Opisina Arenosella Walker Research Articles

Development of Microsatellite Markers and Detection of Genetic Variation betweenGoniozusWasp Populations

Molecular genetic markers reveal differences between genotypes according to the presence of alleles (the same or different) at target loci. Microsatellite markers are especially useful codominant markers that have been used in a wide range of studies to elucidate the population structure and dynamics of a range of organisms, including agriculturally beneficial insects such as parasitic wasps (parasitoids). In the present study, twelve primer pairs were designed for the south Asian , Goniozus nephantidis (Muesebeck) (Hymenoptera: Bethylidae), and 24 for its New World congener, Goniozus legneri Gordh, parasitoids of the larvae of the lepidopteran coconut pest Opisina arenosella Walker (Lepidoptera: Crytophasidae) and other lepidopteran pests, respectively, in order to investigate polymorphism within and between populations. The wasps fingerprinted were a total of 85 G. nephantidis and G. legneri, including individuals belonging to three putatively different strains of G. legneri. Annealing gradient tests (50–65°C) were conducted to study the quality of the PCR amplification across an annealing temperature gradient using a mixed genotype DNA template from each species separately. Seven primer pairs, which amplified clear products of approximately the expected size of G. nephantidis and 18 of G. legneri, were then selected for capillary analysis for fragment size determination on a Beckmann CEQ 8000. Neither G. nephantidis nor G. legneri were polymorphic within populations. However, there were six primer pairs that did show polymorphism between G. legneri populations that originated from different geographical areas within South America (Uruguay and Chile). Furthermore, one primer pair revealed diversity between the two strains collected within Chile. One of the markers was subsequently used to provide unbiased assessment of primary sex ratio in G. legneri.

Development of microsatellite markers and detection of genetic variation between Goniozus wasp populations.

Molecular genetic markers reveal differences between genotypes according to the presence of alleles (the same or different) at target loci. Microsatellite markers are especially useful co-dominant markers that have been used in a wide range of studies to elucidate the population structure and dynamics of a range of organisms, including agriculturally beneficial insects such as parasitic wasps (parasitoids). In the present study, twelve primer pairs were designed for the south Asian , Goniozus nephantidis (Muesebeck) (Hymenoptera: Bethylidae), and 24 for its New World congener, Goniozus legneri Gordh, parasitoids of the larvae of the lepidopteran coconut pest Opisina arenosella Walker (Lepidoptera: Crytophasidae) and other lepidopteran pests, respectively, in order to investigate polymorphism within and between populations. The wasps fingerprinted were a total of 85 G. nephantidis and G. legneri , including individuals belonging to three putatively different strains of G. legneri . Annealing gradient tests (50-65°C) were conducted to study the quality of the PCR amplification across an annealing temperature gradient using a mixed genotype DNA template from each species separately. Seven primer pairs, which amplified clear products of approximately the expected size of G. nephantidis and 18 of G. legneri , were then selected for capillary analysis for fragment size determination on a Beckmann CEQ 8000. Neither G. nephantidis nor G. legneri were polymorphic within populations. However, there were six primer pairs that did show polymorphism between G. legneri populations that originated from different geographical areas within South America (Uruguay and Chile). Furthermore, one primer pair revealed diversity between the two strains collected within Chile. One of the markers was subsequently used to provide unbiased assessment of primary sex ratio in G. legneri .

Monitoring Emergence Pattern of Coconut Black-Headed Caterpillar Opisinaarenosella Walker (Lepidoptera: Oecophoridae) Using Sex Pheromone Traps

The pheromone mass trapping programme for coconut black-headed caterpillar (BHC), Opisinaarenosella Walker under development at the south eastern dry zone of Karnataka calls for a proper monitoring system. Experiments conducted at Bidadi, Nelamangala, Nittur and Thyamagondlu near Bangalore, peninsular India to establish the emergence pattern of BHC indicated that nearly six emergence peaks of moths were recorded in 18 months. The duration of emergence and non-emergence periods of moths was approximately 41 days (SD= ±3.93) and 48 days (SD= ±4.35) respectively. The maximum number of days of moth and non-moth emergence was recorded during March, April and May. The studies on emergence pattern throughout the generation indicated that the moth emergence followed a normal curve. The moth emergence pattern of BHC in four coconut gardens at Nelamangala, Thyamagondlu, Nittur and Bidadi indicated the occurrence of spatially segregated moth emergence. The present studies provided thoughtful information on flight pattern of BHC in each generation and also throughout the year. Such basic results are helpful in designing pheromone based pest control strategies.

