橘小实蝇（Bactrocera dorsalis (Hendel)）是柑橘类水果的毁灭性虫害。雌虫在成功交配后将卵产入成熟果实，导致其发霉腐烂失去经济价值，从而严重危害柑橘产业。自然条件下的橘小实蝇交配时间发生于黄昏时段，此时下降的光照强度是诱发其交配的关键条件。本研究首先通过设置0-30000lux共10种光照强度，从而确定何种光强能够明显调控橘小实蝇的交配行为。进一步选择了三种明显调控其行为的光照强度，测试了这些光照强度对雄虫求偶（振翅）及雌虫对性信息素2,3,5-三甲基吡嗪(2,3,5-trimethylpyrazine TMP)趋向性的影响。最后，在实验室中将强光和黑暗条件人工组合，测试其是否可以阻止橘小实蝇的交配，以期待为未来橘小实蝇的行为调控提供理论基础。结果表明，橘小实蝇成虫能在较低光照（<1000lux）正常交配，光强越强其交配数量越低，在光强达到20000lux以上时几乎无交配。较强光强明显减弱并推迟了雄虫的振翅行为与雌虫对TMP的趋向行为，不同的是雄虫在10000lux下仍有一定程度的振翅，而雌虫在此光强下对TMP几乎无趋向行为。成虫在无光情况下无交配行为，在此过程中雄虫无振翅行为而雌虫则对TMP失去趋向行为。进一步模拟不利光照条件，在强光10000lux一小时后持续无光，橘小实蝇成虫不进行交配。因此，光照条件是对橘小实蝇求偶交配的重要条件，未来可通过人工改变光强或其他手段干扰橘小实蝇成虫感弱光的分子靶标调控其求偶交配行为，从而开发新型绿色的橘小实蝇防控技术。

昆虫的气味受体（Odorant receprot，OR）是它们探测和识别与其生存密切相关的外部化学线索的关键。昆虫识别配体的特异性受体与一个广泛存在的气味受体共受体（Odorant receptor coreceptor，Orco）构成了异聚体复合体。本研究运用CRISPR/Cas9基因敲除技术对我国重大入侵害虫草地贪夜蛾的Orco基因进行了敲除，并揭示了该基因在气味受体调控的嗅觉行为中的重要作用。触角电位结果表明，Orco基因敲除之后，雌雄成虫对8种测试的植物挥发物和两种性信息素的电生理反应均丧失。然而，Orco基因对雌雄成虫交配行为的影响却存在明显的差异：雄虫Orco突变体的交配行为完全被干扰而雌虫Orco突变体的交配行为却不受影响。产卵实验结果表明，Orco突变体雌虫的产卵量比野生型雌虫的产卵量减少了24.1%。总之，这些结果表明了Orco是一个干扰草地贪夜蛾正常行为的优良靶标，并为害虫的防治提供了一种可行的方法。

本研究首先对豌豆修尾蚜触角转录组进行测序，并对鉴定到的气味受体（odorant receptors, ORs）基因进行了表达水平分析。随后，为了研究豌豆修尾蚜识别HIPVs的化学感受机制，利用11种已鉴定的蚜虫为害诱导的HIPVs对ORs的体外功能进行了研究。研究结果表明，在豌豆修尾蚜触角转录组中共鉴定出54个化学感受基因。注释到20个ORs基因，与豌豆蚜ORs进行氨基酸相似性分析，发现McraOR20和McraOR43分别与豌豆蚜的同源受体序列具有较高的保守性，且在触角中的表达量较高。因此对McraOR20和McraOR43的体外功能进行了研究，结果显示豌豆修尾蚜McraOR20与豌豆蚜中的同源基因ApisOR20均能特异地识别一种HIPV顺式-茉莉酮，而McraOR43对测试的11种HIPVs均无电生理反应。本研究证实了两种蚜虫的同源受体OR20均能特异性识别虫害诱导的植物挥发物顺式-茉莉酮，为发展蚜虫的行为调控策略提供了候选的嗅觉受体靶标。

本研究通过系统发育分析鉴定了蚜虫中一个保守的气味受体分支，并对这一支中豌豆蚜气味受体ApisOr23的功能进行了研究。序列分析的结果显示，豌豆蚜、大豆蚜和棉蚜的同源受体Or23序列相似性为94.28%。此外，我们对8种蚜虫同源受体Or23序列进行保守基序 (motif) 分析，进一步验证了Or23分支的高度保守性。组织特异性表达分析结果显示，豌豆蚜ApisOr23主要在触角高表达。随后，我们利用非洲爪蟾卵母细胞表达系统对ApisOr23进行体外功能研究，结果显示在所有测试的化合物中，ApisOr23对反-2-己烯醛、顺-2-己烯醇、庚醇、4’-乙基苯乙酮和乙酸乙酯这5种植物挥发物有明显的电生理活性。其中，反-2-己烯醛作为豆科植物的一种主要挥发物，能够最大程度地激活ApisOr23。本研究揭示了蚜虫中保守的气味受体Or23的功能，推测该受体在蚜虫寄主识别过程中起到重要作用。

