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Mitigating dengue incidence through advanced Aedes larval surveillance and control: A successful experience from Pakistan
- Sohail Abbas, Muneer Abbas, Aleena Alam, Niaz Hussain, Muhammad Irshad, Mudassar Khaliq, Xiao Han, Faisal Hafeez, Donato Romano, Ri Zhao Chen
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- Published online by Cambridge University Press:
- 21 May 2024, pp. 1-10
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Dengue fever is a viral disease caused by one of four dengue stereotypes (Flavivirus: Flaviviridae) that are primarily transmitted by Aedes albopictus (Skuse) and Aedes aegypti (L.). To safeguard public health, it is crucial to conduct surveys that examine the factors favouring the presence of these species. Our study surveyed 42 councils across four towns within the Bhakkar district of Punjab Province, by inspecting man-made or natural habitats containing standing water. First, door-to-door surveillance teams from the district health department were assigned to each council to surveillance Aedes species and dengue cases. Second, data collection through surveillance efforts, and validation procedures were implemented, and the verified data was uploaded onto the Dengue Tracking System by Third Party Validation teams. Third, data were analysed to identify factors influencing dengue fever cases. The findings demonstrated the following: (1) Predominantly, instances were discerned among individuals who had a documented history of having travelled beyond the confines of the province. (2) Containers associated with evaporative air coolers and tyre shops were responsible for approximately 30% of the Aedes developmental sites. (4) Variability in temperature was responsible for approximately 45% of the observed differences in the quantity of recorded Aedes mosquito developmental sites. (5) Implementation of dengue prevention initiatives precipitated a 50% reduction in Aedes-positive containers, alongside a notable 70% decline in reported cases of dengue fever during the period spanning 2019 to 2020, while the majority of reported cases were of external origin. Aedes control measures substantially curtailed mosquito populations and lowered vector-virus interactions. Notably, local dengue transmission was eliminated through advanced and effective Aedes control efforts, emphasising the need for persistent surveillance and eradication of larval habitats in affected regions.
Considering climate change impact on the global potential geographical distribution of the invasive Argentine ant and little fire ant
- Tong Li, Pei Jiang, Jingyuan Liu, Jingquan Zhu, Shouqi Zhao, Zhihong Li, Mina Zhong, Chen Ma, Yujia Qin
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- Published online by Cambridge University Press:
- 16 May 2024, pp. 1-12
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The Argentine ant (Linepithema humile) and the little fire ant (Wasmannia auropunctata) are among the top 100 invasive alien species globally, causing significant ecological and economic harm. Therefore, it is crucial to study their potential geographic distribution worldwide. This study aimed to predict their global distribution under current and future climate conditions. We used distribution data from various sources, including CABI, GBIF, and PIAKey, and key climate variables selected from 19 environmental factors to model their potential geographic distribution using MaxEnt. The AUC values were 0.925 and 0.937 for L. humile and W. auropunctata, respectively, indicating good predictive performance. Suitable areas for L. humile were mainly in southern North America, northern South America, Europe, central Asia, southern Oceania, and parts of Africa, while W. auropunctata suitable areas were mostly in southern North America, most of South America, a small part of Europe, southern Asia, central Africa, and some parts of Oceania. Under climate change scenario, suitable areas for L. humile increased, while highly suitable areas for W. auropunctata decreased. The top four countries with the largest areas of overlapping suitable habitat under current climate were Brazil, China, Australia, and Argentina, while under future SSP585 climate scenario, the top four countries were Brazil, China, Indonesia, and Argentina. Some countries, such as Estonia and Finland, will see an overlapping adaptation area under climate change. In conclusion, this study provides insight into controlling the spread and harm of L. humile and W. auropunctata.
