Lac Insect Research Articles

Laboratory evaluation of different eco-friendly insecticides against the Egyptian fluted scale, Icerya aegyptiaca

Lac cultivation is generally carried out on a limited number of indigenous tree species found scattered in forests and cultivable land. Recent studies show that Flemingia semialata Roxb. (Leguminosae) is an excellent bushy host plant for the cultivation of the kusmi strain of lac insects. The present investigation was carried out with the objective of getting acquainted with the different eco-friendly insecticides under laboratory evaluation against the Egyptian fluted scale, Icerya aegyptica. Maximum nymphal mortality of 81.67 per cent and 78.34 per cent was observed at 0.2 per cent Pestoguard and Neemazal after 12 days of treatment, which is statistically at par with each other. 51.67 per cent mortality was achieved after 12 days of treatment at 1 per cent Uro-insecticide and Green mealikil, which is a microbial pesticide that is also effective against the Egyptian fluted scale, Icerya aegyptiaca. The mortality percentage was low after 1, 3 days and seven days, but it gradually increased after 12 days of treatment, obtaining 48.34% mortality, which is statistically at par with Uro-insecticide. All the eco-friendly insecticides used in the present experiment (Uroinsecticides, Pestoguard, green mealikil and neemazal) are effective in controlling the population of Icerya aegyptiaca. Unlike Malathion and Imidacloprid, they don’t have a quick knockdown effect; however, the mortality due to exposure significantly increases as there is an increase in days or duration of application, and they are safe for the lac insect.

Antioxidant responses of bushy host plants Flemingia semialata and Flemingia macrophylla on inoculation of two different strains of lac insect (Kerria lacca (Kerr))

Antioxidant responses of bushy host plants Flemingia semialata and Flemingia macrophylla on inoculation of two different strains of lac insect (Kerria lacca (Kerr))

CULTURABLE ENDOSYMBIOTIC BACTERIA FROM THE INDIAN LAC INSECT, KERRIA LACCA (KERR)

The Indian lac insect, Kerria lacca (Kerr) (Coccoidea: Tachardiidae) is a commercially important phytosuccivorous and sessile scale insect. Lac insects are cultured on suitable host plants in India and some Southeast Asian countries to produce lac. The lac insect harbours a number of endosymbionts. Isolation of culturable microbial endosymbionts and their identification through 16S rRNA has revealed sex and host-related differences of microbial species. Bacillus boroniphilus, Enterobacter cloacae and Staphylococcus sp. were found only in the lac insects reared on the plant host Cajanus cajan, whereas Bacillus firmus, Lysinibacillus xylanilyticus, Bacillus horneckiae and Bacillus velezensis were recorded only from Flemingia macrophylla. B. firmus and L. xylanilyticus were female-specific and B. horneckiae and B. velezensis were male-specific with Flemingia macrophylla as host; E. cloacae was female-specific and Bacillus boroniphilus and Staphylococcus sp. were male specific with C. cajan. Biochemical characteristics of the isolates, their genetic relationship with their taxonomic kin and their probable role, based on the information available about these endosymbionts in other hosts, have been studied.

Assessing the infestation-induced response on the plant host by the Indian lac insect

Lac, the only natural resin of animal origin is produced by the Indian lac insect- Kerria lacca. It is the by-product of the complex natural interaction between the lac insect and its host plant. Despite several studies on the perspectives of the chemistry of lac and its production, very little work has been carried out to understand the biology of lac and its associated plant taxa. The present work has been designed to understand the preliminary response if any, of the host plant against lac insect infestation. Structural studies and metabolic profiling such as the determination of total phenolics, flavonoids, antioxidants, FTIR, and GC-MS were carried out. The anatomical investigations revealed coagulation/deposition of metabolites in the infested sites. The infested bark showed higher phenolic, flavonoid content, and antioxidant activity in comparison to non-infested bark which was corroborated by Fourier-transform infrared spectroscopy (FTIR) and GC-MS biochemical analysis. This preliminary study will shed some light on understanding the lac plant host's physiological response and the putative mechanism used by the lac insect in overcoming the plant response.

