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Saeed R.,Central Cotton Research Institute | Razaq M.,Bahauddin Zakariya University | Hardy I.C.,University of Nottingham
Pest Management Science | Year: 2016

BACKGROUND: Neonicotinoid seed treatments suppress populations of pest insects efficiently and can enhance crop growth, but they may have negative effects on beneficial arthropods. We evaluated the effects of either imidacloprid or thiamethoxam on the abundances of a sucking pest, the cotton leafhopper (Amrasca devastans), and its arthropod predators under field conditions. We also evaluated the impact of seed treatment on transgenic cotton plant growth, with pests and natural enemies present or absent. RESULTS: Imidacloprid and thiamethoxam reduced pest abundance, with greater effects when dosages were higher. Treatment at recommended doses delayed the pest in reaching the economic damage threshold by around 10-15 days (thiamethoxam) and 20 days (imidacloprid). Recommended doses also enhanced plant growth under all tested conditions; growth is affected directly as well as via pest suppression. Neonicotinoid applications reduced abundance of beneficial arthropods, with lower populations after higher doses, but negative effects of imidacloprid were not apparent unless the manufacturer-recommended dose was exceeded. CONCLUSION: Imidacloprid applied at the recommended dose of 5gkg-1 seed is effective against A. devastans and appears to be safer than thiamethoxam for natural enemies, and also enhances plant growth directly. We caution, however, that possible sublethal negative effects on individual beneficial arthropods were not evaluated. © 2015 Society of Chemical Industry.


Saeed R.,Central Cotton Research Institute | Razaq M.,Bahauddin Zakariya University | Hardy I.C.W.,University of Nottingham
Journal of Pest Science | Year: 2015

Many agricultural pests can be harboured by alternative host plants but these can also harbour the pests’ natural enemies. We evaluated the capacity of non-cotton plant species (both naturally growing and cultivated) to function as alternative hosts for the cotton leaf hopper Amrasca devastans (Homoptera: Ciccadellidae) and its natural enemies. Forty-eight species harboured A. devastans. Twenty-four species were true breeding hosts, bearing both nymphal and adult A. devastans, the rest were incidental hosts. The crop Ricinus communis and the vegetables Abelmoschus esculentus and Solanum melongena had the highest potential for harbouring A. devastans and carrying it over into the seedling cotton crop. Natural enemies found on true alternative host plants were spiders, predatory insects (Chrysoperla carnea, Coccinellids, Orius spp. and Geocoris spp.) and two species of egg parasitoids (Arescon enocki and Anagrus sp.). Predators were found on 23 species of alternative host plants, especially R. communis. Parasitoids emerged from one crop species (R. communis) and three vegetable species; with 39 % of A. devastans parasitised. We conclude that the presence of alternative host plants provides both advantages and disadvantages to the cotton agro-ecosystem because they are a source of both natural enemy and pest species. To reduce damage by A. devastans, we recommend that weeds that harbour the pest should be removed, that cotton cultivation with R. communis, A. esculentus, and S. melongena should be avoided, that pesticides should be applied sparingly to cultivate alternative host plants and that cotton crops should be sown earlier. © 2014, Springer-Verlag Berlin Heidelberg.


Saeed R.,Central Cotton Research Institute | Sayyed A.H.,Bahauddin Zakariya University | Shad S.A.,Bahauddin Zakariya University | Zaka S.M.,Bahauddin Zakariya University
Crop Protection | Year: 2010

The diamond-back moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae) is a destructive cosmopolitan pest of cruciferous crops. The pest is present wherever its host plants exist and is considered to be one of the most widely distributed of all the Lepidoptera. We investigated the effect of various host plants on the fitness of P. xylostella and tested the hypothesis by studying development time, growth, fecundity and survival on cabbage (Brassica oleracea capitata), cauliflower (Brassica oleracea botrytis), radish (Raphanus sativus), turnip (Brassica rapa), mustard (Brassica compestris) and canola (Brassica napus var. canola). The developmental time from eggs to adult eclosion was the shortest (10 days) on canola and the longest (13 days) on turnip. Fecundity was greatest on canola (350) followed by cauliflower (268 eggs) by females eclosed from the pupae reared on canola and cauliflower, respectively, while the minimum numbers of eggs (184) were observed on cabbage. The number of eggs hatched was the highest (80%) when larvae fed on cauliflower. Survival to the adult stage was the highest (94%) on mustard followed by cauliflower and lowest (64%) on turnip. The net replacement rate was lowest for populations reared on cabbage (32.3), which was also reflected by the lowest intrinsic rate of population increase (0.20). The correlation between the intrinsic rate of population increase (rm) and the mean relative growth rate was significant (t = 20.02 d.f. = 4, P < 0.05). Canola and mustard proved to be the most suitable hosts for P. xylostella because of shorter developmental period, higher percentage of survival and higher number of eggs. The data point to the role of host plants in increasing local P. xylostella populations. © 2009 Elsevier Ltd. All rights reserved.


