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  • Monthly, Founded in 1950
    Supervisor:Chinese Academy of Sciences
    Sponsor:Institute of Zoology,Chinese Academy of Sciences
    The Entomological Society of China
    Domestic postal code: 2-153
    Foreign issuance code: Q61
    ISSN 0454-6296
    CN 11-1832/Q
Table of Content
20 November 2019, Volume 62 Issue 11
For Selected: View Abstracts Toggle Thumbnails
  • RESEARCH PAPERS
    Comparative analysis of cell dissociation and programmed cell death in the prothoracic gland and fat body of Bombyx mori during the laval-pupal metamorphosis
    LONG Shi-Hui, LI Yu, TIAN Ling, LI Sheng, LI Kang
    2019, 62(11):  1239-1249.  doi:10.16380/j.kcxb.2019.11.001
    Abstract ( 660 )   PDF (28074KB) ( 234 )   PDF(mobile) (28074KB) ( 88 )     
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     【Aim】 To detect the cell dissociation, autophagy and apoptosis in the prothoracic gland of the silkworm, Bombyx mori during metamorphosis, and to compare tissue demise in the prothoracic gland with that in the fat body, so as to uncover the similarities and differences of tissue remodeling during the larval-pupal metamorphosis. 【Methods】 With the prothoracic gland and fat body tissues of B. mori at the 5th instar, wandering, prepupal and pupal stages as the test materials, the cell dissociation in the prothoracic gland and fat body of B. mori was observed under light microscopy. The autophagy and apoptosis were observed after Lyso-Tracker and TUNEL staining, respectively, under fluorescence confocal microscopy. The expression profile of the autophagy marker gene Atg8 in the prothoracic gland was detected by qRT-PCR. The autophagosome in the prothoracic gland and fat body as well as the morphological changes of mitochondria in the prothoracic gland were observed under transmission electron microscopy. The Caspase3 activity was assayed using Capase3 enzyme assay kit. The expression profiles of Halloween genes Spo, Phm, Dib and Sad were detected by qRT-PCR. The ecdysone content in the prothoracic gland was detected by enzyme-immunoassay (EIA) aiming at furthermore determining the activity of the synthesis of ecdysone. 【Results】 During the transition from larva to pupa of B. mori, both the prothoracic gland and fat body began to undergo cell dissociation on the 1st day of pupation. Autophagy and apoptosis in the fat body began to appear at the wandering stage and day 1 of prepupa, respectively, and gradually increased. However, autophagy and apoptosis did not occur in the prothoracic gland until the 2nd day after pupation. In addition, the morphological changes of mitochondria and the transcription levels of Halloween genes were consistent with the activity of ecdysone synthesis in the prothoracic gland at the corresponding developmental stage of B. mori【Conclusion】 The time of tissue demise is different in different tissues of B. mori during metamorphosis. Cell dissociation appears on the 1st day after pupation in both the prothoracic gland and the fat body; however, autophagy and apoptosis in the prothoracic gland do not occur until the 2nd day after pupation, which may be related to its function in continuous synthesis of ecdysone. This study provides important scientific basis for the in-depth study of tissue demise during the larval-pupal metamorphosis in insects.