Genes involved in chemosensation are essential for odorant-mediated insect behaviors.  Odorant receptors (ORs) bind and respond to pheromones and plant volatiles, regulating insect behaviors such as mating and host-plant selection, while ionotropic receptors (IRs), which are present at lower levels in insects than ORs, influence ion channels, especially in agricultural pests.  Asian corn borer, Ostrinia furnacalis, is the main pest of maize that causes huge economic losses in Asia.  Twenty-one OfurIRs have been identified, but none has been characterized.  In this study, tissue-specific expression profiling, phylogenetic analysis, and electroantennography (EAG) analysis were applied to characterize the evolution, expression, and the potential function of OfurIRs.  It was found that 20 OfurIRs were highly expressed in the antennae, except for OfurIR75p3, whereas 10 and nine OfurIRs were highly expressed in the proboscis and genitalia, respectively, indicating that these OfurIRs were functionally associated with feeding and oviposition.  EAG results showed that seven acids elicited responses in the antennae of O. furnacalis and that 2-oxopentanoic acid displayed a significant female-biased response.  Combined with the phylogenetic analysis, 10 OfurIRs in clade 4 were roughly predicted to be candidate receptors for 2-oxopentanoic acid and other tested acids.  These results provide basic information about OfurIRs and may help advance the knolwedge on the olfactory system of O. furnacalis. 

(E)-β-Caryophyllene is a sesquiterpene compound widely distributed in plants and functions in plant defence.  However, little is known about the sequence and function of (E)-β-caryophyllene synthase in lima bean (Phaseolus lunatus).  Here, we report a new full-length cDNA (PlCAHS) encoding (E)-β-caryophyllene synthase, a possible key enzyme of plant defence.  The cDNA of PlCAHS contains an open reading frame of 1 761 bp, encoding a protein of 586 amino acids with a predicted mass of 67.95 kDa.  The deduced amino acid sequence shows 52% identity with sesquiterpene synthase MtCAHS of Medicago truncatula.  Based on phylogenetic analysis, PlCAHS is classified as the terpene synthases (TPS)-a subfamily.  The recombinant enzyme, expressed in Escherichia coli, catalysed the formation of a major product (E)-β-caryophyllene (82%) and a minor product α-humulene (18%) from farnesyl diphosphate.  Real-time quantitative PCR (qRT-PCR) analysis found that the PlCAHS transcript was significantly up-regulated in leaves after treatment with spider mites and alamethicin (ALA), suggesting its ecological function in plant defence.  

Strategies for insect population control are currently targeting chemical communication at the molecular level. The diamondback moth Plutella xylostella represents one of the most serious pests in agriculture, however detailed information on the proteins mediating olfaction in this species is still poor. This species is endowed with a repertoire of a large number of olfactory receptors and odorant binding proteins (OBPs). As a contribution to map the specificities of these chemical sensors in the moth and eventually unravel the complexity of chemodetection, we have measured the affinities of three selected OBPs to a series of potential odorants. Three proteins are highly divergent in their amino acid sequences and show markedly different expression profiles. In fact, PxylOBP3 is exclusively expressed in the antennae of both sexes, PxylOBP9 is male specific and present only in antennae and reproductive organs, while PxylOBP19, an unusual OBP with nine cysteines, is ubiquitously present in all the organs examined. Such expression pattern suggests that the last two proteins may be involved in non-chemosensory functions. Despite such differences, the three OBPs exhibit similar binding spectra, together with high selectivity. Among the 26 natural compounds tested, only two proved to be good ligands, retinol and coniferyl aldehyde. This second compound is particularly interesting being part of the chemical pathway leading to regeneration of lignin, one of the defense strategies of the plant against insect attack, and might find applications as a repellent for P. xylostella and other pests.

The nicotinic acetylcholine receptors (nAchRs) are cholinergic receptors that form ligand-gated ion channels by five subunits in insect and vertebrate nervous systems. The insect nAChR is the molecular target of a class of insecticides, neonicotinoids. Here, we identified and cloned 11 candidate nAChR subunit genes in Acyrthosiphon pisum using genome-based bioinformatics combined modern molecular techniques. Most A. pisum nAChRs including α1, α2, α3, α4, α6, α8, and β1 show highly sequence identities with the counterparts of other insects examined. Expression profiles analysis showed that all subunit genes were expressed in adult head. At least two subunits have alternative splicing that obviously increase A. pisum nicotinic receptor diversity. This study will be invaluable for exploring the molecular mechanisms of neonicotinoid-like insecticides in sucking pests, and for ultimately establishing the screening platform of novel insecticides.