Interactions between microplastics and Culex sp. larvae in wastewater.

Microplastics (MPs) are a growing issue because they endanger both aquatic organisms and humans. Studies have indicated that wastewater treatment plants (WWTPs) are one of the major contributors to MPs in the environment. However, studies on the abundance of MP contamination in WWTPs and its transmission into aquatic organisms are still scarce, especially in Egypt. The goal of this study was to examine the temporal fluctuations in the distribution of MPs in surface water and the dominant macroinvertebrate fauna (Culex sp. larvae) in a fixed wastewater basin in Sohag Governorate, Egypt. The average of MPs in the surface water was 3.01 ± 0.9 particles/L. The results indicated to seasonal variation of MP abundance in the wastewater basin that was significantly higher in winter than in the other seasons. The risk index for polymers (H), pollution load index (PLI), and potential ecological risk index (RI) were used to assess the degree of MP contamination. The basin has moderate H values (<1000) because of the presence of polymers with moderate hazard scores such as polyester (PES), polyethylene (PE), and polypropylene (PP). According to the PLI values, surface water is extremely contaminated with MPs (PLI: 88 to 120). The RI values of surface water showed higher ecological risk (level V). MPs in Culex sp. larvae were seasonally changed with an 85% detection rate, and an abundance average of 0.24 ± 0.65 particles/ind, MP concentration in Culex sp. larvae was influenced by the MP characters (shape, color, and polymer). The larvae of Culex sp. showed a greater preference for black and red fibrous polyester (PES) with sizes (<1000 µm) of MPs. These findings suggest that Culex sp. larvae prefer ingesting MPs that resemble their food. It is possible to overestimate Culex sp.'s preference for lower sizes because of their catabolism of MPs. To better understand the preferences of Culex sp. larvae for MPs, further controlled trials should be conducted. PRACTITIONER POINTS: Wastewater is highly contaminated with microplastics (MPs) in the different seasons. First report of detection of the seasonal abundance of MP in Culex sp. larvae. Culex sp. larvae showed a stronger feeding preference for MPs with specific characteristics. Smaller size and blue polyester fibers were the dominant characteristics of MPs in wastewater.

Evaluation of the inheritance and dominance of behavioral resistance to imidacloprid in the house fly (Musca domestica L.) (Diptera: Muscidae).

The house fly, Musca domestica, is a cosmopolitan species known for its pestiferous nature and potential to mechanically vector numerous human and animal pathogens. Control of adult house flies often relies on insecticides formulated into food baits. However, due to the overuse of these baits, insecticide resistance has developed to all insecticide classes currently registered for use in the United States. Field populations of house flies have developed resistance to imidacloprid, the most widely used neonicotinoid insecticide for fly control, through both physiological and behavioral resistance mechanisms. In the current study, we conducted a comprehensive analysis of the inheritance and dominance of behavioral resistance to imidacloprid in a lab-selected behaviorally resistant house fly strain. Additionally, we conducted feeding preference assays to assess the feeding responses of genetic cross progeny to imidacloprid. Our results confirmed that behavioral resistance to imidacloprid is inherited as a polygenic trait, though it is inherited differently between male and female flies. We also demonstrated that feeding preference assays can be instrumental in future genetic inheritance studies as they provide direct insight into the behavior of different strains under controlled conditions that reveal, interactions between the organism and the insecticide. The findings of this study carry significant implications for pest management and underscore the need for integrated pest control approaches that consider genetic and ecological factors contributing to resistance.

Analysis of Genes Associated with Feeding Preference and Detoxification in Various Developmental Stages of Aglais urticae.

