Field trial on the effects of the herbicide MCPA on ixodid ticks

Abstract

Studies were conducted to develop a pheromone‐trap monitoring system for the sweet potato weevil, Cylas formicarius (Fabricius), in sweet potato, Ipomoea batatas (L.) Lam., fields in four states: Florida, Louisiana, North Carolina, and Texas. The present studies examined the attractiveness of sex pheromone synthesized by two sources (USDA and AgriSense) and pheromone of different purities (75–99%) to weevils in the field. In all but one trial, weevil counts did not differ between traps baited with pheromone from the two sources for each of two doses (10 and 100 μg). Percentages of weevils caught per replicate per sample date were not consistently positively correlated with purity (significant in four of 10 trials); however, slope estimates were steeper in regions with lower trap counts (North Carolina and Louisiana) than in those with higher trap counts (Florida). Because the pheromone will be used to monitor weevils In both weevil‐free and weevil‐infested regions, the use of pheromone with a purity level >99% is most appropriate. The importance of these data in pheromone‐trap monitoring programmes for this weevil worldwide is discussed.     

Combining visual cues and pheromone blends for monitoring and management of the tarnished plant bug Lygus lineolaris (Hemiptera: Miridae)

BACKGROUND

The tarnished plant bug Lygus lineolaris (Palisot de Beauvois) is considered the most damaging pest of cotton (Gossypium hirsutum L.) in the mid-southern United States. Previous studies have reported the role of different ratios of volatile metathoracic gland components such as hexyl butyrate, (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal in eliciting low-level attraction of L. lineolaris. In this study, we tested different visual cues (colored sticky cards) in combination with olfactory cues (pheromone blends) to optimize the attraction and capture of L. lineolaris in the field.

RESULTS

Red-colored sticky cards were more attractive to L. lineolaris adults than white, blue or yellow cards. Red sticky cards combined with blends of three potential pheromone components attracted significantly more L. lineolaris adults than sticky cards without a blend added. Traps baited with a blend of hexyl butyrate, (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal in 4:10:7 ratio, respectively, caught a significantly higher number of L. lineolaris than those baited with 10:4:2 or 7:10:4 blends or an unbaited control in the first week of the experiment.

CONCLUSIONS

Combining visual cues (red color) with olfactory cues (pheromone blends) significantly increased the capture of L. lineolaris in the field. This device or a future iteration could contribute towards sustainable and environmentally appropriate early-season monitoring and management of L. lineolaris in the field. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.     

Reduction of banana weevil populations with pseudostem traps

Abstract

One‐week‐old traps made from split banana pseudostems were 1.5–1.7‐fold more attractive to adult banana weevils than 2–3‐week‐old traps. In one experiment, all available pseudostem material was used for trapping, and weekly collecting of weevils over an 11‐month trapping period led to a 50% reduction in weevil catches in one field. In another field with a lower initial weevil density the trapping did not reduce weevil populations. In another experiment, the effect of intensive use of pseudostem traps and daily collecting of trapped weevils was estimated by a mark and recapture method over a period of 6 weeks. Reductions in weevil densities were calculated using a modified version of the Lincoln‐Index. Weevil populations were reduced by 48.5% after 3 weeks and by 62.5% after 6 weeks. Trapping efficiency declined during the experiment and appeared to be related to weevil population densities. This cultural control system may be effective in weevil control in small‐farm situations where labour availability is not a limiting factor.     

Development of semiochemical attractants for monitoring bean seed beetle, Bruchus rufimanus

BACKGROUND: Bruchus rufimanus is a serious pest of field beans. The objective here was to develop a semiochemical‐baited trapping system to facilitate monitoring of the pest. RESULTS: Volatile compounds that were electrophysiologically active with the antennae of B. rufimanus females were identified from headspace samples of Vicia faba flowers and from male B. rufimanus. Selected headspace samples and synthetic compounds were tested in olfactometer bioassays. The semiochemicals were then formulated in lures for traps and evaluated in a field trapping experiment. Cone traps baited with a three‐component blend of floral volatiles, releasing (R)‐linalool (17.7 mg day^?1), cinnamyl alcohol (0.4 mg day^?1) and cinnamaldehyde (0.77 mg day^?1), caught significantly more of both sexes of B. rufimanus than unbaited control traps. A male volatile, 1‐undecene, was EAG active with female antennae. It was attractive to females in an olfactometer, indicating that it is a sex pheromone. However, in the field it only enhanced trap catches if it was released together with the floral volatiles. CONCLUSION: The blends of semiochemicals identified were shown to be attractive in cone traps under field conditions. The prototype trapping system developed could be used as a monitoring tool to determine infestation levels of B. rufimanus in bean fields. Copyright © 2011 Society of Chemical Industry     

