Instar Nymphs Research Articles

APLICACIÓN DE TÉCNICAS INMUNOLÓGICAS DE DEPREDACIÓN EN TRIATOMA INFESTANS (HEMIPTERA: REDUVIIDAE)

An immunological technique used to study the interrelation between prey and predator is described.Immune serum was obtained by injecting extracts of eggs of Triatoma infestans of one week of age into rabbits and rats. The presence of antibodies was verified with Ouchterlony test.The specificity of the serum and antiserum was tested in extracts of all stages of Triatoma infestans, in eggs and lst. instar nymphs of Rhodnius proxilus and in adults of Periplaneta americana.Only triatomines showed a positive reaction in Ouchterlony test, indicated by clear precipitation bands. No positive reaction was obtained for Periplaneta americana.These results suggest that the antiserum used presents a marked specificity towards the subfamily Triatominae. This immunological method can ben used, therefore, in the study of triatominophagy by cockroaches and in the study of the role of commonpredator of triatomines and cockroaches.

Unraveling the Sexual Dimorphism of First Instar Nymphs of the Giant Stick Insect, Cladomorphus phyllinus Gray, 1835, from the Atlantic Forest, Brazil.

The first instar nymphs, both male and female, of the giant stick insect Cladomorphus phyllinus Gray, 1835 were carefully described and measured, revealing a remarkable sexual dimorphism that is considered rare among insects and is poorly explored in the order Phasmida. The studied F1 nymphs originated in captivity from eggs laid by a coupled female specimen collected in the Atlantic Forest in the vicinity of Petrópolis city, state of Rio de Janeiro, Brazil. The first instar nymphs of C. phyllinus were measured and illustrated in high-resolution photographs to show the general aspects and details of sexually dimorphic traits, making clear the phenotypic differences in the sexes. A total of 100 nymphs were kept alive until morphological sexual dimorphism was confirmed and quantified. All recently hatched first instar nymphs were separated based on the presumed male and female characteristics, i.e., the presence and absence of the suture in the metanotum in the males and females, respectively, had their sexes confirmed in 100% of the specimens as previously assigned. These results confirm this new morphological trait, which here is named "alar suture" as sex-specific in the first instar nymphs, a novelty in this stage of development of sexual differentiation. In addition, the distinct conformations of the last three abdominal sternites of both sexes were recorded.

Molecular screening of local Indonesian rice to identified resistant varieties against brown planthopper (Nilaparvata lugens) attacks

Abstract. Puspito AN, Tigara MRN, Putra SID, Rozzita N, Ubaidillah M. 2023. Molecular screening of local Indonesian rice to identified resistant varieties against brown planthopper (Nilaparvata lugens) attacks. Biodiversitas 24: 5503-5512. Brown planthopper (Nilaparvata lugens Stal) is a significant pest in rice (Oryza sativa L.), resulting in a yield loss of around 20-80%. Environmentally friendly control involves looking for potential resistance in local Indonesian rice, because it’s naturally resistant to pests and diseases and has several tolerant mechanisms for dealing with stress. However, the resistance potential of local rice has not been widely studied, so it is necessary to carry out screening to identify the resistance possessed by local Indonesian rice and continue with molecular analysis to validate the presence of brown planthopper resistance genes. This study aimed to determine the possible resistance level of 24 Indonesian local rice varieties to brown planthopper pests. The research was conducted at the Agrotechnology Laboratory, Faculty of Agriculture, University of Jember. In June-November 2022. This research included screening using the third instar nymph brown planthopper, preference testing to analyze the preference level for each local rice variety and molecular analysis using six BPH markers (RM 247, RM 6869, RM 19291, g12140-2, RM 3331, and RM 5479) with the MAS technique. The results showed that in the preference test, Lahoten, Fatuk Masin, and Sukamandi had a higher preference value than other local Indonesian rice. In the screening, the average local rice with very resistant criteria is Leukat Medan, while those with moderately vulnerable criteria are Sukamandi. In the molecular analysis of local Indonesian rice, the Aek Sibundong variety had the most resistance, while the Kapuas and Sukamandi varieties had the least resistance.

Luring Triatomines (Hemiptera: Reduviidae) into a Trap: Aliphatic and Aromatic Aldehydes as Attractants of Triatoma infestans.