Herbivorous insects and host plants have developed a close and complex relationship over a long period of co-evolution. Some plants provide nutrients for insects, but plants' secondary metabolites also influence their growth and development. Urtica cannabina roots and leaves are poisonous, yet Aglais urticae larvae feed on them, so we aimed to clarify the mechanism enabling this interaction. At present, studies on the detoxification mechanism of the A. urticae are rare. In our study, first, we used the A. urticae larval odor selection behavior bioassay and choice feeding preference assay to analyze the feeding preferences of A. urticae on its host plant, U. cannabina. Next, we used transcriptome sequencing to obtain the unigenes annotated and classified by various databases, such as KEGG and GO. In this study, we found that U. cannabina could attract A. urticae larvae to feed via scent, and the feeding preference assay confirmed that larvae preferred U. cannabina leaves over three other plants: Cirsium japonicum, Cannabis sativa, and Arctium lappa. The activity of detoxifying enzymes GST and CarE changed in larvae that had consumed U. cannabina. Furthermore, through transcriptomic sequencing analysis, 77,624 unigenes were assembled from raw reads. The numbers of differentially expressed genes were calculated using pairwise comparisons of all life stages; the expression of detoxification enzyme genes was substantially higher in larvae than in the pupal and adult stages. Finally, we identified and summarized 34 genes associated with detoxification enzymes, such as UDP-glucose 4-epimerase gene, 5 Glutathione S-transferase genes, 4 Carboxylesterase genes, 4 Cytochrome P450 genes, 10 ATP-binding cassette genes, 4 Superoxide dismutase, and Peroxidase. Moreover, we identified 28 genes associated with the development of A. urticae. The qRT-PCR results were nearly consistent with the transcriptomic data, showing an increased expression level of four genes in larvae. Taken together, this study examines the correlation between A. urticae and host plants U. cannabina, uncovering a pronounced preference for A. urticae larvae toward host plants. Consistent with RNA-seq, we investigated the mechanism of A. urticae's interaction with host plants and identified detoxification-related genes. The present study provides theoretical support for studying insect adaptation mechanisms and biological control.

Seasonal variations in botanical and nutritive composition, forage availability and ingestive behavior of grazing goats in the semiarid region.

The aim of this study was to assess how the different seasons of the year impact the botanical composition, availability, and quality of forage in the caatinga, as well as the frequency of ingestion and ingestive behavior of goats in a semi-arid region. The experiment used four crossbred castrated males, with an average weight of 30.2 ± 4.76 kg and an average age of 20 months. The experimental period lasted for 12 months, encompassing two rainy seasons and one dry season within this timeframe, with three replications (data collection) per season. All collected forage was categorized based on its stratum (herbaceous, woody, and litter), and a chemical composition analysis was conducted. The goats' behavior was assessed by observing variables such as feeding time, idleness, rumination, displacement, social interaction, and water intake. The findings revealed clear seasonality in both availability and quality of forage, consequently influencing the botanical composition of the goats' diet and their ingestive behavior. In addition, during the grazing period, the goats showed a shift grazing habit, in which idle and feeding peaks were alternated with increased displacement during the morning and rumination in the afternoon. The seasons of the year strongly impact the availability and nutritional quality of forage in the caatinga biome, consequently influencing the ingestive behavior and dietary composition of goats in this ecosystem.

Unravelling the mosquito-haemosporidian parasite-bird host network in the southwestern Iberian Peninsula: insights into malaria infections, mosquito community and feeding preferences.

BAKGROUND: Vector-borne diseases affecting humans, wildlife and livestock have significantly increased their incidence and distribution in the last decades. Because the interaction among vectors-parasite-vertebrate hosts plays a key role driving vector-borne disease transmission, the analyses of the diversity and structure of vector-parasite networks and host-feeding preference may help to assess disease risk. Also, the study of seasonal variations in the structure and composition of vector and parasite communities may elucidate the current patterns of parasite persistence and spread as well as facilitate prediction of how climate variations may impact vector-borne disease transmission. Avian malaria and related haemosporidian parasites constitute an exceptional model to understand the ecology and evolution of vector-borne diseases. However, the characterization of vector-haemosporidian parasite-bird host assemblages is largely unknown in many regions. METHODS: Here, we analyzed 5859 female mosquitoes captured from May to November in five localities from southwestern Spain to explore the composition and seasonal variation of the vector-parasite-vertebrate host network. RESULTS: We showed a gradual increase in mosquito abundance, peaking in July. A total of 16 different haemosporidian lineages were found infecting 13 mosquito species. Of these assemblages, more than 70% of these vector-parasite associations have not been described in previous studies. Moreover, three Haemoproteus lineages were reported for the first time in this study. The prevalence of avian malaria infections in mosquitoes varied significantly across the months, reaching a maximum in November. Mosquito blood-feeding preference was higher for mammals (62.5%), whereas 37.5% of vectors fed on birds, suggesting opportunistic feeding behavior. CONCLUSION: These outcomes improve our understanding of disease transmission risk and help tovector control strategies.

Susceptibility of Eucalyptus trees to defoliation by the Eucalyptus snout beetle, Gonipterus sp. n. 2, is enhanced by high foliar contents of 1,8-cineole, oxalic acid and sucrose and low contents of palmitic and shikimic acid.