Integrated Management of Major Coconut Pests Using Pheromone Lures

Red palm weevil Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae; Rhinoceros beetle Oryctes rhinoceros Linn. (Coleoptera: Scarabidae) and Black headed caterpillar Opisina arenosella Walker (Lepidoptera: Oecophoridae) are the three among major insect pests of coconut in India. Grubs of Red palm weevil (RPW) enter and complete their life cycle within the stem, killing the tree, adults of Rhinoceros beetle (RB) feed on the growing point of the tree and cause yield loss and the larvae of black headed caterpillar scrape and feed on the green part of the coconut leaflets leading to burnt symptoms of the fronds, death of young trees and yield loss. Aggregation pheromones of RPW and RB are used for monitoring and mass trapping of RPW and RB to manage the pest under economic threshold level. During 2006-07 large scale field trials for RPW and RB were carried out in four different states in India by PCI under a partially funded Coconut Development Board (CDB) project using indigenously synthesized pheromone lures. It was demonstrated that the pheromone lures predominantly attracted virgin and gravid females of RPW and RB. Female sex pheromone of black headed caterpillar Opisina arenosella was also identified and developed in India by PCI, under a project partially funded by CDB; dispensers, dosage and traps were standardized under field conditions and further trials were also conducted in India. It was also established that pheromone lures can be used as a monitoring and a surveillance tool for understanding the pest status before the release parasitoids and natural enemies.

Leaf-eating caterpillar ( Opisina arenosella)-induced yield loss in coconut palm

Coconut is one of the major crops of commercial importance among the palms. The leaf-eating caterpillar Opisina arenosella Walker is the most important lepidopteran pest of coconut palm in India and Sri Lanka. Assessment of crop loss is essential for a realistic planning for research and developmental policies. Information on the yield loss in coconut due to O. arenosella attack is very meagre. In the present study, results of investigations carried out on leaf-eating caterpillar-induced yield loss in coconut palms in Kerala, India, for a period of 4 years (2002-2005) are presented. A maximum crop loss of 45.4% in terms of nut yield was recorded from infested palms in the succeeding year of severe pest incidence. The infested palms also showed reduction in bunch and leaf production to the tune of 21.0 and 13.8%, respectively. The pest-attacked palms regained their normal yield potential by the fourth year after heavy pest infestation.

Host Plant Nutrition and Outbreaks of the Coconut Caterpillar, Opisina arenosella Walker in Sri Lanka

The coconut caterpillar, Opisina arenosella, causes locally serious outbreaks with severedefoliation to coconut palms and subsequent loss of yield. However, there appears to be anatural resistance in the host plant to 0. arenosella attack, for infestations are confined tomature and senescing fronds and even within a heavily attacked plantation a few palms mayremain unattacked or only slightly damaged. Also previous work had indicated that potassiumdeficiency benefited O. arenosella. Therefore experiments were carried out to examine thepossible role in host resistance of major plant nutrients and also of certain amino acids.Comparisons were made between plantations with a history of frequent outbreaks('attacked') and those that had never been attacked ('unattacked'). The results showed thatthere were no significant differences between mean amounts of foliar potassium, nitrogen,phosphorus, calcium and magnesium at 'attacked' and 'unattacked' sites. However, thesesamples were taken at the end of unusually long dry seasons when differences in potassiumwould be expected to be relatively small because uptake is limited from dry soil. Potassiumlevels were highest in the youngest fronds which are those not normally attacked whereaspeak amounts of nitrogen occurred in those fronds which are most susceptible to attack. Alsoamounts of 'amide' were notably higher at 'unattacked' sites.It was concluded that further work was required on the relationship between major plantnutrients and levels of attack by 0. arenosella, particularly in relation to changes in nutrientconcentrations which occur at different times of the year. Thus, palms may be moresusceptible to pest attack during critical periods which need to be defined in order to optimisecontrol strategies.

