Large area study on the impact of six versus ten releases of the biocontrol agent, Trichogramma chilonis , besides large plot assessment of ten releases with and without mass trapping (by pheromone traps) for eco-safe management of the sugarcane internode borer (INB) - Chilo sacchariphagus indicus Kapur were undertaken in Natems Sugar factory area, Koppedu Taluk, Chittoor District, Andhra Pradesh, South India. In 2017-18, a large contiguous sugarcane crop area of 400 hectares received six releases of T. chilonis (as Tricho cards @ 5cc.ha/release) in alternate weeks during 5-7 months age of crop, followed by four additional releases during 8-9 months age (totalling ten releases) in 40 hectares area, besides assigning a no release block of 40 hectares in adjacent area. Harvest-time sampling in each treatment block showed that the INB distribution (per cent canes infested) was 80 % in control (no release) block, while it was 42 and 27 %, respectively, for six and ten releases. The INB intensity (per cent internodes infested) was also more (6.2 %) in control block whereas it was only 3.2 % and 1.5 %, in the two respective release regimes. Based on these results the cost-effectiveness of both the regimes was ascertained. In 2018-19, the impact of ten releases of T. chilonis (@5cc/hectare /release) versus same regime plus mass trapping (@25 pheromone traps/ha) was compared in large plots (each of 2.0 ha) along with an untreated control plot. Harvest-time samples showed that INB distribution was 70.3% in control block, compared to 48.3% in Trichogramma release block versus 19.8% in block combining Trichogramma and mass trapping. The respective INB intensity was 6.04 %, 4.04 % and 2.17 % while the estimated cane yields were 81.0, 86.2 and 92.5 tons/ha, respectively. The cost: benefit ratios for Trichogramma release with and without mass trapping were comparable, so confirming that both are cost-effective alternatives to chemical insecticide use in sugarcane agro-ecosystems.

The cotton bollworm Helicoverpa armigera is a well-known pest in many agricultural cropping systems worldwide. The extensive and widespread use of synthetic insecticides against H.armigera has led to the development of resistance against almost all commercially used compounds including new insecticides. The underlying possible effects of Morinda tinctoria against H.armigera were investigated based on the biological and biochemical studies. Root-bark and fruit extracts were tested for mortality of 3rd instar larvae of H.armigera at concentrations of 1, 3 and 5%. 1% ethyl acetate fruit and root-bark extract were the most potent bringing the maximum mortality. The maximum feeding deterrence index of 79.832% was observed in the 5% ethyl acetate extract of root-bark. A significant percentage of the pupa failed to emerge as adult and the emerged ones displayed structural abnormalities in the form of deformed wings. The adults that emerged from larvae fed with extracts produced lesser number of eggs than the control group. There was a decrease in the activity of Carboxylesterase and Acetylcholinesterase compared to the control. Protease activity was least affected by the extracts of the fruit and root bark.

Exploiting the brinjal shoot and fruit borer (BSFB), Leucinodes orbonalis (Crambidae: Lepidoptera) sex attraction with monitoring and/or mass trapping approach is an ecofriendly IPM method. To improve the trapping system components, two field experiments were conducted with superior and waterless pheromone trap designs as alternative to the regular water basin trap. Results showed that the improved delta trap (patent-filed as Delta-Plus) is superior in terms of both catch efficiency and more user-friendly. The additional access vents in three combinations of dimensions and vent numbers led to significantly more moth catches. Further, the moth catches for the same amount of pheromone dispensed in the widely used cheaper funnel trap were observed to be too low and inefficient for BSFB trapping.

Botanical insecticides have been acknowledged as attractive alternatives to synthetic chemical insecticides for pest management as they apparently pose little hazard to the environment or to human health. A number of plant substances have been considered for use as insect antifeedant and repellent. Studying the insecticidal property of plants against the insects is a difficult process. Hence we have done an insecticidal property analysis of phytochemicals derived from Chloroform, Ethyl acetate and Methanol extracts of root-bark and fruit of Morinda tinctoria against the cotton bollworm Helicoverpa armigera using bioinformatics approaches such as molecular structure property analysis, homology modeling and docking studies. Nine compounds from the root-bark and fruit extract of M.tinctoria were observed to strictly follow Tice rule and 8 compounds present in the extract and also known to have insecticidal property from literature were selected as ligands. The enzymes Acetylcholinesterase, Carboxylesterase and Protease of Helicoverpa armigera were decided as targets for the docking studies. The 3D structure of targets was modeled and the interaction between the enzymes and phytochemicals were studied using molecular docking studies in order to find effective insecticide.

