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Fireflies are a diverse group of bioluminescent beetles belonging to the family Lampyridae. Recent research on their diversity, evolution, behavior and conservation has greatly advanced our scientific understanding of these charismatic insects. In this review, we first summarize new discoveries about their taxonomic and ecological diversity, then focus on recent endeavors to identify and protect threatened fireflies around the world. We outline the main threats linked to recent population declines (habitat loss and degradation, light pollution, pesticide overuse, climate change and tourism) and describe relevant risk factors that predict which species will be particularly vulnerable to these threats. Although global coordination of firefly conservation efforts has begun only recently, considerable progress has already been made. We describe work by the IUCN SSC Firefly Specialist Group to identify species currently facing elevated extinction risks and to devise conservation strategies to protect them. To date, IUCN Red List assessments have been completed for 150 firefly taxa, about 20% of which face heightened extinction risks. The conservation status for many species has yet to be determined due to insufficient information, although targeted surveys and community science projects have contributed valuable new data. Finally, we highlight some examples of successful firefly habitat protection and restoration efforts, and we use the framework of the IUCN SSC Species Conservation Cycle to point out high-priority actions for future firefly conservation efforts.

How alien pests invade new areas has always been a hot topic in invasion biology. The spread of the Bactrocera dorsalis from southern to northern China involved changes in food sources. In this paper, in controlled conditions, we take Bactrocera dorsalis as an example to study how plant host transformation affects gut bacteria by feeding it its favorite host oranges in the south, its favorite host peaches and apples in the north, and feeding it cucumbers as a non-favorite host plant, thereby further affecting their fitness during invasion. The result showed that, after three generations of feeding on cucumbers, Bactrocera dorsalis took longer to develop as a larva while its longevity and fecundity decreased and pre-adult mortality increased. Feeding it cucumbers significantly reduced the overall diversity of gut microbiota of Bactrocera dorsalis . The relative abundance of Enterobacter necessary for survival decreased, while the Empedobacter and Enterococcus increased, resulting in decreased carbohydrate transport and metabolism and increased lipid transport and metabolism. Feeding Bactrocera dorsalis Empedobacter brevis and Enterococcus faecalis resulted in a 26% increase in pre-adult mortality and a 2-3 d increase in adult preoviposition period (APOP). Additionally, Enterococcus faecalis decreased the longevity of female and male adults by 17 and 12 d, respectively, and decreased fecundity by 11%. We inferred that the shifted plant hosts played an important role in posing serious harm to Bactrocera dorsalis invading from the south to the north. Therefore, after an invasion of Bactrocera dorsalis into northern China, it is difficult to colonize cucumbers for a long time, but there is still a risk of short-term harm. The findings of this study have established that the interactions between an insect's food source and gut bacteria may have an important effect on insect invasions.

Phthorimaea absoluta (Meyrick) is an invasive pest that has caused damage to tomatoes and other crops in China since 2017. Pest control is mainly based on chemical methods that pose significant threats to food safety and environmental and ecological security. Light-induced control, a green prevention and control technology, has gained attention recently. However, current light-trapping technology is non-specific, attracting targeted pests alongside natural enemies and non-target organisms. In this study, we characterized the phototactic behavior of tomato leaf miners for the development a specific light-trapping technology for pest control. In situ hybridization revealed opsin expression throughout the body. Furthermore, we investigated the tropism of pests (wild T. absoluta , Toxoptera graminum, and Bemisia tabaci ) and natural enemies (Nesidiocoris tenuis and Trichogramma pintoi ) using a wavelength-lamp tropism experiment. We found that 365 ± 5 nm light could accurately trap wild P. absoluta without trapping natural enemies and other insects. Finally, we analyzed the phototactic behavior of the mutant strains LW 2 (-/-) and BL (-/-) . LW2 and BL mutants showed significant differences in phototactic behavior. The LW2 (-/-) strain was attracted to light at 390 ± 5 nm and the BL (-/-) strain was unresponsive to any light. Our findings will help to develop specific light-trapping technology for controlling tomato leaf miners, providing a basis for understanding pest population dynamics and protecting crops against natural enemies.