To assess the attracting capacity of aliphatic and aromatic aldehydes to Triatoma infestans, the Chagas disease vector, laboratory tests were conducted using individual compounds and mixtures to evaluate their potential use in baited traps for intradomicile population dynamics analysis. Commercial samples of hexanal, nonanal, and benzaldehyde were used at 95% purity. The experiments were performed at 25°C and 65% relative humidity using two procedures: a glass arena with filter papers impregnated with 1, 5, and 10 μL of the tested compounds and a double-choice olfactometer. Attraction was scored positively if the insect remained more than 30 seconds on one of the surfaces. The results of the study showed that hexanal was attractive to females at higher concentrations (5-10 μL; P < 0.0001), and IV instar nymphs were only attracted at the highest concentration (10 μL; P < 0.01). Nonanal was attractive to IV instar nymphs at 1 and 5 μL (P < 0.0001), whereas males and females were more attracted at 1 μL (P < 0.01 and P < 0.05, respectively). Benzaldehyde showed significant differences with respect to controls, attracting females at low concentrations (1 μL; P < 0.0001) and IV instar nymphs at 5 and 10 μL (P < 0.0001 and P < 0.001, respectively). In the olfactometer, the 60:40 hexanal/nonanal mixture was the most effective. In conclusion, this study demonstrated that the aliphatic and aromatic aldehydes studied here, both individually and in mixtures, could be used as effective attractants for T. infestans in intradomicile-baited traps. These results suggest that mixtures of these compounds could be implemented in field trials for Chagas disease surveillance.

Exposure to heat stress leads to striking clone-specific nymph deformity in pea aphid.

Climatic changes, such as heatwaves, pose unprecedented challenges for insects, as escalated temperatures above the thermal optimum alter insect reproductive strategies and energy metabolism. While thermal stress responses have been reported in different insect species, thermo-induced developmental abnormalities in phloem-feeding pests are largely unknown. In this laboratory study, we raised two groups of first instar nymphs belonging to two clones of the pea aphid Acyrthosiphon pisum, on fava beans Vicia faba. The instars developed and then asexually reproduced under constant exposure to a sub-lethal heatwave (27°C) for 14 days. Most mothers survived but their progenies showed abnormalities, as stillbirths and appendageless or weak nymphs with folded appendages were delivered. Clone N116 produced more deceased and appendageless embryos, contrary to N127, which produced fewer dead and more malformed premature embryos. Interestingly, the expression of the HSP70 and HSP83 genes differed in mothers between the clones. Moreover, noticeable changes in metabolism, e.g., lipids, were also detected and that differed in response to stress. Deformed offspring production after heat exposure may be due to heat injury and differential HSP gene expression, but may also be indicative of a conflict between maternal and offspring fitness. Reproductive altruism might have occurred to ensure some of the genetically identical daughters survive. This is because maintaining homeostasis and complete embryogenesis could not be simultaneously fulfilled due to the high costs of stress. Our findings shine new light on pea aphid responses to heatwaves and merit further examination across different lineages and species.

Bioefficacy of engineered Beauveria bassiana with scorpion neurotoxin, LqqIT1 against cotton mealybug, Phenacoccus solenopsis and cowpea aphid, Aphis craccivora.

Cotton mealybug, Phenacoccus solenopsis (Tinsley) and cowpea aphid Aphis craccivora (Koch) are notorious polyphagous, hemipteran sap sucking insect pests. A recombinant toxin gene 'LqqIT1' from the scorpion Leiurus quinquestriatus quinquestriatus (Ehrenberg) was cloned in the pAL1 fungal expression vector and then expressed in the entomopathogenic fungus Beauveria bassiana (Balasmo) using genetic modification techniques. The genetically transformed B. bassiana strain (BbLqqIT1-3) and its un-transformed parent strain (Bb-C) were screened to infect the third instar nymphs of P. solenopsis and first instar nymph of A. craccivora through leaf treatment and topical application (spray) method at 1 * 107 spores per ml concentration. The recombinant strain BbLqqIT1-3 was highly pathogenic against A. craccivora but non pathogenic to P. solenopsis. BbLqqIT1-3 induced 72 and 43.33% mortality in A. craccivora nymphs 96 h after leaf treatment and topical application, respectively. The nymphs of A. craccivora infected with BbLqqIT1-3 displayed classical neurotoxic symptoms such as sluggishness, solublize and liquification of the body. Crude soluble toxin protein, BbLqqIT1a-CSE and Bb-WT-CSE was extracted from the BbLqqIT1-3 and Bb-C, respectively using ammonium sulphate precipitation method, and their oral toxicity was analyzed at 5 µg/ml concentration. The survival of the studied insects was negatively affected by the crude soluble toxin extracts. The LT50 values of BbLqqIT1a-CSE against P. solenopsis and A. craccivora were 22.18 and 17.69 h, respectively. Exposure to crude soluble toxin extracts also accounted for the imbalance of ionic concentrations in the hemolymph of treated insects such as hyperpotassemia (3.53-8.18 meq/ml) in the P. solenopsis and hypopotassemia (7.52-0.47 meq/ml) in A. craccivora. The transformed fungus BbLqqIT1-3 strain exhibited promising results in invitro study.

