Ceratovacuna Lanigera Zehntner Research Articles

Field Efficacy of Proteolytic Entomopathogenic Fungi against Ceratovacuna lanigera Zehntner

Entomopathogenic fungi (EPF) are regarded as viable alternatives to insect pest control chemicals that contain a large amount of protease enzyme, which degrades the proteinaceous substances in insect cuticles. The aim of this study was to evaluate the field efficacy of protease-producing EPF against Ceratovacuna lanigera, and to assess the persistence of the Ceratovacuna lanigera, on sugarcane leaves. A total of 10 protease-producing fungi isolates were cultured from different agricultural soils, and identified as Purpureocillium lilacinum on the basis of the morphological features and molecular data, using ITS 1-5.8 S-ITS 2 of the rDNA sequences. The proteolytic activity of the isolates was assessed and expressed as an Enzyme Index (EI). Three isolates (PLTP5, PLPS8, and PLMC11) were found to be the best enzyme producers among the isolates, presenting EI values > 2.0 at 24 h, 48 h, and 72 h during incubation. These three isolates also gave the best results in terms of lethal concentrations (LC50 and LC90) and lethal time (LT50 and LT90) values, based on laboratory virulence evaluation, and were therefore selected for field application; commercial B. bassiana (GHA) was applied as standard treatment. An oil-based formulation of conidia (1 × 108 mL−1) of the isolates was applied in a sugarcane field experiment, with an interval of 10 days for four times. The results revealed that P. lilacinum (PLTP5) showed the highest reduction in the C. lanigera population, of 28.75, 56.02, 67.42, and 77.21%, respectively, after the first, second, third, and fourth spraying. The persistence of the conidia of the isolates on the sugarcane leaves was assessed. Per cent reductions in the conidia population, of 36.94–45.23%, 69.36–80.15%, and 81.75–92.96%, respectively, were found after three, six, and nine days of application. The application impact of EPF on the yield component and sugar content was evaluated. Purpureocillium lilacinum (PLTP5) showed the highest increase, of 18.15, 17.83, 15.07, 11.88, 23.73, and 19.38%, respectively, for leaf length, leaf width, cane height, cane girth, cane weight, and sugar content (brix). Our study indicated that P. lilacinum (PLTP5) was the most effective EPF against C. lanigera in field conditions, and also showed the highest proteolytic activity. Consequently, protease was considered the essential factor regulating the efficacy of P. lilacinum against C. lanigera. Protease would be useful, therefore, as an eco-friendly alternative to chemical pesticides, for the sustainable management of C. lanigera.

Efficacy of Entomopathogenic Trichoderma Isolates against Sugarcane Woolly Aphid, Ceratovacuna lanigera Zehntner (Hemiptera: Aphididae)

Ceratovacuna lanigera Zehntner (Hemiptera: Aphididae) is a destructive insect pest of sugarcane that is responsible for reducing the quality, yield, and sugar content. Ecofriendly methods of pest control, such as the use of biological control, is encouraged since it does not exhibit the harmful effects that are usually seen when using chemical-based pesticides. Here, we evaluated the efficacy of several entomopathogenic fungi isolates against C. lanigera under laboratory conditions. A total of seven isolates were obtained from agricultural soils that were collected from various locations from Sabah, Malaysia, using the insect bait method. Among the seven, four isolates (TMS114, TMS623, TMS628, and TMS707) were positively identified as T. harzianum (Hypocreales: Hypocreaceae), two isolates (TMS45, TMS321) as T. asperellum (Hypocreales: Hypocreaceae), and one isolate (TMS633) as T. hamatum (Hypocreales: Hypocreaceae) based on a combination of morphological characteristics and molecular data using ITS 1-5.8 S-ITS 2 regions of the rDNA. Four different concentrations (1 × 105, 1 × 106, 1 × 107, and 1 × 108 mL−1) of conidia suspensions of the isolates were applied separately on nymphs and adults of C. lanigera. The results showed that mortality in both nymphs and adults was dependent on the conidia concentration and exposure time. Among the four concentrations, the highest mortality of C. lanigera was found to range from 59.99 to 75.70% for nymphs after 72 h and from 57.45 to 72.31% for adults after 6 days of treatments at the concentration of 1 × 108 conidia mL−1. Trichodermaharzianum (TMS623) showed significantly highest mortality of 75.70% for nymphs and 72.31% for adults among the seven isolates. . However, the nymph and adult mortality rates for the isolates were 70.00% & 68.00% for TMS114, 66.42% & 63.10% for TMS628, 67.85% & 65.24% for TMS707, 61.42% & 58.80% for TMS45, 59.99% & 57.45% for TMS321 and 63.56% & 60.91% for TMS633, respectively. For nymph mortality, T. harzianum (TMS623) showed a LC50 (lethal concentration) value of 6.30 × 105 conidia mL−1 and LC90 value of 3.01 × 109 conidia mL−1, respectively, and for adult mortality, the values were found of 6.16 × 105 conidia mL−1 for LC50 and 2.23 × 1010 conidia mL−1 for LC90, respectively. The lethal time (LT) values for nymph and adult mortality were found of 42.65 h and 3.89 days for LT50 and 93.32 h and 8.70 days for LT90 by T. harzianum (TMS623). Therefore, T. harzianum (TMS623) showed more pathogenic potential against C. lanigera and can be further applied to determine its efficacy under field conditions. To our best knowledge, this is the first report of T.harzianum,T.hamatum, and T.asperellum species that are used as entomopathogenic fungi against sugarcane woolly aphid, C. lanigera.