The Entomopathogenic micro-fungal species Metarhizium anisopliae was collected from the agricultural soils of Kanchipuram district of Tamil Nadu, India. Micro-fungal spores of Metarhizium anisopliae were tested for its effect on the feeding of Spodoptera litura at three different concentrations of 103, 105 and 107. The Higher concentration of spore significantly reduce the consumption of leaf. The exposure of fungal spore's concentration decrease the production efficiency. The microfungal infection reduction of Spodoptera litura gut enzymes such as amylase and trehalase and reduced weight gain of infected insects and 33.32% mortality recorded in microfungal infected S.litura .

Annonaceous acetogenins (Annonin-I, IV, VI, VIII & XVI) were tested for their insecticidal property against the dusky cotton bug Oxycarenus laetus Kirby. Bioinformatics approach using PASS indicated Annonin-I to have the highest phosphatase inhibition and toxic activity. The structure of the target (ND1) was modeled using the Robetta server. The Molecular docking of the ligands to the active site of ND1 was carried out using Glide module of Schrodinger and the QikProp program was used to obtain the ADME properties of the analogues. The results indicated that Annonin-I inhibited the enzymes NADH and cytochrome oxidase; which were further validated by in-vitro studies using the lygaeid pest Oxycarenus laetus.

The Heat Tolerant (HT) strain of Trichogramma chilonis Ishii developed (NBAII) was assessed for field impact against the sugar cane early shoot borer (ESB)-Chilo infuscatellus Snellen. Three treatments were compared viz. Trichogramma HT strain release twice a week @ 5cc/ha/release/during nine continuous weeks (T1), compared with local farmers’ practice of two malathion sprays (T2) and no release (T3). ESB (‘deadhearts’) was significantly reduced in the block with the HT strain releases (T1) compared to the ‘no release’ (T3) block. The overall reduction was 66 and 19% in T1 and T2 respectively, over no release (T3). Further, the ESB infestation in T3 block was on par with the block under local practice of insecticide-spray (T2). The scope for adopting the use of HT strain as a cost effective alternative to insecticide use for ESB management in sugar factory areas is discussed.

One hundred and seven species of alkalotolerant fungi were isolated from different layers of litter of the Guindy Reserve Forest, Chennai, South India during a 2-year period. They comprised Zygomycota (7 species), Ascomycetes (4 species), hyphomycetes (86 species) and coelomycetes (10 species). The F1 litter layer, just beneath the recently fallen leaves, had the richest composition of fungi and the fungi were most abundant during the North East monsoons (September to November). Shannon's diversity index and Simpson diversity index λ indicate F1 layer to have the maximum species. The species distribution fell into the log series model and Fishers alpha was also highest for the F1 layer. Species richness indices computed also indicated that none of the species was more predominant. Values of species evenness computed hovered around 0.6 indicating a tilt towards even distribution of the species. The fungal community is a heterogenous assembly of species derived from a homogenous habitat with a log normal pattern of distribution formed due to the interplay of many independent factors governing the relative abundance of the species. Principal component ordination analysis reveals that the greatest variation in the species composition was due to the South West monsoon. Also, detrended correspondence data put the species abundance data for the four seasons in a linear arrangement.

Morinda tinctoria Roxb. is one of the medicinally important plants belonging to the family Rubiaceae and traditionally the leaves and roots are used for treatment of various ailments. Chloroform, Ethylacetate and methanol extracts of the root-bark was subjected to standard biochemical test for the presence of several plant secondary metabolites. Alkaloids, anthroquinones, saponins, steroids, triterpenoids, quinones and cardiac glycosides were present in the rootbark. The extracts were further subjected to chromatographic separation using GC-MS. The chromatogram revealed 21 peaks from Chloroform, 17 from Ethyl acetate and 14 from Methanol extracts. The Chloroform and methanol rootbark extract consist of the potent biologically active phyto-constituents such as Heptacosane, Eicosanedioic acid and Nonadecenoic acid.

