Informatics Publishing Limited

N. Manikandan manilakshmi_144@yahoo.com ¹, J. S. Kennedy ², V. Geethalakshmi ³

Affiliations
1 (Agricultural Meteorology), Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, IN
2 (Department of Entomology), Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, IN
3 (Agro Climate Research Centre), Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, IN

Abstract

Insects, as cold-blooded animals are directly under the control of temperature for their growth and they cannot sustain living below and above certain thresholds. Therefore, temperature is probably the single most important environmental factor influencing insect behavior. Current estimates of changes in climate indicate an increase in global mean annual temperatures of 1°C by 2025 and 3°C by the end of the next century. Such increases in temperature may decrease the developmental time and increase the number of generations per year. An investigation was adopted to understand the effect of five different constant temperatures (28.3°C, 30.6°C, 32.7°C, 34.3°C and 36°C) on the development time of Yellow Stem Borer (YSB). The results revealed that the number of eggs laid by YSB increased at higher temperatures while egg hatching was reduced. Egg hatching was higher (90.6%) in 30.6°C followed by 28.3°C. The development time taken by different stages of the YSB revealed that there was an inverse relationship with development time and incubation temperature level. Insects develop faster which may oviposit early and hence the population was likely to grow earlier than expected.

Keywords

Yellow Stem Borer, Temperature, Climate Change, Global Warming

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N. Manikandan ¹, J. S. Kennedy ²

Affiliations
1 Department of Agricultural Meteorology, Tamil Nadu Agricultural University, Coimbatore T.N., IN
2 Department of Entomology, Tamil Nadu Agricultural University, Coimbatore T.N., IN

Abstract

Temperature is probably the most important environmental factor influencing the insect behaviour, distribution, development, survival and reproduction. Climate change, especially temperature increase, will affect insect physiology, behaviour, and development as well as species distribution and abundance, evidenced by changes in the number of generations a year, increasing survival rates in winter, and the earlier appearance of some insects. An investigation was taken up to understand the effect of different constant temperatures (28.3°C, 30.6°C, 32.7°C, 34.3°C and 36°C) on the egg hatching and development time of brown plant hopper (BPH). The results revealed that the temperature above 32.7°C was detrimental for the oviposoition by BPH females. Eggs hatching also decreased drastically with increase in temperatures. The development time taken by different stages of BPH varied significantly at different temperatures. Development time taken by different stages decreased considerably when the temperature increased. Longevity of the male and female adults also decreased with increasing temperature.

Keywords

Brown Plant Hopper, Climate Change, Development Time, Egg, Global Warming, Temperature

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R. Nisha ¹, J. S. Kennedy ¹

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore, T.N., IN

Abstract

Development and parasitic potential of Acerophagus papayae Noyes on the papaya mealybug, Paracoccus marginatus Williams and Granara de Willink from different host plants like papaya, cotton, mulberry, tapioca, brinjal and hibiscus were studied. The development time of parasitoid, A. papayae in the current study was shortest in mealybugs reared from papaya (10.9 days), followed by cotton (11.8 days), mulberry (12.4 days), brinjal (13.1 days), hibiscus (14.1 days) and recorded 16.3 days of development in tapioca reared papaya mealybug. The parasitisation rate was found to be highest in second instar than third instar and adult female mealybugs from host crop papaya viz., 87.5 per cent followed by cotton (84.2 %), mulberry (80.8 %), brinjal (80.0 %) and potato sprouts (75.8 %) and recorded lowest parasitisation rate in tapioca (67.5%). The parasitization level of parasitoid, A. papayae was maximum in papaya and minimum in tapioca due to the host plant induced changes in the mealybug. The development time was inversely correlated with the parasitic potential and so there was a trade-off between the development and parasitic potential of parasitoid.