Natural enemy fauna of paddy and horticultural ecosystems in upper Assam

Natural enemies of insect pests of rice, sugarcane, and a few selected rabi vegetables and their relative abundance were surveyed during 2014–15 and 2015–16. Sixteen spider species were found in rice ecosystem. Orthoptera, Coleoptera, Hemiptera, Diptera, Hymenoptera and Dermaptera were the dominant as natural enemies in rice ecosystem. The common natural enemies viz., were Conocephalus longipennis (de Haan), Agriocnemis femina Brauer, Micraspis crocea (Mulsant), Cicindela undulate Dejean and C. melancholia, predated upon different rice pests. However, larval parasitoid, Cotesia (Apanteles) angustibasis (Gahan) and egg parasitoid, Trichogramma japonicum Ashmead were more abundant in the rice ecosystem. On the other hand, Metarhizium anisopliae (Metchnikoff) Sorokin and Beauveria bassiana (Bals.-Criv.) Vuill., were the key entomopathogens observed against rice pests. In case of sugarcane, Sturmiopsis inferens Townsend and Cotesia flavipes (Cameron) were the common larval parasitoids of Chilo infuscatellus Snellen whereas Cotesia flavipes (Cameron) was the predominant one against C. tumidicostalis (Hampson); Dipha aphidovora (Meyrick), Micromus igorotus Banks and Chrysoperla spp. were the most common predators on Ceratovacuna lanigera Zehntner. Spalgius epius (Westwood) and chrysopids were observed on papaya mealybug. Cotesia vestalis (Haliday) parasitized the larva of cabbage butterfly, Pieris brassicae (L.). In cabbage, Bhut jalakia and okra ecosystem, Coccinella septempunctata (L.) and C. transversalis F., were the predominant predators.

Biology, feeding potential, standardization of mass production techniques and impact study of Dipha aphidivora Meyrick

Experiments were conducted on the biology, feeding potential and standardization of the mass production of Dipha aphidivora Meyrick predator on sugarcane woolly aphid, Ceratovacuna lanigera Zehntner during 2005-2007, at Agricultural Research Station (ARS), Honnavile, Shimoga (district), Karnataka, India. The duration of the first instar was 2.5 to 3.5 days (average 2.95+0.90 days). The average duration of second, third, fourth and fifth instar, pupal period, adult female and male moth lasted for 4.57+1.33, 8.30+1.11, 11.37+2.96 and 6.10+0.77 days, 8.50+2.15 days, 4.5+0.50 days, 1.5±0.30 days, respectively and the total larval period lasted for 24.5 to 39.5 days. The daily consumption rate by D. aphidivora was 30.8 aphids per day. D. aphidivora or aphid multiplied faster on 7-month-old crop than 5, 6 and 8 month old crop. At the rate of 50 number of D. aphidivora pupae release, highest populations of 4230 per shade net D. aphidivora were harvested. Highest populations of D. aphidivora were harvested when the shade nets were irrigated once in two days with the population of 4123 D. aphidivora per shade net than irrigated once in week with the population of 1490 D. aphidivora per shade net. During the experiment, average temperature was 280C and relative humidity was 78 per cent.

