Lissonota holcocerica Sheng sp.n (Hymenoptera: Ichneumonidae) parasitizing Holcocerus hippophaecolus (Lepidoptera: Cossidae) from China

This paper describes Lissonota holcocerica Sheng sp.n. (Hymenoptera: Ichneumonidae), parasitizing Holcocerus hippophaecolus Hua, Chou, Fang and Chen (Lepidoptera: Cossidae) in Inner Mongolia, Liaoning, and Ningxia, China. The adults of L. holcocerica emerge from a cocoon during the daytime, mostly from 09:00 to 14:00 hr, then start calling and mating, mostly from 08:00 to 12:00 hr. Mating lasts from 15 sec to 15 min. The longevity of males is 5.8 ± 2.4 days, whereas for females longevity is 7.6 ± 4.6 days in the field. Nutritional supplements can significantly extend the life span of L. holcocerica. Mated females search for hosts by walking on the base of Hippophae rhamnoides L. (Rosales: Elaeagnaceae) stem infested by Ho. hippophaecolus, vibrating their antennae and tapping while searching the stem for oviposition sites. Parasitized cocoons of Ho. hippophaecolus collected in field were half the size of normal ones or even smaller.


Introduction
The sea buckthorn carpenterworm, Holcocerus hippophaecolus Hua, Chou, Fang and Chen (Lepidoptera: Cossidae), attacks mainly the roots and trunks of Hippophae rhamnoides L. (Rosales: Elaeagnaceae), a commercially important deciduous shrub in the northern regions of China, thus making most of them hollow and eventually leading to the death of the plant. In recent years, Ho. hippophaecolus populations have sharply increased in Inner Mongolia and Liaoning, Shanxi, Ningxia, Shaanxi, and Gansu provinces in China, which has aggravated the damage to Hi. rhamnoides populations and severely impaired the local eco-environmental construction and economic activities based on this species (Zong et al. 2005(Zong et al. , 2011Luo et al. 2007;Tao et al. 2012). The authors studied the parasitoids of Ho. hippophaecolus, and an important species, Lissonota holcocerica Sheng sp.n., was found and investigated.
The holotype and six paratypes are deposited in the Insect Museum, General Station of Forest Pest Management (GSFPM), State Forestry Administration, P.R. China. Two paratypes have been deposited in the Natural History Museum, London, U.K. (BMNH).

Materials and Methods
Cocoons of Ho. hippophaecolus were collected from Hi. rhamnoides forest heavily infested by Ho. hippophaecolus during the periods of adult emergence, and all cocoons collected were dissected to record the number of parasitic and non-parasitic cocoons. Two square nylon cages (100 × 100 ×100 cm) were set up outdoors, and 10 virgin males and 10 virgin females of L. holcocerica were placed in pairs into each cage. One cage only had water while the other cage had both water and 10% honeydew. The feeding, mating, oviposition, and longevity behaviors were then observed. Additional observations were made in the field on Ho. hippophaecolus infested forests from which L. holcocerica emerged naturally.
The morphological terminology is mostly that of Gauld (1991). Wing vein nomenclature is based on Ross (1936) and the terminology on Mason (1986Mason ( , 1990.
Diagnosis. Face wider than long. Apical margin of clypeus thick. Malar space 0.4 to 1.3 times as long as basal width of mandible. Occipital carina complete, lower end joining oral carina some distance above base of mandible. Epomia absent or short and weak. Propodeum usually with posterior transverse carina, rarely absent. Hind wing vein 1-cu slightly longer than cu-a. Tarsal claws usually   with distinct pectination. First tergum moderately narrowed toward the base, with a rather abrupt constriction at base. Ovipositor sheath 1.1 to 4.5 times as long as hind tibia.
Metasoma. Metasoma robust, apical portion slightly compressed. First tergum about 1.2 times as long as apical width, with dense and distinct punctures, lateral portion rough, subapical with weak and short longitudinal wrinkles, basal-median portion concave and smooth, apical half with irregular longitudinal median groove. Median dorsal carinae vestigial basally. Spiracle located at basal 0.3 of first tergum. Second tergum ( Figure 5) 0.7 to 0.8 times as long as apical width, with dense and distinct punctures, distance between punctures 0.2 to 1.0 times diameter of puncture, apical margin smooth narrowly. Third tergum with dense and more finer punctures than that of second tergum, apical margin smooth narrowly. Fourth tergum with distinct punctures, the punctures sparser and finer than that of third. Fifth tergum with very sparse, irregular and fine punctures. Remaining terga smooth. Apical margin of eighth tergum almost truncated. Apex of hypopygium with a triangular notch.
Ovipositor sheath approximately 2.5 to 3.0 times as long as hind tibia.
Color (Figure 1). Black, except the following. Apical portion of clypeus, legs, except coxae black and hind tarsi dark brown, brown to reddish brown. Spots on lateral-anterior portion of mesoscutum, tegulae and spots of subalar prominences yellow to yellowish brown.
Male (Figure 2). Body length 18.5 to 19.5 mm. Fore wing length 14.5 to 15.0 mm. Antenna with 42 flagellomeres. Ventral profiles of second trochanters and femora, apical portions of hind tibiae blackish brown. Adults emerge during the daytime, mostly from 09:00 to 14:00 hr at room temperature. Newly emerged adults chew a round hole with mouthparts in the epidermis of the cocoons, and then crawl out quickly. Adults groom their antennae and wings after emerging, and then take off, heading towards light places indoors.
Virgin females start their mating behaviors after their adult emergence; mating occurs during the daytime, mostly from 8:00 to 12:00 hr at room temperature, and lasts from 15 sec to 15 min. Before copulation, female wasps chase males, flying around in the rearing cage. After mating, males rest for a while then show gestures of wanting to copulate with other females, but usually they are rejected by females. Copulated females sit still and reject males.
Mated females search for hosts by walking on the base of Hi. rhamnoides stem infested by Ho. hippophaecolus while vibrating their antennae, tapping the stem while searching for oviposition sites. In field, female wasps were seen walking around at the base of trunks, swinging their antenna to detect larvae. Females laid eggs into bodies of Ho. hippophaecolus larvae that lived in the stems of Hi. rhamnoides. After hatching, larvae of wasps fed inside the host larvae. Parasitized moth larvae dug into the soil and formed a cocoon earlier than normal. After depleting all the nutrients of the moth larvae, wasp larvae made membranous cocoons and pupated. Parasitized cocoons collected in field were half the size of normal ones or even smaller.
Male longevity was 5.8 ± 2.4 days whereas female longevity was 7.6 ± 4.6 days in the field. Nonetheless, the longevity of males and females was 5.5 ± 1.8 days when only fed with some water and 7.8 ± 4.0 days when fed with some water and 10% of honeydew (syrup). Therefore, the results show that nutritional supplements can significantly extend the life span of L. holcocerica.