Farmers' knowledge, perception and management of mango mealy bug, Drosicha mangiferae Green (Hemiptera: Monophlebidae), on Mangifera indica in Punjab, Pakistan.

In 2004-05, during the December to February about 141 mango farmers were interviewed during peak activity of mango mealy bug in southern Punjab, Pakistan. The objective was to know the farmers' knowledge, perceptions and practices in the management of mango mealy bug. Most of the farmers (94.33%) reported that Chaunsa variety (king of all mango varieties) was susceptible to mango and irrigation water was the major source of flare up of this pest. Basudin and Supracide were the most commonly used insecticides as 72.92 and 51.77 percent farmers gave positive response and grease bands were applied for the control of mango mealy bug by the majority of the respondents. Hundred percent yield losses was told by 22.7 percent respondents whereas 75 percent, 50 percent and 25 percent losses were reported by 39.7, 31.9 and 14.2 insecticidal spray did not show satisfaction to the respondents for the control of fertilized females of mango mealy bug coming down from the trees. Lack of knowledge about the pest, lack of money, adulterated and shortage of pesticides, lack of unity amongst farmers Further the growers' views were tested in the field for confirmation and small land holdings were the main constraints for the control of mango mealy bug.

Ecological impact on development of hemipterous bug (dysdercus koenigii) (hemiptera: pyrrhocoridae) and boll rot disease of cotton (gossypium hirsutum) grown in the diversified field.

The experiment was conducted at Cotton Research Station, Multan to study the impact of weather factors and Hemipterous bug on development of cotton boll disease in cotton variety bt- 886 for three consecutive years i.e., 2012, 2013 and 2014. The results revealed that the population of Red Cotton Bug (RCB) per plant remain 0.50 and 0.34 during years 2012 and 2013, respectively but increased during 2014 i.e., 3.21 per plant. The number of unopened bolls (UOB) were more during 2012 i.e., 13.43% with yellowish lint (YL) 76.30% and whitish lint (WL) 23.70% at average maximum temperature of 34.73◦C, minimum temperature of 22.83◦C, RH of 77.43% and 11.08 mm rainfall. Similarly during 2013, the number of unopened bolls were less i.e., 0.34 per plant with YL 1.48 and WL 99.53 per plant when average maximum temperature 34.60◦C, minimum temperature 23.37◦C, RH 73.01% and 9.95 mm rainfall. During 2014, RCB population per plant was 3.22 with no UOB and YL was 0.00% and WL was 100% when average maximum temperature 23.70◦C, minimum temperature 23.18◦C, RH 71.67% and 4.55 mm rainfall. So our results concluded that the cotton bolls rot disease was more during 2012 due to abrupt changes in environmental factors. The RCB may be the carrier of boll rot disease pathogen during more rainfall.

Stink bug Agonoscelis spp. (Heteroptera: Pentatomidae) - An emerging threat for seed production in alfalfa crop (Medicago sativa L.) and their successful management.

Fodder crops play an important role in sustainable agriculture as they provide feed for animals, which is ultimately converted to human food. Alfalfa is one of the most important fodder crops having high nutritive value for livestock. However, seed production of alfalfa crop is seriously affected by several factors and the highest reduction in seed yield is caused by stink bug infestation. The current study evaluated different insecticides to control stink bugs during 2016-17. The efficacy of ten insecticides, i.e., acephate, dimethoate, malathion, chlorpyriphos, bifenthrin, lambdacyhalothrin, deltamethrin, acetamiprid, imidacloprid and carbosulfan was tested on Agonoscelis spp. (Heteroptera Pentatomidae). The mortality of stink bug was recorded at one, three, five, seven, ten and fifteen days after insecticide application. Similarly, the population of pollinators was recorded before and one, three and five days after the application of insecticides. It was observed that acetamiprid (81.14%) and acephate (80.65%) caused the highest mortality of stink bug and proved most effective. Insecticides application decreased the pollinators' population one day after spray; however, it was rehabilitated three days after insecticide application. Insecticide application increased seed yield from 28.05 kg/acre (during last four year without chemical control) to 116 kg/acre in 2016-17 (with chemical control). It is concluded that acetamiprid and acephate can be successfully used in integrated management program of increasing alfalfa seed production.