Gonipterus sp. n. 2 (Coleoptera, Curculionidae) is an invasive, commercially important weevil that causes large-scale defoliation of Eucalyptus trees. The weevil specifically feeds on young leaves and new shoots, thus reducing tree growth. The weevil displays a very strong preference for certain Eucalyptus genotypes, however, this behaviour and the chemistry underlying it is poorly understood, thereby complicating the selection of resistant trees. To elucidate the feeding preference of Gonipterus sp. n. 2, we assessed the relative levels of susceptibility of 62 Eucalyptus genotypes from 23 species using a laboratory choice assay. This revealed large intraspecific variation in susceptibility to weevil feeding, which for certain species, exceeded the interspecific variation. A semiquantitative metabolite profile analysis on 13 genotypes revealed strong correlations of 10 metabolites to feeding damage. The behavioural effects of the identified compounds were assessed through an in vitro feeding preference assay using artificial diets as well as under field conditions. This revealed three phagostimulants (1,8-cineole, oxalic acid and sucrose) and two feeding deterrent compounds (shikimic acid and palmitic acid) for Gonipterus sp. n. 2. These chemical markers can be applied to tree breeding programmes for the selection of resistant genotypes to reduce damage caused by Gonipterus weevils.

Microplastic contamination in the dominant crabs at the intertidal zone of Chongming Island, Yangtze Estuary.

Crabs are one of the most critical and dominant species of the intertidal zone. Their feeding, burrowing, and other bioturbation activities are common and intense. However, baseline data on microplastic contamination in wild intertidal crabs are still lacking. In this study, we investigated the contamination of microplastics in the dominant crabs, Chiromantes dehaani, of the intertidal zone in Chongming Island, Yangtze Estuary, and explored their probable relationship with the microplastic composition in sediments. A total of 592 microplastic particles were observed in the crab tissues, with an abundance of 1.90 ± 0.53 items·g-1 (1.48 ± 0.45 items·ind-1). The microplastic contamination in the tissues of C. dehaani varied significantly among different sampling sites, organs, and size groups, but not among different sexes. Microplastics in C. dehaani were mainly rayon fibers with small sizes (<1000 µm). Their colors were mostly dark, which is consistent with the sediments samples. A linear regression showed significant correlations between the composition of microplastics in the crabs and that in sediments, although they differed in various crab organs and sediment layers. The target group index identified the feeding preference of C. dehaani on the microplastics with specific shapes, colors, sizes, and polymer types. In general, the microplastic contamination in crabs is affected by both objective environmental conditions and subjective feeding habits of crabs. In the future, more potential sources should be considered to completely distinguish the relationship between the microplastic contamination in crabs and adjacent environment.

Correlating Eucalyptus leaf metabolomics with preference of the bronze bug, Thaumastocoris peregrinus.

Eucalyptus species are among the most planted trees in forestry production, an ever-increasing commercial activity worldwide. Forestry expansion demands a continuous search for preventive and sanitary measures against pests and diseases. Massive application of phytosanitary products is incompatible with the forestry sector, so forest health management must be based on other principles. In this context, studies on insect plant relationships mediated by plant metabolites may contribute information relevant to plant resistance and genotype selection. In this study, we analyzed the leaf metabolome of four Eucalyptus species commonly planted in southern South America, to correlate this chemical information with feeding preference of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae), an important pest of eucalypt plantations. Gas chromatography mass spectrometry analyses were performed on polar and non-polar leaf extracts from Eucalyptus globulus, Eucalyptus grandis, Eucalyptus robusta, and Eucalyptus tereticornis (Myrtaceae). Feeding preferences were assessed in two-choice laboratory bioassays resulting in a preference gradient of the four plant species. Moreover, a performance bioassay where we contrasted survival and development time between the most and least preferred plants, showed a clear correlation with preference both in survival and developmental time of the most susceptible nymph instar. We found that species with high or low feeding preferences differ significantly in several foliar metabolites, which may be acting as feeding stimulants or deterrents for T. peregrinus. These findings may provide useful criteria for choosing Eucalyptus genotypes when planting in bronze bug infested areas.

Bacillus thuringiensis-based bioinsecticides affect predation of Euborellia annulipes on diamondback moth larvae.