Keywords

Fitness Trade-offs, Parasitoid, Acerophagus papayae, Papaya Mealybug, Paracoccus marginatus

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R. Nisha ¹, J. S. Kennedy ²

Affiliations
1 Department of Crop Protection, Imayam Institute of Agriculture and Technology, Trichy – 621 206, Tamil Nadu, IN
2 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore - 641 003, Tamil Nadu, IN

Abstract

The bioecology study of any parasitoid using alternative hosts imposes divergent selection pressures on parasitoid populations. In this study, we investigated the bioecology potential of parasitoid Acerophagus papayae Noyes and Schauff on papaya mealybug Paracoccus marginatus Williams and Granara De Willink from different plant hosts. The parameters studied were adult longevity (survival of progeny), fecundity and productivity of female mealybugs and sex ratio of progenies of P. marginatus. The results showed significant differences in bioecology of parasitoid on their natal host (P. marginatus from papaya) compared with the non-natal hosts (P. marginatus from non papaya hosts). It is also compared with honey concentration solution and potato sprouts. The parasitoid is well adapted to the natal host that is papaya compared to others host. However, parasitoids showed a similar high fitness on both natal and non natal hosts. This results could be used to increase the effectiveness of biological control programme on different views.

Keywords

Acerophagus papayae, Paracoccus marginatus, native hosts, non native hosts, biology

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Narayanasamy Manikandan ¹, J. S. Kennedy ², V. Geethalakshmi ¹

Affiliations
1 Agro Climate Research Centre, Tamil Nadu Agricultural University, Coimbatore 641 003, IN
2 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641 003, IN

Abstract

A study was undertaken to understand the effect of increasing temperature on population dynamics of yellow stem borer (YSB), Scirpophaga incertulas. Experiments were carried out in a temperature control chamber with five different constant temperatures (28°C, 30°C, 32°C, 34°C and 36°C). The data on agespecific life table at varying temperature regimes revealed that the total lifespan of YSB extended to a maximum of 52 days at 28°C followed by 49 days at 30°C and 46 days at 32°C. In general, survival of the YSB decreased with increasing temperature. Preoviposition period for YSB also decreased with increasing temperature. However, the total number of eggs laid by YSB increased with increasing temperature. Also, 50% fecundity in YSB was recorded on 49.7 days after incubation at 28°C, whereas it was observed as early as 34.4 days at 36°C. All the growth parameters were observed to decrease at 36°C, which reveals that temperature increase above 34°C is detrimental to the development of YSB. The above results reveal that, if the global warming continues at the present phase, it will negatively influence YSB and the population growth will be severely affected in the near future.

Keywords

Global Warming, Life and Fecundity Tables, Population Dynamics, Temperature Regime, Yellow Stem Borer.

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G. Thanavendan ¹, S. Jeyarani ¹, J. S. Kennedy ¹

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore (T. N.), IN

Abstract

Insecticides are unavoidable in pest management programmes especially when the pest crosses economic threshold level (ETL). In this context, some of the insecticides and botanicals that are used in vegetable ecosystem were test verified for their relative safety against the commonly encountered parasitoids viz., Bracon brevicornis Wesmael, Chelonus blackburni Cameron and Cotesia plutellae Kurdjumov. Toxicity effects of five insecticides viz., Acephate 75SP, Chlorpyriphos 20EC, Cypermethrin 10EC, Profenofos 50EC, Quinalphos 25EC and NSKE 5 per cent against B. brevicornis, C. blackburni and Hexane extracts of Lantana camara var. aculeate tested against C. plutellae were evaluated under laboratory conditions. Amongst insecticides tested, Profenofos 50EC was found to be most toxic with LC₅₀ value of 22.27 and 16.280 ppm; Chlorpyriphos 20EC was the least toxic with the highest LC₅₀ value of 198.53 and 314.255 ppm and NSKE 5 per cent had no effect against B. brevicornis and C. blackburni, respectively. C. plutellae pupae were treated with hexane extracts of L. camara resulted of 66.67 and 76.67 per cent with reduction of adult emergence at 8 and 10 per cent, respectively. While, C. plutellae adults were found to be safe at all concentrations except 8 and 10 per cent and its contact toxicity of 63.33 and 96.67 per cent adult mortality recorded within 24h by dry film method. The results suggest that the Chlorpyriphos 20EC and botanical extracts can very well integrate in the management of vegetable insect pests.

Keywords

Chelonus blackburni, Cotesia plutellae, Bracon brevicornis, NSKE, Lantana.

