Entomological Research最新文献

Grylloprimevala jilina Zhou & Ren is the third extant species of Grylloblattodea to be found in China. To understand the various physiological functions of the sensilla on the main sensory organs of G. jilina during its vital activities, this study used scanning electron microscopy to examine the sensilla morphology on its appendages and analyze their abundance and distribution on the antennae. The filiform antennae comprise scape, pedicel and flagellum. The maxillary palps comprise three segments, and the cerci contain four appendages in total. Altogether, 11 morphologically distinct sensilla types were identified on three organs: apertures; Böhm bristles (BB); sensilla auricillica (SA), sensilla basiconica (SB), sensilla campaniformia (SCa), sensilla capitulum (SCap), sensilla chaetica (SCh), sensilla coeloconica (SCo), sensilla filiform (SF) and sensilla trichodea (ST); and spines. Studies of the antennae of G. jilina have revealed that, except in some cases, the types and abundances of the sensilla gradually show a trend of diversification and enrichment as the antennae segments are extended forward. Functional predictions for the 11 morphologically distinct sensilla suggest that they include chemoreceptors, mechanoreceptors and temperature or humidity receptors. As wall-pore sensilla, SA, SB, SCo and ST could be involved in the perception of chemical signals emitted from their living environment. In addition, as mechanical receptors, BB, SCa, SCh and SF may be involved in the perception and feedback of mechanical stimuli. Our findings provide an essential insight into this rare and national first-class protected insect, and provide a necessary theoretical basis for studying the phylogeny of Grylloblattodea.

Frankliniella intonsa Trybom is a common flower-inhabiting thrips species and an economically important pest of numerous horticultural and agricultural crops. Olfactory cues are important for thrips to find host plants. In this study, the olfactory behavioral responses of F. intonsa to volatiles from five Rosa chinensis cultivars (Samantha, Zeprti, Queen Elizabeth, Golden Scepter, and Witte Koster) were tested in Y-tube and six-arm olfactometer experiments. Then the volatile components of the R. chinensis flowers were analyzed by SPME coupled with gas chromatography–mass spectrometry (GC–MS). Both female and male thrips showed significant preferences for volatiles from the five R. chinensis cultivars compared with clean air (CA). However, according to the six-arm olfactometer bioassays, female F. intonsa adults were better than male thrips at recognizing the odor stimulation and showed the strongest olfactory preference for Samantha, followed by Zeprti, Queen Elizabeth, Golden Scepter, and then Witte Koster. SPME-GC–MS analysis identified 56, 53, 53, 57, and 60 components in the volatile profiles of Samantha, Zeprti, Queen Elizabeth, Golden Scepter, and Witte Koster, respectively. Eugenol (12.53%) was the most abundant volatile compound in cultivar Witte Koster, ɑ-pinene was the most abundant compound in Samantha (18.26%) and Zeprti (23.73%), and phenylethyl alcohol was the most abundant in Queen Elizabeth (30.10%) and Golden Scepter (31.33%). Therefore, the olfactory responses of F. intonsa to different R. chinensis cultivars demonstrated that host-related volatiles play an important role in thrip host-searching. Future mitigation approaches, for example, attractant traps, could still be used for key monitoring and control of this pest.

The evolution of pest resistance to insecticidal proteins from Bacillus thuringiensis (Bt) restricts the sustainable application of transgenic Bt crops, and exploring other ecofriendly insecticides to efficiently suppress Bt-resistant populations is thus urgently needed. The plant secondary metabolite rutin possesses pest resistance effects and plays an important role in plant resistance to pests, but the effect of rutin on pink bollworms is unclear. We investigated the effects of rutin on two types (Bt-susceptible and Bt-resistant) of pink bollworms (Pectinophora gossypiella). Rutin had significant inhibitory effects on the growth, development, and oviposition of both Bt-susceptible and Bt-resistant strains. For both strains, rutin ingestion by larvae did not significantly affect larval survival at 7 days after treatment or egg hatching rate but significantly decreased pupation rate, eclosion rate, neonate-to-adult survival, pupal weight and eggs per female and significantly prolonged larval developmental periods, and the effect increased with increasing rutin content. The response to rutin ingestion was basically consistent between Bt-resistant and Bt-susceptible strains, indicating that the Bt-resistant strain did not exhibit cross-resistance to rutin. These results provide a reference basis for green control and resistance management of pink bollworms and may be used as a component of comprehensive management for this pest.