Effect of different density of lac insect (Kerria lacca) infestation on host plant Flemingia macrophylla growth and photosynthetic pigments

Effect of different density of lac insect (Kerria lacca) infestation on host plant Flemingia macrophylla growth and photosynthetic pigments

Characterization of the Fragrant Resin from <i>Shorea roxburghii</i>, a Lac Insect Host Tree of Tropical Deciduous Forest in South India

Characterization of the Fragrant Resin from <i>Shorea roxburghii</i>, a Lac Insect Host Tree of Tropical Deciduous Forest in South India

First report of two insects, Megachile sp. and Armadillidium sp., as new pests on Flemingia spp. In Thrissur, Kerala

A project entitled "Conservation of Lac Insect Genetic Resources" is underway at the Kerala Forest Research Institute (KFRI) at Peechi, Thrissur, Kerala, India. This project includes the maintenance of both a lac insect gene bank and a lac insect host plant gene bank. Two types of host plants, Flemingia semialata (F. semialata) and Flemingia macrophylla (F. macrophylla), are cultivated to support the lac insect, Kerria spp. In the month of May, it was observed that Megachile bees were cutting the leaves of F. semialata and using them to construct nests. Roly-poly (Armadillidium spp) insects were also found affecting the young leaves of seedlings of F. semialata and F. macrophylla at KFRI. These two insects, Megachile and Armadillidium, are newly reported for the first time on the plants of F. semialata and F. macrophylla in Kerala.

Trial for the propagation method in Flemingia spp., a shrub plant and a lac insect host in Thrissur, Kerala

Due to the challenges posed by the poor availability and germination of Flemingia spp. for lac insect cultivation, the Kerala Forest Research Institute in Thrissur experimented with the air layering method and stem cutting (Vegetative Propagation) to enhance the number of seedlings. The layering method was successful for all three treatments, although it is observed variations in the length of the roots. The plant treated with coco peat exhibited longer roots and a greater number of roots, followed by the plants treated with only soil and vermiculite. The stem cutting method (vegetative propagation) was also successful for both plants, suggesting that both techniques can be used as alternatives for cultivating lac insect host plants instead of relying on seed germination.

Production of Lac and Seed of Cajanus cajan under Varying Stresses

Production pulse and lac from the same plant of Cajanus cajan simultaneously provides two cash crops from the same plant is important for pigeonpea growers of both continents - Africa and Asia. The highest raw lac production per plant was 171.17 g while the highest seed yield was 1383.33 g per plant. C. cajan plant with least stress i.e., less lac insects had highest 100 lac cell weight 1.57 g (Low biotic stress) while it was 1.41 g in plants with (Medium biotic stress). The seed yield per plant was highest (1137.78 g) in plants under high biotic stress. It was least (872.22 g) in plants with Low biotic stress.

Weather based forecasting model for emergence of Aprostocetus purpureus (Cameron) – a parasitoid of lac insect, Kerria lacca (Kerr)

Indian lac insect, Kerria lacca is a scale group beneficial insect which suffers by several natural enemies. The establishment of the relationship between the incidences of natural enemies on lac insects with weather variables is essential for formulating management strategies well in advance. The relationship between weather factors and the emergence of A. purpureus was studied from 2011–12 to 2020–21 on the rangeeni summer (baisakhi) lac crop. Correlation and regression analyses were done after pooling ten years data (2011-12 to 2020-21) during the critical lac growth period i.e. SMW 8 to SMW 20. The relative abundance of lac-associated fauna showed that three parasitoids ((Aprostocetus purpureus, Tachardiaephagus tachardiae, and Tyndarichus(=Parechthrodryinus) clavicornis)) and one predator (Eublemma amabilis) were abundant. Among them, A. purpureus recorded maximum percent infestation, which was 84% and 75% on ber and palas, respectively. Maximum number of A. purpureus was emerged during the sexual maturity period (8 to 20 SMW) of the summer lac crop. The incidence exhibited a significant negative correlation with maximum (Tmax) and minimum temperature (Tmin) and a significant positive correlation with morning and evening relative humidity (RH-II). Stepwise regression analysis showed Tmax and RH-II were the most important factors contributing to 68% variation in the incidence of A. purpureus on palas. The present study results indicated that environmental factors played a significant role in the incidence of parasitoids on lac insect.

