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1.
Effectiveness of Some Insecticides on Wheat Blossom Midges in Winter Wheat   总被引:1,自引:0,他引:1  
Orange wheat blossom midge damage can impart serious loss of quantity and quality of winter wheat. Wheat midges were evaluated in large scale field in winter wheat in Bad Lausick (Leipzig, Saxsony) central Germany. The present study aimed at studying the activity of wheat blossom midges WBM, Sitodiplosis mosellana (Géhin) and Contarinia tritici (Kirby) using pheromone, sticky traps and two types of water traps. Management of midges with different treatments was studied; Karate (pyrethroid), Biscaya (neonicotinoid) and NeemAzal T/S (botanical insecticide) were sprayed on wheat at heading stage (GS 55). Monitoring was conducted before the treatment and continued for 4 weeks after the treatment. Pheromone traps were used for forecasting midge adult population and determine the control date. Water traps were used to assess midge larvae, while midge adults were surveyed using sticky traps. A strong correlation between midge catches and weather conditions was obtained; as well a coincidence between pheromone catches and wheat midge infestation in the susceptible growth stages (GS 47–65) was recorded. Insecticide applications to fields of midge-infested winter wheat significantly reduced the wheat midge damage. There were significant differences in wheat midge numbers between treated and untreated; wheat midge numbers were lower in the treated than in control. The results proved that both Karate and Biscaya caused more mortality to wheat midges than NeemAzal T/S.  相似文献   

2.
Abstract

The African rice gall midge, Orseolia oryzivora Harris and Gagne (Diptera: Cecidomyiidae), is an important pest of rice, Oryza sativa, in Burkina Faso as well as other countries in West and East Africa. In spite of its importance, little is known regarding the relationship between gall midge populations and grain yield losses. To determine yield losses the gall midge was reared in cages and adult midges were placed on caged plants of the rice variety ITA 123 at different population levels. The seven treatments consisted of different numbers of insects infested on the plants; 0 insect pairs (non‐infested check), and 1, 5, 10, 15, 20 or 25 midge pairs/cage. The loss in yield in relation to the non‐infested control was highly positively correlated (R2 = 0.81) with the percentage of gall midge damaged tillers. The infestation by the insect on the plants resulted in the compensatory production of tillers which developed in response to the gall midge damage but the compensation was not sufficient to make up for the loss of yield due to the damaged tillers. Yield loss ranged from 0% in the control to 65.3% in the treatment with 25 pairs of adults. One per cent of tillers damaged resulted in 2% grain yield loss.  相似文献   

3.
Abstract

A total of 13 species of shootflies from two genera, Atherigona and Acritochaeta, were reared over a four-year period from a range of sorghum (Sorghum bicolor) cultivars showing typical ‘dead heart’ symptoms. Atherigona soccata Rond. was the dominant species (<99% of the flies reared), while the second most common species was Acritochaeta orientalis Schin. An interesting record was Atherigona eriochloae Mall. reared from tillers of ratooned sorghum. Three species as yet undescribed were recorded. More females than males were reared in the course of the study — the sex ratio was 1:1.27. It was concluded that only A. soccata is likely to be important when considering control of damage to sorghum by resistance breeding or the use of insecticides.  相似文献   

4.
Summary This paper deals with some experiences gained with the use of all metal conical traps in the study of some gall midge flight periods. These conical traps have been described in detail byvan Dinther (1953). The present writer constructed a modification which proved to be very useful for phenological observations on the raspberry cane midge (Thomasiniana theobaldi Barnes), the button top midge of basket willows (Rhabdophaga heterobia H. Lw.) and aClinodiplosis species on poppy. The new type consists of a frame made of zinc, which is built up by two hoops (fig. 1) with diameters 2.5 and 11 inches. The upper hoop is 1 inch, the lower hoop 4 inches wide. The height of the frame is 14 inches. The hoops are connected by two strips of zinc (3) alternating with two strips of metal gauze (4). At the lower hoop four zinc legs are attached to press the trap firmly into the soil. A bottomless jampot (5) is placed over the upper hoop. In this pot a small plastic cone (6) is fixed with Bostik adhesive no. 1775. Small holes at the lower sides enable a good drainage in case of a heavy shower. The gall midges are positively phototropic and move up the cone into the pot. The plastic cone prevents the midges from finding their way out and they can easily be collected by means of an exhauster. The lid of the pot consists of muslin to avoid condensation of water as much as possible.If the midges cannot be collected daily, they may be kept in good condition for taxonomic studies by filling the pot partially with a mixture of glycerin and water. In this case the drainage holes in the plastic cones must be omitted.The dates of emergence in these traps agreed very well with the normal field observations and this will lead to using this new type at the Institute for Phytopathological Research for future phenological observations on gall midges.  相似文献   

