Cent Infestation Research Articles

English

Screening of groundnut (Arachis hypogaea L.) genotypes against spotted pod borer, Maruca vitrata (Geyer) was conducted during rabi 2015-16 at dryland farm, S.V. Agricultural College, Tirupati. Twenty-five genotypes were screened against the spotted pod borer. Among these Percent infestation of M. vitrata was less in K-9, ICGV-86368, TCGS-1426, CS-19 genotypes and more in K-6, Dharani, Narayani and TCGV-1543. The experimental results indicated that spreading type and short stature groundnut cultivars were tolerant to the M. vitrata incidence. Chlorophyll content and Specific Leaf area, these plant physical parameters showed significant effect on incidence of M. vitrata in groundnut crop. Chlorophyll content was negatively correlated with (r =-0.48) with per cent infestation of M. vitrata at 60 DAS. Specific Leaf area was positively correlated with (r=0.43) with per cent infestation of M. vitrata at 60 DAS and also short stature plants groundnut cultivars were tolerant to M. vitrata incidence.

Evaluation of Biorational Component and Chemicals for the Management of Lemon Butterfly Larvae on Citrus

The investigation was conducted with imposed of treatments; Beauveriabassiana(1x108 CFU/ ml), Metarhiziumanisopliae(1x108 CFU/ ml), NSE (5.0%), Neem oil (2.0%), Spinosad 45 SC (0.03%), Imidacloprid 17.8 SL (0.005%), Acetamiprid 20 SP (0.04%), Abamectin 1.8 EC (0.003%) and Control (water spray) on Nagpur Mandarin against nursery pests. Such treatments were arranged in statistical design RBD with three replications, under green shade net nursery. In overall, cumulative effect of four applications of all the treatments, Abamectin 1.8 EC (0.003%) recording lowest (6.10 per cent) leaves infestation of leaf miner and found at par with Spinosad 45 SC (7.18 per cent) leaves infestation. The next best effective treatments, Acetamiprid 20 SP (9.34 per cent) of leaves infestation and Imidacloprid 17.8 SL (10.31 per cent) leaves infestation were at par with each other and found significantly superior to the Neem oil 2%, NSE 5 %, Beauveriabassiana1x108 CFU/ml and Metarhiziumanisopliae 1x108 CFU/ml respectively and these treatment groups were at par with each other. Maximum per cent infestation of leaf minor was noticed in control is (25.14 per cent). Key Words: Lemon Butterfly Larvae; Insecticide and Biorational Components

Screening of certain gram genotypes against Callosobruchuschinensis L. (Coleoptera:Bruchidae)

Chickpea (Cicer arietinum L.), is an important pulse food. During storage this commodity is severely attacked by pulse beetle Callosobruchus chinensis L. (Coleoptera: Bruchidae) and losses in quantity and nutritional quality. Research studies on relative resistance of 8 chickpea genotypes to the attack of C. Chinensis during storage were carried out. The maximum number of eggs laid on genotypes ICCV-07301 (34.35) whole minimum numbers of eggs (17.3) were laid on genotypes ICCV-990126. Significantly higher weight loss (24.98%) was noticed SG-98310 which was followed by SG-950226 (16.64 per cent). Least weight loss (5.78 per cent) was observed in SG-97311 closely followed by SG-98004 (6.36%).. The highest per cent infestation was observed in ICCV-08303 (91.66) and the lowest per cent infestation was observed in ICC-920412 (71.66%) closely followed by ICCV-990126(73.33%). The developmental period was recorded longer on deshi genotypes than kabuli genotypes. After 60 days of infestation the protein content increased by 30.03 per cent in kabuli genotypes and by 48.37 per cent in deshi genotypes.