Efficacy of Acrernonium zeylanicum against Sugarcane Woolly Aphid under Laboratory Conditions

The fungus, Acremonium zeylanicum (Petch) W. Gams and H.C. Evans, was found infectious to sugarcane woolly aphid, Ceratovacuna lanigera Zehntner and caused differential mortality of different instars at varied concentrations. Studies on the efficacy of the entomopathogenic fungus revealed that the mortality of aphids increased with increase in concentration and time of application. First instar nymphs showed the highest mortality (92.5%) at 1x10 10 conidia 1 -1 and as the stage of the insect advanced, the mortality rate declined. On the contrary, lower mortality of aphids was recorded at 1x10 4 conidia 1 -1 after 10 days of application.

Influence of monsoonal weather on sudden establishment of the sugarcane woolly aphid in Sri Lanka

A sudden infestation of the sugarcane woolly aphid (Ceratovacuna lanigera Zehntner, Homoptera: Aphididae) was recorded on sugarcane (Saccaharum hybrid) in January 2006 in the mid country hills of Badulla, Sri Lanka after its first record in 1905. Subsequent out breaks were recorded during November and December of the same year in other areas. An investigation through analysis of relevant meteorological data to find out whether the sudden aphid out break was due to (i) favourable local climatic changes or (ii) dispersal of the pest from the nearby Indian subcontinent revealed mean annual temperature or the rainfall of the period 1900–2006 did not significantly contribute for climate change. However, the association of highest RH (80–82%) and lowest sunshine hours (3.2–3.75 h) observed with the North-East monsoon and the insect out breaks were further confirmed by the post-established population of the aphid too. The positive help of winds for insect dispersal was observed as the winds over the Indian sub continent at the time of first aphid infestation were heading towards Sri Lanka during the North-East monsoon period. Therefore, it can be concluded that C. lanigera was established in Sri Lanka with help of the North East monsoonal weather conditions from the nearest parts of the Indian subcontinent. The present ecological information can be useful for forecasting C. lanigera out breaks in order to plan effective control measures.

Rearing Dipha aphidivora, the pyralid predator of sugarcane woolly aphid Ceratovacuna lanigera, on its frozen host may be unfeasible

In Petri plate tests, neonate or third to fourth instar larvae of the predator Dipha aphidivora Meyrick (Lepidoptera: Pyralidae) were offered its host Ceratovacuna lanigera Zehntner (Homoptera: Aphididae), the woolly aphid of sugarcane, frozen and stored at −4°C, and thawed at room temperature before releasing the predator. In preliminary tests, neonate and grown-up larvae built webs, fed on aphids, pupated and emerged as adults. In two tests with neonate larvae, adult emergence was 45.5 and 80.0% in 17–21 days. The predator moths laid eggs on white coarse filter paper strips but not on hard paper strips of different colors placed in oviposition cages. Egg-laden filter paper or leaf bits placed in Petri plates with frozen aphids showed hatching but larvae did not survive long. Poor survival of neonate larvae in several additional tests with fresh or one-year old frozen aphid indicated that the method may not be useful for long-term rearing of the predator. Short-term survival of grown-up larvae on frozen aphid may enable the use of the latter as food for predator larvae in transit.

Assessment of woolly aphid impact on growth, yield and quality parameters of sugarcane

The impact of woolly aphid Ceratovacuna lanigera Zehntner (Homoptera: Aphididae) attack in five / six month old sugarcane on growth, yield and quality parameters of the crop was assessed in two field trials (cv. Co 86032) in 2004–05 and one trial (cv. Co 7219) in 2006-07. The effect on linear growth was assessed by measuring the incremental growth of benchmarked canes with and without woolly aphid attack at fortnight intervals. The mean aphid intensity rating per leaf on individual canes was recorded alongside in one trial to relate it to cane growth. At harvest, the weight of marked canes were recorded and juice and jaggery analysis for various parameters was performed. In the first trial (cv. Co 86032) with aphid attack in fifth month, incremental growth in infested canes was on par with that in healthy canes. In the second trial (cv. Co 86032) with aphid attack in the sixth month, incremental growth was lower in infested canes in most fortnights. In the third trial (cv. Co 7219) with aphid attack in sixth month, incremental growth was significantly lower in infested canes in the initial stages whereas in the later stages the differences became nonsignificant. Aphid abundance in the early stage and its subsequent abrupt disappearance showed correspondence with the observed pattern in incremental growth. While differential effect on cane and juice weight in the first two trials suggested the role of crop age at the time of attack, the results of the second year study indicated the possible effect of aphid intensity. Higher brix and sucrose% in infested canes in the second trial suggested possible effect of sap feeding on their concentration. Inconsistently higher phenols in infested canes did not positively suggest their role as induced resistant factors. Jaggery analysis did not show definite trends in different trials.

