D0L:10.3109/07388551.2013.791245 Advances in research of Ophiocordyceps sinensis (a) (b) Adult insect Development of DCXC Pupa Egg-masses Infective larvae (3rd-5 th instar） Adult DCXC 5th instar larvae Young larvae Spread of spores Forming spore 3rd instar larvae Figure 1.The life cycle of the insect of the genus Hepialus(a)and the development process of the DCXC(b). mH有032 harc.con 2-4 years in light of the different species involved.For Dasiphora fruticosa (L.)Rydb.and Astragalus membranaceus example,H.yushusis larvae need to take about 996 days (Fisch.Bge.In addition,dozens of the tender roots from to become the pupa,H.kangdingensis 1000 days and H. different plant families can also be chewed,including gonggaensis 875-1040 days.The larvae with different Cyperaceae,Poaceae,Gentianaceae,Primulaceae and instars can be found in the soil all the year around. Juncaceae (Gu et al.,2006;Wu et al.,2007;Zhuo et al., (3)A part of larvae turn into the pupa at the end of every 2008) May,and the pupa stage for most of the larvae is from June to July.During this period,the developmental Artificial culture of the host larvae of Hepialus duration of the pupa needs to take 40 days,when the temperature is 10-15C and the soil relative humidity is The insects Hepialus of the DCXC need take 3-4 years to 40-45%.The peak period of the adult emergence differs finish an alternation of generations.The larval stage generally has six instars,or even seven to eight instars under special from the altitudes.The color variation of Hepialus moth environmental conditions.But,under the conditions of from pre-pupa to emergence is from light to dark. complete artificial rearing,the larvae only take 1-2.2 years (4)The emergence of pupa often happens at 17:00-20:00 to complete an alternation of generations (Yang et al.,2009). every day during June to August.In most producing If we want to implement the artificial cultivation of the areas,the amount of the female adult insects is larger than that of the males.In general,the peak of mating DCXC,the key techniques will be the artificial culture of the host larvae of Hepialus under the condition of soilless,the differs from the altitudes,and meanwhile the number of growth nutrition required and the prevention of diseases. mating is one for females and two to three for males.The g Based on the previous literature,the developmental rate of the duration from opulating to ovipositing is 5-40 min,and eggs may come to 86.75%under the conditions of relative the copulation is beneficial to the ovipositing of the humidity 50%and temperature 15C (Liu et al.,2009).The females.Similarly,to the mating,the peak of ovipositing nutritional components required by the larvae with five instars also varies with the altitude.After copulation,the females can be met by the artificial feeding formula,consisting of can lay about 5-45 eggs once on a nearby meadow.The Rheum pumilum 5.0,sorbic acids 0.5,soybean 15,corn flour longevity of the females is longer than that of the males, 10,wheat bran 8,yeast powder 5.0,agar 10 and water 100 but the females die soon after laying eggs (Liu et al., (g/L).The weight of larvae can be put on by adding the 2008:Wang et al.,2001a;Wang Yao,2011;Yang natural plants of Rheum pumilum,while sorbic acid and Jiang,1995:Yang et al.,1991;Zhu et al.,2007). nipagin esters,which will not affect the growth of larvae, Plant groups of the food of the host larvae can be added as antiseptic agents in the artificial feeds (Wang,2002). The host larvae of Hepialus are the omnivorous insects,which Since the 1970s,there are more than 10 departments lead a troglodytic life in the soil,and prefer to feed on the studying the artificial cultivation of DCXC,but only a few tender roots of plants.There are many plant species fed on by species of host insects were successfully raised in laboratory the host insects and the well-known underground stems of 15 conditions in China.For example,the Hepialus oblifurcus species plants of 10 families can be served as the food of the larvae and Hepialus gonggaensis larvae were artificially larvae.Among them,the larvae prefer to the tender root of raised at low-altitude area in the DCXC research base in Polygonaceae plants,such as Polygonum sphaerostachyum Kangding County by Chongqing Academy of Chinese Meisn,P.viviparum L.and Rheum pumilum Maxim.They can Materia Media.Meanwhile,Hepialus gonggaensis larvae also graze the tender root of Rosaceae plants,such as were also artificially raised at Zhejiang Agriculture RIGH T S L I N K2–4 years