Studies On Reproductive Biology And Feeding Habits Of Blaps Rhynchoptera Fairmaire(Coleoptera: Tenebrionidae)

Blaps rhynchopetera Fairmaire belongs to Tenebrionidae, Coleoptera. It is a traditional folk medicinal insect in Yunnan Province. The defensive secretion of adults contains antibacterial active ingredients.This paper focused on reproductive physiology, fecundity, egg development and hatching, and feeding of B. rhynchopetera for a more systematic and comprehensive study of reproductive biology and feeding habits.1. Structure of reproductive system Anatomy of reproductive system showed that external genitalia of female adults mainly consist of gonostyle, coxite and paraproct. Internal genitalia mainly contain ovaries, fallopian tubes, spermatheca, and spermatheca was slender, gland was not found; External genitalia of male adults mainly contained aedeagus and tegmen which consisted of basal piece and paramera and etc. Internal genitalia mainly consisted of testis, seminal vesicle, accessory gland, vas deferens.2. Effects of factors on mortality and fecundity of adults Mainly focused on fecundity of experimental population, and effects of food, ecological factors, and population structure on oviposition. Fecundity of experimental population showed certain regulary vibration. Single-day mortality of adults had significant variation during the experiment, and the mortality displayed increasing trend with the time. Fecundity variation was more closely related to temperature than ratio of relative humidity to temperature and humidity. Adults fed on wheat straw, rice straw, and rice straw had low single-day fecundity.while adults fed on chicken feed, wheat bran and their mixture had high single-day high fecundity. Fecundity for newly hatched adults showed that variation of individual fecundity and mortality of adults fed on Wheat bran, cornmeal, chicken feed and wheat straw were different. Fecundity of adults fed on bran over time performed continuous irregular fluctuation, and daily fecundity was higher with no adult death. The stage of individual oviposition for adults fed on cornmeal focused in 2 months, and mortality was low. Preovipositon period of two above was about2 months. The stage of individual oviposition for adults fed on chicken feed focused in 1 month, and eggs were hard to find after October. Eggs of adults fed on Wheat straw were foud on December, and no eggs were found at the rest of time. Mortality of adults reared on Wheat bran and chicken feed was higher. Among the factors affecting fecundity, constant temperatures had significant effect on adult fecundity. Eggs of adults under constant temperatures of 10~30℃were found, and fecundity under 22℃reached to maximum. Extreme temperature like 30℃was not suitable for adults survival. Similar natural illumination was more influential on oviposition, while completely light and dark, long light and dark had no significant effects on egg production. Fecundity of adults in 2.10~10.52 /m~2 of population density was higher than in 31.56~52.61只/dm~2 .♀:♂=1:1 is the most suitable sex ratio for oviposition.3. Egg development and hatching Eggs of B. rhynchopetera were oval, and shell surface did not have special structures. Among factors affecting egg hatching, eggs laid in the range of 12 ~ 28℃may hatch out, while eggs laid in 8℃and 31℃without hatching. The developmental threshold temperature required for eggs was 10.08±0.93℃. While the effective accumulated temperature was 99.91±8.11 degree-day. Water content of substrate between 2% and 20% and 0~6 600 Lux were suitable for eggs hatching. Hatching rate was still higher treated in 10℃for 20d, and hatching rate had sudden drop 30d later, Hatching rate of eggs treated under 2℃, 4℃, 6℃and 8℃for 5d or longer decreased rapidly.4. Feeding habits Mainly focused on survey of habitats and indoor experiments. Survey showed that most of larvae and adults were found in the dark, damp habitats and relatively stable environment. Corn stalks, rice straw debris in the larval and adult habitats had a higher percentage of emergence, and feeding behavior of adults was described. Feeding experiment showed that relative consumption rate, food utilization rate, approximate digestibility, and efficiency of conversion of corn flour, chicken feed, wheat bran for 3rd to 9th instars larvae was higher than rice straw, wheat straw. Except for chicken feed having a lower approximate digestibility, Relative consumption rate, food utilization rate, approximate digestibility, and efficiency of conversion of chicken feed, corn flour, bean flour and wheat bran were relatively higher for adults, while those of rice bran, rice straw, corn stalks, wheat straw were lower. The performance of three stages of larvae was different in increased weight per larva, survival rate and development. The primary larvae were the most Vulnerable to food followed by middle aged and mature larvae. The primary and middle aged larvae were apt to take high protein, moderate fat, low crude fiber content of food such as corn flour, chicken feed and wheat bran, and larval weight gain was obvious, and had a higher survival rate. Whereas mature larvae not significant.