Evaluation of the extracts of some tropical plants in the management of Prostephanus truncatus (Horn) infestation in maize (Zea mays L.)

The efficacy of extracts from seven tropical plants, namely Azadirachta indica, Nicotiana tabacum, Ocimum gratissimum, Cola millenni, Tetracarpidium conophorum, Delonix regia, and Vernonia amygdalina at reducing post-harvest loss caused by the larger grain borer, Prostephanus truncatus to maize grains was studied in the laboratory and in a crib. The experiments were laid down using complete randomised design with four replicates. A synthetic insecticide, Actellic25EC, was included in the trials as a check, while maize grains treated with n-hexane were used as control. Extracts from A. indica and N. tabacum were further tested in maize stored in cribs. The results of the study showed that all the plant extracts used were significantly better (P < 0.05) than the control. Measured parameters such as % mean weight loss, % mean grain damage, mean weight of grain dust, mean number of adult P. truncatus and mean number of adult mortality showed that the effects of A. indica and N. tabacum extracts were significantly (P < 0.05) higher than the effects of other extracts. The percentage germination of grains treated with the extracts of N. tabacum and A. indica was 85.0 and 89.0%, respectively, and they were significantly (P < 0.05) higher than 58.0% germination in the control. Extracts of A. indica and N. tabacum have great potential for post-harvest preservation of stored maize against infestation by P. truncatus.     

Reduced survival and infestation of coffee borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae), on coffee fruits, in response to neem sprays in laboratory

Aqueous solutions of neem oil and aqueous extracts of neem seeds and leaves were sprayed on coffee fruits for laboratory evaluation of their efficiency in reducing infestation of the coffee borer, Hypothenemus hampei (Ferrari), in multi-choice preference assays in laboratory. Neem oil and extracts reduced infestation of fruits in a dose-dependent manner, acting as a repellent. At 0.5%, 1% and 1.5%, the oil reduced fruit infestation by 30.2%, 42.5% (P > 0.05), and 58.6% (P < 0.05), respectively, as compared with the control. Seed extracts at 1%, 2% and 4% (w/v) reduced infestation by 30.9%, 38.3% (P > 0.05) and 70.2% (P < 0.05), respectively; seed extracts at 0.15%, 1.5% and 15% (w/v) reduced fruit infestation by 16.5%, 38.5% (P > 0.05) and 56.9% (P < 0.05), respectively. Spraying the emulsifiable oil at 1% on coffee fruits and adult borers was compared with spraying on fruits or adults only. Adult-only spraying caused low mortality (P > 0.05) and low reduction on the number of damaged fruits (P > 0.05). Fruit-only spraying significantly reduced insect survival rates and the number of damaged fruits (P < 0.05). However, spraying on adults and fruits caused the greatest reduction in adult survival (55.6%; P < 0.05) and in fruit infestation (78.7%; P < 0.05), probably due to insect mortality and neem oil repellence acting together.     

The toxicity and biological effect of Pedalium murex L. extracts on the tobacco cutworm,Spodoptera litura (Fabr.) larvae

Petroleum ether, acetone, water and aqueous extract of Pedalium murex L. (Pedalaceae) leaves, root and fruit were tested against fourth instar larvae of the tobacco cutworm, Spodoptera litura (Fabr.) under laboratory conditions using leaf dip method. Larval mortality; larval, pupal and adult periods; pupal weight, pupation and adult emergence; larval and pupal deformities of S. litura were recorded. All the tested solvent extracts of P. murex were effective against S. litura life stages by causing mortality in a dose dependent manner. However, the efficacy was more significant with respect to acetone (leaf and root) and petroleum ether (root) at higher concentrations (0.8%) which leads to 100% larval mortality. The water and aqueous extracts of root caused 86.6 and 88.0% larval mortality respectively at 4% concentration. Among the plant parts tested, root had more importance followed by leaf and fruit. Plant extracts extended the larval, pupal and adult periods; reduced the pupal weight, pupal and adult emergence and caused larval–pupal deformities. Total life time was highly prolonged in acetone extracts of P. murex root. Though all the extracts were found to have insecticide activity, acetone and petroleum ether extracts of P. murex root can be used as an effective alternative to modern synthetic insecticides. Bioactive principles from these extracts can be isolated, identified and integrated in S. litura management.     