The physiological process of molting in insects is governed by hormones. The ecdysteroid hormones coordinate the major stages of insect development by binding to the ecdysone receptor (EcR). Attempts to control insects through targeting the EcR are now gaining importance. In this study the protein sequence of ecdysone receptor of Helicoverpa armigera (Hub) and Spodoptera litura (Fab) were modeled specifically by extracting geometric restraints for corresponding atoms using the Homology modeling approach. The 3D structural comparison of the targets shows that the structures are closely related to each other with the low RMS value of 0.70Å. We analyzed the similarity in the ligand binding domain (LBD) of Ecdysone receptor of the lepidopteran pests by fixing the non-steroidal, synthetic agonist BYI06830 used in agrochemical pest control as the ligand. The comparison of EcR in complex with non-steroidal synthetic agonist results in partially overlapping residues in the LBD and the residue involved in the H-bond formation was found to be identical. We suggest that these findings of ligand-dependent binding pocket similarities have potential applications for developing a potent solution against the challenging pests.

A knowledge of insect biodiversity and patterns of distribution becomes necessary for a better understanding of insect ecology and behavior, as well as to design sampling programs for rapidly assessing pest density and phenological forecasting. In the state of Tamil Nadu about 62 species of acridids or short horned grasshoppers (Order: Orthoptera; Family: Pyrgomorphidae and Acrididae) have so far been recorded. Inventorying of acridids was carried out by surveying, sorting, cataloguing, quantifying and mapping of entities such as individuals, populations, species, habitats and ecosystems. The resulting data were used for further analysis of various parameters of biodiversity. The acridids recorded in Tamil Nadu inhabit a wide range of ecosystems. The present study was focused towards the acridid biodiversity in Tamil Nadu, their occurrence, distribution, richness and abundance from different vegetation sites viz., wasteland, grassland, forestland, and cropland as well as at different altitudes. From the 58 selected study sites in Tamil Nadu, over a period of 24 months, a total of 37 species belonging to 2 families and 11 subfamilies were recorded during the period of survey. The study depicted maximum species richness in forest ecosystem followed by wasteland, grassland and cropland. The diversity decreased with increase in altitude reaching a peak at 1100 MSL. A insignificant positive correlation was obtained between species richness for the longitudinal gradients and a negative correlation was obtained between species richness and the latitudinal gradients, while a significant negative correlation was observed with the altitudinal gradients.

Development of Conocephalus maculatus under controlled environmental conditions was studied. In order to test whether the development of C. maculatus is influenced by environmental factors, it was bred in the laboratory under simulated environmental conditions. Water/moisture had an influence on embryonic development of C. maculatus as no eggs developed without water. No hatching occurred, when the eggs were incubated deprived of water for varied periods from 50 days to 12 months and then transferred to moist conditions. Results from this study revealed that C. maculatus does not sustain in drought conditions and does not undergo any egg diapause. They require constant access to water for the development till hatching. At controlled temperature of 24°C and 35°C, eggs hatched in 21-37 and 14-21 days respectively. At temperature fluctuating between 20°C to 30°C (Mean 28.6±1.7°C) the incubation period ranges between 16-26 days. It is also indicated that the embryonic developmental period is inversely proportional to increase in temperature. Both males and females pass through a 6 nymphal instar life cycle, with an average embryonic developmental period of 43.5±7.4 (range between 39-52 days) days. The duration of post-embryonic development is short (male 27-31 days; female 32-40days) in high temperature (35°C), but longer in low temperature of 25°C (male 40-49 days; female 48-55 days). From this study it is revealed that change in climatic factors will lead to change in growth and development of C. maculatus and it may be considered as an indicator species on climate change.

Lannea coromandelica (Houtt). is a dominant tree of the Nanmagalam Reserve Forest and is frequently defoliated by the Noctuid moth the Hairy caterpillar, Euproctis fraterna (Moore). Studies on the spatial distribution of the tree indicate it to be randomly distributed. Therefore insects preferring to feed on the tree should be ecologically efficient in searching and colonizing on the tree. In quantitative feeding experiments, larvae of E. fraterna (Moore) consumed significantly more of mature leaves than young and senescent leaves of L. coromandelica The food consumption increases with increase in age, and accordingly the maximum leaf consumption was recorded by the fifth larval stage. In terms of weight gain there was a sudden increase in weight gain from the 2nd larval to 3rd larval stage. The approximate digestibility, (AD) was found to increase from the 1st to 3rd larval stage. The efficiency of conversion of ingested food to body substance (ECI) and the efficiency of conversion of digested food to body substance (ECD) increased during the early larval stages and decreased subsequently.