Toxicity risk assessment of flupyradifurone for the predatory pirate bug, Orius strigicollis (Poppius) (Heteroptera: Anthocoridae), a biological control agent of Diaphorina citri Kuwayama (Hemiptera: Liviidae)

Diaphorina citri Kuwayama (Hemiptera: Liviidae), commonly known as the Asian citrus psyllid, is a prominent citrus tree pest that serves as a vector for Asian huanglongbing (HLB). The substantial costs incurred by the citrus industry as a consequence of this disease have spurred considerable interest in the combined control of D. citri using insecticides and natural enemies. However, the successful implementation of such integrated pest management strategies is dependent on ensuring the compatibility of using natural enemies in the presence of insecticides. In this regard, we evaluated the lethal and sublethal effects of flupyradifurone on Orius strigicollis (Poppius) (Heteroptera: Anthocoridae), an important predatory biological control agent, in which we assessed the risk of exposure to flupyradifurone under both in- and off-field scenario. The median lethal rate (LR50) value of flupyradifurone against O. strigicollis (9.089 g a.i. ha−1), was found to be significantly lower than the maximum field recommended rate (MFRR, 170 g a.i. ha−1). Additionally, at 0.254 g a.i. ha−1, flupyradifurone was established to significantly prolong the developmental duration of O. strigicollis from the first to third instar nymphs. Although we detected no significant difference in the survival of immature O. strigicollis subjected to 0.064 g a.i. ha−1 and control treatments, survival was significantly lower in 0.127 and 0.254 g a.i. ha−1 treatments. Moreover, whereas there were no significant differences in adult longevity between the 0.127 g a.i. ha−1 and control treatments, we recorded a significant reduction in fecundity. Furthermore, there were reductions in peak life expectancy, reproductive value, finite rate of increase, intrinsic rate of increase, and net reproduction rate in response to exposure to increasing flupyradifurone rate. Additionally, at 0.127 g a.i. ha−1, the mean generation time was significantly longer than that under control conditions. Following simulated exposure to flupyradifurone for 100 days, population of O. strigicollis in the 0.064 g a.i. ha−1 and control treatments were found to be significantly larger than those exposed to 0.127 g a.i. ha−1. On the basis on LR50 evaluations, whereas the risk of exposure risk was unacceptable for O. strigicollis under in-field scenario, it remained acceptable off-field. Nonetheless, the sublethal effect of prolonged exposure to residual flupyradifurone could pose an unacceptable off-field risk to O. strigicollis (e.g., in adjacent habitats). Consequently, the effects of different flupyradifurone exposure scenarios on O. strigicollis should be thoroughly assessed, and reducing the dosage of flupyradifurone could be advantageous for the control of D. citri when combine with augmentative release of O. strigicollis.

RNA interference-mediated knockdown of genes involved in sugar transport and metabolism disrupts psyllid Bactericera cockerelli (Order: Hemiptera) gut physiology and results in high mortality.

