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Native to East Africa, the giant African snail Lissachatina [= Achatina ] fulica (Bowdich, 1822) is a tropical crop pest and one of the world's top 100 invasive species. It is now present in at least 52 countries worldwide, with an actively expanding range. Lissachatina fulica was first introduced to India in 1847, but subsequent arrivals in India and local patterns of spread remain unclear. This study uses the 16S rRNA gene to identify the extent of genetic variation in India by sampling Indian populations and comparing them with published sequence data. A total of 307 snails were collected from 178 localities in India and from a single locality in the UAE, and the 16S rRNA gene was amplified and sequenced. Eight haplotypes were identified from India of which four are newly recognized. The new haplotypes identified in this study have increased the number of L. fulica 16S rRNA haplotypes from 19 to 23. Examination of haplotype and nucleotide diversities revealed that genetic variation is low in India, the UAE and across Asia as a whole. The number of haplotypes was higher in India when compared to other invasive regions but all of the Asian haplotypes appear to be closely related to the most common haplotypes in the Indian Ocean Islands. Heavy trade between the snail-infested and native-range countries suggests that the variation observed in India might be traced back to its native range, but the lack of sampling and paucity of sequences from East Africa currently prevents a comparison. Tracing back the emergent haplotypes by additional sampling could throw more light on the spread of L. fulica. [ABSTRACT FROM AUTHOR]

The article presents the discussion on giant African snail Lissachatina fulica reported as a pest in rubber plantations adjoining forest fringes in the Western Ghats region of Kerala. Topics include acting as an intermediate host of the rat lung worm Angiostrongylus cantonensis causing eosinophilic meningitis in humans especially children; and snails being found to be in huge numbers and feeding on latex secreted from rubber trees causing damage.

The rapidly spreading Giant African Snail Lissachatina [= Achatina ] fulica (Bowdich, 1822) has been introduced to many parts of the world since the 1800s and is one of the world's most invasive species. We compared cytochrome oxidase subunit I (COI) sequences from four invasive ranges: India, United Arab Emirates (UAE), China and West Africa. Sixteen distinct haplotypes were identified, with nine found in India, four in the UAE, one in China and four in West Africa. Haplotype 5 was the most common haplotype in Asia and haplotype 1 the most common in West Africa. Network analysis suggests that all haplotypes in India, the UAE, China and West Africa were derived from the most common haplotype 5 which is present in all three invasive ranges in Asia. Higher levels of genetic variation were observed in the invasive ranges of Asia than in West Africa. The high genetic variation observed in Asia, together with high levels of trade as exemplified by wood import data, supports the hypothesis that there could have been multiple invasion events in India and the UAE. Additional sampling from the native and invasive ranges in Africa and from other regions of invasion is essential for understanding the movement and spread of L. fulica. [ABSTRACT FROM AUTHOR]

The presence of the body colour polymorphism in the tropical invasive pest giant African snail is reported for the first time from South India. Three different body colour polymorphs were recognised viz. grey, black and white. The grey body colour is the most common polymorph. The black and white colour polymorphs are found to be in almost equal proportions in the reported localities with the grey counterparts. The cytochrome oxidase subunit I (COI) sequences of the three colour polymorphs are found to be identical. The presence of the body colour polymorphism in south India may be attributed to the avian predation and other selection pressures. [ABSTRACT FROM AUTHOR]

Background: The Teak defoliator (Hyblaea puera) is a pest moth of teak woodlands in India and other tropical regions (e.g. Thailand) and is of major economic significance. This pest is of major concern as it is involved in complete defoliation of trees during the early part of the growing season. Defoliation does not kill teak trees, but it results in huge amount of timber loss. Teak defoliator outbreaks are a regular annual feature in most teak plantations in India and it is extremely difficult to predict the exact time and place of occurrence of these outbreaks. Evidence from the study of the population dynamics of H. puera indicated habitual, short range movements of emerging moth populations, suggesting that these populations have spread to larger areas, generation after generation, affecting the entire teak plantations. We were therefore interested in investigating the temporal and spatial relationship among various population groups in Nilambur, Kerala (India) and address the cause of outbreak at the landscape level. Results: The populations were classified into 'endemic', 'epicenter' and 'epidemic' populations based on the time of occurrence and size of infestation. We devised a novel method of screening nuclear and mitochondrial DNA polymorphisms using Randomly Amplified Gene Encoding Primers (RAGEP). We have used this method extensively to evaluate the species specificity, reproducibility and to discriminate among the three different characterised populations of teak defoliator. Conclusions: This method also allowed us to comment with some certainty that the endemic teak defoliator, H. puera do not play a major role in contributing to large-scale infestations. With respect to the hypotheses put forward regarding the origin of outbreaks of the moth, this study confirms the role of migration in outbreak causation, while negating the belief that endemic populations aggregate to cause an epidemic. [ABSTRACT FROM AUTHOR]