Importance of seed Zn content for wheat growth on Zn-deficient soil

Eggplants (Solanum melongena L. cv. Bonica) were grown in a glasshouse during summer under natural light with one unbranched shoot or one shoot with 3 to 4 branches and with or without fruit in quartz sand buffered and not buffered with 0.5% CaCO₃ (w : v), respectively. Nutrient solutions supplied contained nitrate or ammonium as the sole nitrogen source. Compared with nutrient solutions containing nitrate (10 mM), solutions containing ammonium (10 mM) caused a decrease in net photosynthesis of eggplants during early stages of vegetative growth when grown in quartz sand not buffered with CaCO₃. The decrease was not observed before leaves showed interveinal chlorosis. In contrast, net photosynthesis after bloom at first increased more rapidly in eggplants supplied with ammonium than with nitrate nitrogen. However, even in this case, net photosynthesis decreased four weeks later when ammonium nutrition was continued. The decrease was accompanied by epinasty and interveinal chlorosis on the lower leaves and later by severe wilting, leaf drop, stem lesions, and hampered growth of stems, roots, and fruits. These symptoms appeared later on plants not bearing fruits than on plants bearing fruits. If nutrient solutions containing increasing concentrations of ammonium (0.5–30 mM) were supplied after the time of first fruit ripening, shoot growth and set of later flowers and fruits were promoted. In contrast, vegetative growth and reproduction was only slightly affected by increasing the concentration of nitrate in the nutrient solutions. In quartz sand buffered with CaCO₃ ammonium nutrition caused deleterious effects only under low light conditions (shade) and on young plants during rapid fruit growth. If eggplants were supplied with ammonium nitrogen before bloom, vegetative growth was promoted, and set of flowers and fruit occurred earlier than on plants supplied with nitrate. Furthermore, the number of flowers and fruit yield increased. These effects of ammonium nutrition were more pronounced when plants were grown with branched shoots than with unbranched shoots. The results indicate that vegetative and reproductive growth of eggplants may be manipulated without causing injury to the plants by supplying ammonium nitrogen as long as the age of the plants, carbohydrate reserves of the roots, quantity of ammonium nitrogen supplied, and pH of the growth medium are favourable. T W Rufty Section editor     

基于转录组的葡萄花翅小卷蛾三类解毒酶基因家族分析

[目的]葡萄花翅小卷蛾是我国重要的检疫性害虫,一旦入侵我国,将会对我国葡萄产业和林果业生产造成严重损失,国外主要使用化学农药防治该虫.开展葡萄花翅小卷蛾转录组测序及体内细胞色素P450单加氧酶(cytochrome P450 monooxygenase,CYP)、羧酸酯酶(carboxylesterase,CarE)和...     

Neoleucinodes elegantalis (Lepidoptera: Crambidae): an organism invisible to the defences of tomato fruits

Insect–plant interactions involving species of the genus Solanum have been intensively studied, resulting in several articles on insect–plant interactions. However, the interactions between herbivores and the fruits of Solanum lycopersicum (tomato) are not well known. Neoleucinodes elegantalis is a borer that causes great yield losses in S. lycopersicum crops because of the direct damage that it causes to the fruits and the difficulty of controlling it. In the field, the outside of a tomato fruit infested with the larvae of N. elegantalis is visually similar to uninfested fruits. Even a minor injury by herbivores can elicit a defensive response. Due to the lack of studies on interactions between fruit borers and S. lycopersicum, our aim in this study was to determine the locations of S. lycopersicum fruit in which the N. elegantalis larvae prefer to feed. An evaluation of nutritional sources was done through histochemical and biochemical tests and the defensive response of the S. lycopersicum fruit to attack by N. elegantalis larvae was evaluated through the detection of protease inhibitors (PIs) and lipoxygenase (LOX) activity. Our results show that the columella region is preferred by the N. elegantalis larvae and that this region has a nutritional source. Furthermore, attack by N. elegantalis larvae in the columella does not induce a significant increase in lipoxygenase activity and PIs. Thus, our results provide a better understanding of the interaction between the larvae of N. elegantalis and S. lycopersicum fruits and a better understanding of the evolution of plant–herbivore interactions, with an emphasis on the choice of feeding location as a strategy to avoid plant defences.     