Influence of biophysical characteristics of brinjal varieties on the infestation of brinjal shoot and fruit borer, Leucinodes orbonalis Guenée

A study was conducted during summer 2014 (February – May, 2014) and Rabi, 2014 (September, 2014 - January, 2015) at Vegetable Research Station, Palur, Tamil Nadu, India to find the relationship between biophysical characteristics of brinjal genotypes and infestation of Leucinodes orbonalis by screening 35 germplasm of brinjal. Thirty five germplasm were planted in the field having three replications of 05 plants for each treatment. The biophysical characteristics of brinjal genotypes viz., shoot thickness at 2.5 cm below the tip, number of trichomes on under surface of leaves, length of pedicel, calyx and fruit, and diameter of fruit were measured to correlate them with level of infestation by L. orbonalis. At the time of harvesting the per cent infestation of fruit were calculated. The results revealed that the shoot infestation by L. orbonalis negatively, but not significantly correlated with number of trichomes on leaves (r = -0.52) and positively correlated with shoot thickness (r = 0.05). Fruit infestation was positively but not significantly correlated with length of pedicel (r = 0.03) and calyx (r = 0.24) whereas non-significant and negative correlation was recorded between fruit infestation and fruit characters viz., length of fruit (r = -0.25) and diameter of fruit (r = -0.04). The shape and colour of fruit had no significant influence on the level of infestation Journal of the University of Ruhuna 2015 3(1): 21-28

Evaluation of some insecticides against pigeonpea pod fly <italic>Melanagromyza obtusa</italic> Mall

The present investigation was conducted during <italic>kharif</italic> 2011-12 on field of Department of Agricultural Entomology, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. The experiment was planned in randomized block design with gross plot size 4.2 x 4.4 m<sup>2</sup> and net plot size 3.0 x 4.0 m<sup>2</sup> with twelve treatments replicated thrice with the object to study the effect of some insecticides against pigeonpea pod fly, <italic>Melanagromyza obtuse</italic>. In evaluation studyten treatments were tested against pod fly, <italic>Melanagromyza obtuse</italic>. on pigeonpea. The result revealed that treatment Deltamethrin 1 EC + Triazophos 35 EC emerged as the most effective treatment against <italic>M. obtusa</italic> in minimizing the damage to green and drypods as well as grains. Thiaclopride 21.7 SC and Profenophos 50 EC were found significantly effective in minimizing the cumulative mean per cent infestation of pod flyof pigeonpea. These findings indicate that the pigeonpea crop required two sprays of newer insecticides from pod initiation stage at 15 days interval for the management of pigeonpea pod fly, <italic>Melanagromyza obtusa.</italic>

Morphological parameters of soybean plant resistance to lepidopterous defoliators

Plants have defence approaches against various insect feeding strategies which include morphological (antixenosis), biochemical (antibiosis), and molecular (tolerance) mechanisms to offset the effects of herbivore attack. In this experiment the role of morphological characters to determine resistance-susceptibility of soybean (Glycine max L. Merril) genotypes were studied. Ten soybean varieties SL 979, RVS 2001–18, MACS 1340, KDS 708, JS 20–71, RKS 113, NRC 94, MACS 1394, NRC 93, CSB 904, were studied for correlation between field resistance and % infestation of insects viz., tobacco caterpillar (Spodopter litura), bihar hairy caterpillar (Spilosoma obliqa) and semi looper (Thysanoplusia orichalcea). A highly significant negative correlation was found between leaf hair density and per cent infestation for S. obliqua, S. litura and T. orichalcea. While, the other parameters viz., plant height, number of primary branches, nodes and pods were found to be nonsignificant. On the basis of correlation study it was concluded that varieties SL 979, RVS 2001–18, JS 2071 are comparatively more resistant having less infestation, while MACS 1340, MACS 1394 was most susceptible to all three mentioned insect-pests having more infestation.

Efficacy of different pyrethroid alone and in combination with Dimethoate against stem fly of soybean

Experiments were conducted to evaluate efficacy of different pyrethroid alone and in combination with Dimethoate against stem fly of soybean during kharif season of 2011-2012 on field of Department of Agricultural Entomology, Dr. PDKV, Akola. In evaluation study twelve treatments were tested against stem fly Melanagromyza sojae (Zehnt) on soybean. The results revealed that the per cent stem length tunneled due to stem fly was significantly reduced in plots treated with Triazophos 35% + Deltamethrin 1% (36% ready mix formulation) @ 0.09% followed by Triazophos 40 EC @ 0.06% + Deltametrin 2.8 EC @ 0.0028% and Dimethoate 30 EC @ 0.045% were found significantly most effective in minimizing the average per cent infestation of stem fly at 90 days after sowing of soybean. Lastly economics and ICBR were calculated for each treatment.