Population dynamics of the coconut caterpillar, Opisina arenosella Walker (Lepidoptera: Xyloryctidae), in Sri Lanka

Opisina arenosella Walker is a defoliating pest of coconut in Sri Lanka. A firstattempt was made to understand its population dynamics. Analysis of records ofpopulation outbreaks throughout the country from 1965 to 1985 revealed cycles in thepopulation of approximately one generation period, giving the population theappearance of partially discrete generations. There was also evidence for longer cyclesof six-month period. Outbreaks occurred throughout the coconut-growing regions ofSri Lanka, and the numbers of outbreaks per year in different provinces weresometimes correlated, indicating a common, probably climatic, triggering mechanism.Parasitism remained high throughout the outbreaks and there was some evidence thatpupal parasitism increased towards the end of an outbreak. A working hypothesis thatexplains the population dynamics of O. arenosella and the origin of outbreaks ispresented.

On Some Hyperparasites of <i>Opisina arenosella</i> The Black-Headed Caterpillar Pest of Coconut in Malabar, India

Investigations carried out on the parasite-hyperparasite complex of the coconut pest Opisina arenosella Walker indicate that the hyperparasites considerably reduce the population of the parasites and thus lower the efficiency of the latter as biological control agents. Over half the cocoons of the parasitoid Apanteles taragamae Vier., were parasitised by the hyperparasites, with Aphanogmus manilae Ashmead accounting for 27.14% followed by Meteoridea hutsoni (Nixon) (17.14%), Brachymeria nephantidis Gahan and Pediobius imbreus (Walker) (2.86% each) and Eurytoma albotibialis Ashmead (1.42%). P. imbreus also caused 29.8% parasitism on Bracon brevicornis Wesmael. Brief descriptions of the biology of some of the hyperparasites are also given. COCOS, (1985) 3 29-31 doi: 10.4038/cocos.v3i0.819

Competitive interactions between Goniozus nephantidis and Bracon brevicornis, parasitoids of the coconut pest Opisina arenosella

Black-headed caterpillar, Opisina arenosella Walker (Lepidoptera: Crytophasidae) is an endemic, frequently outbreaking pest of coconut in India and Sri Lanka. It also occurs in Bangladesh and Myanmar. Two larval parasitoid wasps Goniozus nephantidis (Muesebeck) (Bethylidae) and Bracon brevicornis Wesmael (Braconidae), are widely employed, either singly or in combination, for the biological control of O. arenosella in India. The co-occurrence of G. nephantidis and B. brevicornis in the field indicates the potential for competitive interactions which may interfere with pest suppression. In order to study the outcome of competitive interactions between these parasitoids, host larvae were exposed to the parasitoid species either alone or in combination. Females of G. nephantidis and B. brevicornis did not discriminate between unparasitised hosts and hosts parasitised by the other species. Survival of G. nephantidis and B. brevicornis from eggs to adult eclosion was 89.6 and 81.8%, respectively, when larvae of O. arenosella were exposed to these parasitoids individually. When both species were released simultaneously, the survival of G. nephantidis was 86.8% and females of that species chased B. brevicornis females, attempting to bite and sting them. The mean percentage of progeny obtained was significantly higher for G. nephantidis than for B. brevicornis. G. nephantidis dominated due to its parental care behaviour producing 87.0% of progeny and a sex ratio (proportion of females) of 0.79, whereas B. brevicornis produced 84.0% progeny and a sex ratio of 0.36. Although parental care by G. nephantidis females serves to protect the progeny from intruders, it may be disadvantageous from the standpoint of pest suppression under field conditions especially, when the pest population density is high.

Economics of production of Goniozus nephantidis (Muesebeck), an important parasitoid of coconut black-headed caterpillar, Opisina arenosella (Walker) for bio-factories.

Black-headed caterpillar, Opisina arenosella (Walker), is a serious pest of coconut palms causing severe defoliation and yield loss. Goniozus nephantidis (Muesebeck), one of the dominant and effective parasitoids of O. arenosella , is being widely used in the biological control programme. Technology for the production and cost economies of G. nephantidis were worked out for the first time. The production of 3,25,000 parasitoids within a period of 6 months required charging of 225 wooden Corcyra boxes @ 75 nos./batch three times. Coreyra cephalonica (Stainton) was used as a laboratory host for rearing the parasitoid. Exposure of 2500 matured C. cephalonica larvae, was required in order to get I lakh parasitoids per month. The cost of production of 100,000 G. nephantidis cocoons was Rs. 27,600. The commercial cost of cocoon in India is Rs. 40,000 per 100,000 parasitoids and the profit would be Rs. 12,400 for producing 100,000 parasitoids. Benefit-Cost of the production of parasitoid was 1:1.45. Employment generated during the production process was four. Hence, this technology is highly feasible and can he adopted for the production and use against the pest. This mass production technology would be suitable for promoting localized production of G. nephantidis at village or district level especially for farmers, unemployed graduates, private and public sector units and NGOs.