Control of flea beetles Podagrica spp. (Coleoptera: Chrysomelidae) infestation on okra (Abelmoschus esculentus (L.) Moench) using Piper guineense seed extracts

Crops in the Family Malvaceae are attacked by various insect pests especially Podagria species (Coleoptera: Chrysomelidae) at different stages of their development. The emergence of biodegradable pesticides (botanicals) as safe option has reduced the problems that result from the use of synthetic insecticides, thus creating a renewed interest in their development and use in integrated pest management of crops. Therefore, field experiments were conducted to investigate the control capability of water extracts of Piper guineense seeds and Cypermethrin on flea beetles (Podagrica spp.) infesting okra (Abelmoschus esculentus (L.) Moench). The experiments were conducted in two locations in the rain forest zone of Nigeria. The first experiment was conducted at the Teaching and Research Farm of The Federal University of Technology Akure, Ondo State (2011 Early cropping season), while the second experiment was carried out at the Teaching and Research Farm of Rufus Giwa Polytechnic, Owo, Ondo State (2011 Late cropping season). A synthetic insecticide (Cypermethrin) was included in the treatments as a standard check alongside the untreated (control). The experimental design was laid out in a randomised complete block design with five treatments replicated three times. The effectiveness of the treatments was determined based on reduction in the population of the adult insects. The results showed that water extract of P. guineense seeds and the synthetic insecticide significantly (p?<?0.05) reduced the population of the flea beetles as compared with the control. The synthetic insecticide-treated plots produced the highest standard check, but this was not significantly different from the dried yield recorded in the plots sprayed with aqueous extracts of P. guineense seeds. The results of field trials in both cropping seasons showed that all the treatments significantly suppressed the infestation by the flea beetles throughout the study period. In view of the ability of water extract of P. guineense seeds to control the infestation of Podagrica spp. its use by farmers is therefore recommended.     

Toxic and Antifeedant Effects of Different Pesticidal Plant Extracts against Beet Armyworm (<i>Spodoptera exigua</i>)

The beet armyworm (BAW), Spodoptera exigua (Lepidoptera: Noctuidae) is a highly destructive pest of vegetables and field crops. Management of beet armyworm primarily relies on synthetic pesticides, which is threatening the beneficial community and environment. Most importantly, the BAW developed resistance to synthetic pesticides with making it difficult to manage. Therefore, alternative and environment-friendly pest management tactics are urgently required. The use of pesticidal plant extracts provides an effective way for a sustainable pest management program. To evaluate the use of pesticidal plant extracts against BAW, we selected six plant species (Lantana camara, Aloe vera, Azadirachta indica, Cymbopogon citratus, Nicotianatabacum, and Ocimum basilicum) for initial screening experiment. Four out of six plant species such as A. indica, N. tabacum, C. citratus and O. basilicum showed promising mortality of more than 50%. Therefore, we selected these four plant extracts for the subsequent experiments. Through contact bioassay, A. indica showed high mortality 66.63%, followed by the N. tabacum 53.33%, at 10% w/v concentration. Similarly, N. tabacum showed the highest mortality rate, 66% at 10% w/v concentration, followed by the A. indica 46% through feeding bioassay. Furthermore, the feeding deterrence assay showed that C. citratus had a high antifeedant index (−50) followed by A. indica (−39), and N. tabacum (−28). In living plant assay, the N. tabacum extract showed a low mean damage score 3.6 on living cotton plant followed by C. citratus 4.5 and A. indica 5.5. Hence, extracts of three plant species provided promising results against the BAW, which can minimize the use of synthetic chemicals, particularly for small landholding farmers. Further studies are also required to evaluate the effects of these plant extract against BAW on cotton plants under field conditions to optimize the further use.     