The causal agent of zebra chip of potato and vein-greening diseases of tomato is "Candidatus Liberibacter solanacearum" (CLso), a fastidious bacterium transmitted by the potato psyllid. In the absence of disease-resistant cultivars, disease management has relied on minimizing vector population size to reduce CLso transmission, which requires frequent insecticide applications. There is growing interest in the use of RNA interference (RNAi) technology to supplant traditional insecticides with biopesticides. This requires knowledge of genes essential for insect livelihood whose knockdown leads to significant mortality or other phenotypes. Such candidate genes can be evaluated by reverse genetics approaches to further corroborate predicted gene function. Here, five potato psyllid genes involved in sugar homeostasis in the potato psyllid gut, α-glucosidase1 (AGLU1), aquaporin2 (AQP2), facilitated trehalose transporter1 (TRET1), Trehalase1 (TRE1), and Trehalase2 (TRE2), were investigated as candidates for effective gene silencing. Potato psyllid dsRNAs were designed to optimize knockdown of gene targets. Third instar PoP nymphs were given a 48-hr ingestion-access period (IAP) on individual or groups of dsRNA in 20% sucrose. Mortality was recorded 0, 3, 5, 7, and 9 days post-IAP. Gene knockdown was analyzed 9 days post-IAP by quantitative real-time reverse-transcriptase polymerase chain reaction amplification. The individual or stacked dsRNA combinations resulted in 20-60% and 20-40% knockdown, respectively, while subsequent psyllid mortality ranged from 20-40% to >60% for single and stacked dsRNA combinations, respectively. Reverse genetics analysis showed that simultaneous knockdown of the five selected candidate genes with predicted functions in pathways involved in sugar-homeostasis, metabolism, and -transport yielded the highest mortality, when compared with single or combinations of targets. Results confirmed the functions afforded by psyllid gut genes responsible for osmotic homeostasis and sugar metabolism/transport are essential for livelihood, identifying them as potentially lucrative RNAi biopesticide targets and highlighted the translational relevance of targeting multiple nodes in a physiological pathway simultaneously.

Seasonal abundance and mutual interference of &lt;i&gt;Diaeretiella rapae&lt;/i&gt; (McIntosh) on &lt;i&gt;Brevicoryne brassicae&lt;/i&gt;

Brevicoryne brassicae (Hemiptera: Aphididae), known as cabbage aphid, is cosmopolitan in distribution that infests cruciferous crops such as broccoli, cabbage, cauliflower, and mustard. Brevicoryne brassicae is suppressed by various species of natural enemies, the most important and abundant being Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae). The present study was carried out at Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni Solan, Himachal Pradesh, on the seasonal abundance and mutual interference of the parasitoid, D. rapae during the years 2020-2021. The study showed the peak population of both host (221.36 aphids/plant) and parasitoid (27.28 mummified aphids/plant) with 12.32 per cent parasitization on the 10th Standard Meteorological Week (SMW). On the 14th SMW of 2021, the aphid population was lowest (2.72 aphids/plant) and parasitization by D. rapae was highest (47.05%). The D. rapae when foraged at densities of 2, 4, 6 and 8 parasitoids per 30 and 50 constant host nymphs, the third-instar host nymphs had a higher mutual interference coefficient than fourth instar host nymphs. Therefore, D. rapae can be utilized as an important biocontrol agent in the management programme of a cabbage aphid (B. brassicae).

Pest categorisation of Pochazia shantungensis.

The EFSA Panel on Plant Health performed a pest categorisation of Pochazia shantungensis (Hemiptera: Auchenorrhyncha: Ricaniidae) for the EU following commodity risk assessments of Malus domestica, Prunus persica, P. dulcis and Robinia pseudoacacia plants for planting from Türkiye in which P. shantungensis was identified as a pest that could potentially enter the EU. The native range of P.shantungensis is China (Shaanxi, Shandong and Zhejiang provinces), but around 2010, the species entered the Republic of Korea and rapidly spread. Small and localised populations were also recently found in Türkiye (Marmara) and southern Russia (Krasnodyarskiy kray). Within the EU, a few individuals have been recorded in Italy (Pistoia province, Tuscany), in one locality in southern France (Alpes-Maritimes), in the Netherlands (Western Netherlands) and in one garden in Germany (Baden-Württemberg) where it was eradicated. P. shantungensis is not listed in Annex II of Commission Implementing Regulation (EU) 2019/2072. It is polyphagous, feeding on plants belonging to more than 200 species including many crop and ornamental plants. Economically important hosts in the EU include apple (M. domestica), citrus (Citrus spp.), walnut (Castanea sp.) and ornamentals such as hibiscus (Hibiscus spp.) and camellia (Camellia japonica), as well as forest trees, mostly deciduous. In the Republic of Korea, the species has one generation per year. It overwinters as eggs and goes through five nymphal instars. Its impact is due to oviposition obstructing the vascular system of its hosts, depletion of the host resources and egestion of honeydew promoting the development of sooty moulds. Plants for planting constitute the main pathway for entry into the EU and for spread. Climatic conditions in southern EU countries and host plant availability in those areas would allow establishment and spread. The introduction of P. shantungensis is expected to have an economic impact in the EU through the reduction in yield, quality and commercial value of fruits and ornamental plants. Phytosanitary measures are available to reduce the likelihood of entry and further spread. P.shantungensis meets the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