Biology of Euwallacea interjectus, an emerging poplar pest, reared on an ambrosia beetle artificial diet and medium of fungal symbiont
- Langlang Zheng, Shengchang Lai, Yang Zhou, Nan Jiang, Dejun Hao, Lulu Dai
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- Published online by Cambridge University Press:
- 08 May 2024, pp. 1-11
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Euwallacea interjectus, a recently discovered pest in poplar plantations, poses a significant economic threat due to its role in causing widespread tree mortality. This pest's cryptic behaviour has hindered research and control efforts, making laboratory rearing a valuable tool for studying its development and biology. We investigated the development period and biological characteristics of E. interjectus using artificial diets and fungal medium. Our findings revealed that the development time for eggs, larvae, and pupae averages approximately 6, 18, and 6 days, respectively. Notably, first and second instar larvae displayed peak moulting periods at 3.45 ± 0.64 SD and 7.92 ± 1.77 SD days, respectively. Furthermore, we measured head capsule widths of postmolt larvae, yielding values of 318.02 ± 7.38 SD μm for first-instar larvae, 403.01 ± 11.08 SD μm for second-instar larvae, and 549.54 ± 20.74 SD μm for third-instar larvae. Our research also uncovered a positive correlation between the number of progeny (eggs, larvae, pupae, and adults) and the mean length of the gallery system. Interestingly, the haplodiploid reproductive strategy did not significantly affect the number of offspring produced by the foundress. Additionally, we observed that foundresses displayed higher fecundity when subjected to nutrient-rich diets as compared to nutrient-poor diets. Our results will deepen our understanding of the biology of E. interjectus and provide criteria for larval instar classification. Additionally, managing nutrient availability within the colony could be considered a viable approach to regulating population size.
It's time for Africa – hidden diversity of the Aphidius colemani species group (Hymenoptera, Braconidae, Aphidiinae) south of the Sahara
- Jelisaveta Čkrkić, Andjeljko Petrović, Korana Kocić, Ana Mitrovski-Bogdanović, Željko Tomanović
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- Published online by Cambridge University Press:
- 07 May 2024, pp. 1-11
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Aphidius colemani is an important biological control agent, used in greenhouses and open fields against aphid pests. Despite this economical importance, A. colemani, along with A. transcaspicus and A. platensis, has gone through a complex taxonomical history. The three species have only recently gained status as separate species again, comprising the morphologically defined Aphidius colemani species group. Other than sporadic records probably as a consequence of escape from greenhouses, the A. colemani species group members prefer warmer regions and there are numerous records from South America, Southern Europe and Asia. Based on slide-mounted material collected in the period 1964–2001 in Africa, we describe five new species belonging to this group, and report A. colemani, A. transcaspicus and A. platensis from several African countries. This data opens questions about the origin of the group and presents potential for the diversification of biological control agents against aphid pests.
Biodiversity of mosquitoes (Diptera: Culicidae) in phytotelmata from Car Nicobar Island, India
- I. P. Sunish, Addepalli Prem Kumar, Kannan Thiruvengadam, A. N. Shriram
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- Published online by Cambridge University Press:
- 06 May 2024, pp. 1-12
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The Culicidae mosquito family breeds in various natural and artificial water bodies. Phytotelmata are plant structures that hold water and are used by many mosquito species during their life cycle. Mosquitoes are disease vectors, and phytotelmata play an important role in harbouring them. Investigating these phytotelmata will facilitate to develop appropriate site specific vector control strategy. Approximately 750 phytotelmata in 16 locations on Car Nicobar Island was examined. Mosquito larvae were collected from different habitats such as tree holes, root holes, leaf axils, and bamboo stumps. On average, the number of larvae per 10 ml of water ranged from 0.003 to 3.833. Among the 16 mosquito species identified, there were vectors of malaria (Anopheles sundaicus), dengue (Aedes aegypti and Aedes albopictus) and filariasis (Culex quinquefasciatus), belonging to seven genera. The most common phytotelmata were coconut trees (17.5%) followed by Java apple trees (10.3%) and bamboo stumps (7.1%). The most widespread mosquito species was Aedes edwardsi, followed by Aedes malayensis and Ae. albopictus, and the per cent of phytotelmata that contained these species were 42.6, 22.0, and 16.8% respectively. Anopheles mosquitoes had the highest container index (6.1%) in root holes, while Aedes and Culex mosquitoes were more frequently found in bamboo stumps. The alpha biodiversity indices indicated that the mosquito population in Car Nicobar Island was highly diverse (S = 16; DMg = 36.9). Tree holes showed the highest diversity, as all 16 species were collected from them. Assessment of phytotelmata, there is a significant relationship observed between mosquito genus, village, habitat, and tree families, on the remote island of Car Nicobar. Considering the presence of disease-transmitting mosquito vectors in the phytotelmata, these habitats should be considered when implementing control measures to eliminate mosquito-borne infections.