    Effects of heavy metal cadmium on the trehalose metabolism in Aedes albopictus (Diptera: Culicidae) larvae
    YU Ling-Yuan, WEI Ying, CHEN Xu-Min, DING Yan-Juan, HU Yao-Wen, TANG Bin, WANG Shi-Gui
    2019, 62(11):  1250-1259.  doi:10.16380/j.kcxb.2019.11.002
    Abstract ( 424 )   PDF (2014KB) ( 110 )   PDF(mobile) (2014KB) ( 37 )     
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    【Aim】 This study aims to understand the toxic effects of cadmium on Aedes albopictus and its adaptation to the extreme environment, and to reveal the possible effects of heavy metal stress on the occurrence of mosquitoes and disease transmission, so as to provide reference for the control of hygienic pests. 【Methods】 The late 3rd instar to early 4th instar larvae of A. albopictus with the same growth status in 320 mL disposable cups were acutely exposed to 200 mL prepared 50, 100, 200, 300, and 400 mg/L Cd2+ solution, respectively, for 12 h, and the larvae cultured in double distilled water were used as the control. The contents of trehalose, sucrose and total glycogen, and the activities of soluble trehalase (TRE1) and membrane-bound trehalase (TRE2) in the larvae at 12 h post treatment were determined by biochemical methods, and the relative expression levels of trehalose-6-phosphate synthase gene (TPS), TRE1 and TRE2 in these larvae were detected by qRT-PCR. 【Results】 The results showed that the trehalose content in A. albopictus larvae exposed to 200 and 300 mg/L Cd2+ solution for 12 h increased significantly, while the glucose content in larvae exposed to high concentrations of Cd2+ solution (300 and 400 mg/L) decreased significantly, as compared with the control. The acute treatment of different Cd2+ concentrations had no effect on the total glycogen content. The activities of TRE1 and TRE2 in larvae exposed to high concentrations of Cd2+ (300 and 400 mg/L) decreased significantly as compared with those in the control group. The relative expression level of TPS was the highest in the 300 mg/L Cd2+ treated group. The relative expression levels of TRE1 and TRE2 in larvae exposed to high concentrations of Cd2+ solution (300 and 400 mg/L) decreased significantly as compared with those in the control group. 【Conclusion】 The acute stress of Cd2+ up-regulates the expression of TPS gene in A. albopictus larvae when the Cd2+ concentration is lower than the LC50 value (217 mg/L), while the relative expression level of TRE gene and the TRE activity decrease,  thereby promoting the conversion of glucose to trehalose and resisting the Cd2+ stress by the production of trehalose. These results indicate that trehalose may play a role in heavy metal stress in A. albopictus larvae, which can improve the resistance to Cd2+ stress by trehalose synthesis.
    Differences in the expression of microRNAs related to wing-morph differentiation and their target genes in the winged and wingless pea aphid, Acyrthosiphon pisum (Hemiptera: Aphididae)
    YANG Zong-Lin, WANG Yi, MA Tian-Tian, HUO Chun-Yue, LIU Xiao, KAN Yun-Chao, LI Dan-Dan
    2019, 62(11):  1260-1270.  doi:10.16380/j.kcxb.2019.11.003
    Abstract ( 454 )   PDF (2712KB) ( 89 )   PDF(mobile) (2712KB) ( 20 )     
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    【Aim】 Previous studies revealed that many microRNAs (miRNAs) showed differential expression in the winged and wingless individuals of Sitobion avenae. This study aims to further clarify the exact stage, during which these miRNAs play roles, and to study the functions of miRNAs in the wing dimorphism of the parthenogenetic pea aphid, Acyrthosiphon pisum. 【Methods】 Five miRNAs (Let-7, miR-92a, miR-92b, miR-92a-1-pand miR-277) with significantly differential expression levels between winged and wingless individuals of S. avenae and their target genes related to ecdysone, insulin signaling pathway and wing development were selected, and the expression profiles of the miRNAs and their target genes in the 3rd-4th instar nymphs and adults of A. pisum as well as in winged and wingless individuals were detected by qPCR. The above target genes of miRNAs were also verified by dual luciferase activity assay. 【Results】 The expression profiling results indicated that the expression levels of the five miRNAs in adults of A. pisum were higher than those in nymphs, but the expression levels of the predicted target genes in the 4th instar nymphs were higher than those in adults, suggesting that miRNAs might play regulatory roles on their target genes in the adult stage. The expression levels of five miRNAs in winged individuals were higher than those in wingless ones of adults, especially for the miR-277, whose expression level in winged individuals was 7.5 times as high as that in wingless individuals of adults, then followed by Let-7 with threefold expression difference. Moreover, the expression difference of Let-7 between winged and wingless individuals of the 3rd instar nymphs was the most significant, its expression level in the winged individuals being 37.8 times as high as that in wingless ones, then followed by miR-277 with 7.6-fold expression difference. The expression patterns of predicted target genes abrupt and Foxo in the 3rd-4th instar nymphs and winged and wingless individuals of adults of A. pisum were opposite to those of miRNA Let-7 and miR-92b, respectively. Luciferase activity assay results showed that the target gene of Let-7 was abrupt, and the luciferase activity was extremely significantly decreased by 53% compared to the control after co-transfection with the mimics of Let-7. The interaction of other miRNAs with their target genes was not obvious. 【Conclusion】 We first found that the regulation of miRNAs on genes related to wing-morph differentiation of parthenogenetic A. pisum might occur during the adult stage. Let-7 may participate in the wing-morph differentiation of parthenogenetic aphids by regulating abrupt gene. This study lays a foundation for further exploring the mechanism of miRNAs participating in the wing dimorphism of parthenogenetic aphids.