Interactions between earwigs and entomopathogens, such as Bacillus thuringiensis (Bt), are still poorly understood. This study tested whether Bt-based bioinsecticides have any effect on the predation of Euborellia annulipes (Lucas) (Dermaptera: Anisolabididae) on Plutella xylostella (L.) (Lepidoptera: Plutellidae), one of the pests with the largest number of cases of use and resistance to Bt. Fourth instar larvae were Bt infected by feeding on collard green leaves treated with Dipel®WG and XenTari®WG at the manufacturer-recommended doses. We used one no-choice condition, in which the predator had access to uninfected or Bt-infected larvae separately, and four free-choice conditions: uninfected vs Dipel®-infected larvae, uninfected vs XenTari®-infected larvae, Dipel®-infected vs XenTari®-infected larvae, and uninfected vs Bt-infected larvae with both bioinsecticides. Uninfected larvae were less consumed than those infected by both Bt-bioinsecticides in the no-choice condition. There was a higher consumption of uninfected over Dipel®-infected larvae in the free-choice condition. Overall, uninfected larvae were preferred over both Bt-based bioinsecticides infected larvae. We also used six different prey densities. The ringlegged earwig's predation rate enhanced as the prey population density increased, but the functional response was not affected by Bt-infection, being type II. The predator invested a low amount of handling time on Bt-fed prey and increased the maximum predation rate. Bt-based bioinsecticides cause effects on E. annulipes predation by altering their feeding preference and some aspects of its predatory behavior. The results of our study provide an important background for understanding interactions between earwigs and Bt. In addition, they can be used for decision making during approaches to integrated P. xylostella management.

Feeding preference and intraguild interactions between the parasitoid Trichogramma achaeae and the predator Macrolophus pygmaeus, two biological agents of Tuta absoluta.

BACKGROUND: Tuta absoluta is an exotic species and a major pest of tomato crops in Europe. Macrolophus pygmaeus and Trichogramma achaeae are two biocontrol agents widely used in integrated pest management programs of the South American tomato pinworm Tuta absoluta. In this study, we evaluated under laboratory conditions the (i) voracity of M. pygmaeus females fed on single diets of Tuta absoluta eggs parasitized or unparasitized by Trichogramma achaeae, (ii) voracity and feeding preference of M. pygmaeus females provided with mixed diets of Tuta absoluta eggs unparasitized and parasitized by Trichogramma achaeae and (iii) effect of competitive and intraguild interactions between M. pygmaeus and Trichogramma achaeae on the number of Tuta absoluta eggs consumed and/or parasitized. Lastly, we assessed under field conditions the effect of interspecific and intraspecific interactions between natural enemies on the number of Tuta absoluta eggs consumed and/or parasitized. RESULTS: Macrolophus pygmaeus consumed more unparasitized than parasitized eggs of Tuta absoluta. Under mixed diet regimes, Manly indices revealed a feeding preference for unparasitized eggs, and a decrease in the total number of eggs consumed, as the proportion of available parasitized eggs increased, whereas the unparasitized eggs were consumed in direct proportion to their availability. Conspecific interactions between M. pygmaeus, in contrast to Trichogramma achaeae, revealed the possible occurrence of intraspecific competition. For intraguild heterospecific interactions, the number of Tuta absoluta eggs consumed by M. pygmaeus and parasitized by Trichogramma achaeae was lower than that predicted for additive and non-interactive scenarios. Under field conditions, a significant difference between the conspecific treatment and heterospecific treatments revealed a slightly higher success rate in controlling Tuta absoluta when both M. pygmaeus and Trichogramma achaeae were used simultaneously. CONCLUSION: Macrolophus pygmaeus prefers unparasitized eggs of Tuta absoluta but inflicts intraguild predation on Trichogramma achaeae. In conspecific experiments, mutual interference between M. pygmaeus predators intensifies as the number of individuals increases, but for Trichogramma achaeae, it occurs in an unpredictable manner. Adding Trichogramma achaeae could significantly increase the level of control of Tuta absoluta compared to what could be achieved when only M. pygmaeus is present in glasshouse tomatoes. © 2023 Society of Chemical Industry.

Distribution characteristics of microplastics and corresponding feeding habits of the dominant shrimps in the rivers of Chongming Island.