Potential for lab rearing of Apanteles taragamae, the larval endoparasitoid of coconut pest Opisina arenosella, on the rice moth Corcyra cephalonica

A lab rearing technique was standardised for Apanteles taragamae Viereck (Hymenoptera: Braconidae), the early larval parasitoid of the coconut leaf-eating caterpillar, Opisina arenosella Walker on the alternate host Corcyra cephalonica Stainton (Lepidoptera: Pyralidae). The parasitoid took 23.3 ± 3.2 days to complete the egg to adult period. Adult longevity for males and females was 15.3 ± 4.6 and 13.8 ± 4.6 days respectively. Fecundity was 14.8 ± 4.3 eggs per female. The percentage parasitism was 60.6 ± 5.7 on the alternative host C. cephalonica and 64.6 ± 5.5 on the natural host O. arenosella. Eight- to ten-day-old caterpillars were the ideal stage of C. cephalonica for rearing A. taragamae. The results indicated the amenability of rearing A. taragamae on C. cephalonica in the laboratory.

Field evaluation of Goniozus nephantidis (Muesebeck) against coconut black-headed caterpillar in Kerala using different release techniques.

Many entomophagous insects attack the black-headed caterpillar of coconut, Opisina arenosella Walker during its developmental stages. Goniozus nephantidis (Muesebeck) is a gregarious larval parasitoid of O. arenosella . During summer months of 2003-04 and 2004-05 the parasitoid was evaluated in the field in Kerala by following two methods - trunk and crown release that were compared with control. There was significant reduction in the population of O. arenosella after third to sixth releases in treated palms, when compared to control palms. There was no significant difference between the two methods of release of G. nephantidis in reducing the population of O. arenosella . Hence farmers could easily and effectively adopt the trunk release method.

Field evaluation of anthocorid predator, Cardiastethus exiguus Poppius against Opisina arenosella Walker (Lepidoptera: Oecophoridae) in Kerala

Blackheaded caterpillar, Opisina arenosella Walker is a major pest of coconut in India. Cardiastethus exiguus Poppius is a potential predator of eggs and newly hatched larvae of O. arenosella . Field release and evaluation of C. exiguus was carried out during summer months of 2003–04 and 2004–05 in two pest-infested areas of Kerala, The release rates were 50 and 100 nymphs/adults per tree in the crown region. Totally three releases were made. There was significant reduction in the population of O.arenosella after release of the predator. The two release rates (50 and 100 nos./tree) were found equally effective in reducing the population of O. arenosella .

Preliminary attempt at biological control of coconut leaf eating caterpillar, Opisina arenosella Walker using two Trichogramma species

A preliminary attempt was made for biological control of coconut leaf eating caterpillar, Opisina arenosella Walker, by releasing two Trichogramma species viz. T. chilonis Ishii and T. embryophagum Hartig @ 1,000 to 4,000 parasitised eggs per palm in Bangalore, India. The mean percent reduction in larval population by 75.6, 60.0, 33.3 and 50.0% in T. chilonis and 88.8%, 175.0, 66.7 and 75.0% in T. embryophagum was recorded in treated palms during 1st, 2nd, 3rd and 4th generation of the pest compared to untreated control. There was non- significant difference between various release rates irrespective of the species, indicating that lower release rate of 1,000 parasitised eggs/palm as adequate. On sentinel egg cards, parasitism was low 2.0 - 5.0%, 0.0 - 2.0% and 0.0% in T. chilonis, and T. embryophagum released palms and untreated control palms, respectively. The field trial gave an indication that Trichogramma could be a potential parasitoid against O. arenosella and it is suggested that the parasitoids could be released and tested on a large scale in endemic areas to authenticate efficacy.