Microorganisms can affect host reproduction, defense, and immunity through sexual or opportunistic transmission; however, there are few studies on insect reproductive organs and intestinal bacterial communities and their effects on mating. Tuta absoluta is a worldwide quarantine pest that seriously threatens the production of Solanaceae crops, and the microbial community within tomato leafminers remains unclear. In this study, 16s rRNA sequencing was used to analyze bacterial communities related to the reproductive organs and intestinal tracts of tomato leafminers (the sample accession numbers are from CNS0856533 to CNS0856577). Different bacterial communities were found in the reproductive organs and intestinal tracts of females and males. Community ecological analysis revealed three potential signs of bacterial sexual transmission: (1) Mating increased the similarity between male and female sex organs and intestinal communities. (2) The bacteria carried by mated individuals were found in unmated individuals of the opposite sex but not in unmated individuals of the same sex. (3) The bacteria carried by unmated individuals were lost after mating. In addition, the abundances of bacterial communities carried by eggs were significantly higher than those of adult worms. Our results confirm that mating leads to the transfer of bacterial communities in the reproductive organs and gut of tomato leafminers, and suggest that this community strongly influences the reproductive process.

Despite the importance of circadian rhythms in insect behavior, our understanding of circadian activity and the molecular oscillatory mechanism in parasitoid wasp circadian clocks is limited. In this study, behavioral activities expected to be under the control of the endogenous circadian system were characterized in an ectoparasitoid wasp, Pachycrepoideus vindemmiae . Most adults exhibited emergence between late night and early morning, while mating only occurred during the daytime, with a peak at midday. Oviposition had three peaks in the early morning, late day, or early night and late night. Additionally, we identified eight putative clock genes from P. vindemmiae . The quantitative PCR (qPCR) results indicate that most clock genes showed significant rhythmic expressions. Our comparative analysis of clock genes in P. vindemmiae and 43 other parasitoid wasps revealed that none of the wasps possessed the timeless and cry1 genes commonly found in some other insect species, suggesting that the circadian clock system in parasitoid wasps is distinct from that in other non-Hymenoptera insects such as Drosophila . Thus, this study attempted to build the first hypothetical circadian clock model for a parasitoid wasp, thus generating hypotheses and providing a platform for the future functional characterization of P. vindemmiae clock genes as well as those of other parasitoid wasps. Finally, these findings on P. vindemmiae circadian activity will aid the development of effective field release programs for biological control, which can be tested under field conditions.

Understanding the host-selection behavior of herbivorous insects is important to clarify their efficacy and safety as biocontrol agents. To explore the host-plant selection of the beetle Ophraella communa , a natural enemy of the alien invasive common ragweed ( Ambrosia artemisiifolia ), we conducted a series of outdoor choice experiments in cages in 2010 and in open fields in 2010 and 2011 to determine the preference of O. communa for A. artemisiifolia and three non-target plant species: sunflower ( Helianthus annuus ), cocklebur ( Xanthium sibiricum ), and giant ragweed ( Ambrosia trifida ). In the outdoor cage experiment, no eggs were found on sunflowers, and O. communa adults rapidly moved from sunflowers to the other three plant species. Instead, adults preferred to lay eggs on A. artemisiifolia , followed by X. sibiricum and A. trifida , although very few eggs were observed on A. trifida . Observing the host-plant selection of O. communa in an open sunflower field, we found that O. communa adults always chose A. artemisiifolia for feeding and egg laying. Although several adults (<0.02 adults/plant) stayed on H. annuus , no feeding or oviposition were observed, and adults quickly transferred to A. artemisiifolia . In 2010 and 2011, 3 egg masses (96 eggs) were observed on sunflowers, but they failed to hatch or develop into adults. In addition, some O. communa adults crossed the barrier formed by H. annuus to feed and oviposit on A. artemisiifolia planted in the periphery, and persisted in patches of different densities. Additionally, only 10% of O. communa adults chose to feed and oviposit on the X. sibiricum barrier. These findings suggest that O. communa poses no threat to the biosafety of H. anunuus and A. trifida and exhibits a robust dispersal capacity to find and feed on A. artemisiifolia . However, X. sibiricum has the potential to be an alternative host plant for O. communa .