Rapid and specific detection of Pentastiridius leporinus by recombinase polymerase amplification assay
- Omid Eini, René Pfitzer, Mark Varrelmann
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- Published online by Cambridge University Press:
- 06 May 2024, pp. 1-8
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Pentastiridius leporinus (Hemiptera: Cixiidae) is the main vector of an emerging and fast spreading sugar beet disease, the syndrome ‘basses richesses’ (SBR), in different European countries. The disease is caused by the γ-3-proteobacterium ‘Candidatus Arsenophonus phytopathogenicus’ and the phytoplasma ‘Candidatus Phytoplasma solani’ which are exclusively transmitted by planthoppers and can lead to a significant loss of sugar content and yield. Monitoring of this insect vector is important for disease management. However, the morphological identification is time consuming and challenging as two additional cixiid species Reptalus quinquecostatus and Hyalesthes obsoletus with a very close morphology have been reported in sugar beet fields. Further, identification of females and nymphs of P. leporinus at species level based on taxonomic key is not possible. In this study, an isothermal nucleic acid amplification based on recombinase polymerase amplification (RPA) was developed to specifically detect P. leporinus. In addition, real-time RPA was developed to detect both adults (male and female) and nymph stages using pure or crude nucleic acid extracts. The sensitivity of the real-time RPA for detection of P. leporinus was comparable to real-time PCR, but a shorter time (< 7 min) was required. This is a first report for real-time RPA application for P. leporinus detection using crude nucleic acid templates which can be applied for fast and specific detection of this vector in the field.
SlCarE054 in Spodoptera litura (Lepidoptera: Noctuidae) showed direct metabolic activity to β-cypermethrin with stereoselectivity
- Li Xu, Hongyu Liu, Bo Li, Guangling Li, Runqiang Liu, Dongzhi Li
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- Published online by Cambridge University Press:
- 06 May 2024, pp. 1-9
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Carboxylesterases (CarEs) is an important detoxification enzyme system in phase Ⅰ participating in insecticides resistance. In our previous study, SlCarE054, a CarEs gene from lepidoptera class, was screened out to be upregulated in a pyrethroids and organophosphates resistant population. Its overexpression was verified in two field-collected populations of Spodoptera litura (Lepidoptera: Noctuidae) resistant to pyrethroids and organophosphates by qRT-PCR. Spatiotemporal expression results showed that SlCarE054 was highly expressed in the pupae stage and the digestive tissue midgut. To further explore its role in pyrethroids and organophosphates resistance, its metabolism activity to insecticides was determined by UPLC. Its recombinant protein showed significant metabolism activity to cyhalothrin and fenvalerate, but not to phoxim or chlorpyrifos. The metabolic activity of SlCarE054 to β-cypermethrin showed stereoselectivity, with higher metabolic activity to θ-cypermethrin than the enantiomer α-cypermethrin. The metabolite of β-cypermethrin was identified as 3-phenoxybenzaldehyde. Further modelling and docking analysis indicated that β-cypermethrin, cyhalothrin and fenvalerate could bind with the catalytic triad of the 3D structure of SlCarE054. The interaction of β-cypermethrin with SlCarE054 also showed the lowest binding energy. Our work provides evidence that SlCarE054 play roles in β-cypermethrin resistance in S. litura.
