Prevalence of Wolbachia in 10 Tenebrionidae stored-product insects and spatiotemporal infection dynamics in Tribolium confusum(Jaquelin Du Val)(Coleoptera:Tenebrionidae)

Insect symbionts Wolbachia used for pest population control has focused on vector pest species and agricultural insects while rare reports in Chinese stored-product insect samples.In this paper,we surveyed the prevalence of Wolbachia using a PCR detection method in ten Tenebrionidae stored-product insects.Subsequently,the spatiotemporal Wolbachia infection dynamics in Tribolium confusum and Wolbachia elimination patterns using tetracycline treatment were investigated in detail by TaqMan®probe real-time quantitative PCR,and host reproductive fitness parameters were compared.T.confusum was the only Wolbachia infected species in all the surveyed species.Wolbachia infection density consistently increased with the development of T.confusumand plateaued at 3.7×107 wsp copies per individual insect at the young adult stage.Wolbachia densities in females were higher than that in males with a significant difference at the pupae stage and varied among different tissues and organs.Uninfected female beetles were completely incapable of producing mature progenies when crossed with Wolbachia infected males.Embryogenesis and egg hatch rate were specifically inhibited after Wolbachia elimination,while other traits,including the number of eggs,pupation rate and sex ratio,remained unaffected by tetracycline treatment.Our results showthat the TaqMan®probe qPCR is a reliable detection method for quantifying the density of Wolbachia as compared to qualitative detection of wsp gene by PCR and relatively quantified by real-time qPCR.The fitness results indicated that Wolbachia infection was not an obligate symbiont and benefited the host confused flour beetle.

Morphological and molecular identification of Xylocoris flavipes(Hemiptera:Anthocoridae)in southern China

During the investigation of natural enemy insects in grain depots,we've found an Anthocoridae insect accounted for a high proportion of natural enemy insects.We identify the enemy insects from morphology and molecular biology,so as to realize more accurate and effective control of storage pests by using the enemy insect.The images of the insects under the ultra-depth microscope(VHX-5000)showed that the insect adults were black brown in colour;the antennas of both the female and male had four segments,which increase in length sequentially from the base to the end,and had a length of 756.2μm for the female and 741.1μm for the male.The rostrums of both the female and the male insects were composed of three segments,the male's rostrum(596.8μm)were shorter than the female's(734.6μm),and the former two segments of the female's rostrum were significantly longer than the male's.The abdomen of the insect was bilaterally symmetrical,the female's abdomen was wider than the male,and the male insect had a dent between its eighth and ninth segments of the left abdomen,in which its male genitalia was located.In addition,the nymphs as a whole were tangerine in colour,and the eggs were elliptic with creamy white gloss and gridding patterns on the surface.The cytochrome C oxidase I(COI)gene sequences of the insects were identified by DNA barcoding technique,and the determined COI sequences were then submitted to the Genbank database for Blast alignment,and the results showed that the COI gene sequences had a high degree of similarity(99%)with X.flavipes records in the Genbank database.Therefore,we could determine that the insect was X.flavipes.In addition,the neighbor joining(NJ)was used to construct the evolutionary tree,and 1,000 repeated tests were conducted on the confidence levels of each branch.Based on the phylogenetic tree,we've found that X.flavipes belongs to Xylocoris genus.Based on morphology and COI sequence identification,we confidentiy determined that the collected natural enemy insect was X.flavipes.This is the first time that the identification of X.flavipes is being investigated from morphology and molecular biology.The research results are helpful to identify and distinguish the species of flower bugs,and beneficial for the better application of X.flavipes in biological control.