A semi-synthetic diet for rearing Dipha aphidivora (Lepidoptera: Pyralidae), a promising predator of woolly aphid in sugarcane

Dipha aphidivora (Meyrick), a lepidopteran predator of sugarcane woolly aphid (SWA) Ceratovacuna lanigera Zehntner was successfully reared for three successive generations, for the first time on a freeze-dried beef liver-based larval semi-synthetic diet. We compared biological parameters viz., larval survival, adult weight, pre-and oviposition period, fertility, fecundity and female longevity of D. aphidivora reared on the semi-synthetic diet with the predators reared on SWA. Development time of larvae reared from first instar to pupation was 20.6 days on the semi-synthetic diet and 12 days on SWA, while survival of the larvae to adults was 61.8 and 91.8% on larval semi-synthetic diet and SWA, respectively. Fecundity recorded from semi-synthetic diet (41 eggs/female) was significantly less than those produced on SWA (58 eggs/female). However, fertility and longevity of the predators reared on SWA and semi-synthetic diet did not differ significantly. The study revealed the possibility of rearing D. aphidivora larvae using synthetic diet.

Effect of repeated in vitro sub-culturing on the virulence of Metarhizium anisopliae against Helicoverpa armigera (Lepidoptera: Noctuidae)

The effect of repeated conidial sub-culturing of Metarhizium anisopliae on its virulence against Helicoverpa armigera (Hübner) was studied. The LT50 observed against third instar larvae of H. armigera for the first sub-culture was 3.4 days; it increased to 4.5 and 5.6 days for the 20th and the 40th sub-cultures, respectively. The LT50 values after passage of the 40th sub-culture on H. armigera decreased to 4.4 and 3.7 days for the 40th (first in vivo) and the 40th (fifth in vivo) passages, respectively. Similarly, the LC50 of M. anisopliae towards third instar larvae of H. armigera increased from the first sub-culture (0.17×104) to (3.0×104) for the 40th conidial transfers on potato dextrose agar and again decreased to 0.74×104 and 0.23×104 in the 40th (first in vivo) and the 40th (fifth in vivo) passage, respectively. Similar trends for LC50 and LT50 values were seen when sugarcane woolly aphid, Ceratovacuna lanigera Zehntner was used as a host. Significant variation in appressorium formation and cuticle-degrading enzyme production such as chitinase, chitin deacetylase, chitosanase and protease during subsequent sub-culturing and passage through H. armigera was observed. Though there was no effect on internal transcribed spacer (ITS) sequence pattern, interestingly, in randomly amplified polymorphic DNA (RAPD), significant differences in the band intensities and in the banding pattern for different sub-cultures of M. anisopliae were observed. As stable virulence towards the insect pest is desirable for commercialisation of a mycoinsecticide, such changes in virulence due to repeated in vitro transfer need to be monitored and minimised.

Natural occurrence of Gibberella fujikuroi and its potential for control of the woolly aphid Ceratovacuna lanigera (Homoptera: Aphididae) in Indian sugarcane plantations

Studies were conducted to determine the natural occurrence of entomopathogenic fungi and their potential for utilisation in biological control of the woolly aphid (Ceratovacuna lanigera Zehntner) in Indian sugarcane plantations. A fungus Gibberella fujikuroi (Sawada) Wr. (Synonym: Fusarium verticillioides (Sacc.) Nirenberg, Synonym: Fusarium moniliforme (Sheld.) emend. Snyd. and Hans.) was found to be a promising biocontrol agent. It was further characterised and its field performance was studied. Reductions of aphid populations up to 60% were observed when the fungus was applied as two sprays at a week interval in the field.

Population Fluctuations of Sugarcane Woolly Aphid, Ceratovacuna lanigera Zehntner (Homoptera:Aphididae), and its Natural Enemies in Plant and Ratoon Sugarcane Crops in Assam

The seasonal incidence of sugarcane woolly aphid, Ceratovacuna lanigera Zehntner (Homoptera: Aphididae), and its natural enemies was studied at Instructional-Cum-Research (ICR) Farm, Assam Agricultural University (AAU), Jorhat and at Sugarcane Research Station (SRS), Buralikson, Golaghat during 2004-05. Out of five species of natural enemies recorded at ICR Farm, AAU, Jorhat, Eupeodes confrater (Wiedemann), Chrysoperla carnea (Stephens), Coelophora biplagiata (Mulsant) and Dipha aphidivora (Meyrick) had significant positive impact on sugarcane woolly aphid population, while non-significant negative correlation of aphid population was observed with the population of Encarsia flavoscutellum Zehntner. Multiple regression analysis of different natural enemies with the population of C. lanigera showed 89.0 per cent relationship with the aphid population. At SRS, Buralikson, Golaghat, the only observed natural enemy D. aphidivora showed significant positive impact on woolly aphid population.