Melon fruit fly (Bactrocera cucurbitaeCoq.) infestation and management on bottle gourd in West Bengal, India

Seasonal trends in infestation level of Bactrocera cucurbitae were analyzed to determine the factors that influence the infestation by melon fruit fly in the field and adoption of suitable insecticidal management on bottle gourd. The experiment was conducted during pre-kharif and kharif seasons in 2012 and 2013. Percentage of infestation was recorded on the basis of infested and total fruits. The highest fruit infestation i. e. 56.56 and 49% was recorded during 25th (17th June) and 24th (9th June) standard weeks during respective years. The correlation coefficient between per cent infestation by melon fly with weather parameters exhibited a significant positive correlation with maximum temperature and negative correlation with RH-I and RH-II. In case of management chlorphenapyr, acephate, spinosad and deltamethrin were most effective bio-rational insecticide for managing melon fly and provided higher yield.

Seasonal abundance ofScaphisoma tetrastictumChamp on oyster mushroom and its relation to meteorological factors

A study on the seasonal incidence of the beetle Scaphisoma tetrastictum Champ and the relationship of various meteorological factors with its incidence in oyster mushroom ( Pleurotus ostreatus Jacq. Ex Fr.) was conducted in the Department of Plant Pathology, Assam Agricultural University, Jorhat (India) during 1999–2000. Seasonal variation in the population density of adult beetles and per cent fruit body infestation by the adults and grubs were observed. Incidence of the beetle was recorded from March to November 1999 revealing the highest number (12.35) of adults per fruit body and per cent infestation (29.96) during July, 1999. The mushroom remained free from beetle incidence during the winter months. Beetle population per fruit body (10.43) and extent of infestation (26.03%) were higher during monsoon (June to August) where as the pre-monsoon period (March to May) recorded the beetle population and per cent infestation of 4.64 and 9.61%, respectively. Beetle population showed positive significant correlations with maximum ( r = 0.7460, P < 0.05) and minimum temperature ( r = 0.6884, p < 0.05) and number of rainy days ( r = 0.9102, p < 0.01). Per cent fruit body infestation by the beetle exhibited positive significant correlations with maximum temperature ( r = 0.8032, p < 0.05), minimum temperature ( r = 0.7666, p < 0.05), total rainfall ( r = 0.6823, p < 0.05) and number of rainy days r = 0.9299, p < 0.01).

Biochemical differences in some forage sorghum varieties in relation toPyrilla perpusillaWalker infestation

Assessment of the qualitative losses in different varieties of sorghum following Pyrilla perpusilla Walker infestation revealed the significant decrease in vitro dry matter digestibility of whole plant, leaves and stem by about 6.0, 3.5 and 3.0 per cent, respectively at more than 60 per cent infestation level and was mainly due to the corresponding increase in tannin content. The fibre components (NDF and ADF) were acting as an additional factor in reducing the dry matter digestibility. The dry fodder yield was also reduced by 46 to 53 per cent in different varieties of sorghum with an increase in infestation level from 0 to >60 per cent. The stem of all the varieties was more fibreous than the leaves as it had high content of NDF, ADF, cellulose and lignin. Leaves on the other hand had high amount of protein, total soluble sugars and reducing sugars than stem and were therefore more digestible than stem.