Population dynamics and life tables of Conocephalus maculatus were studied by field census data and laboratory rearing. Five differents localities, representing four habitat types such as forestland (Guindy Reserve Forest), agricultural crop field (Kanchipuram), grasslands (Nungambakkam and Kodambakkam) and wasteland (Chenglepet) were selected as study sites. Adults as well as nymphs were recorded throughout the year in all habitats except at Chenglepet (wasteland) where they were observed only during rainy months from September to November. In general, adult populations showed a slightly decreasing trend in abundance from January to June each year, with the population building up from August and attaining a peak in October. More or less similar trend was observed in all the three years of study. Laboratory breeding was done at a mean temperature of 23°C and a relative humidity of 60% and baby corn (an immature flowering part of Zea mays ) as food material. Pieces of Panicum maximum were provided for oviposition. Life tables based on age specific survival and fecundity of mated females, were constructed following the standard procedure. The results from the laboratory observations revealed that 49% mortality was prevalent at the egg stage itself. Survival of C.maculatus decreased with increase in the age. The total generation mortality in laboratory studies is less when compared to the wild population because in the laboratory conditions they are devoid of natural enemies and are not affected by extreme weather conditions. The proportion of female births obtained in the next generation was very low. This is because of the high mortality in the early nymphal stages. The net reproductive rate for the next generation was lowered considerably. In sum this study indicates that the temperature and rainfall play a vital role in the population dynamics of C.maculatus . The differences in the population dynamics of C. maculatus in different habitats may be due to their local physical environment including availability of hosts.

From a global perspective the Tettigoniids or the Long-horned grasshoppers, appear to be a lesser known group of orthopteroid insects, probably because of the difficulties in sampling, laboratory rearing, and also because of its behavioural and ecological uniqueness. Available information on the bioecological characteristics of tettigoniids around the world is very meager. Moreover, no record is available on the biology of Tettigoniidae of Indian subcontinent. The paper presents the mating and ovipositional behaviour of tettigoniid species Himertula vidhyavathiae Ingrisch and Muralirangan, 2003.

Die Diversität der Tettigoniidae von vier Biotoptypen in Chennai, Indien, wurde untersucht: Waldbiotope, Brachen, Grasgesellschaften und landwirtschaftlich genutzte Flächen. Arten- und Individuenzahlen wurden in einem Untersuchungszeitraum von 24 Monaten aufgezeichnet. 17 Arten aus 5 Unterfamilien, davon 9 aus der Unterfamilie Phaneropterinae, wurden nachgewiesen. Die Ermittlung von Wurzelgewichten sollte Hinweise auf artspezifische Unterschiede ergeben, und anhand von Prioritätsanalysen wurden Untersuchungen zur Habitatwahl durchgeführt. Die Wälder, gefolgt von den Brachen, waren die artenreichsten Biotope. Auch Berechnungen der Diversität und des Shannon-Index ergaben die höchsten Werte für die Wälder. Auf der Grundlage verschiedener Reichhaltigkeits-Schätzmethoden wurde die Zahl zusätzlicher Arten ermittelt, die bei höherer Untersuchungsintensität zu erwarten gewesen wären. Im Gegensatz zu den ACE- und ICE-Schätzungen ergaben das Michaelis-Menten-Modell sowie die Coleman-Kurve frühe Asymptoten für die Grasbiotope, Brachen und Äcker. - Übereinstimmend waren dagegen die Ergebnisse der verschiedenen Schätzmethoden für die Waldbiotope. Berechnungen der Diversität ergaben einerseits, dass sich die Wald- und Grasbiotope sowie die Brachen in Artenzusammensetzung ähnelten, sich aber in den Abundanzen der Arten unterschieden, und andererseits, dass die Brachen die Waldbiotope in der Artenreichhaltigkeit ergänzten.StichwörterComplementarity, Priority analysis, Tettigoniidae, Biodiversity, Species conservation.