Comparison of biological and conventional insecticide treatments for the management of the pineapple fruit borer, Strymon megarus (Lepidoptera: Lycaenidae) in Costa Rica

Carbaryl is currently one of the most commonly used insecticides for the control of the pineapple fruit borer, Strymon megarus (Godart), in commercial pineapple production. To evaluate more sustainable biological alternatives to conventional insecticides, three microbial and one botanical insecticide were studied. Beauveria bassiana, Metarhizium anisopliae, Bacillus thuringiensis (Bt) and a plant extract from Quassia amara were compared with carbaryl in replicated field trials in Costa Rica during 2005 and 2006. In both years of testing, the untreated control received over 50% fruit damage from S. megarus. Bt and carbaryl provided the highest level of control and the lowest level of fruit damage compared to all other treatments. Based on the results of this study, Bt appears to be an acceptable biological alternative to the conventional insecticide (carbaryl) for control of S. megarus on pineapple. In addition, Bt was the least expensive treatment used in this study.     

Physical and chemical cues affect oviposition by Neoleucinodes elegantalis

Recognition and acceptance of a suitable host plant by phytophagous insects requires the integration of visual, physical and chemical cues. The present study investigates the host cues that a specialist insect integrates to optimize oviposition decisions and whether these cues are weighted in a specific way. The study also determines whether the tomato fruit borer Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae), an important pest on Solanaceae in Brazil, shows a preference for oviposition sites that differ in physical and/or chemical cues. When styrofoam balls are provided as artificial fruits, N. elegantalis deposit significantly more eggs on rough artificial fruits than on smooth ones. Hexane fruit extracts applied to the artificial fruits stimulate female oviposition strongly. Physical and chemical cues also affect the oviposition of females when offered together. Furthermore, certain parts of the artificial fruits are prefered, irrespective of the presence of chemical cues. Both physical and chemical cues affect oviposition decisions; hence, the fruit borer relies on cues of different sensory modalities.     

枣园桃蛀果蛾寄生蜂种类及其与寄主的关系

桃蛀果蛾(Carposina sasakii Matsumura)是我国十分重要的果实性害虫,其中枣受害最严重,因其幼虫在果实内蛀食危害、高度隐蔽性的生活而较难防治。寻找有效天敌,开展生物防治成为必然。2009年与2010年研究调查了我国大枣部分产区陕西、山西、河南与宁夏枣园桃蛀果蛾寄生性天敌,共发现了3种寄生蜂,即中华齿腿姬蜂(Pristomerus chinensis Ashmead)、章氏小甲腹茧蜂(Chelonus(Microchelonus)zhangi Zhang)和金小蜂(Pteromalidae),3种寄生蜂均从桃蛀果蛾的茧中羽化而出,其中中华齿腿姬蜂和章氏小甲腹茧蜂为优势天敌,但它们表现出十分明显的地域性分布。同时,对中华齿腿姬蜂和章氏小甲腹茧蜂羽化、寄生率以及与寄主之间的关系进行了初步研究,结果表明,中华齿腿姬蜂越冬代成虫出蛰活动始于6月中旬,越冬代寄生率较低,第1代成虫羽化在8月下旬至9月上旬,这代寄生蜂具有较高的寄生率,可达25%;章氏小甲腹茧蜂第1代成虫羽化集中在8月中下旬和9月上旬,由于在2009年与2010年对样地进行不施用杀虫剂的管理,该天敌在2010年自然寄生率显著提高,最高时可达64.52%。因此,科学管理,合理保护与利用当地天敌成为实现该害虫生物防治的关键。     

The potential for controlling Megalurothrips sjostedti (Thysanoptera: Thripidae) on cowpea,Vigna unguiculata (L.) Walp flowers using extracts of cashew (Anacardium occidentale L.) products