Leaf‐roll gall formation in Reynoutria × bohemica and its implications for biological control with Aphalara itadori

AbstractThe psyllid Aphalara itadori Shinji (Hemiptera: Psyllidae) is a biocontrol agent against invasive knotweed species (Polygonaceae) in Europe and North America. Despite an extensive release program, successful establishment of the agent has never been confirmed. The slow establishment of A. itadori in its introduced range appears to be predominantly the result of nymphal mortality, either through desiccation, predation, or the adaptation of captive populations to low‐stress environments. In 2016, CABI UK collected a new line of psyllids from Murakami, Niigata Prefecture, in Japan, where it was observed causing severe leaf‐roll galling on one of the many varieties of native knotweeds. The induction of leaf‐roll galls by Murakami psyllids on invasive Bohemian knotweed, Reynoutria × bohemica, has the potential to alleviate some or all of the observed nymphal mortality factors. We conducted a series of growth chamber experiments to explore the psyllid behaviors that initiate leaf‐roll galls, and the ways in which the galls might benefit the psyllids and inhibit invasive knotweed. Reynoutria × bohemica exposed to A. itadori for 4 weeks suffered reduced stem elongation and leaf area compared to control plants. Artificial leaf‐roll galls were consistently utilized by developing A. itadori nymphs, and contributed to their survival. Leaf‐roll galling in R. × bohemica was predominantly initiated by early instar nymphs of A. itadori, and only occurred when leaves were attacked at a very early stage in their development. Our results can inform the knotweed biocontrol program in several key ways. Releases of A. itadori should be timed so that developing nymphs have access to newly emerging leaves. Monitoring efforts at release sites should focus on the growing tips of R. × bohemica, where the highly mobile nymphs appear to migrate. Finally, our results provide motivation to seek additional lines of A. itadori that may affect other invasive knotweed species in similar ways.

The Jinggangmycin-induced Mthl2 gene regulates the development and stress resistance in Nilaparvata lugens Stål (Hemiptera: Delphacidae)

Methuselah (Mth) belongs to the GPCR family B, which regulates various biological processes and stress responses. The previous transcriptome data showed jinggangmycin (JGM)-induced Mthl2 expression. However, its detailed functional role remained unclear in brown planthopper, Nilaparvata lugens Stål. In adult N. lugens, the Mthl2 gene showed dominant expressions, notably in ovaries and fat body tissues. The 3rd instar nymphs treated with JGM increased starvation, oxidative stress, and high temperature (34 °C) tolerance of the adults. On the contrary, under dsMthl2 treatment, completely opposite phenotypes were observed. The lipid synthesis genes (DGAT1and PNPLA3) of both females and males treated with JGM in the nymphal stage were observed with high expressions, while the lipolysis of the Lipase 3 gene was observed with low expressions. The JGM increased triglyceride (TG) content, fat body droplet size, and the number of fat body droplets. The same treatment also increased the Glutathione S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) activities. An increase in the heat shock protein (HSP70 and HSP90) expression levels was also observed under JGM treatment but not dsMthl2. The current study demonstrated the influential role of the Mthl genes, particularly the Mthl2 gene, in modulating the growth and development and stress-responsiveness in N. lugens. Thus, providing a platform for future applied research programs controlling N. lugens population in rice fields.

New data on Urostylis lateralis Walker, 867 (Heteroptera, Urostylididae) from the south of the Russian Far East

Nymphal Urostylis lateralis Walker, 1867 were reared in cages from eggs that had overwintered in forest under oak rhytidome in the south of Primorsky Krai, Russia. Instar I nymphs hatch before the onset of oak’s growing season and develop under rhytidome, feeding on the jelly-like coating of egg clutch and molting. As oak leaves unfold, instars II–III leave their shelters and begin feeding on leaf sap. Adults live in the oak crown. The sequence of molts of all nymphal instars, their feeding, and the timing of seasonal development of the species in nature are documented.