There is increasing global concern regarding microplastics. Rivers play a key role in the transportation and storage of microplastics on the Earth's surface. Here, we aimed to investigate the spatial-temporal variations in the distribution of microplastics in water as well as in the dominant species of the macrobenthic fauna Exopalaemon modestus and Macrobrachium nipponense in the river system of Chongming Island by setting up 16 fixed sampling sites. We found that the abundance of microplastics in the water of the rivers on the Chongming Island was 0.48 ± 0.10 n/L. There was no significant difference among different reaches. The abundance of microplastics in the major rivers was significantly higher in summer than in the other seasons. Detection rates of microplastics in Exopalaemon modestus and Macrobrachium nipponense were 50.12 % and 64.58 %, with mean abundances of 1.92 ± 0.52 n/g and 1.49 ± 0.30 n/g, respectively. The composition characteristics of the microplastics in shrimps were affected by the microplastics in the aquatic environment. The microplastic content in the shrimps and water were linearly correlated in terms of the same characteristics (shape, color, and polymer). Shrimps showed a stronger feeding preference {Target Group Index (TGI) > 1} for microplastics with fibrous shapes, transparent and green colors, rayon (RA) and polyethylene (PE) polymers, and relatively small sizes (<400 µm). These results indicate that shrimps prefer to consume microplastics that have similar appearance to their prey. Their benthic dwelling habits may limit their feeding space to the bottom of the water, which in turn leads to an increase in the feeding probability on microplastics of greater densities (e.g., RA). The catabolism of microplastics in shrimps may lead to an overestimation of their feeding preference for smaller sizes. Further controlled experiments should be carried out to obtain deeper insights into the preferences of shrimp for microplastics.

Feeding Behavior Comparison of Bean Bugs, Riptortus pedestris and Halyomorpha halys on Different Soybean Cultivars.

Riptortus pedestris (Fabricius) and Halyomorpha halys (Stål) are the major pests that feed on soybean pods, seeds, and fruits. Higher populations and damage occur during the soybean maturity stages (podding to harvest). To compare the feeding behavior of R. pedestris and H. halys, we used the six most cultivated cultivars (Daepung-2ho, Daechan, Pungsannamul, Daewon, Seonpung, and Seoritae) in Korea using the electropenetrography (EPG) technique. Both R. pedestris and H. halys, the NP (non-penetration), a non-probing waveform, was the shortest in the Pungsannamul (298 and 268 min) and the longest in the Daepung-2ho (334 and 339 min), respectively. The feeding waveforms Pb (phloem feeding: E1-Salivation and E2-Sap feeding) and G (xylem feeding) were the longest in Pungsannamul and the shortest in Daepung-2ho. In addition, as a result of investigating the damage rate by planting six cultivars of beans in the field, as expected, the proportions of damage types B and C were highest in Pungsannamul and lowest in Daepung-2ho. These results reveal that both bug species ingest xylem sap from leaflets and stems using a salivary sheath strategy to acquire water and nutrients from soybean pods/seeds with cell-rupture tactics. This study provides perceptive information to understand the feeding behavior, field occurrence, and damage patterns of R. pedestris and H. halys, which may have key implications for the management of hemipteran pests by determining the specificity and susceptibility of host plants.

Developmental, Reproduction, and Feeding Preferences of the Sitobion avenae Mediated by Soil Silicon Application.

Silicon occupies an important position in the nutrient requirements of wheat. It has been reported that silicon enhances plant resistance to phytophagous insects. However, only limited research has been carried out on the effects of silicon application to wheat and Sitobion avenae populations. In this study, three silicon fertilizer concentrations were treated for potted wheat seedlings, including 0 g/L, 1 g/L, and 2 g/L of water-soluble silicon fertilizer solution. The effect of silicon application on the developmental period, longevity, reproduction, wing pattern differentiation, and other vital life table parameters of the S. avenae were determined. The cage method and the Petri dish isolated leaf method were used to determine the effect of silicon application on the feeding preference of the winged and wingless aphid. The results showed silicon application had no significant effect on the aphid instar of 1-4; although, 2 g/L silicon fertilizer prolonged the nymph stage and 1 and 2 g/L of silicon application all shortened the adult stage and reduced the longevity and fertility of the aphid. Two instances of silicon application reduced the net reproductive rate (R0), intrinsic rate of increase (rm), and finite rate of increase (λ) of the aphid. A 2 g/L silicon application prolonged the population doubling time (td), significantly reduced the mean generation time (T), and increased the proportion of winged aphids. The results also demonstrated that the selection ratio of winged aphids in wheat leaves treated with 1 g/L and 2 g/L silicon was reduced by 8.61% and 17.88%, respectively. The number of aphids on leaves treated with 2 g/L silicon was significantly reduced at 48 and 72 h of aphids released, and the application of silicon to wheat was detrimental to the feeding preference of S. avenae. Therefore, the application of silicon at 2 g/L to wheat has an inhibitory effect on the life parameters and feeding preference of S. avenae.

Population Density and Host Preference of the Japanese Pine Sawyer (Monochamus alternatus) in the Qinling-Daba Mountains of China.