Evaluation of a multisurface trap for the capture ofEphestia kuehniella in stored wheat

An experiment was conducted to assess the use of a multisurface trap for the capture ofEphestia kuehniella Zeller (Lepidoptera: Pyralidae) in a horizontal-type warehouse in southern Greece, filled with approx. 200 tons of wheat. This type of trap consists of five white rectangular adhesive cardboard strips, suspended vertically from a cruciform apparatus. Four different types of traps were placed in the warehouse, one at each corner (pheromonebaited multisurface, unbaited multisurface, pheromone-baited single, and unbaited single trap). Traps were checked at 15-day intervals from July to November 2000. Approx. 85% of the total number of captured adults were recorded by late August. The highest numbers of moths were observed from mid-July until mid-August. As compared with the unbaited multisurface trap, the baited single and the unbaited single, the baited multisurface traps caught approximately 4.2, 4.8 and 41.2 times moreE. kuehniella adults, respectively. For all trap types, significantly higher numbers of adults were captured at the lower part of the sticky surface, as compared with the central and upper parts (P<0.05). A considerable percentage of the moths captured was found at the edges of the trapping surfaces, especially on the unbaited traps, where the figure exceeded 36%. With the exception of the unbaited single trap, significantly more adults were recorded at the lower edge of the trap (P<0.001), while the upper edge — as compared with the other edges — captured the fewest adults. Exposure of the trapping surface to illuminated areas of the warehouse, or location of the trapping surfaces close to walls, had no significant effect on captures. http://www.phytoparasitica.org posting Dec. 16, 2002.     

Derelomus piriformis Hoffmann (Curculionoidea: Curculionidae: Curculioninae: Derelomini), a new invasive species in Israel

Derelomus piriformis (Hoffmann), a weevil species developing onPhoenix canariensis, is recorded from Israel for the first time. The species belongs to the group of weevils that are pollinators of palms.D. piriformis is a pollinator ofP. canariensis, but at the same time is injurious to male flowers and occasionally also to female flowers. This group of weevils has not been previously recorded from Israel and adjacent countries. http://www.phytoparasitica.org posting July 19, 2006     

Biology and integrated pest management for the banana weevil Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae)

The banana weevil Cosmopolites sordidus (Germar) is the most important insect pest of bananas and plantains (Musa spp.). The larvae bore in the corm, reducing nutrient uptake and weakening the stability of the plant. Attack in newly planted banana stands can lead to crop failure. In established fields, weevil damage can result in reduced bunch weights, mat die-out and shortened stand life. Damage and yield losses tend to increase with time. This paper reviews the research on the taxonomy, distribution, biology, pest status, sampling methods, and integrated pest management (IPM) of banana weevil. Salient features of the weevil's biology include nocturnal activity, long life span, limited mobility, low fecundity, and slow population growth. The adults are free living and most often associated with banana mats and cut residues. They are attracted to their hosts by volatiles, especially following damage to the plant corm. Males produce an aggregation pheromone that is attractive to both sexes. Eggs are laid in the corm or lower pseudostem. The immature stages are all passed within the host plant, mostly in the corm. The weevil's biology creates sampling problems and makes its control difficult. Most commonly, weevils are monitored by trapping adults, mark and recapture methods and damage assessment to harvested or dead plants. Weevil pest status and control options reflect the type of banana being grown and the production system. Plantains and highland bananas are more susceptible to the weevil than dessert or brewing bananas. Banana production systems range from kitchen gardens and small, low-input stands to large-scale export plantations. IPM options for banana weevils include habitat management (cultural controls), biological control, host plant resistance, botanicals, and (in some cases) chemical control. Cultural controls have been widely recommended but data demonstrating their efficacy are limited. The most important are clean planting material in new stands, crop sanitation (especially destruction of residues), agronomic methods to improve plant vigour and tolerance to weevil attack and, possibly, trapping. Tissue culture plantlets, where available, assure the farmer with weevil-free material. Suckers may be cleaned by paring, hot water treatment and/or the applications of entomopathogens, neem, or pesticides. None of these methods assure elimination of weevils. Adult weevils may also invade from nearby plantations. As a result, the benefits of clean planting material may be limited to a few crop cycles. Field surveys suggest that reduced weevil populations may be associated with high levels of crop sanitation, yet definitive studies on residue management and weevil pest status are wanting. Trapping of adult weevils with pseudostem or corm traps can reduce weevil populations, but material and labour requirements may be beyond the resources of many farmers. The use of enhanced trapping with pheromones and kairomones is currently under study. A combination of clean planting material, sanitation, and trapping is likely to provide at least partial control of banana weevil.Classical biological control of banana weevil, using natural enemies from Asia, has so far been unsuccessful. Most known arthropod natural enemies are opportunistic, generalist predators with limited efficacy. Myrmicine ants have been reported to help control the weevil in Cuba, but their effects elsewhere are unknown. Microbial control, using entomopathogenic fungi and nematodes tend to be more promising. Effective strains of microbial agents are known but economic mass production and delivery systems need further development.     