Abstract

The efficacy of aqueous extracts of cashew, Anacardium occidentale L. products was tested on Legume flower bud thrips on field cowpea in the 1999 and 2000 seasons using nutseed and nutshell at 10% w/v, bark and leaf at 20% w/v. Aqueous extract of cashew nutshell was superior to other cashew products in reducing thrip populations in cowpea flowers and compared favourably with cypermethrin + dimethoate. Pod density per plant was significantly enhanced on cowpea plants sprayed with aqueous extract of cashew nutshell compared to other extracts. Cashew extract contains cardole (a caustic substance) and anacardic acid, which may have been responsible for its insecticidal effect on thrips. This result indicates the potential of cashew products especially the nutshell for integrated management of thrips in legume crops.     

Effect of application of different concentrations and appropriate schedules of aqueous garlic (Allium sativum L.) bulb extracts against Maruca vitrata and Clavigralla tomentosicollis on cowpea,Vigna unguiculata (L.) Walp

Abstract

Three concentrations (5, 10 and 20% w/v) and spraying schedules (2×, 4× and 6× weekly applications) of garlic, Allium sativum L. bulb extracts were assayed for efficacy against Maruca vitrata Fab. and Clavigralla tomentosicollis Stal. on cowpea under rain fed conditions in two seasons. The results showed that application of aqueous garlic bulb extracts at all the treatment levels significantly (p < 0.05) reduced the populations of the target pests compared with the untreated check. Application of 10 and 20% garlic bulb extracts with 4 or 6 weekly applications gave better control of these pests, protected the pods from damage and increased grain yields on treated cowpea compared with 5% extract at all three application schedules and were comparable to the synthetic insecticide treatment. This material could play a role in the integrated management of M. vitrata and C. tomentosicollis on cowpea fields managed by limited resource farmers in developing countries. The plant material is readily available, cheap, safe, non phytotoxic and technologically simple to use.     

Effects of fruit fly host, fruit species, and host egg to female parasitoid ratio on the laboratory rearing of Biosteres arisanus

The host suitability of the oriental fruit fly, Bactrocera dorsalis (Hendel), for development of Biosteres arisanus (Sonan), a braconid parasitoid, was compared with three other fruit fly species, namely, Mediterranean fruit fly, Ceratitis capitata Weidemann, melon fly, Bactrocera cucurbitae Coquilett, and Malaysian fruit fly, Bactrocera latifrons (Hendel). In addition, effects of five different fruit species, namely, Carica papaya L. (solo papaya), Musa sapientum (L.) O. Ktze. (apple banana), Mangifera indica (L.) (Haden mango), Terminalia catappa (L.) (false kamani), and Citrus aurantiifolia (Christman) Swingle (common lime), on the parasitization rate of B. dorsalis and sex ratio of parasitoid progenies were evaluated. Effects of host egg to female B. arisanus ratios on parasitoid progeny yields were likewise determined. The host suitability of fruit flies for development of B. arisanus was ranked as: B. dorsalis>C. capitata=B. latifrons=B. cucurbitae. Based on percent parasitization of B. dorsalis, preference of B. arisanus females for host eggs varied with fruit species, however, preferential oviposition displayed by female parasitoids did not influence sex ratios of subsequent parasitoid progenies. Increases in host egg to female parasitoid ratios of 5:1, 10:1, 20:1, 25:1, and 30:1 corresponded with increases in parasitoid progeny yield reaching a plateau at 20:1.     

Effectiveness of plant extracts to control purple blotch and Stemphylium blight diseases of onion (Allium cepa L.) in Assiut,Egypt