Monochamus alternatus is a serious trunk-boring pest and is the most important and effective vector of the pine wood nematode Bursaphelenchus xylophilus, which causes pine wilt disease. The pine wilt disease poses a serious threat to forest vegetation and ecological security in the Qinling-Daba Mountains and their surrounding areas. In order to clarify whether the population density of M. alternatus larvae is related to the host preference of M. alternatus adults, we investigated the population density of M. alternatus overwintering larvae and explored the host preference of M. alternatus adults on Pinus tabuliformis, P. armandii, and P. massoniana. The results show that the population density of M. alternatus larvae was significantly higher on P. armandii than those on P. massoniana and P. tabuliformis. The development of M. alternatus larvae was continuous according to the measurements of the head capsule width and the pronotum width. Adults of M. alternatus preferred to oviposit on P. armandii rather than on P. massoniana and P. tabuliformis. Our results indicate that the difference in the population density of M. alternatus larvae between different host plants was due to the oviposition preference of M. alternatus adults. In addition, the instars of M. alternatus larvae could not be accurately determined, because Dyar's law is not suitable for continuously developing individuals. This study could provide theoretical basis for the comprehensive prevention and control of the pine wilt disease in this region and adjacent areas.

Revision of some mensural measurements, food preference, and haematological parameters in breeding pairs of blue rock pigeon, Columba livia sampled from Punjab Pakistan / Revisão de algumas medidas mensurais, preferência alimentar e parâmetros hematológicos em pares de criação de pombo blue rock (Columba livia), amostragem de Punjab, Paquistão

The present study describes the haematological profile, feeding preference, and comparison of morphometric characters of blue rock pigeon (Columba livia) breeding pairs. For this purpose, 25 pairs (25 samples per sex) were sampled through Mist nets from district Okara and Bahawalnagar, Punjab, Pakistan. Birds were then anaesthetized with a combination of ketamine HCL (10 mg/kg) and diazepam (0.2 mg/kg) and subjected to morphometric measurements. 5µL blood also was taken from the jugular vein of each anaesthetized bird for haematological analysis. Few pairs were also dissected to remove gastrointestinal tracts (GITs) for food preferences. Results revealed that there are no significant differences in the haematological parameters and feeding preference of breeding pairs of Columba livia. The gut analysis further revealed, the major portion of gut contents consisted of pea and corn in most of the pairs. Regarding the mensural measurements, significant differences were recorded in the body weight, length of the longest primary feather, and chest circumference, whereas the rest of the studied parameters remain nonsignificant between sexes. So, it is concluded that apart from 3 morphometric parameters (body weight, length of longest primary feather and chest circumference), both sexes are alike in term of morphometry, haematology and food preference.

O presente estudo descreve o perfil hematológico, a preferência alimentar e a comparação de caracteres morfométricos de casais reprodutores de pombo-rocha (Columba livia). Para tanto, 25 pares (25 amostras por sexo) foram amostrados por meio de redes de névoa do distrito de Okara e Bahawalnagar, Punjab, Paquistão. As aves foram então anestesiadas com uma combinação de cetamina HCL (10 mg/kg) e diazepam (0,2 mg/kg) e submetidas a medidas morfométricas; 5 µL de sangue também foram retirados da veia jugular de cada ave anestesiada para análise hematológica. Poucos pares também foram dissecados para remover o trato gastrointestinal (GITs) para preferências alimentares. Os resultados revelaram que não há diferenças significativas nos parâmetros hematológicos e na preferência alimentar dos casais reprodutores de Columba livia. A análise intestinal revelou ainda que a maior parte do conteúdo intestinal consistia em ervilha e milho na maioria dos pares. Em relação às medidas mensurais, foram registradas diferenças significativas no peso corporal, comprimento da pena primária mais longa e circunferência torácica, enquanto os demais parâmetros estudados permanecem não significativos entre os sexos. Assim, conclui-se que além de três parâmetros morfométricos (peso corporal, comprimento da pena primária mais longa e circunferência torácica), ambos os sexos são semelhantes em termos de morfometria, hematologia e preferência alimentar.

