The complete mitochondrial （mt） genome of the plant bug, Apolygus lucorum, an important cotton pest, has been sequenced and annotated in this study. The entire circular genome is 14 768 bp in size and represents the...The complete mitochondrial （mt） genome of the plant bug, Apolygus lucorum, an important cotton pest, has been sequenced and annotated in this study. The entire circular genome is 14 768 bp in size and represents the smallest in presently known heteropteran mt genomes. The mt genome is encoding for two ribosomal RNA （rRNA） genes, 22 transfer RNA （tRNA） genes, 13 protein coding genes and a control region, and the order, content, codon usage and base organization show similarity to a great extent to the hypothetical ancestral model. All protein coding genes use standard initiation codons ATN. Conventional stop codons TAA and TAG have been assigned to the most protein coding genes; however, COIII, ND4 and ND5 genes show incomplete terminator signal （T）. All tRNA genes possess the typical clover leaf structure, but the dihydrouridine arm of tRNAser（A6N） only forms a simple loop. Secondary structure models of rRNA genes are generally in accordance with the former models, although some differences exist in certain parts. Three intergenic spacers have never been found in sequenced mt genomes of Heteroptera. The phylogenetic study based on protein coding genes is largely congruent with previous phylogenetic work. Both Bayesian inference and maximum likelihood analyses highly support the sister relationship ofA. lucorum and Lygus lineolaris, and Miridae presents a sister position to Anthocoridae.展开更多
Dicyphus maroccanus Wagner and Nesidiocoris tenuis Reuter （Hemiptera： Miridae） are 2 biological control agents in tomatoes. Through the crop seasons, a natural shift in the occurrence of both mirids in favor ofN. t...Dicyphus maroccanus Wagner and Nesidiocoris tenuis Reuter （Hemiptera： Miridae） are 2 biological control agents in tomatoes. Through the crop seasons, a natural shift in the occurrence of both mirids in favor ofN. tenuis has been observed at the end of the cropping cycle in eastern Spain. To better optimize their conservation, the reasons for the observed change, such as intraguild interactions （IGP） or the influence of environmental conditions, are worth elucidating. To do this, we first studied the IGP of adult females on heterospecific nymphs in the laboratory. We next studied exploitative competition between adults and nymphs of each species when feeding on Ephestia kueniella Zeller （Lepidoptera： Pyralidae） eggs in the laboratory. Finally, to analyze the competitive displacement between both mirids, we conducted a semifield experiment in which both predators were released together. All experiments were conducted at 2 temperature regimes （20 and 25~C）. Adult- to-nymph intraguild interactions occurred only at 25 ~C at very low levels, showing that N. tenuis attacked and consumed a greater proportion ofheterospecific nymphs. Nesidiocoris tenuis was a better competitor than D. maroccanus when feeding on the shared prey in the presence of its heterospecific nymph at 25 ~C. In semifield conditions, N. tenuis showed a competitive advantage over D. maroccanus at both temperatures. We conclude that there is not direct interference between both species, however, N. tenuis has a greater ability to outcompete, since it is best adapted to higher temperatures and it is able to remove food sources for D. maroccanus.展开更多
基金This research is supported by grants from the Special Fund for Agroscientific Research in the Public Interest （Nos. 201103012, 201103022, 201303024）, National Ba- sic Research Program of China （No. 2013CB 127600）, the Natural Science Foundation of Beijing （No. 6112013）, the special Foundation for Scientific Research （No. 2012FY 111100） and the National Natural Science Foun- dation of China （Nos. 1061160186, 31111140015）.
文摘The complete mitochondrial （mt） genome of the plant bug, Apolygus lucorum, an important cotton pest, has been sequenced and annotated in this study. The entire circular genome is 14 768 bp in size and represents the smallest in presently known heteropteran mt genomes. The mt genome is encoding for two ribosomal RNA （rRNA） genes, 22 transfer RNA （tRNA） genes, 13 protein coding genes and a control region, and the order, content, codon usage and base organization show similarity to a great extent to the hypothetical ancestral model. All protein coding genes use standard initiation codons ATN. Conventional stop codons TAA and TAG have been assigned to the most protein coding genes; however, COIII, ND4 and ND5 genes show incomplete terminator signal （T）. All tRNA genes possess the typical clover leaf structure, but the dihydrouridine arm of tRNAser（A6N） only forms a simple loop. Secondary structure models of rRNA genes are generally in accordance with the former models, although some differences exist in certain parts. Three intergenic spacers have never been found in sequenced mt genomes of Heteroptera. The phylogenetic study based on protein coding genes is largely congruent with previous phylogenetic work. Both Bayesian inference and maximum likelihood analyses highly support the sister relationship ofA. lucorum and Lygus lineolaris, and Miridae presents a sister position to Anthocoridae.
文摘Dicyphus maroccanus Wagner and Nesidiocoris tenuis Reuter （Hemiptera： Miridae） are 2 biological control agents in tomatoes. Through the crop seasons, a natural shift in the occurrence of both mirids in favor ofN. tenuis has been observed at the end of the cropping cycle in eastern Spain. To better optimize their conservation, the reasons for the observed change, such as intraguild interactions （IGP） or the influence of environmental conditions, are worth elucidating. To do this, we first studied the IGP of adult females on heterospecific nymphs in the laboratory. We next studied exploitative competition between adults and nymphs of each species when feeding on Ephestia kueniella Zeller （Lepidoptera： Pyralidae） eggs in the laboratory. Finally, to analyze the competitive displacement between both mirids, we conducted a semifield experiment in which both predators were released together. All experiments were conducted at 2 temperature regimes （20 and 25~C）. Adult- to-nymph intraguild interactions occurred only at 25 ~C at very low levels, showing that N. tenuis attacked and consumed a greater proportion ofheterospecific nymphs. Nesidiocoris tenuis was a better competitor than D. maroccanus when feeding on the shared prey in the presence of its heterospecific nymph at 25 ~C. In semifield conditions, N. tenuis showed a competitive advantage over D. maroccanus at both temperatures. We conclude that there is not direct interference between both species, however, N. tenuis has a greater ability to outcompete, since it is best adapted to higher temperatures and it is able to remove food sources for D. maroccanus.