Predicting the current and future suitable distribution range of Trilocha varians (Walker, 1855) (Lepidoptera: Bombycidae) in China
- Qianqian Qian, Danping Xu, Wenkai Liao, Zhihang Zhuo
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- Published online by Cambridge University Press:
- 03 May 2024, pp. 1-10
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Trilocha varians is one of the major pests of Ficus spp. Based on 19 bioclimatic variables provided by the Worldclim, our study analysed the suitable distribution areas of T. varians under current and future climate changes (SSP1-2.6, SSP2-4.5, SSP5-8.5) for two periods (the 2050s and 2090s) using the maximum entropy algorithm (MaxEnt) model. Key environmental variables affecting the geographic distribution of T. varians were also identified, and the changes in the area of suitable range under current and future climate changes were compared. The results showed that the key environmental variables affecting the distribution of T. varians were temperature and precipitation, comprising annual mean temperature (bio1), temperature seasonality (standard deviation × 100) (bio4), precipitation of driest month (bio14), and precipitation of driest quarter (bio17). Under the current climatic conditions, the suitable distribution area of T. varians is within the range of 92°13′E–122°08′E, 18°17′N–31°55′N. The current high, medium, and low suitable areas for T. varians predicted by the MaxEnt model are 14.00 × 104, 21.50 × 104, and 71.95 × 104 km2, of which the high suitable areas are mainly distributed in southern Guangdong, southwestern Guangxi, western Taiwan, Hong Kong, and Hainan. Under different future climatic conditions, some of the high, medium, and low suitability zones for T. varians increased and some decreased, but the mass centre did not migrate significantly. The Pearl River Basin is predicted to remain the main distribution area of T. varians.
Risk of spread of the Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) in Ghana
- Kodwo Dadzie Ninsin, Philipe Guilherme Corcino Souza, George Correa Amaro, Owusu Fordjour Aidoo, Edmond Joseph Djibril Victor Barry, Ricardo Siqueira da Silva, Jonathan Osei-Owusu, Aboagye Kwarteng Dofuor, Fred Kormla Ablormeti, William K. Heve, George Edusei, Lakpo Koku Agboyi, Patrick Beseh, Hettie Arwoh Boafo, Christian Borgemeister, Mamoudou Sétamou
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- Published online by Cambridge University Press:
- 03 May 2024, pp. 1-20
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The impact of invasive species on biodiversity, food security and economy is increasingly noticeable in various regions of the globe as a consequence of climate change. Yet, there is limited research on how climate change affects the distribution of the invasive Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera:Liviidae) in Ghana. Using maxnet package to fit the Maxent model in R software, we answered the following questions; (i) what are the main drivers for D. citri distribution, (ii) what are the D. citri-specific habitat requirements and (iii) how well do the risk maps fit with what we know to be correctly based on the available evidence?. We found that temperature seasonality (Bio04), mean temperature of warmest quarter (Bio10), precipitation of driest quarter (Bio17), moderate resolution imaging spectroradiometer land cover and precipitation seasonality (Bio15), were the most important drivers of D. citri distribution. The results follow the known distribution records of the pest with potential expansion of habitat suitability in the future. Because many invasive species, including D. citri, can adapt to the changing climates, our findings can serve as a guide for surveillance, tracking and prevention of D. citri spread in Ghana.
Peat mine as a threat to the diversity of aquatic beetles (Coleoptera: Dytiscidae) in the protected area Nature 2000 in Poland
- Katarzyna Kuczyńska, Robert Czerniawski, Tomasz Krepski
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- Published online by Cambridge University Press:
- 29 April 2024, pp. 1-8
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Peatlands, shaped by centuries of human activities, now face a primary threat from mining activities. Vulnerable to drainage and hydrological instability, peatland areas encounter challenges that compromise their ecological integrity. This study hypothesised that permanent water reservoirs within mines could serve as refugia for water beetles from adjacent areas prone to drying in the summer. Employing standard methods, including entomological scraping and water traps, samples were collected. Results revealed that, in most cases, water beetles exhibited a preference for the Nature 2000 area untouched by mining. Despite unfavourable conditions, the Nature 2000 area showcased a more diverse water beetle fauna. Remarkably, the selected Nature 2000 area, despite its identified degradation based on flora, remained a biodiversity hotspot for peatland water beetle fauna. The study underscores the significance of assessing insects, particularly beetles, as rapid responders to environmental changes. This evaluation holds crucial implications for peatland restoration planning and decision-making regarding mining investments in proximity to peatland areas.