Mass Production of Dipha aphidivora (Meyrick) (Lepidoptera:Pyralidae), a Potential Predator of Sugarcane Woolly Aphid, in Shade Nets

Mass production of Dipha aphidivora (Meyrick), a potential predator of sugarcane woolly aphid, Ceratovacuna lanigera Zehntner, was attempted in 'makeshift' type green shade nets of 40 and 50% mesh with temporarily installed bamboo frames by covering 6 and 7 months old sugarcane crop on small scale (25 m 2 ). Seven-month-old sugarcane crop with 60-70% SWA infestation covered by 50% green shade net in bamboo frame of 5 × 5 m size yielded a maximum of 2700 larvae and pupae of D. aphidivora within 75 days.

A simple mass rearing method for dipha aphidivora, the pyralid predator of sugarcane woolly aphid ceratovacuna lanigera

A simple laboratory method for mass rearingDipha aphidivora (Meyrick) (Lepidoptera: Pyralidae), a predominant predator of sugarcane woolly aphid (SWA)Ceratovacuna lanigera Zehntner (Homoptera: Aphididae), was developed as an alternative to rearing in shade net houses. The predator was reared on field-collected SWA infested sugarcane leaf bits in GI trays of 60 cm x 45 cm x 10 cm size. Of the several problems faced in the rearing, two major ones required solutions to make the methodology a success: (i) extensive dispersal of aphids from the rearing trays and (ii) the labour intensive process of collectingDipha larvae from drying old leaf bits and inoculating them on fresh bits at every change. The first problem was solved by stacking one tier of uninfested leaf bits above every tier of infested leaf bits and at right angle to the lower layer. The second problem of manual collectionof Dipha larvae was overcome by stacking new leaf bit sets contiguous to the old ones which facilitated the predator larvae to disperse from drying old leaf bit sets to the new ones on their own. Sets comprising 50 infested and 50 uninfested leaf bits stacked in four tiers and inoculated with 500 eggs ofD. aphidivora followed by provisioning of the same numbers of leaf bits in the same fashion six times at 3 day intervals, gave 78.5% pupal recovery at the end of the rearing period of 18 days. Protocols for producing 35,000 cocoons ofD. aphidivora in single cycle or staggered modes are outlined.

Functional GNA expressed in Escherichia coli with high efficiency and its effect on Ceratovacuna lanigera Zehntner

The mannose-specific GNA (Galanthus nivalis agglutinin, snowdrop lectin) are the resistant proteins with many bioactivities. Snowdrop lectin is different with plant organs and development periods in lectin species, content, and bioactivities. It is an effective and cheap way to obtain much active GNA through overexpression of GNA gene in Escherichia coli. Constructs encoding mature GNA fused with an N-terminal pelB signal sequence protein (PelB) were expressed in E. coli with high efficiency. Recombinant protein productivity was higher than values published before. The insecticidal activity of purified recombinant proteins was assayed on feeding sugarcane wooly aphid (Ceratovacuna lanigera Zehntner), as well as spraying on sugarcane plants infected by aphids. The insecticidal activity was found to be comparable to native GNA. Oral delivery has obvious positive implications for crop protection against insect pests since peptides can be present in, or sprayed on, plant tissues susceptible to damage. A highly efficient expression of functional recombinant GNA would decrease the cost of GNA and promote its wide use, especially to give crop protection in the field.

Ceratovacuna lanigera Zehntner (Homoptera:Aphididae) a Serious Pest of Sugarcane in Maharashtra and Attempts at its Management by Biological Means

Serious and unprecedented infestations by the sugarcane woolly aphid, Ceratovacuna lanigera Zehntner were witnessed on the leaves of 4·9 month old sugarcane crop in Kolhapur and Pune districts of Maharashtra during September-October, 2002. During surveys for natural enemies, seven predators were recorded in Kolhapur, of which Dipha?aphidivora (Meyrick) was observed to be the most promising. In Pune district, only Cheilomenes sexmaculata (Fabricius) was recorded. Limited field releases of the coccinellid, Synonycha grandis (Thunberg) collected from the bamboo woolly aphids at Bangalore and the chrysopid, Chrysoperla carnea (Stephens) were made in a small area at Kolhapur. S. grandis adults and C. carnea eggs were recovered 2 to 3 weeks after release, indicating their survival in the field.