Automated detection of the yellow-legged hornet (Vespa velutina) using an optical sensor with machine learning

BACKGROUND

The yellow-legged hornet (Vespa velutina) is native to Southeast Asia and is an invasive alien species of concern in many countries. More effective management of populations of V. velutina could be achieved through more widespread and intensive monitoring in the field, however current methods are labor intensive and costly. To address this issue, we have assessed the performance of an optical sensor combined with a machine learning model to classify V. velutina and native wasps/hornets and bees. Our aim is to use the results of the present work as a step towards the development of a monitoring solution for V. velutina in the field.

RESULTS

We recorded a total 935 flights from three bee species: Apis mellifera, Bombus terrestris and Osmia bicornis; and four wasp/hornet species: Polistes dominula, Vespula germanica, Vespa crabro and V. velutina. The machine learning model achieved an average accuracy for species classification of 80.1 ± 13.9% and 74.5 ± 7.0% for V. velutina. V. crabro had the highest level of misclassification, confused mainly with V. velutina and P. dominula. These results were obtained using a 14-value peak and valley feature derived from the wingbeat power spectral density.

CONCLUSION

This study demonstrates that the wingbeat recordings from a flying insect sensor can be used with machine learning methods to differentiate V. velutina from six other Hymenoptera species in the laboratory and this knowledge could be used to help develop a tool for use in integrated invasive alien species management programs. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Efficiency of inorganic fungicides against the formation of Erysiphe necator chasmothecia in vineyards

BACKGROUND

A reduction in chasmothecia, an important inoculum of grape powdery mildew (Erysiphe necator Schwein.), is essential for disease control in vineyards; the use of fungicides during the formation of chasmothecia on vine leaves, late in the growing season, may accomplish this. Inorganic fungicides, such as sulphur, copper, and potassium bicarbonate, are very useful for this purpose because of their multisite mode of action. The aim of this study was to evaluate chasmothecia reduction using different fungicide applications late in the growing season in commercially managed vineyards and in an exact application trial.

RESULTS

Chasmothecia on vine leaves were reduced in commercial vineyards by four copper (P = 0.01) and five potassium bicarbonate (P = 0.026) applications. The positive effect of potassium bicarbonate was also confirmed in the application trial, where two applications showed lower chasmothecia numbers than the control (P = 0.002).

CONCLUSION

The application of inorganic fungicides reduced the amount of chasmothecia as the primary inoculum source. Potassium bicarbonate and copper are of further interest for disease control as these fungicides can be used by organic and conventional wine growers. The application of these fungicides should be carried out as late as possible before harvest to reduce chasmothecia formation and, consequently, the potential for powdery mildew infestation in the subsequent season. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Characteristics of infestation of sweet potato by sweet potato weevil Cylas formicarius (Coleoptera: Apionidae)

Studies were conducted to examine the characteristics of infestation of vines of sweet potato plants by the sweet potato weevil, Cylas formicarius (F.). The use of terminal tender vine cuttings, taken even from heavily weevil‐infested sweet potato, to grow a new crop and planting such a crop in plots surrounded by barriers to reduce weevil migration from the outside to the newly planted area, produced a practically weevil‐free crop. On the contrary, crop planted to old vine cuttings in an open field was severely damaged by the weevil. Consequently, crop planted using tender vine cuttings produced significantly more root yield than the one planted to old vine cuttings, irrespective of whether the planting was done in an open field or in an insect‐protected field. Sweet potato weevil infestation of 1‐ to 8‐week‐old plants increased significantly with plant age. The insect preferred sweet potato roots over sweet potato vines when both plant parts were available for infestation. Dipping the vine cuttings for 30 min in carbofuran solution prior to planting protected the newly planted sweet potato crop for up to 6 weeks after planting.     