Effect of host plant on cornucopia of mango fruit flies (Diptera: Tephritidae) and their triumphant management in context of climate change.

A study was performed to assess the preference of fourteen mango cultivars for fruit flies and their management by bagging. So the choice of Tephritid flies to mango cultivars during fruiting phase is crucial. Fourteen different cultivars of mango viz., 'Dusehri', 'Malda', 'Langra' early cultivars, 'Chaunsa', 'Fajri Klan', 'Sensation' medium whereas 'Sanglakhi', 'Retaul-12', 'Mehmood Khan', 'Tukhmi', 'Kala Chaunsa', 'Chitta Chaunsa', 'Dai Wala' and 'Sobey De Ting' late cultivars were assessed for their suitability for fruit flies. The results indicate that the population density of fruit flies was higher on late cultivars like 'Sanglakhi' (20.61 percent), 'Mehmood Khan' (20.22 percent) and 'Reutal-12' (19.92 percent) were proved to be highly susceptible to fruit flies. Among these the cultivar 'Reutal-12' was selected being commercial and future cultivar for the management of fruit flies through bagging. The results reported that the attack of tephritid fruit flies and other insect pests were zero in bagged fruits as compared with control. It was further recorded that the bagged fruits has maximum average fruit weight i.e. 203.50 and 197.83 g per fruit was noted in those treatments where butter paper bag and brown paper bag was wrapped with better coloration as compared with un-bagged fruit with 159.5 g per fruit. Similarly, on an average fruit length were more i.e. 90.17, 91.33 mm in bagged fruit and 85.33 in un-bagged fruits. Furthermore, bagged fruits have zero incidence of disease with reduced fruit crack, fruit sunburn, mechanical damage, bird damage, fruit blemished and agrochemical residues on the fruit. So, it is concluded that the special attention should be given on 'Reutal-12' for the management of fruit flies when devising an IPM program for the control of fruit flies. Further, bagging has proved to be the good agricultural practices for the production of quality mango.

The impact of adjacent habitats on population dynamics of red cotton bugs and lint quality.

Red cotton bugs [Dysdercus spp. (Hemiptera: Pyrrhocoridae] are among the most destructive pests of cotton and many other crops. Red cotton bugs (RCBs hereafter) damage cotton plants by sucking sap and deteriorate lint by staining. The incidence of RCBs causes boll injury along the field margins neighboring with various peripheral areas. The adjacent habitat/crops strongly mediate the population dynamics of RCBs. However, limited is known about the impact of adjacent habitat on population dynamics of RCBs and lint quality. This two-year field study evaluated the impact of adjacent habitat (okra, unpaved road, water channel and Eucalyptus trees) on population dynamics of RCBs and lint quality of cotton. The RCBs were sampled weekly from margins to 4 meter inside the cotton field. The RCBs' populations were monitored and plucked cotton bolls were examined for internal damage. The highest incidence of RCBs was recorded for cotton field adjacent to okra and water channel. Similarly, the highest number of damaged bolls were observed for the field side neighboring with okra and water channel. Furthermore, the highest number of unopened bolls were recorded for okra and water channel sides with higher percentage of yellowish lint. Field sides bordering with Eucalyptus trees and unpaved road had lower RCBs incidence and lint staining. Nonetheless, RCBs incidence was higher at field margins compared to field center indicating that population was strongly affected by adjacent habitat. It is concluded that sowing okra and weedy water channels adjacent to cotton would support RCBs population and subsequent lint staining. Therefore, water channels must be kept weed-free and okra should not be sown adjacent to cotton. Nonetheless, detailed studies are needed to compute monetary damages caused by cotton pests to the crop. Furthermore, effective management strategies must be developed to manage RCBs in cotton to avoid lint-staining problem.

