Font Size: a A A

Effects Of Environmental Factors On Four Kinds Of Stored Product Insect Pests

Posted on:2002-02-24Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y X DengFull Text:PDF
GTID:1103360032454877Subject:Agricultural Entomology and Pest Control
Abstract/Summary:PDF Full Text Request
The development of a sound stored product pest management program depends on a thorough understanding of pest biology and ecology. Therefore, effects of environmental factors such as temperature, humidity, food, and gas on development, reproduction, mortality of four kinds of stored product insect pests were researched as follows. 1. Effects of temperature and host on development and reproduction of the southern cowpea weevil, Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) The family Bruchidae at present consists of approximately 1300 species, distributing in every continent except Antarctic. The largest number of species lives in the tropical regions of Asia, Africa, Central and South America. More than 20 beetles of the family Bruchidae are serious pests of cultivated leguminous seeds (pulses) such as the southern cowp.a weevil, CaJIosobruchua chlnenais (L.); the bean weevil, Acanthoacelld.a obt.ctua Say; cowpea weevil, C. maculatus (Fab.); the Mexican bean beetle, Zabrotes sub fasciatus (Boheman). The southern cowp.a weevil, Calloaobruchus chln.naia (L.) is one of the moot serious stored pulse pests in R R. China. There are two different geographical populations in Chongqlng and Xichang In Southwest China. The two geographical populations have no morphological difference, but they damage different legume seeds in its original places. Broad bean, VIcia faba and soybean, Glymine max are Infested In Xlchang, whereas mung bean, Vigna radiatus, adzuki bean, V. angularls, and cowpea, V alnensis are infested in Chongqing. The difference of bionomics and ecologics of the two populations on mung bean ( Vigna radiatua) at six constant temperatures( 20,25,28,30,32, 35C) and 75%rh was researched. At thee. temperatures, th. developmental period of Chongqlng population from egg to adult (immature stage) were 55.9, 27.1, 23.6, 22.2, 20.6, and 25.0 days, respectively, whereas the developmental period of Xichang population 54.4,25.9,22.5,23.2, respectively. The eggs of Xichang population could not hatch at 35C. ANOVA showed that temperature affected the development period significantly (P<0.05). t-test Indicated there was significant difference of the combined immature stage between the two geographical populations (Pc0.05) at 25 and 32C. Th. minimum temperature for egg development and inside bean( larva .0. pupa) were 14.15C and 13.53 for Chongqing population and 12.05 C and 12.34 for Xichang population. Obviously, low temperature threshold differed between the two populations. A nonlinear Wang-Nang-Ding model describing the relationship between the developmental rate and temperature was conducted. Adult longevity and oviposition period declined linearly as temperature increased. Adult and ovipositon period of Chongqing population was longer than that of Xichang population at the same temperature. Within the range of 25-320C, temperature affected adult and oviposition period insignificantly (P>0.05), but significant difference existed between the two geographical population at 25, 28, 30 . Temperature also affected fertility significantly (PcO.05). The average oviposition (eggs per female) between the two geographical populations differed significantly at the same temperature (P0.05). The intrinsic rate of increase (Fm) was calculated accordin...
Keywords/Search Tags:Environmental factors, Callosobruchus chinensis (L.), Zabrotes subfasciatus (Boheman), Tribolium confusum Jacquelin du Val, Rhythopertha dominica (Fab.)
PDF Full Text Request
Related items