    External morphology of the compound eye of Rhopalosiphum padi (Hemiptera: Aphididae) observed using scanning electron microscopy
    GUO Xin, PENG Xiong, YANG Zhuo-Lin, CHEN Mao-Hua
    2019, 62(11):  1271-1278.  doi:10.16380/j.kcxb.2019.11.004
    Abstract ( 576 )   PDF (12096KB) ( 126 )   PDF(mobile) (12096KB) ( 34 )     
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    【Aim】 This study aims to analyze the difference in the visual ability of Rhopalosiphum padi adults by comparing the external morphology of compound eyes of five different forms (winged virginoparae, wingless virginoparae, male, oviparae and gynoparae) 
    and wingless virginoparaes from holocyclic and anholocyclic life cycles, so as to provide a basis for further exploring the reproductive transformation and host searching mechanism of R. padi. 【Methods】 The external morphology and types of compound eyes in holocyclic and anholocyclic wingless virginoparae of R. padi and adults of five forms produced by the holocyclic aphids at low temperature (12℃) and short photoperiod (8L∶16D) were observed using scanning electron microscopy (SEM). 【Results】 The compound eye of adult R. padi is oval and located at the base of antenna in the head, without sensory hairs in the separation of ammatidias. There is no significant difference in the size (long axis diameter and short axis diameter) and arc height of compound eyes, the amount of ommatidia and the diameter of ommatidium between holocyclic and anholocyclic wingless virginoparae of R. padi. However, there are significant differences in the size and arc height of compound eyes, the amount of ommatidia, and the diameter of ommatidium among the five forms of R. padi with holocyclic life cycle at low temperature and short photoperiod. Male, winged virginoparae and gynoparae have larger compound eye area and a larger number of ommatidia than wingless virginoparae and oviparae, and oviparae has the smallest compound eye area and the lowest number of ommatidia.【Conclusion】 Combining the results of the five parameters, it was assumed that the visual ability of the five forms of R. padi from strong to weak is as below: male, winged virginoparae, gynoparae, wingless virginoparae and oviparae. The variances in compound eyes and ocelli might be associated with reproductive transformation and host searching of R. padi.
    Effects of acetamiprid on queen rearing in the western honey bee, Apis mellifera (Hymenoptera: Apidae)
    SHI Jing-Liang, JIANG Wu-Jun, YAN Wei-Yu, WU Xiao-Bo
    2019, 62(11):  1279-1285.  doi:10.16380/j.kcxb.2019.11.005
    Abstract ( 675 )   PDF (1174KB) ( 74 )   PDF(mobile) (1174KB) ( 13 )     
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    【Aim】 The aim of this study is to determine the effects of acetamiprid residue in queen cell on queen rearing in the western honey bee, Apis mellifera. 【Methods】 Queen cells were made with dissolved beeswax and by adding acetamiprid solution, and queen cells containing four different doses of acetamiprid (0, 10, 100 and 1 000 μg/kg beeswax) respectively were obtained. Meanwhile, a queen was restricted in a comb to lay eggs for 6 h. When the larvae hatched from those eggs, 1-day-old larvae were grafted into the above queen cells followed by feeding in bee colonies. On day 3 and day 6 after graft, the acceptance and capped rates of larvae in queen cells of each group were respectively counted. The number of emerged queens in all groups was recorded, and the birth weight, 
    thorax weight and thorax width of these queens were measured. The relative expression levels of vitellogenin gene (Vg) and hexamerin genes (hex110 and hex70b) in queen ovaries were detected by qPCR. 【Results】 The emergence rates of reared queens of A. mellifera in the acetamiprid dose groups of 100 μg/kg beeswax and 1 000 μg/kg beeswax were significantly lower than those in the 0 μg/kg beeswax dose group and the 10 μg/kg beeswax dose group, while there were no significant differences among other dose groups. There were no significant differences in the acceptance rate and capped rate of the larvae, and the birth weight, thorax weight and thorax width of emerged queens among the four dose groups. The results of qPCR showed that the relative expression levels of Vg gene decreased with the increasing concentrations of acetamiprid. Among them, the relative expression level of Vg in the 1 000 μg/kg beeswax dose group was significantly lower than those in the 10 μg/kg beeswax dose group and the 0 μg/kg beeswax dose group, but there was no significant difference between the other dose groups. Furthermore, the expression levels of hex110 and hex70b showed no significant difference among the four groups. 【Conclusion】 When the residue of acetamiprid in queen cells is over 100 μg/kg beeswax, it will generate negative effects on the process of queen rearing in  A. mellifera.