Revision of some mensural measurements, food preference, and haematological parameters in breeding pairs of blue rock pigeon, Columba livia sampled from punjab Pakistan

Abstract The present study describes the haematological profile, feeding preference, and comparison of morphometric characters of blue rock pigeon (Columba livia) breeding pairs. For this purpose, 25 pairs (25 samples per sex) were sampled through Mist nets from district Okara and Bahawalnagar, Punjab, Pakistan. Birds were then anaesthetized with a combination of ketamine HCL (10 mg/kg) and diazepam (0.2 mg/kg) and subjected to morphometric measurements. 5µL blood also was taken from the jugular vein of each anaesthetized bird for haematological analysis. Few pairs were also dissected to remove gastrointestinal tracts (GITs) for food preferences. Results revealed that there are no significant differences in the haematological parameters and feeding preference of breeding pairs of Columba livia. The gut analysis further revealed, the major portion of gut contents consisted of pea and corn in most of the pairs. Regarding the mensural measurements, significant differences were recorded in the body weight, length of the longest primary feather, and chest circumference, whereas the rest of the studied parameters remain nonsignificant between sexes. So, it is concluded that apart from 3 morphometric parameters (body weight, length of longest primary feather and chest circumference), both sexes are alike in term of morphometry, haematology and food preference.

Resumo O presente estudo descreve o perfil hematológico, a preferência alimentar e a comparação de caracteres morfométricos de casais reprodutores de pombo-rocha (Columba livia). Para tanto, 25 pares (25 amostras por sexo) foram amostrados por meio de redes de névoa do distrito de Okara e Bahawalnagar, Punjab, Paquistão. As aves foram então anestesiadas com uma combinação de cetamina HCL (10 mg/kg) e diazepam (0,2 mg/kg) e submetidas a medidas morfométricas; 5 µL de sangue também foram retirados da veia jugular de cada ave anestesiada para análise hematológica. Poucos pares também foram dissecados para remover o trato gastrointestinal (GITs) para preferências alimentares. Os resultados revelaram que não há diferenças significativas nos parâmetros hematológicos e na preferência alimentar dos casais reprodutores de Columba livia. A análise intestinal revelou ainda que a maior parte do conteúdo intestinal consistia em ervilha e milho na maioria dos pares. Em relação às medidas mensurais, foram registradas diferenças significativas no peso corporal, comprimento da pena primária mais longa e circunferência torácica, enquanto os demais parâmetros estudados permanecem não significativos entre os sexos. Assim, conclui-se que além de três parâmetros morfométricos (peso corporal, comprimento da pena primária mais longa e circunferência torácica), ambos os sexos são semelhantes em termos de morfometria, hematologia e preferência alimentar.

Revision of some mensural measurements, food preference, and haematological parameters in breeding pairs of blue rock pigeon, Columba livia sampled from punjab Pakistan / Revisão de algumas medidas mensurais, preferência alimentar e parâmetros hematológicos em pares de criação de pombo blue rock (Columba livia), amostragem de punjab, Paquistão

Abstract The present study describes the haematological profile, feeding preference, and comparison of morphometric characters of blue rock pigeon (Columba livia) breeding pairs. For this purpose, 25 pairs (25 samples per sex) were sampled through Mist nets from district Okara and Bahawalnagar, Punjab, Pakistan. Birds were then anaesthetized with a combination of ketamine HCL (10 mg/kg) and diazepam (0.2 mg/kg) and subjected to morphometric measurements. 5µL blood also was taken from the jugular vein of each anaesthetized bird for haematological analysis. Few pairs were also dissected to remove gastrointestinal tracts (GITs) for food preferences. Results revealed that there are no significant differences in the haematological parameters and feeding preference of breeding pairs of Columba livia. The gut analysis further revealed, the major portion of gut contents consisted of pea and corn in most of the pairs. Regarding the mensural measurements, significant differences were recorded in the body weight, length of the longest primary feather, and chest circumference, whereas the rest of the studied parameters remain nonsignificant between sexes. So, it is concluded that apart from 3 morphometric parameters (body weight, length of longest primary feather and chest circumference), both sexes are alike in term of morphometry, haematology and food preference.

Resumo O presente estudo descreve o perfil hematológico, a preferência alimentar e a comparação de caracteres morfométricos de casais reprodutores de pombo-rocha (Columba livia). Para tanto, 25 pares (25 amostras por sexo) foram amostrados por meio de redes de névoa do distrito de Okara e Bahawalnagar, Punjab, Paquistão. As aves foram então anestesiadas com uma combinação de cetamina HCL (10 mg/kg) e diazepam (0,2 mg/kg) e submetidas a medidas morfométricas; 5 µL de sangue também foram retirados da veia jugular de cada ave anestesiada para análise hematológica. Poucos pares também foram dissecados para remover o trato gastrointestinal (GITs) para preferências alimentares. Os resultados revelaram que não há diferenças significativas nos parâmetros hematológicos e na preferência alimentar dos casais reprodutores de Columba livia. A análise intestinal revelou ainda que a maior parte do conteúdo intestinal consistia em ervilha e milho na maioria dos pares. Em relação às medidas mensurais, foram registradas diferenças significativas no peso corporal, comprimento da pena primária mais longa e circunferência torácica, enquanto os demais parâmetros estudados permanecem não significativos entre os sexos. Assim, conclui-se que além de três parâmetros morfométricos (peso corporal, comprimento da pena primária mais longa e circunferência torácica), ambos os sexos são semelhantes em termos de morfometria, hematologia e preferência alimentar.