Informal Notes on the 4th East African Herbicide Conference at Arusha,Tanzania

Abstract

An IPM schedule using synthetic sex pheromone (Z‐3‐dodecenol‐E‐2‐butenoate) as the principal component against sweet potato weevil has been evaluated for the first time in India. The components of the IPM Programme were: (a) disinfecting the planting materials by dipping the slips in monocrotophos 0.05% for 10 min; (b) installation of pheromone traps from the first day of planting at 10 m distance (one trap/100 m²) to destroy the male weevils; and (c) re‐ridging the crop at 30 and 60 days after planting. The continuous elimination of the male population by pheromone traps in the treatment has resulted in a drastic decline in the population build‐up of the weevil and consequent reduction in the damage, leading to increased production of marketable tubers over 53%. In the first season weevil damage was reduced from 33% to 9.7% and in the second season from 39% to 9.5% by adopting the IPM schedule. The control field showed a four‐ to seven‐fold increase in the pest population (516 to 741 in the control and 114 to 128 in the treatment).     

Evaluation of the effectiveness of a new pheromonic trap for monitoringlasioderma serricorne (F.) in tobacco stores

The “Black Stripe Moth Trap”, a funnel type one (commercially available from AgriSence Inc.) designed for monitoring storage and field moths, was tested in tobacco stores in order to evaluate its effectiveness onLasioderma serricorne. The experiment took place for a 12 months-period (in 1996), in a private warehouse in Thessaloniki, Macedonia, Greece. The trap was applied baited (with 15 mg “serricornin”) and unbaited (control). The pheromonic trap has shown an impressive efficacy in trapping the tobacco beetle adults as it caught ∼95.4% of the total number of the insects, during the whole experimental period.     

Phenology, damage and parasitoids of the apple leaf cutter Coenorhinus pauxillus (Germ.) (Col.: Attelabidae)

An outbreak on apple permitted a closer look at Coenorhinus pauxillus (Germar) (Col.: Attelabidae). The adult weevils emerge from mid-March onwards and attack the first unfolding leaves. Infested leaves drop when the larvae are in the 1^st or 2^nd instar, and it takes a further 4 weeks before the larvae are ready to pupate. Rearing of field-collected eggs and larvae is described. Leaf decomposition is an essential condition for pupation, as the fully-grown larvae do not leave their mine actively. Part of the population pupates more or less immediately and produces adult weevils in autumn. However, up to 70% of the weevils remain in prolonged diapause; their pupation does not take place before the summer of the following year. Damage by the weevil involves not only the loss of leaves of flower clusters and shoots, but also feeding damage to young fruits. Two parasitoids were found. Observations indicate that 3–4 subsequently more abundant generations of Anaphes brachygaster Debauche (Hym.: Mymaridae) develop in eggs of C. pauxillus. Probles brevicornisHorstmann (Hym.: Ichneumonidae, Tersilochinae) emerges in May and oviposits in young weevil larvae on the tree. The parasitoid does not develop into a pupa until its host starts pupating. The outbreak of apple leaf cutter did not decline over three years, but did not spread into adjacent plantings.     

Bioactivity of short-chain aliphatic ketones against adults of the granary weevil, Sitophilus granarius (L.)

BACKGROUND: The granary weevil, Sitophilus granarius (L.), is one of the most damaging pests of stored grains, causing severe quantitative and qualitative losses. Sustainable control means, alternative to the commonly used fumigants and broad‐spectrum contact insecticides, are urgently needed owing to legislative limits, the development of resistant insect strains and increasing consumer demand for safe food. Short‐chain aliphatic ketones, known to be emitted by cereal grains and previously identified as repellents to adult granary weevils, were evaluated for their ability to disrupt insect orientation towards wheat grains and as possible natural fumigants. RESULTS: In behavioural bioassays, 2‐pentanone, 2‐hexanone, 2‐heptanone and 2,3‐butanedione significantly reduced insect orientation towards odours of wheat grains, with 2‐hexanone and 2‐heptanone being the most active. In fumigation tests, all compounds were effective in killing weevil adults, but they performed differently according to chemical structure, speed of action and presence of wheat grains. In the presence of grains, the highest fumigant toxicity was shown by 2‐pentanone (LC₅₀ = 8.4 ± 1.0 mg L^?1) after 24 h exposure, and by 2‐pentanone (LC₅₀ = 4.5 ± 0.3 mg L^?1), 2‐heptanone (LC₅₀ = 7.1 ± 0.3 mg L^?1) and 2‐hexanone (LC₅₀ = 8.1 ± 0.6 mg L^?1) 1 week after the treatment end. CONCLUSION: Short‐chain aliphatic ketones have potential for applications in IPM programmes for the granary weevil because of their behaviour‐altering activity and fumigant toxicity. Copyright © 2011 Society of Chemical Industry     