Correction: Pest susceptibility, yield and fiber traits of transgenic cotton cultivars in Multan, Pakistan.

[This corrects the article DOI: 10.1371/journal.pone.0236340.].

Pest susceptibility, yield and fiber traits of transgenic cotton cultivars in Multan, Pakistan.

Cotton (Gossypium hirsutum L.), being a cash and fiber crop is of high significance in Pakistan. Numerous insect pests and viral diseases in Pakistan and around the world attack cotton crop. Genetically modified cotton (transgenic, resistant to lepidopteran insects), hereafter written as 'Bt-cotton' has been introduced in many regions of the world to combat bollworms. However, cultivars differ in their pest susceptibility, yield response and fiber quality traits. Nonetheless, recent studies have indicated that lepidopteran pests are evolving resistance against 'Bt-cotton'. Several 'Bt-cotton' cultivars have been developed in Pakistan in the past decade; however, limited is known about their pest susceptibility, seed-cotton yield and fiber quality traits. This two-year field study evaluated pest susceptibility, yield and fiber quality traits of thirteen newly developed 'Bt-cotton' cultivars in Pakistan. The cultivars differed in their susceptibility to sucking insects during both years of study. The cultivars 'FH-647', 'SLH-8', 'FH-Lalazar' and 'IUB-013' were more susceptible to jassid, whereas 'BS-52' exhibited higher susceptibility to whitefly during both years of study. Similarly, cultivars 'AGC-999' and 'MNH-992' proved highly susceptible to thrips during each study year. Although 'Bt-cotton' is resistant to bollworms, cultivars 'SLAH-8', 'VH-305' and 'BH-184' were susceptible to spotted bollworm, while 'SLAH-8', 'RH-647' and 'VH-305' were infested by American bollworm. The most susceptible cultivars to cotton leaf curl virus (CLCuV) attack were 'RH-647', 'IR-NIBGE-7' and 'VH-305'. The highest seed-cotton yield was recorded for 'FH-Lalazar' during both years of study. Similarly, the highest ginning out turn was recorded for cultivars 'BS-52', 'VH-305', 'RH-647', 'IUB' and 'AA-919'. The cultivar 'FH-Lalazar' exhibited low pest susceptibility and CLCuV infestation compared to the rest of cultivars. The highest and the lowest gross and net incomes and benefit:cost ratio were noted for 'FH-Lalazar' and 'RH-647, respectively. Keeping in view the low pest susceptibility and high seed-cotton yield, 'FH-Lalazar' could be recommended for higher yield and economic returns in Multan, Pakistan. Nonetheless, regional trials should be conducted for site-specific or region-specific recommendations.

Seasonal Abundance of Aphids and Aphidophagous Insects in Pecan.

Seasonal occurrence of aphids and aphidophagous insects was monitored for six years (2006-2011) from full leaf expansion in May to leaf fall in October in "Desirable" variety pecan trees that were not treated with insecticides. Aphid outbreaks occurred two times per season, once in the spring and again in the late summer. Yellow pecan and blackmargined aphids exceeded the recommended treatment thresholds one time and black pecan aphids exceeded the recommended treatment levels three times over the six seasons. Increases in aphidophagous insect abundance coincided with aphid outbreaks in five of the six seasons. Among aphidophagous insects Harmonia axyridis and Olla v-nigrum were frequently collected in both the tree canopy and at the ground level, whereas, Coccinella septempunctata, Hippodamia convergens were rarely found in the tree canopy and commonly found at the ground level. Green lacewing abundance was higher in the ground level than in the tree canopy. Brown lacewings were more abundant in the tree canopy than at the ground level. Dolichopodid and syrphid fly abundance, at the ground level increased during peak aphid abundance in the tree canopy. Application of an aqueous solution of fermenting molasses to the pecan foliage during an aphid outbreak significantly increased the abundance of ladybeetles and lacewings and significantly reduced the abundance of yellow pecan, blackmargined and black pecan aphids.