Phoracantha semipunctata is a destructive invasive alien forest pest worldwide. It primarily damages the eucalyptus via adults, affecting almost all parts of the eucalyptus. Its larvae develop in almost all major tissues of the plant. Phoracantha semipunctata spreads both via the migration of adults and global trade in intercontinental translocation. Currently, this pest has spread to six continents worldwide, except Antarctica, resulting in substantial economic losses. Based on global occurrence data and environmental variables, the potential global geographical distribution of P. semipunctata was predicted using an ensemble model. The centroid shift, overlap, unfilling, and expansion scheme were selected to assess niche dynamics during the global invasion process. Our results indicated that the AUC and TSS values of the ensemble model were 0.993 and 0.917, respectively, indicating the high prediction accuracy of the model. The distribution pattern of P. semipunctata is primarily attributed to the temperature seasonality (bio4), mean temperature of the warmest quarter (bio10), and human influence index variables. The potential geographical distribution of P. semipunctata is primarily in western and southwestern Asia, western Europe, western and southern North America, southern South America, southern Africa, and eastern and southern Oceania. The potential geographical distribution of P. semipunctata showed a downward trend in the 2030s and the 2050s. The distribution centroid showed a general tendency to shift southward from the near-current to future climate. Phoracantha semipunctata has largely conserved its niche during the global invasion process. More attention should be paid to the early warning, prevention, and control of P. semipunctata in the countries and regions where it has not yet become invasive.

Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) are two invasive cryptic species of the Bemisia tabaci species complex (Hemiptera: Aleyrodidae) that cause serious damage to agricultural and horticultural crops worldwide. To explore the possible impact of climate change on their distribution, the maximum entropy (MaxEnt) model was used to predict the potential distribution ranges of MEAM1 and MED in China under current and four future climate scenarios, using shared socioeconomic pathways (SSPs), namely SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5, over four time periods (2021-2040, 2041-2060, 2061-2080, and 2081-2100). The distribution ranges of MEAM1 and MED were extensive and similar in China under current climatic conditions, while their moderately and highly suitable habitat ranges differed. Under future climate scenarios, the areas of suitable habitat of different levels for MEAM1 and MED were predicted to increase to different degrees. However, the predicted expansion of suitable habitats varied between them, suggesting that these invasive cryptic species respond differently to climate change. Our results illustrate the difference in the effects of climate change on the geographical distribution of different cryptic species of B. tabaci and provide insightful information for further forecasting and managing the two invasive cryptic species in China.

Bactrocera dorsalis (Hendel), as a quarantine pest in many countries and regions, has shown a trend of northward diffusion in the past century in China. In order to determine whether B. dorsalis will cause great harm to the dominant northern fruits, the age-stage two-sex life tables of peaches and apples were constructed, with oranges as the control. The results showed that the developmental rate, intrinsic rate of increase ( r ), and finite rate of increase ( λ ) on oranges and peaches were significantly greater than on apples. Additionally, the prediction of population growth 90 days after oviposition revealed that the whole population on oranges and peaches increased by 13,667.3 and 12,112.1 times, respectively, indicating that B. dorsalis is very likely to endanger peach orchards. The population increased on apples by 4311 times, though this is lower than that on oranges and peaches. Overall, peaches with high fitness similar to oranges are very suitable as a host for B. dorsalis and are likely to become a new favorable host, while apples may also become a potentially new host, though with lower fitness. Therefore, the most pressing solutions to take are population monitoring, comprehensive prevention, and control in the case of any potential large-scale outbreak of B. dorsalis in northern China.