Ceuthorrhynchus suturalis,een voor uien schadelijke snuitkever

Summary In 1960Ceuthorrhynchus suturalis F., the onion weevil, was very abundant in onion fields in the south-western part of the Netherlands. PreviouslyLli (1954) in Yugoslavia andJancke & Nietzke (1939) andRogoll (1959) in East-Germany have studied this pest.Investigations on the biology and the control of the weevil in the Netherlands have given the following results. In early spring the weevils concentrate on the young onion crops, feeding on the leaves. Their feeding may cause serious damage to the plants (fig. 3). At a later stage of development of the plants the weevils oviposit in the leaves, mainly towards the tips. The larvae which hatch from the eggs, are free-living in the hollow leaves (fig. 1). They feed upon the leaf tissue with the exception of the epidermis, and cause transparent oblong spots, similar to those caused by the larvae ofAcrolepia assectella Zell. (fig. 2). The larvae pupate in the surface layers of the soil. After emergence the adult weevils remain for some days in the onion fields, feeding on the leaves. They then migrate to hibernate elsewhere.C. suturalis has only one generation a year.The young onion plants should be sprayed as soon as the damage caused by the weevils becomes visible. Plants in later stages of development should also be sprayed, if many transparent spots are present.The weevils are very susceptible to Gusathion. This insecticide should be used at a dosage of 300 g active ingredient per hectare. The larvae too are very susceptible to this insecticide (tables 1, 2 and 3); they are less susceptible to insecticides containing N-methylnaphthylcarbamate. The latter chemical has to be used at a dosage of 750 g active ingredient per hectare. To obtain a uniform cover of the plants it is advisable to apply the insecticide in a minimum amount of 500 liter of spray liquid per hectare and to add a detergent if not already present.     

The elimination of (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide) by the boll weevil

Boll weevils, Anthonomus grandis Boheman, were either dipped in or injected with a solution of [¹⁴C]diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide) or fed on cotton squares that had been treated with the chemical to determine its turnover time and metabolic fate. No significant differences were observed between male and female weevils in their ability to eliminate [¹⁴C]diflubenzuron. Only minor differences were observed when immersion and injection treatments were compared. When weevils were treated with 66.3 ng of [¹⁴C]deflubenzuron per weevil by injection, the insects contained 13 to 15% of the radiolabel after 6 days and 4 to 6% after 13 days. The remainder of the radiolabel was in the frass. When weevils fed for 66 hr on cotton squares that had been treated with a wettable [¹⁴C]diflubenzuron preparation (Dimilin W-25), the insects averaged 120 ng of diflubenzuron per weevil. Forty-four hours after removing insects from the treated squares, 50% of the radiolabel had been excreted. In all cases, the radiolabel found in the frass or in the weevil was unchanged diflubenzuron. There were no data to indicate that the boll weevil could metabolize appreciable amounts of diflubenzuron.     

Comparative acute toxicity of neonicotinoid and pyrethroid insecticides to non‐target crayfish (Procambarus clarkii) associated with rice–crayfish crop rotations