Biology of aphid, Aphis gossypii Glover in cumin

The experiment on biology of aphid, Aphis gossypii infesting cumin crop was conducted under ambient conditions in the Entomology Laboratory, Agricultural Research Station, Mandor, Jodhpur. The study was conducted on potted plants of cumin variety GC-4. The aphid, A. gossypii nymphs were moulted four times before attaining the adult stage. The mean body length, width, antennal length and cornicle length of first, second, third and fourth instar nymphs were 0.50 ± 0.04, 0.28 ± 0.03, 0.28 ± 0.02 and 0.036 ± 0.01 mm; 0.90 ± 0.04, 0.38 ± 0.04, 0.40 ± 0.03 and 0.065 ± 0.01 mm; 1.11 ± 0.05, 0.49 ± 0.04, 0.54 ± 0.03 and 0.095 ± 0.01 mm and 1.31 ± 0.06, 0.65 ± 0.05, 0.64 ± 0.04 and 0.175 ± 0.01 mm, respectively. The mean body length, width, antennal length and cornicle length of adult aphid were 1.68 ± 0.06, 0.71 ± 1.53, 0.88 ± 0.02 and 0.266 ± 0.01 mm, respectively. The mean duration period of first, second, third and fourth instar nymphs were 1.30 ± 0.42, 2.05 ± 0.62, 2.40 ± 0.52 and 1.45 ± 0.45 days, respectively. The total nymphal duration was 7.75 ± 1.61 days. The mean longevity of adult aphid was 9.65 ± 1.75 days with an entire life span of 17.75 ± 2.91 days. The pre-reproductive, reproductive and post-reproductive periods were 1.35 ± 0.56, 7.20 ± 1.47 and 1.75 ± 0.71 days, respectively. The fecundity of the adult female was 24.45 ± 6.21 nymphs per female and the intrinsic rate of single female per day was an average of 4.80 ± 2.01 nymphs/day.

Seasonal activity of spotted lanternfly (Hemiptera: Fulgoridae), in Southeast Pennsylvania.

The spotted lanternfly, Lycorma delicatula (White, 1845), is an invasive species in the United States. This pest causes damage to vineyards and has the potential to negatively affect other crops and industries. Information describing the seasonal timing of life stages can improve its management. In 2019 and 2020, spotted lanternfly seasonal activity was followed weekly from spring egg hatch to the first hard freeze. Weighted mean timing of activity for each nymphal instar, early adults, late adults, total adults, and egg mass deposition are presented for 2019 and 2020 on Acer rubrum and 2020 on Ailanthus altissima. Logistic equations describing the percentage completion of each activity period on these hosts were fitted using a start date of 1 January to calculate accumulated degree days (ADD). For the adult and egg mass deposition periods, we additionally used a biofix of the date adults were first observed to calculate ADD. ADD from 1 January adequately estimated the timing of nymphal instars but ADD from observation of the first adult better estimated the timing of adult activity and egg mass deposition. Late adult activity and egg mass deposition periods appeared to be influenced by another environmental cue, such as day length. Maps of season-long ADD show that spotted lanternflies are unlikely to reach adulthood in colder regions of the northeast United States, and therefore may not establish there. We also report a strong seasonal trend in sex ratio on A. rubrum, where the population shifted from over 80% male to over 80% female in October.

Sublethal and transgenerational effects of broflanilide on Myzus persicae (Sulzer) (Hemiptera: Aphididae)

Myzus persicae (Sulzer) is an important agricultural pest worldwide that imparts substantial damage to various horticultural and agricultural crops. Broflanilide is a newly developed insecticide that exhibits high activity against crop pests such as M. persicae. Nevertheless, the effects of sublethal levels of broflanilide on M. persicae fitness and population growth remain unclear. We assessed the sublethal and transgenerational effects of broflanilide on M. persicae performance using an age-stage, two-sex life table. Our results reveal that broflanilide is highly toxic to M. persicae with a 72-h LC50 of 2.541 mg/L. The LC25 of broflanilide significantly reduced the longevity and fecundity of the F0 and F1 generations, and the LC10 and LC25 of broflanilide significantly prolonged the developmental period of the third instar nymph in the F1 generation. The net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) were significantly lower in the LC25-treated aphids. LC25 broflanilide treatment significantly downregulated the reproduction-related genes ERR and Vg and significantly upregulated JHEH expression in the F0 generation. LC25 and LC10 broflanilide treatments significantly upregulated the detoxification-related genes CarE and CYP6CY3, respectively, which may be related to broflanilide resistance in M. persicae. These results showed that broflanilide LC25 exhibited a significant inhibitory effect on M. persicae populations, which can persist in the F1 generation. Our study facilitates the understanding of the sublethal effect of broflanilide on aphid performance and helps develop methods and programs for controlling M. persicae using low broflanilide doses.