Microorganisms in the guts of insects enhance the adaptability of their hosts with different lifestyles, or those that live in different habitats. Tuta absoluta is an invasive pest that is a serious threat to tomato production in China. It has quickly spread and colonized Xinjiang, Yunnan and other provinces and regions. We used Illumina HiSeq next generation sequencing of the 16S rRNA gene to study and analyze the composition and diversity of the gut microbiota of three geographical populations of T. absoluta . At the phylum level, the most common bacteria in T. absoluta across all three geographical populations were Proteobacteria and Firmicutes. An uncultured bacterium in the Enterobacteriaceae was the dominant bacterial genus in the T. absoluta gut microbiotas. There were no significant differences in alpha diversity metrics among the Spanish, Yunnan and Xinjiang populations. The structures of the gut microbiota of the three populations were similar based on PCoA and NMDS results. The results confirmed that the microbial structures of T. absoluta from different regions were similar.

Helicoverpa zea , a well-documented and endemic pest throughout most of the Americas, affecting more than 100 species of host plants. It is a quarantine pest according to the Asia and Pacific Plant Protection Commission (APPPC) and the catalog of quarantine pests for plants imported to the People's Republic of China. Based on 1781 global distribution records of H. zea and eight bioclimatic variables, the potential geographical distributions (PGDs) of H. zea were predicted by using a calibrated MaxEnt model. The contribution rate of bioclimatic variables and the jackknife method were integrated to assess the significant variables governing the PGDs. The response curves of bioclimatic variables were quantitatively determined to predict the PGDs of H. zea under climate change. The results showed that: (1) four out of the eight variables contributed the most to the model performance, namely, mean diurnal range (bio2), precipitation seasonality (bio15), precipitation of the driest quarter (bio17) and precipitation of the warmest quarter (bio18); (2) PGDs of H. zea under the current climate covered 418.15 × 10 4 km 2 , and were large in China; and (3) future climate change will facilitate the expansion of PGDs for H. zea under shared socioeconomic pathways (SSP) 1-2.6, SSP2-4.5, and SSP5-8.5 in both the 2030s and 2050s. The conversion of unsuitable to low suitability habitat and moderately to high suitability habitat increased by 8.43% and 2.35%, respectively. From the present day to the 2030s, under SSP1-2.6, SSP2-4.5 and SSP5-8.5, the centroid of the suitable habitats of H. zea showed a general tendency to move eastward; from 2030s to the 2050s, under SSP1-2.6 and SSP5-8.5, it moved southward, and it moved slightly northward under SSP2-4.5. According to bioclimatic conditions, H. zea has a high capacity for colonization by introduced individuals in China. Customs ports should pay attention to host plants and containers of H. zea and should exchange information to strengthen plant quarantine and pest monitoring, thus enhancing target management.

The position of the chromatin opening of Bemisia tabaci undergoes significant changes under different temperature stresses, and numerous regulatory factors have been found. In this study, we verified two key factors, cytochrome P450 4C1 and carbonic anhydrase 3. The results showed that invasive whiteflies had a significantly lower heat resistance after silencing BtCYP 4C1 and BtCar3 . In addition, whiteflies had a higher cold tolerance after silencing BtCYP 4C1 . These results indicate that BtCYP 4C1 and BtCar3 are key regulators in the temperature adaptation of B. tabaci . Moreover, they may be key factors in influencing the geographical distribution and dispersal of B. tabaci as an invasive species in China.

The whitefly, Bemisia tabaci (Gennadius) cryptic species Mediterranean (MED), is a destructive insect pest worldwide. In order to contribute to controlling B. tabaci by non-chemical methods, we examined the possibility of using a combination of trap/barrier crops and a parasitoid natural enemy in cotton. We performed field experiments using cantaloupe ( Cucumis melo ) and sunflower ( Helianthus annuus ) as trap crops and maize ( Zea mays ) as a barrier crop combined with periodic releases of the parasitoid Eretmocerus hayati in Hebei Province, Northern China. All treatments significantly reduced immature whitefly densities. Parasitism rate was significantly higher in cotton plots intercropped with sunflower and with perimeter-planted cantaloupe. Adult whitefly density was negatively related to parasitoid abundance and was significantly lower in cotton plots intercropped with maize than in the control plots. Intercropping was more effective than perimeter-planting at reducing B. tabaci densities and increasing yield. Parasitoid dispersal was not hampered by barrier crops, indicating that the two methods of control are compatible. These results contribute to the development of integrated pest management methods against this important pest.