First report of the genus Phytodietus Gravenhorst, 1829 (Hymenoptera: Ichneumonidae: Tryphoninae) from Thailand

Abstract Background The genus Phytodietus Gravenhorst, 1829 is a species rich group of ichneumonid parasitoid wasps. It is represented in all zoogeographical regions, but knowledge of Phytodietus species in the Oriental region is patchy and restricted to some countries. New information Here the genus Phytodietus is recorded from Thailand for the first time based on three species. Diagnosis and illustrations of P. longicauda (Uchida, 1931), P. pitambari Kaur et Jonathan, 1979 and P. spinipes (Cameron, 1905) are given. Furthermore, known distributional and biological data of the species are summarised and an identification key to the species is provided.


Introduction
Phytodietus Gravenhorst, 1829 (Hymenoptera, Ichneumonidae) belonging to the subfamily Tryphoninae, tribe Phytodietini, consists of species that are koinobiont ectoparasitoids of semi-concealed larvae of several families of Lepidoptera, mainly Tortricidae and Pyralidae (Bennett 2015). The genus is distributed worldwide and currently includes 122 described species (Bennett 2015, Kasparyan and Khalaim 2013, Kostro-Ambroziak 2011a, Kostro-Ambroziak 2011b, Kostro-Ambroziak 2012, Kostro-Ambroziak and Broad 2016. To date, 22 species of Phytodietus have been recorded in the Oriental region: 10 species from India, 7 from Philippines, 6 from Myanmar, 5 from China, 4 from Taiwan, 3 from Indonesia and 1 from Sri Lanka (Gupta 1987, Kaur and Jonathan 1979, Yu et al. 2012. Based on distributional data, some of the Phytodietus species were expected to occur also in other countries of South East Asia, but no species of this genus had been recorded from Thailand so far.
Here three species of the genus Phytodietus are recorded as new to Thailand and an identification key to these taxa is provided.

Materials and methods
The current study was based on material collected by the TIGER project, a collaborative effort between staff at the Queen Sirikit Botanic Garden (QSBG), the Thai Forestry Group, the Hymenoptera Institute of the University of Kentucky, and the Natural History Museum of Los Angeles County. Photographs were taken using an opto-digital microscope DSX110 in the Laboratory of Ecology and Evolutionary Biology of Insects (University of Bialystok, Poland). Morphological terminology follows Gauld et al. 1997.  (Fig. 2d). This species is distinguished from other Phytodietus species known from Thailand also by the following features: epomia present (Fig. 2c), distinct wrinkles on propodeum and metapleuron (Fig. 2d) and a constriction between the base and spiracles of the first metasomal segment (Fig. 3a).

Distribution
P. longicauda is one of the most widely distributed species of Phytodietus and has already been recorded in China, India, Japan, Myanmar, Russia and Taiwan (Yu et al. 2012).

Biology
P. longicauda probably has more than one generation per year. It has been recorded in: May in India (Kaur and Jonathan 1979) and Thailand, June in Myanmar (Kasparyan 1998), July in Amami-Oshima island within the Ryukyu Archipelago (Japan) (Momoi 1970), August in Russia (Kasparyan and Tolkanitz 1999), October in Japan (Kaur and   (Figs 4,5) can be easily recognized from the two congeneric species known from Thailand by the following characters: areolet of the fore wing absent (Fig.  4) and submetapleural carina not expanded anteriorly into a lobe (Fig. 6). It is distinguished from other species of Phytodietus lacking the areolet by having the first abscissa of Cu 1 shorter than cu-a. P. pitambari is similar in colour to the Oriental species P. namkumensis Kaur et Jonathan but differs in having the occipital carina present (absent in P. namkumensis) and the distance between 2rs-m and 2m-cu 1.8 times length of 2rs-m (3.4 for P. namkumensis).

Distribution
This species has already been recorded in India, Philippines (Jonathan 1995, Kaur and Jonathan 1979) and Japan (Shimizu and Watanabe 2015).

Biology
P. pitambari has been recorded in: April in Philippines, April and May in India (Kaur and Jonathan 1979), May, July, August in Japan (Shimizu and Watanabe 2015), and the a b  beginning of August in Thailand suggesting that it has more than one generation per year. It has been noted at an altitude of 1228 and 610 m a.s.l. in India, and 455 m a.s.l. in Philippines (Kaur and Jonathan 1979 (Fig. 3c, d) (mostly rounded in the other species (Fig. 3a, b)), and the body predominantly black (Fig. 7), with numerous yellow marks (predominantly yellow in the other two species (Figs 1, 4)). Among other Oriental species of Phytodietus which are similar in colour pattern P. spinipes is relatively easy to recognize by the following combination of characters: eye orbits yellow (Fig. 8a), face completely or largely yellow (sometimes very pale yellow), hind femur orange, and hind tibia and tarsus black (sometimes tibia slightly paler basally).

Distribution
P. spinipes was originally described from Sri Lanka (Cameron 1905) but it has also been recorded in China, India, Indonesia, Myanmar and Taiwan (Yu et al. 2012).

Biology
Data suggests that P. spinipes also has more than one generation per year. It has been recorded in: March in Myanmar, October in Java (Kaur and Jonathan 1979), January, February, April, May and the beginning of the June in Thailand. It has been collected at an altitude of 1000 m a.s.l. in Myanmar (Kaur and Jonathan 1979)  P. spinipes is known to be a parasitoid of Homona coffearia (Nietner) (Tortricidae), the tea Tortrix in Sri Lanka, Taiwan (Gupta 1987) and India (Muraleedharan and Selvasundaram 1991). In Java this species has been reared from Homona sp. (Kaur and Jonathan 1979). First report of the genus Phytodietus Gravenhorst, 1829 (Hymenoptera: Ichneumonidae: ...

Identification keys
Key to the species of Phytodietus Gravenhorst, 1829 from Thailand 1 Areolet of fore wing absent, submetapleural carina not expanded anteriorly into a lobe P. pitambari Kaur et Jonathan, 1979 -Areolet of fore wing present, submetapleural carina expanded anteriorly into a lobe 2 2 Pleural carina and epomia absent, body in general black with yellow marks P. spinipes (Cameron, 1905) -Pleural carina and epomia present, body in general yellow with black marks P. longicauda (Uchida, 1931)