The present investigation aimed to isolate the causative agents of onion purple blotch and Stemphylium blight diseases and evaluate the efficacy of certain plant extracts against the two identified pathogens, in vitro and under greenhouse condition. Fourteen isolates of S. vesicarium and two isolates of Alternaria porri were tested for pathogenicity. The results indicated that all isolates were able to produce the symptoms of Stemphylium blight and onion purple blotch diseases with different degrees of severity ranging from 10.42 to 81.25%. A. porri No. 6022 caused the highest disease severity (81.25%), while S. vesicarium No. 6003 was the best one out of the tested 14 isolates (37.5%). Antifungal activity of some aqueous plant extracts (Azadirachta indica, Cydonia oblonga, Datura stramonium, Eucalyptus globulus, Foeniculum vulgare, Ocimum basilicum, Rosmarinus officinalis and Salix mucronata) was assayed in vitro by dry weight technique. The data indicated that there were significant differences between these extracts in their effect on fungal growth of A. porri and S. vesicarium and the best were A. indica and D. stramonium. Under greenhouse conditions, application of the aqueous extract of A. indica either before or after 48?h A. porri inoculation produced the highest reduction in disease severity comprising 70 and 74.7%, respectively. On the other hand, the highest percentage of disease reduction before and after 48?h S. vesicarium inoculation was produced by Ridomil gold plus reached to 84.4 and 95.8% respectively, followed by the aqueous extract of A. indica (74.1 and 89.7, respectively). According to our results, it can be concluded that plant extracts of A. indica and D. stramonium can be used for the biocontrol of purple blotch and Stemphylium blight diseases instead of fungicides to minimise the risks and hazards of using toxic fungicides.     

Postharvest Infiltration of BTH Reduces Infection of Mango Fruits (Mangifera indica L. cv. Tainong) by Colletotrichum gloeosporioides and Enhances Resistance Inducing Compounds

Mango fruits (Mangifera indica L.) were treated by vacuum infiltration of 1.0 mm benzo‐(1,2,3)‐thiadiazole‐7‐carbothioic acid s ‐methyl ester (BTH) after harvest. Seventy‐two hours after the treatment with BTH, the fruit were inoculated with 15 μl of conidial suspension of Colletotrichum gloeosporioides (1 × 10⁵ conidia/ml) and incubated at 13°C, 85–90% RH for disease development. Disease incidence and lesion diameter in mango fruit after the inoculation were significantly (P < 0.05) reduced by the BTH treatment during the incubation. Peroxidase, polyphenoloxidase, phenylalanine ammonia‐lyase, chitinase and β‐1,3‐glucanase activities and total phenolic compounds content in the fruits were all enhanced by the BTH treatment during the incubation. The catalase activity in the fruit was inhibited, whereas the level of hydrogen peroxide was increased by the BTH treatment during the infection. These responses may be involved in the induced resistance against the pathogen infection in mango fruit by BTH treatment. Application of BTH in fruit possesses promising results in the control of postharvest diseases as an alternative to traditional methods.     

Age as a factor in induction of systemic acquired resistance in tomato against bacterial speck by aqueous fruit extracts of Azadirachta indica

In the present study, the effect of aqueous fruit extracts of Azadirachta indica on activity of Peroxidase (POX) at different ages of Tomato (Lycopersicon esculentum) leading to induction of systemic resistance against Pseudomonas syringae pv. tomato was evaluated. For this evaluation, four ages, that is, 6, 8, 10 and 12?weeks of plants were selected. A single leaf at the third node from base of each plant was treated either singly or with different combinations of Neem extract and pathogen. Samples were collected at an interval of 24?h for up to five days and after two weeks of the treatment from both treated and untreated nodes. The change in the activity of defence enzyme POX and expression of its isoforms was studied. The results demonstrate that systemic acquired resistance induced by the Neem fruit extract increases as the plant matures but it is not only the limiting factor.     

Efficacy of a simply resting box baited with crude fruit and leaf ethanol extracts of Phytolaccadodecandra (L’ Herit) in capturing and killing of indoor mosquitoes (Diptera: Culicidae) at Korando,Western Kenya