Ahmed M.Z.,South China Agricultural University | Ahmed M.Z.,University of Pretoria | De Barro P.J.,CSIRO | Greeff J.M.,University of Pretoria | And 3 more authors.
Pest Management Science | Year: 2011

BACKGROUND: The cotton whitefly, Bemisia tabaci (Gennadius), is a cryptic species complex, and members of the complex have become serious pests in Pakistan because of their feeding and their ability to transmit cotton leaf curl virus (CLCuV). Here, an analysis was made of the identity of B. tabaci collected from cotton and a range of non-cotton hosts in the cotton-growing zones in Punjab and Sindh, the main cotton-producing provinces of Pakistan, using a portion of the mitochondrial cytochrome oxidase 1 gene. The geographic distribution of the different members of the complex was then compared with the incidence of CLCuD. RESULTS: Using the Dinsdale nomenclature, the results revealed three putative species, Asia 1, Asia II 1 and Middle East-Asia Minor 1. Asia II 1 (also referred to in the literature as biotypes K, P, PCG-1, PK1, SY and ZHJ2) was only recorded from Punjab cotton plants, whereas Asia 1 (also referred to in the literature as biotypes H, M, NA and PCG-2) was found in both Sindh and Punjab. Middle East-Asia Minor 1 (commonly known as biotype B and B2) was found only in Sindh. Moreover, Asia II 1 was associated with high incidences of CLCuD, whereas regions where Middle East-Asia Minor 1 was present had a lower incidence. Phylogenetic analysis showed that the Middle East-Asia Minor 1 population in Sindh formed a distinct genetic subgroup within the putative species, suggesting that the Sindh province of Pakistan may form part of its home range. So far, no individuals from the putative species Mediterranean (commonly known as biotypes Q, J and L) have been found in Pakistan. CONCLUSIONS: The capacity to manage pests and disease effectively relies on knowledge of the identity of the agents causing the damage. In the case of CLCuD in Pakistan, this knowledge has been obscured to some extent because of the inconsistent approach to identifying and distinguishing the different B. tabaci associated with CLCuD. The situation has now been clarified, and a strong association between disease incidence and vector identity and abundance has been shown. Given this advance, future research can now focus on factors that influence the capacity of different vector species to transmit the viruses that cause CLCuD, the reason for differences in vector abundance and the lack of geographic overlap between the cryptic vector species. This knowledge will contribute to the development of improved methods with which to manage the disease in Pakistan. © 2010 Society of Chemical Industry.


Ahmad M.,Central Cotton Research Institute | Mehmood R.,Central Cotton Research Institute
Journal of Economic Entomology | Year: 2015

The armyworm Spodoptera litura (F.) is a very serious pest of many crops, vegetables, and ornamentals. Due to persistent application of insecticides, this pest has developed resistance to conventional as well as new chemistries. The present studies investigated the level of resistance to new chemistry insecticides, having novel modes of action, in the Pakistani field populations of S. litura during 1997-2010 by using a leaf-dip bioassay. Generally, a low to moderate resistance was recorded to indoxacarb, abamectin, fipronil, and methoxyfenozide; along with a very low resistance to spinosad. Resistance to emamectin benzoate, chlorfenapyr, and lufenuron was none or very low, in spite of their intensive use against S. litura. The insecticides, showing no or very low resistance, can be used in rotation in conjunction with other integrated pest management tactics to manage insecticide resistance in S. litura. © 2015 The Authors.


Shah S.I.A.,Central Cotton Research Institute
Pakistan Journal of Zoology | Year: 2014

The researchers and progressive farmers of cotton growers of Punjab, Pakistan had been worrying for six years from 2005 to 2010 for an obscure causing agent of the warts and internal lint damage (rotting) of cotton bolls. Consequently, a two years study was launched in 2010 and 2011 thoroughly aimed at investigating the actual causing insect pest of warts on the internal carpel wall of cotton bolls. The cotton stainer, Dysdercus koenigii F., (Hemiptera: Pyrrhocoridae), dusky cotton bug, Oxycarenus spp. (Hemiptera: Lygaeidae) and stink bug (Hemiptera: Pentatomidae) were considered as the suspected insect pests and were planned to be caged. A total of six observations were made with 7 days interval, with a total duration of 41 days for each of the experiments. In each observation, 10 bolls were observed in which the highest average of 4.8 warts boll-1 were recorded at the 5th observation while lowest average 0.8 warts boll-1 were observed at the 2nd observation. Whereas, in control and dusky cotton bug cages, there were no warts and no damage was recorded throughout the course of experiments. Copyright 2014 Zoological Society of Pakistan.