Lateralised courtship behaviour and its impact on mating success in Ostrinia furnacalis (Lepidoptera: Crambidae)
- Sohail Abbas, Aleena Alam, Muneer Abbas, Arzlan Abbas, Jamin Ali, Menno Schilthuizen, Donato Romano, Chen Ri Zhao
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- Published online by Cambridge University Press:
- 19 April 2024, pp. 1-9
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Lateralisation is a well-established phenomenon observed in an increasing number of insect species. This study aims to obtain basic details on lateralisation in courtship and mating behaviour in Ostrinia furnacalis, the Asian corn borer. We conducted laboratory investigations to observe lateralisation in courtship and mating behaviours in adult O. furnacalis. Our goal was also to detect lateralised mating behaviour variations during sexual interactions and to elucidate how these variances might influence the mating success of males. Our findings reveal two distinct lateralised traits: male approaches from the right or left side of the female and the direction of male turning displays. Specifically, males approaching females from their right side predominantly exhibited left-biased 180° turning displays, while males approaching females from the left-side primarily displayed right-biased 180° turning displays. Notably, left-biased males, executing a 180° turn for end-to-end genital contact, initiated copulation with fewer attempts and began copulation earlier than their right-biased approaches with left-biased 180° turning displays. Furthermore, mating success was higher when males subsequently approached the right side of females during sexual encounters. Left-biased 180° turning males exhibited a higher number of successful mating interactions. These observations provide the first report on lateralisation in the reproductive behaviour of O. furnacalis under controlled laboratory conditions and hold promise for establishing reliable benchmarks for assessing and monitoring the quality of mass-produced individuals in pest control efforts.
The bug-killer fly Gymnosoma rotundatum (L.) (Diptera: Tachinidae) forms the respiratory funnel independently of the host's immune response
- Shin Komagata, Kota Ogawa, Takuji Tachi
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- Published online by Cambridge University Press:
- 17 April 2024, pp. 1-9
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In internal parasitism, the respiration strategy within the host's body is as essential as evading attack from the host's immune system. Tachinid flies are parasitoids of terrestrial arthropods, mostly insects, during their larval stage. To obtain oxygen while living in the host body, they build a cylindrical structure known as the respiratory funnel at the aperture opened by the tachinid larva on the host integument or trachea. These funnels can be divided morphologically into sheath and cone types. Previous research on sheath-type funnels revealed that they are derived from the encapsulating substance produced by the host's immune system. In contrast, the cone-type funnels cover part of the body of the larval tachinid and may be constructed independently from the host immune system. To determine the mechanisms of cone-type funnel formation, histological observations were carried out on Gymnosoma rotundatum (L.) (Diptera: Tachinidae), which possesses this type of funnel. The respiratory funnel of G. rotundatum was found to be derived from the tube-shaped faeces wrapped with the peritrophic membrane and excreted by the fly larva, not from host tissue or haemocytes. Additionally, secretory glands putatively involved in the funnel formation were discovered around the larval anal plate of G. rotundatum. A comparison of funnel types within Tachinidae revealed that Phasiinae and Dexiinae have cone-type funnels, which may be created by the same mechanism as in G. rotundatum. These new findings suggest that funnel formation that does not use the host immune system is relevant to tachinid phylogeny.
First report of Leucinodes africensis and Leucinodes laisalis on Solanum aethiopicum and Solanum melongena in farmer's fields in southern Ghana
- Ken Okwae Fening, Stanley Osafo Okyere, Ethelyn Echep Forchibe, Babatoundé Ferdinand Rodolphe Layodé, Tegbe Enyonam Richmond, Lakpo Koku B. A. Agboyi, Kwame Afreh-Nuamah, Francis Onono Wamonje
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- Published online by Cambridge University Press:
- 17 April 2024, pp. 1-15
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The eggplant fruit and shoot borer (EFSB) is a devastating pest of eggplants (Solanum aethiopicum L. and Solanum melongena L.) in Ghana, causing significant economic losses. Although initially thought to be the Leucinodes orbonalis Guenee species found in Asia, recent European and Mediterranean Plant Protection Organization reports suggest its absence in Africa. However, eight Leucinodes species have been recently described in Africa, including two new species, Leucinodes africensis sp. n. and Leucinodes laisalis Walker, which were intercepted in eggplant fruits exported from Ghana to the United Kingdom. Despite the reported absence of L. orbonalis in Africa, it remains on the pest list of Ghana as a species known to attack eggplants. To accurately determine the identity of the EFSB complex occurring on eggplant in Southern Ghana, molecular and morphological taxonomic tools were employed, and adult male populations were monitored in on-farm conditions. Our results revealed the presence of two EFSB species, L. africensis and L. laisalis, in the shoot and fruits of eggplants, with L. africensis being the dominant species and widely distributed in Southern Ghana. Notably, L. africensis males were attracted to the pheromone lure of L. orbonalis despite the two species being biologically distinct. This study provides crucial information on correctly identifying the EFSB species attacking eggplants in Southern Ghana and has significant implications for developing management interventions against these pests and their effects on international eggplant trade.