5.
Abstract

The incidence, economic importance, ecology, biology and control measures are described in brief for common pests of sorghum and millets in India. At present, shoot flies, stem borers, earhead midges, birds and rats are considered major pests. However formerly occasional or minor pests are becoming a menace in some states due to changes in cultural practices. For most of the recently recorded pests, information on factors responsible for their outbreak, bionomics, yield losses etc. is needed before planning the control operations. As an immediate remedy, chemicals have been used extensively, mainly on high yielding varieties and hybrids of sorghums. It is emphasized that studies should be intensified on varietal resistance, mass rearing techniques, predators and parasites and manipulation of population by cultural practices leading to the possibility of using all available methods on an integrated basis for future pest management programmes for sorghum and millets.  相似文献   

6.
为明确LED风吸式杀虫灯对茶小绿叶蝉Empoasca onukii的防治效果,室内测定诱虫光源对茶小绿叶蝉卵和若虫生长的影响,温室内测定不同灯高和不同灯距组合下杀虫灯诱捕的茶小绿叶蝉数量,并计算杀虫灯对茶小绿叶蝉成虫的有效控制范围、诱杀中距离、诱杀黄金距离,并通过2年田间试验比较杀虫灯有效控制范围内不同灯距处、有效控制范围外茶小绿叶蝉成虫数量。结果显示:诱虫光源对茶小绿叶蝉卵和若虫的生长无显著影响,若虫生长历期为18.5 d,存活率为46.85%。随着灯距和灯高的增加杀虫灯对茶小绿叶蝉的诱捕量下降,灯高20~40 cm时,杀虫灯对茶小绿叶蝉的平均有效控制范围、平均诱杀中距离和平均诱杀黄金距离分别为58.17、30.41和23.86 m。茶园内灯距5 m处,茶小绿叶蝉成虫数量率先达到5个灯距中的最大值,不同灯距下茶小绿叶蝉成虫数量随时间推移而呈现出显著差异,虫口峰期时灯距25 m内的茶小绿叶蝉成虫数量为灯距120 m处的49.5%~64.4%。表明LED风吸式杀虫灯可通过诱杀茶小绿叶蝉成虫显著抑制其诱杀黄金距离内茶小绿叶蝉的成虫数量。  相似文献   

7.
施用药剂杀灭小(?)吸浆虫成虫,是防治吸浆虫重要方法之一。以几种有机氯杀虫剂进行室内、田间杀虫作用和药效等研究,证明γ 666、艾氏剂、狄氏剂和DDT 均具有强大的触杀作用,其中以γ 666毒效最怏,DDT 最慢。γ 666及艾氏剂还具有相当强的熏蒸杀虫作用。田间试验结果也说明γ 666粉剂浓度虽低至0.1%,仍能杀虫95%以上。0.25% γ 666粉剂效果与0.5%的相若,试验也证明,不同浓度的γ 666粉剂兑土稀释为0.25%药粉,稀释土的种类,对杀虫效果均无影响,并在全国不少地区推广应用均证明效果显著,解决了药剂供应问题,扩大了防治面积。田间残效试验证明,不同浓度的666粉剂,在羽化盛期前2天施用,均能毒杀羽化盛期的成虫;但如在前5天施用,除1%粉剂效果较好外,0.25%及0.5%粉剂浓度的防治效果均不理想。  相似文献   

8.
Abstract

The attractiveness of six different traps, one hand-made and five commercially available, on olive fruit fly adults, was compared in the field. Experiments were undertaken at three different localities of Messinia Co., SW Greece, with varying conditions of fruit load and pest population density. The Glass-Plastic Elkofon Trap attracted more adult flies than any other type of trap. Satisfactory catches were also given by the Glass McPhail trap, the Plastic McPhail trap and the Plastic Elkofon trap, whereas low attractiveness was demonstrated by the Bottle trap and the Pouch trap. It is clear from the findings of this study that trap captures of the olive fruit fly are significantly influenced by trap design (e.g. shape, materials, special features), especially during the period of the high population peak (mid-September – early November) as well as in olive orchards with a high pest population density. In olive orchards with a low pest population density no significant differences were recorded among captures of different trap types. We discuss ways of improving the mass-trapping technique as a control method against olive fruit fly.  相似文献   

