Diagnosis - All legs with tarsi 4-segmented (3-segmented in Trisecodes); fore tibial spur short and straight. Antenna usually with 2, 3 or 4 funicular segments (rarely 1 or 5), funicle of male sometimes branched. Fore wing with marginal vein (MV) relatively long, postmarginal (PMV) and stigmal (STV) veins often quite short. Mesoscutum with or without well-marked notauli; axilla often produced forward of the scuto-scutellar suture. Metasoma constricted basally, not broadly attached to mesosoma. Eulophids are often soft-bodied and may shrivel and collapse after death; colour varying from metallic to black to yellow.
Classification and distribution
- The Eulophidae is the largest family of Chalcidoidea and they are
probably the most commonly collected members of the superfamily in
all geographic realms. The family currently comprises almost 4300
described species in 290 genera worldwide (Noyes,
2001). The closest relatives of the Eulophidae are not clear.
Families which may be related to the Eulophidae are the Trichogrammatidae,
Aphelinidae, Signiphoridae and Tetracampidae. Further study is required
to resolve the relationships of these groups.
The classification of the Eulophidae has recently been revised by
Gauthier et al. (2000).
It is currently divided into four subfamilies, Entedoninae, Euderinae,
Eulophinae and Tetrastichinae, all of which are cosmopolitan in distribution
(there are three small tribes which are currently unplaced, Ophelimini,
Anselmellini, Platytetracampini; however, these do not contain species
which attack leafminers). Of these four subfamilies, leafminer parasitoids
are found in the Entedoninae, Eulophinae, and Tetrastichinae.
Identification - Keys to the subfamilies
and/or discussions of classification within the family are provided
by Graham (1987), Boucek
(1988), Schauff et al.
(1997), and Gauthier et
al. (2000). Keys to all eulophid genera exist for Australasia
(Boucek, 1988) and North America
(Schauff et al. 1997).
Gauthier et al. (2000)
provided a reclassification, and list all genera in each subfamily
and tribe. Noyes (2003) provided
an electronic catalogue for the entire Chalcidoidea.
Biology - Although eulophids are generally
parasitoids of holometabolous insects, the overall range of hosts
and biologies in Eulophidae is incredibly diverse, and the family
attacks a very wide range of hosts as parasitoids and also contains
a few phytophagous or “predatory” species. Parasitoid
forms can be internal (endoparasitoids) or external (ectoparasitoids);
idiobionts or koinobionts; solitary or gregarious; primary parasitoids,
hyperparasitoids or facultative hyperparasitoids; specialists or generalists.
Parasitoid species can attack eggs, larvae, pupae or even adults in
a few cases. Predatory eulophids display a specialised form of parasitism
where the wasp larva consumes many prey within an enclosed space (such
as a gall or an egg sac), and species that develop this way are known
to consume spider eggs in silken egg sacs (La
Salle, 1990), eriophyid mites in galls (Taylor,
1909; Vereschagina, 1961)
or even nematodes (van den Berg
et al., 1990). Phytophagous species again display a variety
of life styles, and may be inquilines within galls (Sheng
& Zhao, 1995), gall-formers themselves (Somerfield,
1976; Hawkins & Goeden, 1982;
Headrick et al., 1995)
or internal seed feeders (Boucek,
1988; La Salle, 1994).
The Eulophidae is probably the most important family in terms of leafminer
parasitoids, with a variety of genera specialising on leafminers.
However, most of the eulophid leafminer parasitoids are generalists
in behaviour. They are rarely host specific and usually attack a variety
of hosts, either as external parasitoids, idiobiont internal parasitoids,
or even facultative hyperparasitoids (Murphy
& La Salle, 1999). Even those thought to be specific are often
seen to attack a variety of hosts when more thorough studies are performed
(Massa et al., 2001).