    Effects of feeding on diets containing components of different plants on the development and detoxifying enzyme activities in Pagiophloeus tsushimanus (Coleptera: Curculionidae) larvae
    LI Shou-Yin, CHEN Cong, LI Hui, FAN Bin-Qi, WANG Yan, HAO De-Jun
    2019, 62(11):  1286-1296.  doi:10.16380/j.kcxb.2019.11.006
    Abstract ( 734 )   PDF (2200KB) ( 107 )   PDF(mobile) (2200KB) ( 31 )     
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    【Aim】 This study aims to determine the effects of feeding on diets containing components of different plants on the growth and development and detoxification enzyme activitiesof Pagiophloeus
    tsushimanus larvae, so as to explore the roles of host plants on the feeding habits and resistance capabilities of P. tsushimanus.【Methods】 Three semi-artificial diets were prepared separately by using twig powders of three plant species of Lauraceae (Cinnamomum camphora, Cinnamomum chekiangensis, and Phoebe chekiangensis) as the plant components, and fed to P. tsushimanus larvae. The developmental duration, body weight, mortality rate, and pupation rate of the larvae fed on the semi-artificial diets were measured. After the 4th instar larvae were subjected to starvation for 12 h and then fed on the three semi-artificial diets, the temporal changes in the activities of detoxification enzymes[glutathione S-transferase (GST), carboxylesterase (CarE) and acetylcholinesterase (AChE)] were measured. 【Results】 There were significant differences in the developmental duration of P. tsushimanus larvae fed on the semi-artificial diets containing different plant components. The developmental duration of P. tsushimanus larvae fed on the semi-artificial diet containing C. camphora components was the shortest (100.13 d), while that of larvae fed on the semi-artificial diet containing P. chekiangensis components was the longest (123.33 d). In the larval stage, the mortality rate of P. tsushimanus larvae
    fed on the semi-artificial diet containing C. chekiangensis components was the highest (41.67%), while that of larvae fed on the semi-artificial diet containing C. camphora components was the lowest (10.00%). The pupation rate of P. tsushimanus larvae fed on the semiartificial diet containing C. camphora components was the highest (87.32%). The growth rate of larvae fed on the semi-artificial diet containing C. camphora components was also significantly higher than that of larvae fed on the semi-artificial diet containing C. chekiangensis or P. chekiangensis components. Meanwhile, there was no significant difference in the activities of GST and AChE between the larvae fed on the semi-artificial diets containing different plant components after being subjected to starvation for 12 h (P>0.05), while the CarE activity in the larvae fed on the semi-artificial diet containing C. camphora components increased significantly at 60 h after feeding. 【Conclusion】 The results suggest that P. tsushimanus has strong physiological adaptability to its natural host plant C. camphora, which may be related to its host specificity. Meanwhile, P. tsushimanus can adapt to different host plants by adjusting its growth and metabolic detoxification.