Nuclear Polyhedrosis Viruses from Coconut Blackheaded Caterpillar, Opisina arenosella Walker and Sorghum Spotted Stern Borer, Chilo partellus (Swinhoe)

Two nuclear polyhedrons viruses from the coconut black headed caterpillar, Opisina arenosella Walker and sorghum spotted stem borer, Chilo partellus (Swinhoe) were Isolated and reported for the first time from India. The pathogenicity of both the NPVs have been tested and proved along with gross pathological symptoms.

A novel method of field release of Goniozus nephantidis (Muesebeck), an important primary parasitoid of Opisina arenosella Walker on coconut

Goniozus nephantidis (Muesebeck) is an important primary parasitoid of Opisina arenosella Walker in coconut eco-system. The method of release of G. nephantidis was standardized for the first time. It was found that 90-100 per cent of the parasitoids released at the trunk (1.2 m from the ground level) reached the crown of the palm irrespective of the height of the tree. The mean time taken by each batch of the parasitoids to reach the crown varied from 13 to 22 minutes. It was also found that the parasitoids preferred to crawl on the tree rather than flying. Hence it is suggested that G. nephantidis adults may be released at the trunk (1.2 m height from the ground level) of the coconut palm for the management of O. arenosella instead of releasing at the crown region of the palm or arbitrarily on unit area basis.

Growth Disruption in Opisina arenosella Walker by Plumbagin, A Naturally Occurring Insect Growth Regulator

—Plumbagin, a napthoquinone from the plant Plumbago zeylanica , delayed pupation when topically applied to newly moulted final instars of the leaf eating caterpillar Opisina arenosella Walker (Lepidoptera: Oecophoridae). Pupae from treated larvae emerged into non-viable adults and had abnormalities such as deformed wings and shrunken abdomens; they also died much before the control insects. The results suggest that plumbagin interferes with the process of development and ecdysis of the insect.

Ants (Hymenoptera: Formicidae) as egg predators of coconut pests, especially in relation to biological control of the coconut caterpillar, Opisina arenosella Walker (Lepidoptera: Xyloryctidae), in Sri Lanka

AbstractA study was made of ants in Sri Lankan coconut plantations, especially of species foraging and nesting in palm crowns. At least 11 species were found nesting in the spadices, and a special study was made of interactions between some likely to be insect egg predators or to interfere with predation. Oecophylla smaragdina (F.) and Paratrechina longicornis (Latreille) were mutually exclusive, but some non-dominant species such as Monomorium spp. commonly nested and foraged in palms occupied by large populations of dominants such as O. smaragdina and Crematogaster sp. Eggs of the coconut pest Opisina arenosella Walker (and of Corcyra cephalonica (Stainton), which were used to simulate the former on palm fronds) were rapidly found and removed by certain ant species, notably M. floricola (Jerdan) and Crematogaster sp. Oecophylla smaragdina and P. longicornis seemed erratic as egg predators. Surveys of ants in areas where Opisina arenosella does, and does not, develop to outbreak populations showed that Monomorium spp. in particular were notably more common in the non-outbreak areas. However, other ants, notably Technomyrmex albipes (F. Smith), were sometimes common in outbreak areas and were seemingly good egg predators. The presence of thriving Oecophylla smaragdina colonies on currently attacked palms shows that this otherwise well-recognized predator has little or no effect on Opisina arenosella. It is concluded that several species of ants which nest in coconut palm crowns probably contribute importantly to the mortality of eggs of O. arenosella and help keep it in its rare endemic state in most places most of the time, even in outbreak areas.

Identities and provenance of the gelechioid moths originally described by Francis Walker from ‘unknown countries’

Abstract. The taxonomic placement and possible type‐localities of twelve species and one genus of Gelechioidea described by Francis Walker from ‘unknown countries’ are discussed. Opisina arenosella Walker is the senior synonym of Nephantis serinopa Meyrick and Opisina Walker is the senior synonym of Nephantis serinopa Meyrick and Opisina Walker the senior synonym of Nephantis Meyrick; Aroga compositella (Walker), new combination, is the senior synonym of A.coloradensis (Busck); Cryptolechia metaphaeella Walker is a junior synonym of Antaeotricha schlaegeri (Zeller); A.albulella (Walker), new combination, is the senior synonym of A.vestalis (Zeller), and A.spurcatella (Walker), new combination, is the senior synonym of A.chloromis (Meyrick). A lectotype for C.metaphaeella Walker is designated.