Impact of Biotic and Abiotic Stress on Survival of Lac Insects Kerria lacca Kerr. on Pigeonpea (Cajanus cajan (L.) Millsp)

Cajanus cajan is generally grown in rainfed condition. The crop is also a good annual host plant of lac insect. C. cajan is widely reported to have biotic stress due to insect pests on it. Lac insect is phloem sap feeder and hence imparts biotic stress. The present field study was conducted to evaluate the percent survival of lac insects on C. cajan by adjusting different levels of biotic and abiotic stress on the host plant. The biotic stress due to insect pests on C. cajan was minimised with periodic spray of contact insecticides. The varying level of biotic stress i.e., No, Low, Medium, and High level was maintained on C. cajan plants with lac insects on it. The three levels of abiotic stress in this experiment were considered in terms of soil moisture stress. It was managed through irrigation per plant through drip system, it was considered that creating different levels of moisture stress in soil will impact the host plant. The abiotic stress was of three levels i.e., Low, Medium, and High. The result reveals that survival percent of Lac insect from brood lac inoculation to the harvest of lac crop was highest 37.52 percent on C. cajan with one primary branch and its secondary branches with lac insect (L1- Low biotic stress). It was 32.13 percent (W3- Low soil moisture stress). The study indicates that biotic and abiotic stress play a major role in the survival of K. lacca.

Settlement behavior of crawlers of Rangeeni strain of lac insect on different host

Under the auspices of NP-CLIGR, the Department of Entomology, RCA, Udaipur conducted the current inquiry on investigations on the settlement behavior of Rangeeni lac bug, Kerria lacca (Kerr) on various hosts during 2021–2022. To determine the best location for lac brood tying and the ideal configuration of plant hosts in a field from which the greatest amount of lac could be harvested, the settlement behavior of lac insect crawlers on various hosts was examined in relation to the cardinal direction and twig girth of the host plant. On the Acacia host the crawlers traveled the greatest mean distance, 19.67 cm, from the site of inoculation, followed by Flemingia, Ber, Palas, and Pigeon pea. On the Kikar and Custard Apple, the crawlers traveled the least mean distance, 10.49 cm and 12.93 cm, respectively, from the site of brood lac inoculation. There was a negative connection between the crawlers’ initial settlement and the diameter of the host twig (r = -0.26). Regardless of where the plants were located, the lower part of the host plant was where crawlers settled more frequently. As opposed to branches developing in the east and west of the plant, lac insect crawlers favored branches growing in the north and south of the plant.

Bioinspired Natural Shellac Dressing for Rapid Wound Sealing and Healing.

Developing safe and effective wound dressings that address the complexities of wound healing is an ongoing goal in biomaterials research. Inspired by the shield used to protect lac insects, we have designed and developed a type of bioactive shellac-based wound dressing in this paper. The dressing exhibited a high adhesion energy of 146.6 J·m-2 in porcine skin and showed a reversible binding due to its pH sensitivity. Meanwhile, a novel "shellac-like" compound, n-octacosanol gallate ester, has been synthesized and added to the dressing to improve its antibacterial and blood coagulation properties. The novel shellac-based dressing could be sprayed to form a sticky film within 70 s for rapid hemostasis and wound sealing, which could be conveniently applied to various wounds on extensible body parts. In addition, the shellac-based dressing can actively promote the healing of a full-thickness wound in the skin of mice. We also used molecular dynamics simulations to investigate the interactions between the shellac molecule and the phospholipid bilayer and attempted to show that the shellac molecule was beneficial for wound healing. This work provides a novel and practical bioinspired wound dressing with significant properties, facile preparation, and ease of use, which is an interesting alternative to its traditional counterparts.

