摘要:

In the Sahelian countries, the main pest problem in stored grain cowpea is the cowpea weevilCallosobruchus maculatus.In Senegal, the groundnut oil treatment and the fumigant carbon tetrachloride failed to give control of this pest. Among eight tested active ingredients commonly used to protect stored food‐stuffs, the best results were obtained with pirimiphos‐methyl. This insecticide treatment at 12–5 ppm has been extended in two farmer pilot area of the Sahelian zone, and is efficacious for six months. In the future, resistant varieties and the use of local plant substances to control cowpea weevil could be alternative control methods or part of integrated pest management.

ISSN:0143-6147    

DOI:10.1080/09670878609371062

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

At least fivePenthocratesspp. (Lep: Limacodidae) are recognized from the Philippines. The larvae of these moths attack coconut and oil palms and during outbreaks can cause considerable economic damage. Previously, the true identity of these pests had not been realized. The biology of the known species is described with notes on natural parasitism (byApantelessp.,Aroplectrus dimerus. Nesolynxsp.,Paraphylaxsp.,Goryphussp. andEupelmussp.). Details of a number of outbreaks on coconuts in the Philippines are summarized and control measures discussed.

ISSN:0143-6147    

DOI:10.1080/09670878609371063

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The within‐plant and between‐plant distribution of the cotton whiteflyBemisia tabaciwas studied in cotton fields (cv. Deltapine 15/21) near Adana/Turkey and two methods of estimating nymphal numbers on single leaves were tested in order to develop an optimal sampling technique. Counting the nymphs on only one leaf sector as well as rating the leaves according to a logarithmic scale can largely reduce the counting effort. The latter method results very often in overestimation, but this drawback can possibly be overcome by better training of the observers. The main stem nodes 3–7 (counted from the top) constitute, in general, the region most infested by third and fourth instar nymphs during the early growing season; leaf samples taken from this region give the best results.

ISSN:0143-6147    

DOI:10.1080/09670878609371064

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Stem borer attack varied significantly on sorghum sown during different fortnights, ranging from 4.7 to 24.0% and 9.5 to 37.4% at 30 and 45 days after sowing (d.a.s.) respectively. The crop sown during the first fortnight of March was highest, followed by that sown in the second fortnight of February, in terms of stem borer damaged plants, damage rating, percentage dead hearts and percentage stem tunnelling. The least damage was in the crops shown during the second fortnight of June and of October. There was an indication that for every 1°C reduction in minimum temperature, there was a decrease of 1.69% stem borer damage at 30 d.a.s. At 45 d.a.s. none of the weather elements significantly contributed to the damage. During the summer the duration of egg to adult period ofC. partelluson sorghum was significantly shorter at 39.48 days than in winter when it was 56.5 days. Double the rate of fecundity and higher fertility rate was also observed in summer.

ISSN:0143-6147    

DOI:10.1080/09670878609371065

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

An isolate ofTrichoderma harzianum(IMI no. 238493) directly attacked and lysed the mycelium and sclerotia ofSclerotium rolfsiiwhen the two fungi were grown in dual culture. The type of interactions between the antagonist and pathogen were hyphal coiling, entry through haustoria‐like structure and direct entry in the hyphae and sclerotia ofS. rolfsii, the host fungus. In a glasshouse experiment,T. harzianumapplied in the form of sorghum culture to 5.rolfsiiinfested soil gave as high as 76 and 88% disease control in first and second growth cycle of sugarbeet seedlings respectively. The degree of disease control obtained increased with the increase in the amount ofT. harzianumapplied. This isolate ofT. harzianumwas found tolerant to PCNB (Pentachloronitrobenzene)in vitro.PCNB at low concentration when integrated withT. harzianumimproved disease control. Under field conditions, integration of PCNB andT. harzianumsignificantly reduced the incidence of Sclerotium root rot (76% disease control) and increased the root, green foliage and sucrose yield per ha.

ISSN:0143-6147    

DOI:10.1080/09670878609371066

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The changes in the population density of sugarcane internode borer,Chilo sacchariphagus indicus(Kapur), and their causes were quantified on susceptible sugarcane variety Co.6304 planted during early and late main season in 1979 and on susceptible Co.6304 and resistant CoJ.64 during 1980 under artificial infestation conditions. The 1979 life tables showed an increasing trend index of 1.24 and 1.16 of cohort population in early and late main season planted crops respectively. The 1980 life tables showed an increasing trend by 2.42 times on Co.6304 while the cohort showed a trend index of 0.57 on CoJ.64 indicating the decline in population density. The survivorship curves fitted to type IV of Slobodkin indicating that high mortality occurred in the early stages of the Insect life cycle. The mortality factors included parasitization by hymenopterous parasites, arthropod predation, desiccation, infertility and wind in egg stage, suspected arthropod predation and dispersal loss in the first instar and migration and unknown losses, parasitization and granulosis virus infection during the other larval instars. Pupal mortality was caused by the failure to emerge due to unknown reasons, parasitization and virus infection. TheK‐factor analysis showed suspected arthropod predation and dispersal loss during the first instar and loss due to migration and unknown causes in other larval instars were the key mortality factors. The list of hymenopterous parasites, suspected arthropod predators and pathogens was also given and their role was discussed.

ISSN:0143-6147    

DOI:10.1080/09670878609371067

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878609371068

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A mast sprayer for the control of small quelea roosts and breeding colonies is described. Avicide liquid is atomized by five Mini‐ulva rotary atomizers mounted on a light aluminium mast which is adjustable up to 9 m in height. Power is supplied by sealed rechargeable batteries which drive the atomizers and a small positive displacement gear pump. Droplet size can be varied by altering the voltage applied to the atomizers. The batteries require recharging or replacing after approximately 2.5 hours of spraying. The sprayer is operated by two men and, with practice, can be carried in the upright position, whilst operating, so as to locate it correctly with respect to the prevailing wind. The sprayer is designed to operate silently to avoid frightening the birds.

ISSN:0143-6147    

DOI:10.1080/09670878609371069

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The acute oral toxicity of 4‐aminopyridine and the repellency of methiocarb, trimethacarb and copper oxychloride were determined on: rock doves,Columba livia;rose‐ringed parakeets,Psittacula krameri;house sparrows,Passer domesticus;and white‐backed munias,Lonchura striata, common pest birds to crops in Bangladesh. Methiocarb was the most repellent, and copper oxychloride was the least repellent, of the compounds. The chemical 4‐aminopyridine was extremely toxic to all species, with doves being the most susceptible (LD50= 2.5 mg/kg) and the house sparrow being the least susceptible (LD50= 4.2 mg/kg). The toxicity (LD50) of methiocarb ranged from 3.5 mg/kg for munias to 14.1 mg/kg for sparrows. These data will permit a safer, more effective use of these chemicals to protect food crops from birds in Bangladesh.

ISSN:0143-6147    

DOI:10.1080/09670878609371070

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878609371071

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor