalaya (Tutin et al. 1968;Chittenden 1981). The host aphid M. daphnidis Bö rner is holocyclic and monoecious on Daphne (Heie 1994).

Collection of specimens
Specimens were collected during 1995-2004 in several localities in Greece. Samples from various host plants bearing aphid colonies, consisting of both live and mummified aphids, were collected. Furthermore, samples from D. oleoides plants bearing aphid colonies consisting of both live and mummified aphids were collected from Mt Tymphi (Epirous, western Greece) (type locality) ( Figure 27). Live aphids were preserved in 90% ethylalcohol and 75% lactic acid (2:1) (Eastop and van Emden 1972). Mummified aphids were placed in small plastic boxes subsequently placed inside a growth cabinet. On the lid of each box there was a circular opening covered with muslin for ventilation in order to maintain inside the boxes similar conditions to those existing in the growth cabinet (22.5uC, relative humidity 65%, 16 h light: 8 h dark) (Kavallieratos et al. 2001).
The external structure of the emerged parasitoids was studied using Leica MZ6 and Olympus SZX 9 stereomicroscopes. Several specimens were gold coated and examined using a Cambridge S150 scanning electron microscope. The holotype specimen of the new species was slide-mounted in Canada balsam.

Diagnostic characters used in the key
The diagnostic characters were used in the key as follows: number of maxillary palps, number of labial palps, number of longitudinal placode sensilla on first flagellomere (5F 1 ), length of F 1 , width of F 1 , colour of F 1 , number of antennal segments, length of stigma, width of stigma, length of distal abscissa of R 1 (5metacarpus), length of r-rs vein, length of 3/Rs vein, number of antennal segments, length of tergite 1, width of tergite 1, prominence of ovipositor sheath, sculpture of anterolateral area of tergite 1, colour of body.

Depositories
The material examined in this study is deposited in the collection of the Laboratory of Agricultural Zoology and Entomology (CLAZE), Agricultural University of Athens (Greece). The holotype is deposited in the collection of the Belgrade Natural History Museum (BNHM) (Serbia and Montenegro). The paratypes are deposited in CLAZE.

Terminology
The terminology used in this paper regarding the diagnostic characters of the aphidiines is based on Huber and Sharkey (1993) and Kavallieratos et al. (2001).         times as long as wide, with six longitudinal placode sensilla. F 1 little longer than F 2 (F 1 / F 2 51.07). Maxillary palps four-segmented, labial palps three-segmented. Mesosoma: mesonotum with notaulices distinct in the fore part, slightly crenulated, effaced on the disc. Propodeum ( Figure 24) areolated with narrow pentagonal central areola. Upper lateral areola with nine setae and lower lateral areola with four setae (Figure 24).

Key
Fore wing: stigma (Figure 21) about 4.0 times as long as wide and about 1.9 times as long as distal abscissa of R 1 ; r-rs vein (Figure 21) about 1.1 times as long as 3/R S vein; R 1 vein (Figure 21) about 2.1 times longer than stigma width.
Metasoma: tergite 1 (Figure 25) about 3.8 times as long as wide at spiracles with eight costulae on its anterolateral area and with moderately prominent mediodorsal carina. Ovipositor sheath (Figure 26) slightly concave on its dorsal margin.
Colour: head black. Eyes black. Face with mouthparts yellow. Clypeus yellow. Mandibles yellow except for dark apices. F 1 black with yellow base, remainder of antenna black. Prothorax brown, remainder of thorax black. Wings hyaline with brown venation. Tergite 1 brown to dark brown. Rest of metasoma dark brown. First and second pair of legs yellow, with dark apices. The mummy is brown.
Body length about 3.0 mm.
Male. Antenna 18-segmented, filiform, with semi-erected and adpressed setae which are shorter than diameter of the segments. Stigma 3.4 times as long as wide and about 1.9 times as long as distal abscissa of R 1 ; R 1 vein 1.4 times longer than stigma width. Tergite 1 2.7 times as long as wide at spiracles with five costulae on its anterolateral area. Colour: head, eyes, face black. Mandibles dark brown except for black apices. Clypeus dark brown. Maxillary and labial palps dark brown to black. Antennal scape dark brown. Antennal pedicel dark brown with light brown apex. Remainder of antenna dark brown. Propleuron, pronotum, mesopleuron, metapleuron, scutellum, postscutellum, mesonotum, and metanotum dark brown to black. Wings hyaline with brown venation. Tergite 1 dark brown. Rest of metasoma dark brown. Legs dark brown.
Body length 2.6 mm.

Diagnosis
The new Aphidius species is separated from other congeneric species by the synopsis of the following characters: 19-segmented antennae, F 1 about 3.6 times as long as wide, with three longitudinal placode sensilla, short distal abscissa of R 1 (stigma about 1.9 times as long as distal abscissa of R 1 ). Aphidius apolloni resembles Aphidius rosae Haliday, 1834 in the number of longitudinal placode sensilla on the F 1 , slightly longer F 1 than F 2 and short distal abscissa of R 1 (stigma 1.6-1.9 times as long as distal abscissa of R 1 ), but it is immediately distinguished from A. rosae by the proportions between: length and width of

Etymology
The new species took its name from the ancient Greek God Apollo.

Remarks
Recently, we described Aphidius montenegrinus Tomanović and Kavallieratos from Acyrthosiphon daphnidis Ilharco, 1994/Daphne alpina L. associations (Tomanović et al. 2004). The host plant, Daphne, is a typical ancient Mediterranean genus with Laurasian pattern of distribution and early Tertiary origin. We have presumed the Mid-Tertiary origin of both associations: Macrosiphum daphnidis/Aphidius apolloni and Acyrthosiphon daphnidis/ Daphne alpina and the ancient Mediterranean origin of A. apolloni and A. montenegrinus. Biogeographically, A. apolloni and A. montenegrinus are characterized most probably by a disjunctive distribution. This type of partition can be attributed to successive paleogeographical and climatic changes. At the end of the Miocene period, the large, probably rapid, climatic subversion must have brought aridity to southeastern Europe, rendering it uninhabitable to the majority of humidity-dependent species (Hsü 1972). However, impermeable sediments on Dinarides massif, including Montenegro's mountains and northern Greek mountains, had kept enough humidity for the survival of many plants and associated herbivorous insects. Subsequently, with decreasing aridity, southeastern Europe became the main centre of dispersion of different insect groups to the east and west, as well as to the north and south. This fact explains some close interrelationships between many local faunal elements inhabiting the Iberian Peninsula, the Apennines, the Crimea, and the Caucasus, on the one hand, and elements inhabiting southeastern Europe on the other. From Macrosiphum daphnidis/Daphne oleoides associations we reared Aphidius ervi Haliday, 1834 and the hyperparasitoid Asaphes suspensus (Nees) (five specimens).