In baculovirus-insect systems, a mixed-mode transmission strategy involving vertical transmission of virus from parent to offspring, and horizontal transmission from infected to susceptible or from the environment is well known. In this study, we examined the role of soil and excreta as alternative routes of horizontal transmission of Hyblaea puera nucleopolyhedrovirus (HpNPV) in the teak defoliator H. puera and how larval crowding influences these processes. The laboratory experiment failed to identify horizontal transmission of the virus from the soil during pupation or eclosion. However, the role of soil as a reservoir cannot be ignored as chances of transport of viral particles from soil to tree bark are expected through termite nests built on teak stems, which needs further examination. On the other hand, the experiments proved excreta as a major route of horizontal transmission and the rate of infectivity during crowding of larvae was significantly higher. Further research on other routes of horizontal transmission and host behaviour influencing the same are discussed here in the context of their role in managing of teak defoliator outbreaks. [ABSTRACT FROM AUTHOR]

The defoliation caused by Hyblaea puera can result in approximately 44% reduction in the annual volume increment of teak, a major timber tree. Several management options used in the past to control the pest were not effective due to high cost and environmental problems. In the present study we have used the vertical transmission characteristics of Hyblaea puera nucleopolyhedrovirus (HpNPV) for cost-effective and environment-friendly control of the most devastating pest. First, a laboratory experiment was conducted to verify the vertical transmission of HpNPV and later field spraying was done to study the effect under natural conditions. Vertical transmission of HpNPV in the laboratory ranged between 13% and 59%. The sublethal transmission caused reduction in pupation, adult emergence, male and female longevity, egg-laying period, fecundity, hatching of F1 eggs, F1 mortality, F1 pupation and F1 fecundity, but had no influence on the F2 survival compared to the control. Spraying of HpNPV in the epicentre population of the pest resulted a viral epizootic at the F2 generation and led to collapse of the host population. Seeding of HpNPV in the epicentre populations of the teak defoliator has been proved to be an economical and environmentfriendly method for management of the pest. [ABSTRACT FROM AUTHOR]

An important aspect of an NPV biocide is its safety to different non-target organisms. The safety of the formulated and crude HpNPV against second instar silkworm Bombyx mori larvae was tested. Larvae fed with crude virus and formulated HpNPV did not show variation in larval weight, pupation percentage, fresh weight of cocoons, shell weight and fecundity. Bird fed with NPV infected H. puera larvae, presence of the viral occlusion bodied was noted in the faecal droppings within an hour of post feeding. Presence of viral particles in the faeces was observed until 24 hrs post-feeding. This suggested that the viral particle did not remain in the body of the bird for long . The test bird behaved normally and remained healthy throughout the observation period of three months suggesting no deleterious effect of HpNPV. Formulated and semi-purified HpNPV was also tested against three cell lines such as human larynx cell line (Hep2), Green monkey kidney cell line (Vero) and Spodoptera frugiperda ovary cell line (Sf-9). After inoculation with the virus, the cell lines did not show any symptom of infection. These studies have explicitly proved the safety of HpNPV. [ABSTRACT FROM AUTHOR]

A new species of mealybug, Formicococcus tectonae Joshi, Bindu Gullan sp. n., is described and illustrated based on adult females collected from teak, Tectona grandis (Lamiaceae), in plantations in Thrissur district, Kerala, southern India. The mealybug lives in tunnels made by the teak trunk borer, Cossus cadambae (Moore) (Lepidoptera: Cossidae). Ants of a Tapinoma species were found in the tunnels, tending the mealybugs. The new mealybug is most similar morphologically to F. polysperes Williams and F. robustus (Ezzat McConnell) comb. rev. A key to adult females of all the Formicococcus species recorded from India is provided.

Hyblaea puera nucleoployhedrovirus (HpNPV) is a potential biocontrol agent of the teak defoliator, Hyblaea puera (Cramer) (Lepidoptera: Hyblaeidae). To quantify the growth of the virus in the host larvae, three larval stages of the teak defoliator were subjected to quantitative bioassays using specified dilutions of HpNPV. The HpNPV production was found to be dependent on the dose, incubation period as well as stage specific responses of the host insect used. As larvae matured, production of the virus per mg body weight was not found to be in a constant proportion to the increase in the body weight. The combination which yielded the greatest virus production of 3.55 x 10(9) polyhedral occlusion bodies (POBs) was that in which larva weighing 26-37 mg was fed with 1 x 10(6) POBs, incubated for 6 h and harvested at 72 h post infection (h p.i.). The response of the fourth instar larvae was found to be more productive than the third and fifth instar larvae, which makes it an ideal candidate for mass production of the virus in vivo.

Hyblaea puera nucleopolyhedrovirus (HpNPV) is a potential biocontrol agent against the teak defoliator H. puera (Cramer) (Lepidoptera: Hyblaeidae). As part of optimization of the mass production of this nucleopolyhedrovirus, three methods of inoculation were evaluated against the host larvae with various yield parameters as selection criteria. The inoculation methods compared were controlled dose on diet in rearing tubes using a micropipette, controlled dose on leaf discs (prepared from teak leaves) using a micropipette and spraying onto diet filled rearing tubes using an atomizer. Fifth instar H. puera larvae of the weight classes 75-100, 101-125, 126-150, 151-175 and 176-200mg were used for the bioassay. With reference to percentage of harvested larvae, virus production per larva and virus production per inoculated larva (VPIL), spraying viral suspension into rearing tubes filled with artificial diet using a hand sprayer was found to be the most efficient method of inoculation. It was observed that the method of inoculation and age of the larvae has discrete as well as interactive influence on the virus yield parameters.