Lathrolestes

Lathrolestes

Lathrolestes Förster, 1869: 196. Type-species: Tryphon clypeatus Zetterstedt. Camporychus Förster, 1869. Type-species: Lathrolestes marginatus Thomson; Culmina Benoit, 1955. Type-species: Culmina ruwenzorica Benoit;

Ecclinops Förster, 1869. Type-species: Tryphon orbitalis Gravenhorst;

Homalomma Förster, 1869. Type-species: Homalomma caliroae Rohwer;

Laphyroscopus Förster, 1869. Type-species: Tryphon gorskii Ratzeburg;

Lathrolestus Thomson, 1883. Type-species: Lathrolestus clypeatus Zetterstedt Luphyroscopus Thomson, 1883. Type-species: Luphyroscopus gorskii Ratzeburg Ritzemabosia Smits van Burgst, 1912. Type-species: Ritzemabosia meridionalis Smits van Burgst; Tryphonopsis Brauns, 1898. Tryphonopsis ensator Brauns

Diagnosis. Small to medium sized species, 4.0– 7.5 mm. Occipital carina not intercepting hypostomal carina. Clypeus profile flat, its apical margin thick. Mandibles with lower tooth distinctly longer than the upper. Areolet petiolate, oblique. Second recurrent vein with a single bulla. Nervellus intercepted below or at its middle. Tarsal claws pectinate, with 1 or 3 teeth or with basal lobe. Glymmae deep. Apex of subgenital plate of male not incurved on hind margin. Tip of aedeagus somewhat decurved and swollen, its apex rounded. Ovipositor sheath 0.3 to 15 × as long as metasomal height.

Biology. Their larvae are koinobont endoparasitoids usually on leafmining sawfly larvae of the tribe Fenusini (Hymenoptera, Tenthredinidae); these feed on foliage of deciduous trees or shrubs (Pschorn-Walcher & Altenhofer 1989) excluding Metallus gei, feeding on Geum urbanum. A few species are known to attack leafmining lepidopteran larvae of the family Eriocraniidae— L. clypeatus (Zetterstedt 1838) and L. mnemonicae (Rohwer 1914) (Rohwer 1914; Heath 1961; Carlson 1979) and leafmining beetle larvae of the family Megalopodidae— L. zeugophorae Barron, 1994. Some Lathrolestes species attack sawflies with a different lifestyle such as Lathrolestes ensator, which is a parasitoid of the carpophagous, Hoplocampa testudinea (Nematinae, Hoplocampini). Lathrolestes caudatus attacks larvae of Ardis brunniventris (Blennocompinae, Blennocompini), which feeds within branches of dog rose. Lathrolestes luteolator attacks larvae of slug sawflies, Caliroa (Heterarthrinae, Caliroini) (Carl, 1976). Data on trophic interections of the genus Lathrolestes is provided in Table 1.

......continued on the next page

......continued on the next page

Biological control. The leaf mining sawfly Fenusa pusilla is a pest of birch in Northern America (Coulson 1992, Barron 1994, van Driesche et al. 1997). This species was brought from Europe (Friend 1933) and became an important pest (Fuester et al. 1984). Lathrolestes nigricollis has been successfully used against this species of sawfly (Raske & Jones, 1975, Guevremont & Quednau, 1977, van Driesche et al., 1997, Langor et al., 2000, Casagrande et al., 2009). An attempt was made to use the same species of Lathrolestes against another invasive birch pest, Profenusa thomsoni (Langor et al., 2000). However, during the successful biological control studies of P. thomsoni, two new species of the genus were discovered (Reshchikov et al, 2010), L. thomsoni and L. soperi and both these species are used against P. thomsoni successfully (Soper et al. 2015).