Evaluation the efficacy of Ethanol Extract Derived from Wild Mint on the Life Parameters of the Aphis fabae (Hemiptera: Aphididae) (Sco-poli) under laboratory conditions

The black bean aphid, Aphis fabae is a significant economic pest with a global presence, impacting a wide range of plant species. This study aimed to assess the effectiveness of ethanol extract derived from wild mint (Mentha longifolia) under laboratory conditions on various life performance criteria of A. fabae. The evaluation involved measuring mortality rates of nymphs and adults, as well as adult productivity, utilizing three different extract concentrations (1%, 2%, and 3% w/v). The results revealed that the ethanol extract of plant leaves had a substantial effect on all life stages of the aphid, with a more pronounced impact observed at higher concentrations and longer exposure periods. In the first nymphal instar, the mortality rate reached 81% at a concentration of 3%, and in the second nymphal instar, it was 80% at the same concentration. For the third and fourth nymphal instars, the mortality rates were 82% and 82.5%, respectively, at a concentration of 3%. As for adult aphids, the mortality rate was 81.333% at a concentration of 3%. Moreover, the extract significantly reduced the productivity of adult aphids, with rates of 1.68%, 1.82%, and 1% at concentrations of 1%, 2%, and 3%, respectively.

Revisiting Biguembia Szumik, 1997 (Embioptera: Archembiidae): New species, phylogeny and natural history

Two new species of Biguembia Szumik, 1997 (Embioptera: Archembiidae): B. flavibrunnea n. sp. and B. pulchra n. sp. from the Cerrado domain, state of Tocantins, Brazil are described, diagnosed and illustrated. A cladistic analysis of the genus using 104 morphological characters is performed, and the systematic position of the two new species is analyzed and discussed. For the order Embioptera, the data/information presented here where all the instars (eggs, nymphs and adults) of both sexes are incorporated on the original description of one of the species including notes of developmental time, constitute a fundamental contribution to the understanding for the classification of the group. Additionally, an identification key for males of the genus is provided.

Host stage and temperature for the rearing of Aridelus rufotestaceus (Hymenoptera: Braconidae), with notes on acceptance and suitability of 2 stink bug species.

Nezara viridula (L.) (Hemiptera: Pentatomidae) is a harmful pest of many agricultural crops in different parts of the world. This stink bug is the preferred host species of Aridelus rufotestaceus Tobias (Hymenoptera: Braconidae), an endoparasitoid of nymphs and adults of pentatomids. With the aim to improve the rearing procedure of this beneficial insect, the acceptance and suitability of all mobile stages of N. viridula (from first instar nymph to adult) were evaluated. At 25 °C, all host stages were accepted and suitable for A. rufotestaceus development, but the highest parasitoid cocoon and adult yields were obtained from second instar nymphs. The possibility to reduce the development time of A. rufotestasceus by increasing the rearing temperature was also evaluated, but 28 °C proved to be detrimental for parasitoid development, as shown by the very low cocoon and adult numbers obtained. The acceptance and suitability of the invasive pentatomid species Halyomorpha halys (Stål) for A. rufotestaceus was also tested. Female wasps were observed piercing H. halys nymphs with the ovipositor, but no cocoons were obtained, nor were larvae or head capsules detected in the exposed stink bugs.

Comparative prey predation ability of big-eyed bug Geocoris ochropterus (Fieber) (Hemiptera: Geocoridae)

We investigated the predation ability of big-eyed bugs Geocoris ochropterus on different single prey species of thrips, whiteflies, and aphids. Results indicated that G. ochropterus adults consumed the highest number of aphids per day (33.6 ± 3.35). First instar nymphs of G. ochropterus showed low ability to consume prey, while from second to fifth instar nymphs showed high ability to consume prey with significant differences. The number of eggs deposited per female fed on whiteflies was significantly different larger than other prey types. In addition, development time of Geocoris ochropterus nymphs first to fourth instar was longest when fed on aphids and significantly different among prey types. Results suggest that G. ochropterus consumed the highest numbers of aphids, with the order of preference aphids &gt; whiteflies &gt; thrips.