Ashfaq M.,National Institute for Biotechnology and Genetic Engineering NIBGE | Ashfaq M.,University of Guelph | Asif M.,National Institute for Biotechnology and Genetic Engineering NIBGE | Anjum Z.I.,Central Cotton Research Institute | Zafar Y.,PAEC
Molecular Ecology Resources | Year: 2013

Although two plastid regions have been adopted as the standard markers for plant DNA barcoding, their limited resolution has provoked the consideration of other gene regions, especially in taxonomically diverse genera. The genus Gossypium (cotton) includes eight diploid genome groups (A-G, and K) and five allotetraploid species which are difficult to discriminate morphologically. In this study, we tested the effectiveness of three widely used markers (matK, rbcL, and ITS2) in the discrimination of 20 diploid and five tetraploid species of cotton. Sequences were analysed locus-wise and in combinations to determine the most effective strategy for species identification. Sequence recovery was high, ranging from 92% to 100% with mean pairwise interspecific distance highest for ITS2 (3.68%) and lowest for rbcL (0.43%). At a 0.5% threshold, the combination of matK+ITS2 produced the greatest number of species clusters. Based on 'best match' analysis, the combination of matK+ITS2 was best, while based on 'all species barcodes' analysis, ITS2 gave the highest percentage of correct species identifications (98.93%). The combination of sequences for all three markers produced the best resolved tree. The disparity index test based on matK+rbcL+ITS2 was significant (P < 0.05) for a higher number of species pairs than the individual gene sequences. Although all three barcodes separated the species with respect to their genome type, no single combination of barcodes could differentiate all the Gossypium species, and tetraploid species were particularly difficult. © 2013 John Wiley & Sons Ltd.


Arif M.I.,Central Cotton Research Institute | Rafiq M.,Central Cotton Research Institute | Wazir S.,Central Cotton Research Institute | Mehmood N.,Central Cotton Research Institute | Ghaffar A.,Central Cotton Research Institute
International Journal of Agriculture and Biology | Year: 2012

The biological studies on cotton mealybug Phenacoccus solenopsis Tinsley, were undertaken to explore the role of its natural biocontrol agents. Cotton mealybug was active throughout the year on various crops, ornamental plants and weeds with two population peaks in Multan and nearby districts. Females reached adult stage after three nymphal moults whereas, male nymphs shed two moults before pupation. Reproduction was only sexual. Promising natural enemies such as parasitoid, Aenasius bambawalei and predators, Brumoides suturalis, Scymnus coccivora, Menochilus sexmaculatus and spiders were found associated with mealybug in large numbers round the year. Some other species, Coccinella undecimpunctata, C. septempunctata, Hyperaspis maindroni, Chrysoperla carnea, Diadiplosis sp. and Geocoris sp. were relatively less abundant, while Orius sp. and Campylomma sp. were incidentally recorded on the mealybug. Population dynamics and feeding efficiency tests for natural enemies indicated their significance as bio-control agents in integrated management of mealybug if allowed to act in congenial conditions. © 2012 Friends Science Publishers.


Ahmad M.,Central Cotton Research Institute | Ahmad M.,Nuclear Institute for Agriculture and Biology | Arif M.I.,Central Cotton Research Institute | Naveed M.,Central Cotton Research Institute
Journal of Pest Science | Year: 2010

Field populations of adult whiteflies, Bemisia tabaci, from Pakistan were monitored from 1992 to 2007 for their susceptibility to seven organophosphate and three carbamate insecticides using a leaf-dip method. Malathion, quinalphos and chlorpyrifos generally exhibited no or a very low level of resistance in B. tabaci over a 16-year monitoring period. Resistance to profenofos, triazophos, parathion-methyl and ethion was usually low to high up to 1995, and then it dropped to very low levels during 1996-2004. Resistance levels again picked up from low to moderate levels for triazophos during 2005-2007, for parathion-methyl during 2003-2007, and for ethion in 2006. Among carbamates, thiodicarb resistance was high during 1994-1996, which dropped to moderate levels in 1997 and 1998 and to very low levels during 1999-2001, but again increased from low to high levels during 2002-2007. Methomyl resistance was moderate in 1994 and 1995, which dropped to very low levels during 1996-2002, and then increased to low levels during 2003-2007. Butocarboxim resistance remained very low during 1994-2003 and then increased from low to high levels during 2004-2007. The insecticides exhibiting no, very low or low resistance, and no cross-resistance among themselves can be exploited in devising an insecticide resistance management strategy to combat whitefly resistance in the field. © 2010 Springer-Verlag.


Ahmad M.,Nuclear Institute for Agriculture and Biology | Arif M.I.,Central Cotton Research Institute
Crop Protection | Year: 2010

Field populations of beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), from Pakistan were assessed for their resistance to the chlorinated hydrocarbon endosulfan, the organophosphates chlorpyrifos and quinalphos, and the pyrethroids cypermethrin, deltamethrin, bifenthrin and fenpropathrin. Using a leaf-dip bioassay, resistance to endosulfan was high during 1998-2000 but declined to very low, to low levels during 2001-2007, following a reduced use of the insecticide. Organophosphates and pyrethroids were consistently used over the past three decades, and the resistance had been increasing to these insecticide classes. Generally, the resistance to chlorpyrifos and pyrethroids remained low from 1998 to 2002-2003, but resistance increased to moderate to high levels from 2003-2004 to 2006-2007. For deltamethrin, resistance was very high during 2004-2007. Quinalphos resistance remained low during 1998-2006. Correlation analysis of LC50 and LC90 values showed a positive correlation between organophosphates and pyrethroids, but no correlation between endosulfan and organophosphates or pyrethroids tested herein. These results suggest that the conventional chemistries should be replaced with new chemistries for the successful management of S. exigua. © 2010 Elsevier Ltd.

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