New Hostplant Record for Lac Insect <i>Kerria</i> spp. from Andhra Pradesh

Lac is the only natural resin of animal origin produced by lac insects. The host range of lac insect is more than 400 plant species. Thick dark brown lac encrustation on the stem of an exotic plant Conocarpus lancifolius Engl., was noticed and recorded as a new host plant for lac insect from Andhra Pradesh, India.

Relative Abundance, Emergence Profile and Parasitization of Lac Insect (<i>Kerria lacca</i>) Associated Fauna in Rangeeni Crops

Relative abundance, emergence profile and parasitization of parasitoids and predators associated with lac insect were recorded during rangeeni summer season (baisakhi) and rainy season (katki) lac crops on ber and palas under two different conditions viz., spray of fipronil + chlorothalonil and only chlorothalonil. It revealed that three parasitoids (Aprostocetus purpureus, Tachardiaephagus tachardiae, Tyndarichus clavicornis) and one predator Eublemma amabilis were abundant in both lac crops. Lac associated fauna were recorded more on lac crop sprayed with chlorothalonil only compared to fipronil + chlorothalonil on both crops on both lac hosts. Among the lac associated fauna, A. purpureus was recorded in more numbers in both crops and spray conditions. Maximum level of parasitization was recorded at the time of sexual maturity period (19 to 22 Weeks After Inoculation (WAI)) during baisakhi whereas in katki, at crop maturity period (16 to 19 WAI) on ber and palas.

DNA Barcoding, Morphological Description and Field Diagnostics of <i>Eublemma amabilis</i> (Lepidoptera: Erebidae)

Lac is an important commodity because of its versatile usage, biodegradability, and potentiality to sustain the livelihood of tribal community of India. Lepidopteran pest of Indian lac insect, Eublemma amabilis Moore [1884] (Lepidoptera: Erebidae) causes significant loss than any other lepidopteran pest thereof, both in wild and cultivated crop. Even though it’s a regular pest recorded for decades, its taxonomic studies are lacking. In the present study, we have redescribed E. amabilis added photographic illustrations of male and female genitalia and which is also supported by a novel mitochondrial cytochrome oxidase I DNA barcode.

Status of Lac Production and Marketing in West Karbi Anglong District of Assam

West Karbi Anglong district of Assam State is historically a major lac producing area in the North Eastern India from where lac was used to be exported to China and Japan during 17th and 18th. The farmers in these areas have been cultivating making lac (cultivation)delete since time immemorial. .Among several indigenous communities inhabiting West Karbi Anglong district, Karbis are rearing lac insects (Kerria lacca Kerr), locally called Laha, on naturally growing host plants in forests and on pigeon pea (Cajanus cajan) in a traditional practice. The present investigation attempted to examine the present status of production and marketing of lac in West Karbi Anglong. The primary data was collected from 75 lac farmers to find out the present status of production and marketing of lac. More than 35tons of lac are exported to other states from West Karbi Anglong districts annually. Due to their traditional practice these producers are receiving a low price for their product as low as compared to the market rate. The product is marketed to local intermediaries, local traders and distant traders. Lack of awareness and knowledge on value addition and the prevailing market price, marketing agencies and industries resulted in lower price of the product. Lack of scientific knowledge on production and processing of lac is the major problem encountered by the farmers. Lack of processing unit is another major problem for which the lac producers received a low price for their product.