in light of the different species involved. For example, H. yushusis larvae need to take about 996 days to become the pupa, H. kangdingensis 1000 days and H. gonggaensis 875–1040 days. The larvae with different instars can be found in the soil all the year around. (3) A part of larvae turn into the pupa at the end of every May, and the pupa stage for most of the larvae is from June to July. During this period, the developmental duration of the pupa needs to take 40 days, when the temperature is 10–15 C and the soil relative humidity is 40–45%. The peak period of the adult emergence differs from the altitudes. The color variation of Hepialus moth from pre-pupa to emergence is from light to dark. (4) The emergence of pupa often happens at 17:00–20:00 every day during June to August. In most producing areas, the amount of the female adult insects is larger than that of the males. In general, the peak of mating differs from the altitudes, and meanwhile the number of mating is one for females and two to three for males. The duration from opulating to ovipositing is 5–40 min, and the copulation is beneficial to the ovipositing of the females. Similarly, to the mating, the peak of ovipositing also varies with the altitude. After copulation, the females can lay about 5–45 eggs once on a nearby meadow. The longevity of the females is longer than that of the males, but the females die soon after laying eggs (Liu et al., 2008; Wang et al., 2001a; Wang & Yao, 2011; Yang & Jiang, 1995; Yang et al., 1991; Zhu et al., 2007). Plant groups of the food of the host larvae The host larvae of Hepialus are the omnivorous insects, which lead a troglodytic life in the soil, and prefer to feed on the tender roots of plants. There are many plant species fed on by the host insects and the well-known underground stems of 15 species plants of 10 families can be served as the food of the larvae. Among them, the larvae prefer to the tender root of Polygonaceae plants, such as Polygonum sphaerostachyum Meisn, P. viviparum L. and Rheum pumilum Maxim. They can also graze the tender root of Rosaceae plants, such as Dasiphora fruticosa (L.) Rydb. and Astragalus membranaceus (Fisch.) Bge. In addition, dozens of the tender roots from different plant families can also be chewed, including Cyperaceae, Poaceae, Gentianaceae, Primulaceae and Juncaceae (Gu et al., 2006; Wu et al., 2007; Zhuo et al., 2008). Artificial culture of the host larvae of Hepialus The insects Hepialus of the DCXC need take 3–4 years to finish an alternation of generations. The larval stage generally has six instars, or even seven to eight instars under special environmental conditions. But, under the conditions of complete artificial rearing, the larvae only take 1–2.2 years to complete an alternation of generations (Yang et al., 2009). If we want to implement the artificial cultivation of the DCXC, the key techniques will be the artificial culture of the host larvae of Hepialus under the condition of soilless, the growth nutrition required and the prevention of diseases. Based on the previous literature, the developmental rate of the eggs may come to 86.75% under the conditions of relative humidity 50% and temperature 15 C (Liu et al., 2009). The nutritional components required by the larvae with five instars can be met by the artificial feeding formula, consisting of Rheum pumilum 5.0, sorbic acids 0.5, soybean 15, corn flour 10, wheat bran 8, yeast powder 5.0, agar 10 and water 100 (g/L). The weight of larvae can be put on by adding the natural plants of Rheum pumilum, while sorbic acid and nipagin esters, which will not affect the growth of larvae, can be added as antiseptic agents in the artificial feeds (Wang, 2002). Since the 1970s, there are more than 10 departments studying the artificial cultivation of DCXC, but only a few species of host insects were successfully raised in laboratory conditions in China. For example, the Hepialus oblifurcus larvae and Hepialus gonggaensis larvae were artificially raised at low-altitude area in the DCXC research base in Kangding County by Chongqing Academy of Chinese Materia Media. Meanwhile, Hepialus gonggaensis larvae were also artificially raised at Zhejiang Agriculture Figure 1. The life cycle of the insect of the genus Hepialus (a) and the development process of the DCXC (b). DOI: 10.3109/07388551.2013.791245 Advances in research of Ophiocordyceps sinensis 3 Critical Reviews in Biotechnology Downloaded from informahealthcare.com by Fudan University on 07/22/13 For personal use only.