Consequences of insect herbivory on grape fine root systems with different growth rates

Herbivory tolerance has been linked to plant growth rate where plants with fast growth rates are hypothesized to be more tolerant of herbivory than slower-growing plants. Evidence supporting this theory has been taken primarily from observations of aboveground organs but rarely from roots. Grapevines differing in overall rates of new root production, were studied in Napa Valley, California over two growing seasons in an established vineyard infested with the sucking insect, grape phylloxera (Daktulosphaira vitifoliae Fitch). The experimental vineyard allowed for the comparison of two root systems that differed in rates of new root tip production (a 'fast grower', Vitis berlandieri x Vitis rupestris cv. 1103P, and a slower-growing stock, Vitis riparia x Vitis rupestris cv. 101-14 Mgt). Each root system was grafted with a genetically identical shoot system (Vitis vinifera cv. Merlot). Using minirhizotrons, we did not observe any evidence of spatial or temporal avoidance of insect populations by root growth. Insect infestations were abundant throughout the soil profile, and seasonal peaks in phylloxera populations generally closely followed peaks in new root production. Our data supported the hypothesis that insect infestation was proportional to the number of growing tips, as indicated by similar per cent infestation in spite of a threefold difference in root tip production. In addition, infested roots of the fast-growing rootstock exhibited somewhat shorter median lifespans (60 d) than the slower-growing rootstock (85 d). Lifespans of uninfested roots were similar for the two rootstocks (200 d). As a consequence of greater root mortality of younger roots, infested root populations in the fast-growing rootstock had an older age structure. While there does not seem to be a trade-off between potential growth rate and relative rate of root infestation in these cultivars, our study indicates that a fast-growing root system may more readily shed infested roots that are presumably less effective in water and nutrient uptake. Thus, differences in root tip production may be linked to differences in the way plants cope with roots that are infested by sucking insects.

Effect of sowing dates and fertilizer on the severity of stem borer (Busseola fusca Fuller, Lepidoptera: Noctuidae) on sorghum in Eritrea

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.

REACTION OF ACID LIME SELECTIONS TO CITRUS LEAF MINER INCIDENCE

Studies on leaf miner incidence in 57 promising acid lime selections/genotypes collected from different districts of Western Maharashtra indicated wide range of variation in their susceptibility. Based on mean per cent infestation of leaf miner for two years, no genotype was found immune or resistant. One was found less susceptible, 39 susceptible and 17 highly susceptible. The Sel. 124, Sel.49, Sel. 107 and Sel.159 had lowest incidence and also posses desirable attributes of high yield and quality traits.

Survey of the prevalence of warble fly larvae in market cattle in Great Britain.

A survey of warble-infested 'fat' cattle in 57 selected livestock markets in Great Britain was carried out during June 1972 and during May each year from 1973 to 1984. The annual total number of cattle inspected varied from 41,587 to 60,481. The level of infestation increased from 22.3 per cent in 1972 to 38.0 per cent in 1976 and then declined slightly to 34.3 per cent in 1978. Following the introduction of legislation and the warble fly eradication campaign in 1978 there was a rapid decrease to 8.6 per cent infestation by 1979 and by 1984 the level was less than 0.02 per cent.

Laboratory and Field Tests of Insecticides against Douglas Fir Seed Wasp (Megastigmus spermotrophus Wachtl)

SUMMARYTests were made to select insecticides which would kill adult seed wasps in crowns of cone‐bearing Douglas ftr trees. In the laboratory, gamma BHC, malathion and diazinon were found to be active against females. In further tests, on males and females, gamma BHC and malathion were active when the insects were allowed contact with treated surfaces; fenitrothion was less active. The effectiveness of gamma BHC was partly due to fumigant action whereas malathion and fenitrothion had no fumigant effect. In separate field experiments between 1962 and 1966 in Kent and Herefordshire, gamma BHC and fenitrothion gave no control but malathion gave good control. In 1968, trees in Kent to which malathion was apphed three times at 10‐day intervals during June had about 13 per cent infestation of potentially sound seed, when assessed in September, compared with about 45 per cent infestation on unsprayed trees. Malathion plus gamma BHC did not further reduce infestation.

Airplane Dusting for the Control of Vegetable Pests on the Mexican West Coast1

Airplane Dusting for the Control of Vegetable Pests on the Mexican West Coast1