Effective capture and elimination of indoor resting mosquito population is important in the fight against mosquito borne diseases. This study aimed at evaluating the efficacy of a simply resting box baited with crude fruit and leaf ethanol extracts of Phytolacca dodecandra in attracting and killing indoor mosquitoes at Korando, Western Kenya. The study was conducted in three phases: pre-intervention, intervention and post intervention. Simple resting boxes made from galvanized wire frame measuring 30 cm × 30 cm × 30 cm, covered in blue and black tunic in and out and lined with carton boards were used. The boxes were baited with socks with strong human odour and 80 ml/100mls (e/w) solution of either crude ethanol fruit or leaf extracts of P. dodecandra, ethanol leaf extracts of Azadiracta indica or Deltamethrin. Deltamethrin and Azadiracta indica were used as positive and water as negative control. The treatments were applied at the intervention phase only. The boxes were left overnight in the houses and mosquitoes collected by 6.30 h. It was observed that more Culicines than Anopheline were captured irrespective of phase or treatment used. Mosquito densities reduced with phase of activity. P. dodecandra leaf extracts killed more mosquitoes than fruit or A. indica leaf extracts though the number were less than that of Deltamethrin or WHO threshold of >80% mortality. In conclusion, the simple resting boxes were effective in collecting and killing indoor mosquitoes though lethality did not matched the WHO threshold. With improved structural set up and use of pure extracts of P. dodecandra, the resting boxes can serve as effective tools for capture, elimination and management of mosquito borne diseases.     

Fruit extract capped colloidal silver nanoparticles and their application in reduction of methylene blue dye

Green synthesis of silver nanoparticles (AgNPs) has become a promising environmentally benign synthetic route in nanoscience and nanotechnology during recent years. In the present work, we have developed an environment-friendly and low-cost method for synthesis of silver nanoparticles from silver nitrate using aqueous fruit extract of Dillenia indica. The as-synthesized nanoparticles were characterized by UV-Vis spectrophotometer, transmission electron microscopy (TEM) and X-ray diffraction (XRD). FTIR study was performed to know the interaction of bio-molecules present in the fruit extract with AgNPs. The catalytic application of the as-synthesized AgNPs was demonstrated against degradation of methylene blue (MB) in aqueous system. The absorption spectra of colloidal suspension of AgNPs showed characteristic surface plasmon resonance (SPR) band centred at a wavelength of 416?nm. TEM image showed that the AgNPs were almost spherical in shape having an average diameter of 10.78?±?.48?nm. XRD pattern and selected area electron diffraction (SAED) pattern with bright spots signify the crystalline nature of nanoparticles. The fruit extract-capped AgNPs was highly stable and have showed the effective catalytic activity in reduction of MB dye.     

Pheromone-mediated mass trapping and population diversion as strategies for suppressing Carpophilus spp. (Coleoptera: Nitidulidae) in Australian stone fruit orchards

1 Five experiments were conducted during 1995–99 in stone fruit orchards on the Central Coast and in inland New South Wales, Australia, on the use of synthetic aggregation pheromones and a coattractant to suppress populations of the ripening fruit pests Carpophilus spp. (Coleoptera: Nitidulidae). 2 Perimeter‐based suppression traps baited with pheromone and coattractant placed at 3 m intervals around small fruit blocks, caught large numbers of Carpophilus spp. Very small populations of Carpophilus spp. occurred within blocks, and fruit damage was minimal. 3 Carpophilus spp. populations in stone fruit blocks 15–370 m from suppression traps were also small and non‐damaging, indicating a large zone of pheromone attractivity. 4 Pheromone/coattractant‐baited suppression traps appeared to divert Carpophilus spp. from nearby (130 m) ripening stone fruit. Ten metal drums containing decomposing fruit, baited with pheromone and treated with insecticide, attracted Carpophilus spp. and appeared to reduce populations and damage to ripening fruit at distances of 200–500 m. Populations and damage were significantly greater within 200 m of the drums and may have been caused by ineffective poisoning or poor quality/overcrowding of fruit resources in the drums. 5 Suppression of Carpophilus spp. populations using synthetic aggregation pheromones and a coattractant appears to be a realistic management option in stone fruit orchards. Pheromone‐mediated diversion of beetle populations from ripening fruit may be more practical than perimeter trapping, but more research is needed on the effective range of Carpophilus pheromones and the relative merits of trapping compared to attraction to insecticide‐treated areas.