BACKGROUND: Most insecticides used to control rice water weevil (Lissorhoptrus oryzophilus Kuscel) infestations are pyrethroids. However, pyrethroids are highly toxic to non‐target crayfish associated with rice–crayfish crop rotations. One solution to the near‐exclusive reliance on pyrethroids in a rice–crayfish pest management program is to incorporate neonicotinoid insecticides, which are insect specific and effective against weevils but not extremely toxic to crayfish. This study aimed to take the first step to assess neonicotinoids as alternatives to pyrethroids in rice–crayfish crop rotations by measuring the acute toxicities of three candidate neonicotinoid insecticides, clothianidin, dinotefuran and thiamethoxam, to juvenile Procambarus clarkii (Girard) crayfish and comparing them with the acute toxicities of two currently used pyrethroid insecticides, lambda‐cyhalothrin and etofenprox. RESULTS: Neonicotinoid insecticides are at least 2–3 orders of magnitude less acutely toxic (96 h LC₅₀) than pyrethroids to juvenile Procambarid crayfish: lambda‐cyhalothrin (0.16 µg AI L^?1) = etofenprox (0.29 µg AI L^?1) ? clothianidin (59 µg AI L^?1) > thiamethoxam (967 µg AI L^?1) > dinotefuran (2032 µg AI L^?1). CONCLUSION: Neonicotinoid insecticides appear to be much less hazardous alternatives to pyrethroids in rice–crayfish crop rotations. Further field‐level neonicotinoid acute and chronic toxicity testing with crayfish is needed. Copyright © 2009 Society of Chemical Industry     

Unusual behavior of oviposition and development of <Emphasis Type="Italic">Sitophilus zeamais</Emphasis> (Coleoptera: Curculionidae) in peach and apple fruits

The maize weevil Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae) is a worldwide pest on stored products, as maize, wheat and rice grains. However, in South Brazil, these weevils have been found attacking fruits in field conditions. It was reported that adults attack fruits to feeding, but there was no information of oviposition and larval development on these hosts. Furthermore, due to monitoring apple orchards, was observed that some fruits showed distinct kind of punctures, suggesting a oviposition by these weevils. The present study reports first record an unusual behavior of S. zeamais by oviposition and larval development in peach and apple fruits. The study was conducted in laboratory conditions (temperature: 25?±?1 °C, RH: 70?±?10% and photophase of 14 h). Peach and apple fruits were offered to S. zeamais females. The oviposition and duration of immature stages in peach were measured in fruits and in corn grains, used as control observation. The oviposition and larval development occurred in peach and apple fruits, with a development until to adult. The average of egg-to-adult was 47.4 d in peach and and 45.1 d apple fruits, respectively, while in corn grains, its natural host, the duration was 38.2 d. These results show that the damage caused by S. zeamais in peach and apple fruits may be due to oviposition and the development of immature stages. So, the novelty is in demonstrating that the maize weevil does not just feed as an adult opportunistically on the fruits, but can complete a full life cycle using fresh fruits.     

基于MaxEnt模型的菜豆象和蚕豆象在中国的适生区预测

为减少外来入侵物种菜豆象Acanthoscelides obtectus和蚕豆象Bruchus rufimanus对中国造成的潜在威胁,收集这2种豆象的全球地理分布数据,采用Pearson相关性分析和主成分分析分别从19个环境变量中筛选关键环境变量,采用MaxEnt模型对历史气候条件下和未来气候情景下这2种豆象在中国的适生区进行预测,并对预测结果进行分析。结果显示,经Pearson相关性分析共筛选出4个关键环境变量用于菜豆象适生性区的模型构建,分别为最暖季度平均温度、最干月份降水量、年气温变化范围及最湿季度降水量,其对MaxEnt模型的累积贡献率分别为31.6%、28.4%、26.3%和13.7%;经Pearson相关性分析共筛选出4个主要关键环境变量用于蚕豆象适生性区的模型构建,分别为最冷季度平均温度、最干月份降水量、最热月份最高温度和最湿月份降水量,其对MaxEnt模型的累积贡献率分别为48.5%、39.5%、7.8%和4.2%。MaxEnt模型重复运行10次后,菜豆象训练数据的平均AUC值为0.938,蚕豆象训练数据的平均AUC值为0.963,均显著高于随机模型的AUC值,表明基于MaxEnt模型的菜豆象和蚕豆象在中国适生区的预测结果准确。未来气候情景下,这2种豆象在中国的适生区均呈现向北扩张的趋势,需加强对这2种豆象的检疫与防治,严防发生区域进一步扩大。     

警惕危险性害虫辣椒花象甲入侵我国

辣椒花象甲Anthonomus eugenii是一种毁灭性害虫,原产于中美洲,可为害至少35种商业辣椒品种,对辣椒为害严重,可使其减产33%～90%。该害虫于1993年入侵加拿大,并于2014年进入欧洲。频繁的全球贸易及国际运输将加速该害虫的传播和扩散,并有入侵我国的风险。该文对辣椒花象甲的生物学特性、寄主植物、为害特征、分布范围及传播进行总结,分析其对我国的入侵风险及对我国辣椒产业造成的潜在损失,并提出风险管理措施。