Host Preference Of Cryptolestes Ferrugineus(Stephens) And Cryptolestes Turcicus(Grouvelle)

Cryptolestes ferrugineus(Stephens) and Cryptolestes turcicus(Grouville) are two important secondary stored product pests, which occur seriously in storage environments due to the high temperature as well as high humidity in southern China in recent years. In order to understand their population dynamics, host preference of these two pests to different physical stored product properties was evaluated. Researches focused on the following two contents.First, observation on the host preference of these two target pests to the damaged stored products caused by primary pests Sitophilus oryzae(Linnaeus) and Rhizopenha dominica(Fabficius), and then analyzed the semiochemical relationship between these two kinds of pests. Secondary, tested the fitness of target pests in different substrate and size of stored products. Our main results was showed as followed:1. The semiochemical relationship between flat grain beetles and primary pests.On orientation behavior experiments, the tendency of flat grain beetles to the grains damaged by the primary stored product pests, Sitophilus oryzae(Linnaeus) and Rhizopenha dominica(Fabficius), was clearly observed. Volatiles from the grains damaged by the primary stored product pests were collected with solid phase microextraction technology, and analyzed with GC-MS. We found the chemical compounds of volatiles were not only different between damaged grains and intact grains, but among damaged grains damaged in various time. After GC-MS, We chose three specific compounds, γ-butyrolactone, strawberry acid, Oleamide and then mixed each of them with diet to test the orientation behavior of these flat grain beetles. Results showed that Cryptolestes turcicus(Grouville)did not significantly response to γ-butyrolactone and strawberry acid in any setting concentration, while famale Cryptolestes turcicus(Grouville)showed significant orientation behavior to Oleamide in a concentration between 0.01 ~ 1μg /10μL. But strawberry acid could repel both female and male Cryptolestes turcicus( Grouville) in a concentration of 10μL/10μL. There was no significant orientation behavior for male Cryptolestes ferrugineus(Stephens)to Oleamide,but in a concentration of 0.01μg /10μL, female exhibited a attraction to it. Female and male Cryptolestes ferrugineus(Stephens)responsed opposite to γ-butyrolactone in a concentration of 10μL/10μL, and male Cryptolestes ferrugineus( Stephens) showed some degree of avoidance of strawberry acid.2. The fitness of flat grain beetles in different substrate and size of stored products.We found a high population growth trend when Cryptolestes ferrugineus(Stephens)and Cryptolestes turcicus(Grouville)were reared on diet with additive yeast powder. This result indicated that additive yeast powder could significant improve the nutrition condition of stored products, which provide a good referrence for mutiplying their population in experiment. In the set size range of grains, their population structures and growth trend were similar, grain size bigger than 60 M had no effect on the fitness of the flat grain beetles. Both of them showed preference in smaller size grain, Cryptolestes ferrugineus( Stephens)preferred to live in the grain in a particle-size more than 50 %, while Cryptolestes turcicus( Grouville) had a higher adult population in whole-wheat flour. Our experiments also showed that adult Cryptolestes turcicus(Grouville)grow with a high population in the grains damaged by Sitophilus oryzae(Linnaeus) and Rhizopenha dominica(Fabficius), however, the increase of adult Cryptolestes turcicus( Grouville) population only occurred in grain damaged by Rhizopenha dominica(Fabficius)...