Studies On Biology And Artificial Feeding Of Epicauta Gorhami Marseul And Epicauta Tibialis Waterhouse

The family Meloidae, blister beetles, contains about 2500 species, divided among 80 genera and three subfamilies, of which 130 species occur in china. Its secretion (cantharidin) can be used in treating many kinds of cancers. Due to medicinal demands, scholars conduct many studies about the analogues of cantharidin, synthesis of their derivatives and their clinical application in our country. But there are few studies about blister beetles itself. Especially, there are few studies about its artificial feeding, its reproduction and its ecology (they are seldom reported homeland).The dissertation researches in biological characteristics and artificial feeding of Epicauta gorhami Marseul & Epicauta tibialis Waterhouse systematically.The main results include as the following:1. The study about its biological characteristics indicates that Epicauta gorhami Marseul & Epicauta tibialis Waterhouse occur generally in Guizhou province. In Guiyang region Epicauta gorhami Marseul is bivoltine, but Epicauta tibialis Waterhouse is univoltine. Their larvae have seven instars (1st instar larva--triungulin, 2nd, 3rd, 4th, 5th and 7th instar larvae-grub type,6th instar larva--coarctate type subnymph, 1st-5th instar larvae--a period of rapid growth,7th instar larva--no feeding, pupa-exarate pupa).2. They both pass the winter by subnymph, laying eggs in masses in the ground and pupating in the ground. They have the same mode of mating. The female adult mates only once before laying eggs. And the male adult has many times of mating in its life. The female adult of Epicauta tibialis Waterhouse can lay eggs 2-4 times all in its life. The first time they can lay about 200 eggs, and about 20 eggs at the last time. The female adult of Epicauta gorhami Marseul can lay eggs 3-5 times all in its life (80 eggs the first time, 20 eggs the last time).3. Adults of Epicauta gorhami Marseul and Epicauta tibialis Waterhouse like to eat many kinds of foods, such as leaves of soybean, fern, tomato and potato. They like to eat leaves of soybean much more than those of fern, tomato and potato.4. The body of Epicauta gorhami Marseul is small. The adult weight on average is as follows: female adult (0.15g), male adult (0.14g).The rate of its reproduction is high. At constant temperatures of 18,21,24,27 and 30°C, the developmental time of Epicauta gorhami Marseul in laboratory was studied. The results show that under the condition (The temperature is 27°C;Relative humidity is 60%;The illumination is 1500Lx of 15 hours ;the darkness period is 9 hours ), adult begins to mate ,feeding 2-3 days after eclosion, then laying eggs after 7 days, later hatching after 10 days. Finally they eclosion after they prey on eggs of locusts 20 days. One generation of blister beetles is 40 days approximately in the laboratory. The success rate of its reproduction is high relatively.5. The body of Epicauta tibialis Waterhouse is larger than Epicauta gorhami Marseul. Its adult weight average is as follows : male adult (?) (0.35g), female adult (0.33g).The rate of its reproduction is low relatively. At constant temperatures of 27°C and 30°C,The developmental time of Gallerucida ornatipennis in laboratory was studied.The results show that Eggs need 40 days to hatch in 27℃. The larva phase is 70 days. Because of these, it is not suitable for artificial feeding on scale.6. The species of food influence the female adult's laying eggs. The order of the 4 kinds of food beneficial to the femal adult's laying is leaves of soybean, fern, tomato and potato.7. l-5th instar larvae eat only eggs of locusts. They fight with each other when they meet in the same ootheca. The result is one alive, the other dead.8. The two kinds of Meloidae both diapause at 6th instar larva. Maybe low temperature can induce diapause on the larva of Epicauta gorhami Marseul. It is easier for breaking off diapause of larva of Epicauta tibialis Waterhouse in changing temperature than in one constant high temperature.9. There are parasitic phenomenons to blister beetle larva. Such as two kinds of mites of Trombidae and Beauveria bassiana were found in the experiment.10. The cantharidin content is no distinct difference between the Epicauta gorhami Marseul fed in laboratory and those living in the nature. The content of cantharidin in the adult that just eclosion is a little higher than that in the adult that lay eggs.11. The model about artificial feeding of Epicauta gorhami Marseul and the biological control of oxya chinensis Thunberg is established.