    Effects of fruit species and developmental stage on the larval boring rate and pupal weight of Grapholitha molesta (Lepidoptera: Tortricidae)
    YU Qin, DU En-Qiang, FENG Yun-Tao, GUO Xiao-Jun, ZHANG Run-Xiang, HAO Chi
    2019, 62(11):  1297-1304.  doi:10.16380/j.kcxb.2019.11.007
    Abstract ( 619 )   PDF (1145KB) ( 98 )   PDF(mobile) (1145KB) ( 31 )     
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    【Aim】 This study aims to clarify the relationship between the boring rate and pupal weight of the oriental fruit moth, Grapholitha molesta, on host fruits and host species and fruit developmental stage, so as to provide the theoretical basis for its prediction and control. 【Methods】 The boring rates of the newly hatched larvae of G. molesta on fruits of six varieties of three fruit species [Malus pumila (variety Gala apple), Amygdalus persica (varieties Dajiubao peach, Fengbai peach and Xiaguang nectarine), Pyrus bretschneideri (varieties Dangshan pear and Yuluxiang pear)] at different developmental stages and on four fruit varieties (Dajiubao peach, Fengbai peach, Dangshan pear and Yuluxiang pear) with different fruit statuses at 72 h post inoculating eggs were determined in the laboratory. The boring rates of the newly hatched larvae on different apple varieties (Gala apple, Fuji apple and Golden delicious apple) at different 
    developmental stages at 24 h and 72 h post inoculating eggs were compared. The pupal weight of G. molesta on Golden delicious apple, Fuji apple, Gala apple, Dangshan pear and Fengbai peach at different developmental stages were also determined. 【Results】 The boring rate of the newly hatched larvae of G. molesta at 72 h post inoculating eggs was the highest on Xiaguang nectarine, followed by on Gala apple, Dangshan pear, Yuluxiang pear, Dajiubao peach and Fengbai peach. Except Xiaguang nectarine, the developmental stage of the other five fruits significantly affected the boring rate of the newly hatched larvae. The boring rates of the newly hatched larvae at 72 h post inoculating eggs were 73.69% and 32.51% on young fruit and coloring fruit of Gala apple, respectively. The boring rates of the newly hatched larvae on Dajiubao peach, Fengbai peach, Dangshan pear and Yuluxiang pear at 72 h post inoculating eggs increased with the developmental stage of host fruits. The boring rates of the newly hatched larvae on the coloring fruits and mature fruits of three apple varieties significantly reduced with treatment time, but the boring rates on young fruits showed no significant change. Meanwhile, the host species and their developmental stage also affected the pupal weight of G. molesta, the female and male pupal weight of G. 
    molesta on mature peach and pear were significantly higher than those on immature ones, and coloring apples are unsuitable to the female and male pupal weight of G. molesta【Conclusion】 Fruit species and developmental stage significantly affect the boring rate 
    of the newly hatched larvae and the pupal weight of G. molesta, and the boring rate of the newly hatched larvae and the pupal weight of G. molesta on mature pear and peach are significantly higher than those on immature ones.
    Sequencing and phylogenetic analysis of the complete mitochondrial genome of Scythropus yasumatsui (Coleoptera: Curculionidae)
    ZHANG Feng, HONG Bo, WANG Yuan-Zheng, LI Ying-Mei, CHEN Zhi-Jie
    2019, 62(11):  1305-1314.  doi:10.16380/j.kcxb.2019.11.008
    Abstract ( 789 )   PDF (3132KB) ( 156 )   PDF(mobile) (3132KB) ( 44 )     
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    【Aim】 To explore the phylogenetic relationship between Scythropus yasumatsui and related species at the mitochondrial genome level. 【Methods】 Using Illumina MiSeq platform, the mitochondrial genome of S. yasumatsui was sequenced, and the genome sequences were assembled, annotated and characterized. Based on the nucleotide sequences of 13 protein-coding genes in the mitochondrial genome, the Bayesian and ML phylogenetic trees of 13 species of the family Curculionidae were constructed. 【Results】 The results showed that the sequence length of the mitochondrial genome of S. yasumatsui is 16 472 bp (GenBank accession no.: MF807224), including 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes and 2 non-coding regions, and the order of genes is consistent with that of the ancestral insect mitochondrial genes. All of the 13 PCGs use ATN as the start codon, and except that cob and nad1 use TAG as the termination codon, other 11 PCGs use TA(A) as the termination codon. All of the 22 tRNA genes were predicted to contain typical cloverleaf secondary structures except the gene trnS1 lacking DHU arm and changing anticodon from GCT to TCT. Phylogenetic tree based on the nucleotide sequences of 13 PCGs showed that the phylogenetic relationship among eight subfamilies of the family Curculionidae was: (((Cryptorhynchinae+(Curculioninae+Molytinae))+Platypodinae)+(Entiminae+Cyclominae))+Dryophthorinae+Scolytinae). 【Conclusion】 The phylogenetic tree based on the mitochondrial genome showed that among the 13 species of the family Curculionidae, S. yasumatsui and Naupactus xanthographus belonging to the subfamily Entiminae clustered together in the same branch of phylogenetic tree, and this result is consistent with that of traditional morphological classification.