9.
Field-trapping experiments with synthetic 2,7-nonadiyl dibutyrate, the female-produced sex pheromone of the orange wheat blossom midge, Sitodiplosis mosellana (Géhin), demonstrated that pheromone traps were highly attractive to males and caught very few non-target organisms. Different formulations of pheromone were tested to identify the optimum release rate and dispenser type for use in pheromone traps in the UK. Key findings were that racemic pheromone was as effective as enantiomerically pure (2S,7R)-2,7-nonadiyl dibutyrate, that release rates higher than 0.5 microg day(-1) were not necessary and that the optimal formulation was a 1 mg pheromone loading in a rubber septum. Pheromone traps gave a reliable indication of peak midge emergence, onset of flight and abundance of midges throughout the season. A strong correlation between maximum trap catch and crop infestation levels was obtained.  相似文献   

10.

The influence of sowing date and fertilizer application on the incidence anddamage ofthe maize stemborer (Busseolafusca Fuller) in sorghum(Sorghumbicolor L.) was investigated at the Halhale Research Centre in Eritrea during 1997 - 99. The trials were conducted in a splitplot design with sowing date as the main plot and fertilizer as subplots. There were six sowing dates at an interval of 15 days starting fromearly April tomid-June. There were fertilized and unfertilized subplots. Data on larval count, per cent infestation, per cent deadheart, heading and maturity dates, plant height and yield were recorded for each plot. Fertilizer had no effect on the incidence and damage of the stem borer (B. fusca). There was no interaction between fertilizer and sowing dates on the larval population and damage by stem borers. Sowing date had a significant effect on stem borer incidence and damage levels. Early sowing dates (April 1 and 15) had a significantly lower number of larvae, infestation, deadheart and gave higher yields compared with the other sowing dates while late sowing dates (mid-May- mid-June) resulted in significantly higher infestation and damage. The highest infestation and damage were recorded from mid-May sowings. High stem borer infestations in delayed sowing was due to the coincidence of the susceptible stage of the crop (3 - 6 weeks after germination) with high populations ofstemborer larvae fromthe first generationin late June and July. Mid- and late sown crops were also later attacked by the second generation at the grain-filling stage in September- October. These results indicate that early planting (April) is effective in reducing stem borer damage on sorghum in the highlands of Eritrea.  相似文献   

11.
Replicated field plot trials were carried out to evaluate the role of fish as biocontrol agents of insect pests of rice in the Philippines. Evidence from suction sampling, examination of fish gut contents, and rice plant damage assessment strongly suggest that Common Carp Cyprinus carpio (L.) and Nile Tilapia Oreochromis niloticus (L.) do significantly reduce the densities of stemboring moths and chironomid midges, while the abundance levels of other arthropods are not significantly affected. This impact by fish often was more important in the wet season when heavy rains and wind likely caused the arthropods to become dislodged from the plant and fall onto the water. Predation by fish was particularly evident during the first 45 days of the crop during the wet season when adult chironomid midge abundance was high. The fish gut content analysis revealed that all insect guilds are represented in the diet of both of the fish species regardless of whether the life-cycle of the arthropod prey is aquatic, semi-terrestrial, or terrestrial. Thus, fish in rice fields are part of the assemblage of natural enemies of rice pests. While fish alone cannot completely suppress rice pest populations below the economic threshold, their significant contribution should not be overlooked.  相似文献   

12.
Abstract

Agroecosystems in the tropics include growing two or more crops in diverse polycultural patterns. In Kenya, cowpea Vigna unguiculata (Walp.) is grown in combination with cereals such as maize and sorghum, perennial legumes such as pigeon peas and root crops such as cassava and sweet potatoes. In the present investigations, field experiments were conducted to study the incidence and damage caused by Clavigralla tomentoscollis Germ, and C. shadabi after flowering, on cowpea intercropped with maize. It was evident from the present studies that C. tomentoscollis and C. shadabi were more prevalent on cowpea during the first season rather than during the second season. Both species had a preference for feeding on cowpea intercropped with maize than when it was grown in pure stands. Consequently more pod damage was recorded on cowpea planted with maize. It was therefore concluded that this agricultural system, which is commonly practised by small‐scale farmers in Kenya, is undesirable from the point of view of bug damage.  相似文献   

13.
Abstract

Tests were made using coloured sticky traps to determine trap efficacy in catching adult Myndus crudus Van Duzee (Homoptera, Cixiidae) under field conditions. Blue traps caught more M. crudus adults than any of the other colour traps tested. Blue traps caught adults of both sexes during the day and night although significantly more adults were caught during the day. A sampling bias was shown in that blue traps caught significantly more males than expected from the field population. Blue sticky traps were more effective at sampling adult M. crudus populations than previous sampling techniques based on host plant attractiveness and should be considered for use in future sampling.  相似文献   