Long-term suitability of an alternative host for rearing the sugarcane stalk borer parasitoid Tetrastichus howardi
- Natalia Carolina Bermúdez, Nataly de la Pava, Juan Sebastián Dueñas Cáceres, Christian Sherley Araújo da Silva-Torres, Jorge Braz Torres
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- Published online by Cambridge University Press:
- 17 April 2024, pp. 1-12
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The continuous utilisation of an alternative host may influence parasitoid performance across successive generations due to conditioning in natal hosts. Tetrastichus howardi (Olliff) has successfully been reared using Tenebrio molitor L. pupae as a feasible alternative host. However, the extended rearing of T. howardi on this alternative host may impact the biological features of the parasitoids. Parasitoids were reared using T. molitor pupae for 30 consecutive generations. Quality criteria were assessed during the generations F5, F15, and F30, offering pupae of the target pest, Diatraea saccharalis (Fabr.), and compared with the F0 generation (parasitoids reared in D. saccharalis pupae). Criteria included assessments of parasitism performance, host selection, and wing form variation in the parasitoid wasps. Additionally, we examined the fecundity of T. howardi females that emerged from both hosts, considering their age, egg loading before and after one oviposition, as well as parasitism of sugarcane stalk borer pupae. Rearing T. howardi using pupae of T. molitor did not affect its biological traits or preference for the target pest for 30 generations. After parasitism, the parasitoid left the host pupa inside the stalk, and one oviposition was enough to kill D. saccharalis pupae and obtain viable parasitoid progeny. Female sexual maturation and egg loading occurred 72 and 96 h after parasitoid emergence. Egg-loading recovery after parasitism did not happen within 24 h. T. howardi can be reared for up to 30 generations using alternative hosts without compromising its parasitism performance or egg loading.
Asymmetrical reproductive interference between two sibling species of tea looper: Ectropis grisescens and Ectropis obliqua
- G.-H. Zhang, Z.-J. Yuan, K.-S. Yin, J.-Y. Fu, M.-J. Tang, Q. Xiao
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- Published online by Cambridge University Press:
- 11 August 2016, pp. 1-8
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Ectropis grisescens Warren and Ectropis obliqua (Prout) are two morphologically similar sibling species with overlapping ranges. In this study, manipulative laboratory experiments were conducted to examine the possibility of reproductive interference in sympatric populations of E. grisescens and E. obliqua and the potential consequences of the mating interaction. Our results showed that the presence of males or females of different species could incur mating interference and significant reduction of F1 offspring. The reduction was not significant relevant to the initial relative abundance of E. grisescens and E. obliqua. Detailed observations of mating opportunity showed that female mating frequencies of both species were not significantly affected by the absolute species density, but the mating success of E. obliqua females with conspecific males depended on species ratio. In addition, adding males to the other species resulted in lower number of offspring suggesting that the males’ behaviour might be linked with mating interference. Males of both E. grisescens and E. obliqua could interfere the intraspecific mating of the other species, but the impact of the mating interference differed. These combined data indicated that asymmetric reproductive interference existed in E. grisescens and E. obliqua under laboratory conditions, and the offspring of the mixed species were significantly reduced. The long term outcome of this effect is yet to be determined since additional reproductive factors such as oviposition rate and progeny survival to adulthood may reduce the probability of demographic displacement of one species by the other in overlapping niches.