    Observation on the morphological characteristics forage identification of Macrosiphoniella sanborni (Hemiptera: Aphididae) and the ultrastructure of its antennal sensilla(In English)
    ZHONG Jian, GUO Yan-Hong, XU Ting, LI Da-Wei, ZHANG Qi-Xiang, SUN Ming
    2019, 62(11):  1315-1324.  doi:10.16380/j.kcxb.2019.11.009
    Abstract ( 453 )   PDF (39992KB) ( 80 )   PDF(mobile) (39992KB) ( 22 )     
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    【Aim】 This study aims to observe the morphological characteristics of different ages and wing types of Macrosiphoniella sanborni and the ultrastructure of its antennal sensilla, so as to provide a reference for identification of different ages and a basis for study on the sensillal function and odour recognition mechanism of M. sanborni. 【Methods】 The whole-body morphology and ultrastructure of antennal sensilla of M. sanborni were observed under super-depth microscope and scanning electron microscopy (SEM), and the amount, distribution and size of antennal sensilla were statistically and comparatively analyzed. 【Results】 The results revealed that the qualitative indexes such as the wing bud, the projection angle of the end of abdomen and cauda can be utilized for accurate age identification of M. sanborni. Cauda shape can be used to distinguish adults from nymphs. The 3rd and 4th instar apterous nymph don’t have wing bud, while the alatae have. Wing bud shape can be used to distinguish alatae at the 3rd and 4th instars. Projection angle of the end of abdomen can be used to distinguish apterate at the 3rd and 4th instars. The antenna of M. sanborni is of the filiform type, contains five segments in the 1st and 2nd instars, and six segments in the rest. Five morphologically unique sensilla types were found and described: placoid sensillum, coeloconic peg, trichoid sensillum type I, trichoid sensillum type II and campaniform sensillum. Nymphs are different from adults in antennal segments, sensilla types and sensilla amounts. Differences also exist in the type, amount and array
    of sensilla on the antennae between alatae and apterae. 【Conclusion】 Different types of M. sanborni can be identified accurately by morphological indexes such as wing bud, projection angle of the end of abdomen and cauda. The antennal sensilla of different ages and wing types of M. sanborni differ in types, numbers and distribution positions, which may directly affect their behavioral performance on locating host plants.
    REVIEW ARTICLES
    Advances in the degradation of lignocellulose by microbes in fungus combs of fungus-cultivating termites
    LIANG Shi-You, WANG Cheng-Pan, YIN Xue-Jie, LI Hong-Jie, MO Jian-Chu
    2019, 62(11):  1325-1334.  doi:10.16380/j.kcxb.2019.11.010
    Abstract ( 817 )   PDF (4551KB) ( 133 )   PDF(mobile) (4551KB) ( 32 )     
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    The mechanism that termites and their symbiotic microorganisms synergistically degrade the lignocellulose-rich cell wall of plant has been well noticed and investigated by scientists around the world. Higher termites with fungus-cultivating ability have more diverse diets than lower termites. In this article, we reviewed the advances in the degradation of lignocellulose by microbes in fungus combs, so as to provide some references for a better understanding of the process and mechanism of the lignocellulose degradation in fungus combs, exploring the lignocellulosedegrading capacity of fungus combs, and developing biomimetic system of fungus combs to utilize biomass. Fungus-cultivating termites rely on the external symbiotic system, fungus combs, to degrade diverse plant materials. Funguscultivating termites cultivate their symbiotic fungi, Termitomyces spp., on the spongy structure, fungus combs built by plant materials. They develop specific food processing to degrade lignocelluloses gradually with the cooperation of symbiotic microbes. Younger workers ingest food foraged by older workers together with nodules of symbiotic fungi from combs, and excrete primarily feces to establish fresh combs on the surface of combs. In the gut passage of younger workers, Termitomyces release lignin-degrading enzymes to break the lignin