14.
Striga hermonthica and S. gesnerioides pose serious threats to cereal and cowpea production, endangering peoples' livelihoods on the Abomey plateau, Benin. A 2-year joint experiment was undertaken with farmers in two hamlets to investigate the potential of managing sowing dates of cowpea, sorghum transplanting, and trap cropping as ways of increasing agricultural production and reducing Striga damage. Early sowing of cowpea failed due to dry spells. Late sowing reduced cowpea yield due to water deficiency at the end of the growing season. Transplanting sorghum seedlings raised in fertilised or Striga-free nurseries doubled or tripled cereal yield and substantially reduced S. hermonthica infestation compared to direct early-sown sorghum. Transplanting sorghum from plant hills to fill gaps was unsuccessful. Trap crops such as cowpea and groundnut increased subsequent maize yield. Trap cropping had only a small effect on S. hermonthica infestation. The very poor soils in Somè central were a major constraint upon yield improvement to acceptable levels even after the introduction of the new crop (and Striga) management methods.  相似文献   

15.
Abstract

In the present study the incidence of Chilo partellus and its mortality due to natural enemies on sorghum intercropped with cowpea and maize were investigated in the 1984–6 cropping seasons. The lowest larval density was recorded in sorghum/ cowpea intercrop (mean 0. 18 larvae/plant); and the highest density in sorghum/maize (mean 1. 8 larvae/plant), although significant differences in larval density were observed only in three out of five seasons. Life table analysis showed first‐generation mortality of C. partellus to be highest in the age interval from egg to early‐instar larva (95–98% real mortality) and attributable mainly to predation; first‐generation mortality due to parasitoids and pathogens was negligible. Significantly higher (P < 0. 05) apparent pupal mortality due to Dentichasmias busseolae (Heinrich) (Ichneumonidae), in the second generation occurred in sorghum/cowpea (42.8%) than in sorghum/maize (12.5%). It was concluded that predators play a significant role and that intercropping sorghum with cowpea or maize does not interfere with their activity. Intercropping sorghum with cowpea gave nearly 40% higher yield index than sorghum monocrop. The implications of these findings on management  相似文献   

16.
为明确二点委夜蛾Athetis lepigone(M?schler)在河南省的发生规律,于2012—2013年在该省各地采用灯光诱集法对二点委夜蛾成虫进行诱测。结果表明:河南省二点委夜蛾每年发生4代,其中越冬代成虫在4—5月陆续羽化,未形成明显的高峰,第1代成虫高峰期为6月上中旬,第2代成虫高峰期为7月中下旬,8月下旬9月初为第3代成虫高峰期,其中第2代成虫密度明显大于第1代和第3代。2012年二点委夜蛾在河南省北部地区发生较重,浚县第2代成虫密度为4 916头,2013年河南省中东部发生较重,民权县和长葛市第2代成虫密度分别达到8 409头和5 390头。对成虫监测结果分析发现,2012—2013年河南省二点委夜蛾成虫发生期与降雨量和温度的关系不稳定,但每年第2代成虫密度与该年5、6月下旬日均降雨量呈显著正相关,依据5、6月下旬的降雨量和温度建立的2012年和2013年第2代成虫密度自然对数回归方程的均方根误差分别为0.612和0.752,可较好地反映二点委夜蛾第2代成虫的发生密度。  相似文献   

