Study On Biological Characters And Nutritional Value Of Euconocephalus Nasutus Thunberg

Euconocephalus nasutus Thunberg belongs to Orthoptera, Conocephalidae, Euconocephalus Karny. It mainly distributed in the southwest of China, and was widely eaten among the people in Sichuan province, but the breeding and development of it has not formed the scale. For providing the supports of the theory and technology, this paper studied on the biological characteristics of Euconocephalus nasutus Thunberg by outdoor experiments and indoor experiments, mensurating nutritive value of Euconocephalus nasutus Thunberg of two habitats. The results were summarized as follows:1.Euconocephalus nasutus Thunberg is paurometabolous insect whose development period consist of three forms:egg, larva and adult. The larva has5instars, the morphological indexes have reached significant differences among each instars, but them between male and female of larva have no significant difference. From the second instar larva,wings buds have growed, and the sex have be distinguished, the male have two body-colours and will change after the third instar.2.Euconocephalus nasutus Thunberg occurres one generation per year in Yucheng district of Yaan, Sichuan province, and its eggs mainly overwinter or sometimes adult(usually female) overwinter. The eggs, which overwinter, begin to hatch in the late May, and the incubation period is long, which can continue to the early July, the first instar larva and adult can be found at the same time.The adult and larva both are not active during the day whereaa active in night, its ecdysis and eclosion are always happen from8a.m. to10a.m., and from15p.m. to17p.m.. adult and larva of Euconocephalus nasutus Thunberg both have strong hygrotaxis, and the first to second instar larva have trooping, they may murder each other When the short of food and just eclosion or just ecdysis,.3.Euconocephalus nasutus Thunberg often do not feeding in the daytime, and the frequency of feeding is low in the afternoon, but the frequency of feeding gradually increase until18p.m. there is a feeding peak between19p.m. to20p.m..The feeding area and feeding preferences of Euconocephalus nasutus Thunberg have greaterchanges coming along with the increase of the instar.The first to third instar larva only eat Hemarthria altissima(Poir.) Stapf et C. E. Hubb and a small quantity of Alternanthera philoxeroides(Mart.)G, and after fourth instar larva,the insect also eat rice leaf and grain, and the frequency of eat Alternanthera philoxeroides(Mart.)G is relatively lowest.4.Under the condition of19℃、22℃、25℃、28℃、31℃、the developmental duration of each instar of the larva was6.4d-15.0d(first instar),6.9d-15.8d(second instar),7.Id～16.1d(third instar),7.3d～16.6d(fourth instar),7.6d～16.9d (fifth instar). The developmental zero temperature of the larva was11.61℃, the effective accumulative temperature was718.06day-degrees.5.The chirping peak of the male was from18p.m. to22p.m.. The mating began from18p.m., and it continued to2a.m., and the mating peak was between19p.m. and21p.m., which is tally accord with the chirping peak. The courtship and mating were connected with the chirping, and mating frequency was also connected with the time that duration of chirping in unit time, the more the male chirping in a hour, the higher the frequency of the mating would be.6.Euconocephalus nasutus Thunberg from grassland and paddy field contained abundant nutrients:Moisture (73.50%and75.68%), protein (18.39%and9.34%), fat (5.93%and13.22%), ash(0.65%and0.52%)and carbohydrate(0.27%and0.28%); total amino acid content of samples from grassland and paddy field were19.832%and10.957%respectively, the content of the sulfur-containing amino acids are high essential amino acids comprised82.441%and98.245%, and ratios of essential to unessential amino acids from the two locations were45.185%and49.557. The insect, which collected from the grassland, contained two limiting amino acids, threonine and lysine. The insect from the paddy field, only contained one limiting amino acids, lysine. The ratios of unsaturated fatty acids and were59.66%and69.72%, respectively. The ratio of monounsaturated fatty acid were relatively higher,44.73%and60.77%, Ratios of polyunsaturated to saturated fatty acids were0.44and0.29. Besides, Euconocephalus nasutus Thunberg contained minerals and trace elements, including Ca、Fe、Zn、Na、 Cu、Mn、P. Based on these data,the potential for utilization of Euconocephalus nasutus Thunberg was evaluated.