barrier. Then, microbes including Termitomyces decompose lignin further, and turn polysaccharides to short chains, making the substrates of combs degraded from bottom to top. Finally, mature combs in the bottom are consumed by older workers. Endogenous enzymes of the midgut and microbes in the hindgut utilize the short chains. In conclusion, fungus combs and their microbes are fundamental for fungus-cultivating termites to utilize lignocelluloses efficiently. Studies of chemical changes in fungus comb indicated that fungus comb can decompose lignocelluloses and detoxify plant secondary compounds. Termitomyces might play a role in these processes, but the efficiency and specific functions vary in different genera of symbiotic fungi. Meanwhile, the specific functions of comb microbes require further investigation. Unlike lower wood-feeding termites which utilize lignocelluloses with the assistance of symbiotic microbes in the hindgut, fungus-cultivating termites degrade lignocelluloses based on fungus comb with two advantages, no requirement for anaerobic environment and fewer limits of food types. Imitation of fungus comb to process lignocelluloses is of great significance for the recycling use of dead wood and fallen leaves in forests.
    Mechanisms of sex determination in hymenopteran insects
    WANG Zi-Long, PAN Lu-Xia, HU Wan-Wan, LI Mang, ZENG Zhi-Jiang
    2019, 62(11):  1335-1343.  doi:10.16380/j.kcxb.2019.11.011
    Abstract ( 1325 )   PDF (1514KB) ( 280 )   PDF(mobile) (1514KB) ( 61 )     
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    The sex determination mechanisms of insects are diverse and complex. In hymenopteran insects, males are haploid and females diploid. In this article, we reviewed the modes and molecular mechanisms of sex determination in hymenopteran insects. Six patterns for sex determination of hymenopteran insects have been reported, including the complementary sex determination (CSD), multiple-locus hypothesis (multiple-locus CSD, ml-CSD), genomic imprinting, maternal effects, endosymbionts inducing female parthenogenesis, and paternal genome elimination (PGE). Among them, CSD is a widely accepted model of sex determination in hymenopteran insects represented by honeybees. Sex determination of honeybees is controlled by the cascade of csd→fem→dsx.
    SHORT COMMUNICATIONS
    Observation of the morphological and biological characteristics of Thaumantis hainana (Lepidoptera: Nymphalidae)
    GE Si-Xun, ZHOU Xing-Miao
    2019, 62(11):  1344-1350.  doi:10.16380/j.kcxb.2019.11.012
    Abstract ( 876 )   PDF (9199KB) ( 164 )   PDF(mobile) (9199KB) ( 58 )     
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    【Aim】 This study aims to determine the morphological and biological characteristics of different developmental stages of Thaumantis hainana and to define its host plant. 【Methods】 Female adults of T. hainana were collected from wild habitats and put into triangular paper envelopes for laying eggs. Its larvae were bred with the obtained eggs in an incubator under the conditions of 26℃, 40% relative humidity and 16L∶8D photoperiod with Phoenix loureirii leaves. The morphological characteristics of larvae were observed, and the body length and the width of head capsule of larvae of different instars were recorded. Some morphological characteristics of other developmental stages were also recorded. 【Results】 T. hainana exhibits complete metamorphosis with four developmental stages including egg, larva, pupa and adult. Eggs are round and have a smooth surface. Eggs are about 2.5-2.8 mm in diameter. The larva has 5 instars, and the body length and the width of head capsule of the larva increase gradually with the increase of larval instar. And it has hanging pupa. Adults do not show sexual dimorphism.【Conclusion】 This study primarily clarified the morphological and biological characteristics of different developmental stages of T. hainana, and defined P. loureirii as one of its host plants, enriching the basic data of T. hainana.
    CONTENTS
    Contents of Vol. 62 Issue 11
    2019, 62(11):  1350-1350. 
    Abstract ( 337 )   PDF (486KB) ( 53 )   PDF(mobile) (486KB) ( 12 )     
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