The role of Wolbachia and the environment on sex determination of the Indian lac insect, Kerria lacca (Coccoidea: Tachardiidae)

• In Kerria lacca , presence of endosymbiont Wolbachia is developmental-stage dependent. • Administration of antibiotic enhances the sex ratio of the lac insect multifold. • The lac insect sex ratio is influenced by environmental factors. • Mode of metamorphosis together with Wolbachia dynamics explains sex ratio changes. The Indian lac insect, Kerria lacca (Kerr) exhibits a highly variable sex ratio, apparently influenced by various environmental factors, in the absence of a chromosomal sex determination mechanism. The endosymbiont Wolbachia, well known as sex ratio distorter, was reported in this species but its role in the sex determination of the host has hitherto remained unexplored. Distinct variation in the presence of Wolbachia was observed in relation to the developmental stages and the sexes of K. lacca as well as the host plant species; adult males of W + whereas adult females are W -. The post-settlement environmental factors such as host plant, season and genetic makeup affect the sex ratio in this insect, probably mediated through Wolbachia dynamics. Denser settlement of the crawlers led to comparatively higher Wolbachia presence with an elevated sex ratio. Suppression of Wolbachia through antibiotic administration resulted in a nearly three-fold increase in the sex ratio. Distinct transitions in the proportion of insects with heterochromatic genome (cytological males) have been observed during the first instar on different host plants, indicating that changes in the sex ratio occur during early development phase. Environmental factors appear to influence Wolbachia , which in turn brings about sex ratio changes, probably mediated through changes in juvenile hormone levels, as the male and female lac insects show distinct modes of metamorphosis.

Studies on the pests of the lac insect host plant Flemingia semialata and Flemingia macrophylla in Kerala

The present study attempted to record the insect pests of lac insect host plants in Kerala Forest Research Institute, Peechi, Thrissur. Hand picking and swiping methods were used to collect the insects for identification. From the observation 26 species of pest insects belonging to 4 orders and 19 families were recorded. It was found that all major parts of Flemingia were heavily infested but significant damage was caused by the defoliators, mostly heterocera. Out of the 26 insect pests, 15 have been recorded as foliage feeders, 9 as sapsuckers, 1 as pod borer and 1 stem borer. During rearing, 3 species of parasites were found, belonging to three families that were collected and identified. Insects belong to the order Lepidoptera were profoundly seen on Flemingia. They cause severe damage to the plant. Hypena rectivittalis belonging to the family Noctuidae was found as a major pest and bag worm Psychids was found to be the minor pest. The study reveals that the most serious sapsuckers belong to the order Hemiptera and majority of them are beetles and bugs. During the months of April-May Iceryasp and white flies (Trialeurodes vaporarium) cause heavy damage in Flemingia. The study thus concludes that the major pests belong to the order Lepidoptera (42%) followed by order Hemiptera (41%). Most Lepidopterans are defoliators and Hemipterans are sapsuckers.

Shellac: From Isolation to Modification and Its Untapped Potential in the Packaging Application

Recently, terms such as sustainable, bio-based, biodegradable, non-toxic, or environment-benign are being found in the literature, suggesting an increase in green materials for various applications in the future, particularly in the packaging application. The unavoidable shift from conventional polymers to green materials is difficult, as most bio-sourced materials are not water-resistant. Nonetheless, Shellac, a water-resistant resin secreted by a lac insect, used as a varnish coat, has been underutilized for packaging applications. Here, we review Shellac’s potential in the packaging application to replace conventional polymers and biopolymers. We also discuss Shellac’s isolation, starting from the lac insect and its conversion to Sticklac, Seedlac, and Shellac. Further, the chemistry of shellac resin, the chemical structure, and its properties are examined in detail. One disadvantage of Shellac is that it becomes stiff over time. To enable the usage of Shellac for an extended time in the packaging application, a modification of Shellac via physical and chemical means is conferred. Furthermore, the usage of Shellac in other polymer matrices and its effect are reviewed. Lastly, the non-toxic and biodegradable nature of Shellac and its potential in packaging are explored by comparing it with traditional crude-based polymers and conventional bio-based materials.