Wolbachia, an endosymbiotic bacterium, has a significant impact on the reproductive biology and pathogen transmission capabilities of various arthropods, including mosquitoes. This study aimed to assess the prevalence of Wolbachia in Culex molestus, a vector mosquito species, in South Korea. Mosquito samples were collected from different locations and taxonomically identified. Individual mosquito DNA was extracted, and polymerase chain reaction (PCR) was conducted targeting the Wolbachia surface protein gene (wsp) and three multi-locus sequence typing (MLST) (gatB, hcpA, and ftsZ) genes. Gel electrophoresis was performed to determine the prevalence of Wolbachia by analyzing PCR products. Our findings revealed that Wolbachia was present in 100% of the tested Culex mosquitoes from South Korea, with one major Wolbachia strain (supergroup B) detected using the wsp gene and subgrouping determined with the gatB as well as hcpA, and ftsZ. These results underscore the widespread occurrence of Wolbachia in Cx. molestus mosquito within the studied region, thus suggesting the potential for leveraging this endosymbiont to devise novel strategies for mosquito-borne disease control. Future research should investigate the influence of Wolbachia on mosquito biology and vector competence in South Korea.

Frankliniella occidentalis is an important pest globally and causing serious damage to vegetables and flowers. Exogenous phytohormones can induce host plant resistance and reduce loss caused by pests. This study investigated the effects of detoxification enzyme activity and related gene expression in F. occidentalis after feeding on jasmonic acid (JA)- and ethylene (ET)-cotreated faba bean plants. Change in MFO activity was nonsignificant at 6 and 48 h after F. occidentalis fed on the cotreated faba bean plants; but significantly decreased at 24 h compared with control group. The peak activities of carboxylesterase (CarE) and glutathione S-transferase (GSTs) at 48 h showed a significant increase of 2.31-fold and 1.15-fold, respectively. Additionally, CarE and GSTs activities remained consistent and significantly higher than those of the control group at the remaining timepoints. The expression levels of the P450 genes CYP4-3, CYP6-2, and CYP6-3 in F. occidentalis were significantly upregulated at 6 h and those of CYP6-2 and CYP4-5 were significantly upregulated at 24 h. The expression of the CarE gene CL4503.Conting2 was significantly upregulated at 6 and 48 h that of the GSTs gene FoGSTd1 was significantly upregulated at 24 and 48 h, that of FoGSTs1 was significantly upregulated at all three timepoints, and that of GSTs1 was only significantly upregulated at 6 h and significantly downregulated at 24 and 48 h. These results indicate that F. occidentalis can adjust the activity and gene expression of detoxification enzymes to adapt to the defense response of faba bean induced by JA and ET.

Honey, which is medicinally very important, is the major product of honeybees. The role of the honeybee queen is crucial in maintaining the health and stability of the colony as it is responsible for reproducing and maintaining the population of the hive. Productive and healthy honeybee queens ensure the success of the colony. Various factors, such as parasites, diseases, lack of food and habitat, climate change, genetic defects, and exposure to pesticides, can lead to the failure of the queen bee. Therefore, applications of artificial queen-rearing techniques in beekeeping positively affect the growth of honeybee queens with desirable characteristics. This current research was conducted at the KUST Model Bee Form of Kohat University of Science and Technology, on Apis mellifera honeybee colonies during spring 2021. In this study, the Doolittle grafting method was used for the rearing of the A. mellifera queen bee. A total of 230 larvae of different ages (12–24, 24–48, and 48–72 h old larvae were used for grafting. Of these 230 grafted larvae, the number of queen cup cells accepted was 139 and the number of emerged queen cup cells was 82. The queen cell acceptance rate was significant (P = 0.000; P < 0.05). The effect of larval age, and the addition of royal jelly in queen cup cells prior to grafting, on the acceptance rate of queen cup cells was also studied. Young larvae, that is, from 12–24 up to 48 h of age, showed high acceptance rates. The acceptance rates of 12–24, 24–48 and 48–72 h old larvae were 76.7%, 55.7% and 20.0%, respectively. This shows that a queen produced from a 1 day old larva has the highest acceptance rate. The addition of royal jelly into queen cup cells before grafting showed the highest larval acceptance rate in March and April. In this study the acceptance rate for queen cup cells with wet and dry grafting were 89.5% and 46.1%, respectively. However further studies are recommended to determine the effect of all factors on the morphology of the queen.