17.
Samenvatting De tegenstrijdige meningen, die bestaan over de vraag of de koolzaadga Imug (Dasyneura brassicae Winn.) voor zijn ei-afzetting is aangewezen op beschadigde hauwen, gaven aanleiding dit punt nader te onderzoeken. Uit infectieproeven, waarbij de galmug òf planten met uitsluitend gave òf planten met beschadigde hauwen kreeg aangeboden om zijn eieren te leggen, bleek, dat deze eieren uitsluitend in de van te voren beschadigde hauwen werden gevonden. Ook waarnemingen over het gedrag van de mug in het veld ondersteunden de opvatting, dat de eieren uitsluitend door reeds bestaande boorgaten in de hauw worden afgezet. De koolzaadsnuitkever (Ceuthorrhynchus assimilis Payk.) zal ongetwijfeld de belangrijkste veroorzaker van deze beschadigingen zijn. De bestrijding van de kever zal in de regel niet in staat zijn het aantal beschadigde hauwen zo sterk te verminderen, dat de eerste galmugvlucht geen gelegenheid tot ei-afzetting meer heeft. Door de vermindering van het aantal keverlarven als gevolg van de effectieve keverbestrijding, kan een vermindering van het a antal uitkruipgaten der larven bereikt worden, die wèl belangrijk is, daar de tweede galmugvlucht voor ei-afzetting vooral op deze gaten is aangewezen.
On the relation between the infestation by the cabbage seed pod midge, Dasyneura brassicaeWinn. and the seed pod weevil, Ceuthorrhynchus assimilisPayk
Summary The controversy of whether or not the cabbage seed pod midge (Dasyneura brassicae Winn.) uses only damaged pods for depositing its eggs was reason for further investigation. Experiments with potplants were started. Midges were caged on colza-plants which had only undamaged pods as well as on plants which had pods artificially damaged by prickling with a needle. Eggs were only found in the damaged pods. The behaviour of the midge in the field, when it is intending to oviposite, also shows its need for damaged places as the midges were observed continuously walking on the pods, trying with their ovitubus to find a hole in the wall of the pod. The cabbage seed pod weevil (Ceuthorrhynchus assimilis Payk.) is undoubtedly the chief contributor to the number of damaged pods. Economic control of this weevil will only have a limited indirect effect on infestation by the first midge flight. However as it reduces the number of pods with weevil larvae, it reduces the number of exit holes in the pods. These exit holes are especially used by the second midge flight which therefore is controlled indirectly to some extent.


Destijds werkzaam bij het Instituut voor Plantenziektenkundig Onderzoek (I.P.O.) te Wageningen; thans werkzaam bij het Laboratorium voor Entomologie van de Landbouwhogeschool te Wageningen.  相似文献   

18.
Abstract

Seeds of 22 rice strains carefully selected for resistance by continuously testing under high gall midge pressure at Cuttack (Orissa) through 1979–198’ and three such strains from Raipur (Madhya Pradesh) were assembled along with susceptible standard Jaya and were simultaneously tested at both locations (Cuttack and Raipur) against the Asian rice gall midge Orseolia oryzae Wood‐Mason in wet season 1985. Eighteen entries proved resistant at both locations. While Asha, Usha and Samrudhi were resistant at Raipur and susceptible at Cuttack, Shakti IR.36, IR.50, Daya and Pratap were resistant at Cuttack and susceptible at Raipur, based on which characterization of the Cuttack (Orissa) and Raipur (Madhya Pradesh) gall midge biotypes was proposed. In gall midge biotypes testing, meticulous selection of only such entries with consistently proven resistance to gall midge at least at one location, carrying forward seed from resistant plants only each season under high gall midge pressure (with 100% seedling/hill infestation in oft repeated susceptible check) and classification of test entries at the strain's level either as resistant or as susceptible without scope for the third ‘moderate’ category to intervene, generally ignored by earlier workers, were stressed.  相似文献   

19.

A survey was conducted to gain insight into the perceptions of Lesotho's farmers with regard to insect pests of maize and sorghum, to identify management practices that could impact on stalk-borer numbers and to shed light on other farming practices such as variety selection and crop residue management. Field studies were conducted to determine the incidence and distribution of Busseola fusca (Lepidoptera: Noctuidae) and Chilo partellus (Lepidoptera: Pyralidae) larvae in sorghum and maize residues and to determine the effect of certain crop residue management practices on stalk-borer survival. Results indicated that farmers regard stalk-borers as important pests that sometimes need to be controlled. However, most farmers never apply control measures, mainly due to lack of resources. Residues of maize and sorghum plants are largely used as animal fodder with maize being cut and fed to animals after harvest. Sorghum crop residues are largely left on fields after harvest to be used by free-grazing animals. While stacks of maize stalks were not important in the winter survival of B. fusca larvae, stacking of sorghum ensures winter survival of C. partellus larvae. Detasselling of maize plants is commonly done at plant senescence and the upper halves of plants are fed to animals. Detasselling of maize plants had no effect on the number of borer larvae in plants at harvest.  相似文献   

20.

Development of sorghum downy mildew, incited by Peronoscleospora sorghi (Weston and Uppal) C.G. Shaw, on maize, sorghum and Johnson grass was investigated at two locations in Uganda during three seasons (1994 and 1995). More sorghum downy mildew developed on the Johnson grass and sorghum than on the maize at all locations and in all seasons. No significant differences were observed in sporulation of P. soghi on the three hosts. Leaf shredding occurred on the three hosts but was the least on maize. Cross-inoculation with both conidia and oospores was achieved on the three hosts. Since the fungal population formed oospores and sporulated readily on the three hosts, which is typical of the sorghum strain, the disease in Uganda is attributed to the sorghum strain.  相似文献   

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