Population Parameters and Feeding Preference of Spodoptera litura (Lepidoptera: Noctuidae) on Different Asparagus officinalis Tissues.

Spodoptera litura is an important pest that seriously affects Asparagus officinalis production. To clarify the population characteristics and feeding preference of S. litura on different asparagus tissues, asparagus stems and leaves were selected as the research objects, related studies were conducted by constructing the life table and the feeding preference experiment. The results showed that S. litura could complete its development and reproduction normally on asparagus stems or leaves. Although the adult longevity and fecundity of S. litura on the two types of tissues were not significantly different, the development duration of larvae and pupae, and total preoviposition period on leaves were significantly longer than those raised on stems. The intrinsic rate of increase and finite rate of increase were 0.186 d-1 and 1.204 d-1 on stems, which were significantly higher than those fed on leaves (0.161 d-1 and 1.175 d-1). The mean generation time on stems (32.88 d) was significantly lower than on leaves (36.88 d). It indicated that stems were more suitable for its population growth. In the feeding preference, the third and fifth instar larvae preferred to feed on leaves, and other instar larvae (except for the sixth instar of 2.5 h) had no significant difference. These results will provide a theoretical reference for further research and forecasting and integrated control.

Effects of blood meal sources on the biological characteristics of Aedes aegypti and Culex pipiens (Diptera: Culicidae).

Mosquitoes transmit many diseases to humans and animals e.g., malaria, yellow fever, dengue, filariasis and encephalitis. The fundamental target of this search was to study the effect of three different blood meal sources (human; rabbit and pigeon) on some biological and behavioral properties of Aedes aegypti and Culex pipiens. The results have assured that the females of the mosquito Ae. aegypti that were fed on human blood meal has registered the highest feeding activity from feeding on the blood meal whereas the females of the other mosquito Cx. pipiens have shown the highest feeding activity after being fed on pigeons when compared with its feeding on other factors. The results have shown non-significant variation in the average time necessary to digest the blood meal on both mosquito species Ae. aegypti and Cx. pipiens that were fed on vertebrate hosts under laboratory conditions. Furthermore, results assured that the difference in blood meal sources has yielded distinct variation in the reproductive capacity and efficiency of both female mosquitoes under investigation where both species Ae. aegypti and Cx. pipiens already fed on human blood meal have yielded a pronounced distinctive increase in egg production (oviposition) when compared with females that were fed on pigeon or rabbit blood meal respectively. Moreover, feeding of the female mosquitoes under lab conditions on different blood meal sources did not affect the level of the hatching eggs that were laid by both mosquito females.

Concentration Dependent Feeding on Imidacloprid by Behaviorally Resistant House Flies, Musca domestica L. (Diptera: Muscidae).

The house fly (Musca domestica L.) is a cosmopolitan and synanthropic pest fly commonly associated with confined animal facilities, known to mechanically vector numerous disease-causing pathogens. Control of adult house flies often relies on insecticides formulated into insecticidal baits, though many baits have failed due to insecticide resistance. House fly resistance to imidacloprid, the most widely used neonicotinoid insecticide available for fly control, has evolved through physiological and behavioral mechanisms in field populations. Behavioral resistance to imidacloprid was documented in field populations of flies from southern California dairies. Lab colonies of these flies were established and behavioral resistance to imidacloprid was selected over several generations. The current study examined the ability of these lab-selected flies to feed on varying concentrations of imidacloprid formulated in sucrose, and if these flies would demonstrate a feeding preference for different concentrations of imidacloprid when exposed in bioassays. Behaviorally resistant flies preferred to feed on untreated sucrose as opposed to treated sucrose at concentrations greater than 25 µg/g imidacloprid when provided sucrose treated with and without imidacloprid. When provisioned with only sucrose treated with a low and high imidacloprid concentration, flies fed on the low concentrations (≤100 µg/g) imidacloprid but reduced feeding on either treatment when concentrations were >100 µg/g imidacloprid. The current study extends the body of knowledge on house fly behavioral resistance to imidacloprid, which could provide insights into future failures of granular fly baits.