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G. Thanavendan ¹, J. S. Kennedy ¹, M. Kannan ²

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore (T.N.), IN
2 Department of Nanoscience and Technology, Tamil Nadu Agricultural University, Coimbatore (T.N.), IN

Abstract

The present investigation was carried out to identify organic volatiles components present in Lantana leaves and found to exert biopesticidal-repellent action on many pests of horticultural crops. Volatile organic chemicals (VOCs) eluted from [Lantana camara var. aculeata (L.) Moldenke] was extracted ascrude oil and analysed by gas chromatography-mass spectrometry (GC-MS). A total of 10 to 15 volatile compounds present in ethanol and methanol extracts were identified. These compounds were found distributed in several chemical classes namely, alcohols, carbonyl compounds (ketones, aldehydes, and esters), fatty acids, terpenes, nitrogenous and sulphur compounds. Of these various classes of compounds identified,Phenol-2-methyl-5-(1,2,2- trimethylcyclopentyl) - (S)-(CAS)-10.36 per cent and 2-(p-Methylphenyl) benzimidazole-7.86 per cent constituted major groups accounting for ethanol and whereas sulphur compounds viz.,stigmast-5-en-3-ol, (3.beta.) 15.48 per cent, caryophyllene (7.63%) and phenol having 14.96 per cent constituted major groups in methanol extracts.

Keywords

Crude Extracts, Leaf Volatiles, Soxhlet Extraction, Lantana Plant, GC-MS.

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I. Merlin Kamala ¹, J. S. Kennedy ¹

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore -641003, Tamil Nadu, IN

Abstract

The efficacy of microbials against jasmine blossom midge (Contarinia maculipennis Felt) was evaluated under in vitro and field conditions. The results revealed that Metarhizium anisopilae @ 1 × 10⁸ spores ml^-1 recorded maximum maggot mortality over untreated control (80.06 per cent) followed by Beauveria bassiana @ 1 × 10⁸ spores ml^-1 spores ml^-1 recording 67.57 per cent mortality. The Paecilomyces lilacinus @ 1 × 10⁸ spores treated maggots recorded minimum reduction of 50.56 per cent. However, the standard profenophos 50 EC treated maggots recorded 83.78 per cent reduction. Further, field evaluation for confirmation revealed similar trend confirming the efficacy of M. anisopilae with minimum infestation of 8.32, 7.69 and 7.31 per cent followed by B. bassiana recording 8.86, 8.93 and 8.50 per cent and L. lecani recording 9.97, 10.26 and 11.77 per cent infestation after first, second and third round of application respectively.

Keywords

Blossom Midge, Entomopathogens, Formulations, Jasmine.

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M. Saranya ¹, J. S. Kennedy ¹

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641003, Tamil Nadu, IN

Abstract

The rugose spiralling whitefly (RSW) Aleurodicus rugioperculatus Martin is an invasive pest of coconut in India. The behavioural response of its parasitoid Encarsia guadeloupae Viggiani (Hymenoptera: Aphelinidae) on healthy and RSW infested host plants of coconut, banana, sapota and guava has been assessed in this study using a six arm olfactometer. Parasitoids’ attraction was maximum with the infested banana leaves (1.62± 0.28) followed by coconut (1.28± 0.20), guava (1.05± 0.24) and sapota (0.82± 0.24). The results obtained also reveal that E. guadeloupae can be mass reared on banana plants infested with RSW nymphs to enable better mass production of the parasitoid.

Keywords

Aleurodicus rugioperculatus, , behavioural response, infested, healthy leaves,coconut, banana, sapota, guava, host: parasitoid ratios, parasitisation potential

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T. D. Jayabal ¹, J. S. Kennedy ¹

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641003, Tamil Nadu, IN

Abstract

The legume pod borer Maruca vitrata (F.) (Crambidae: Lepidoptera) causes considerable yield loss in major edible legumes including dolichos bean Lablab purpureus var. typicus. This study analyses the M. vitrata incidence and abundance in relation to the four plant parts during two consecutive cropping seasons of 2019. The results revealed that peak incidence of 80.00 ± 2.83% was in the 11th week after planting during rabi, 2019, and it was more in unopened flower buds (64.00 ± 8.76%) and mature pods (13.00 ± 0.80%). There existed significant differences between the four growth stages of the crop in the order- flower buds (maximum) ˃ mature pods ˃ immature pods ˃ open flowers (least) during summer 2019. The occurrence of single and multiple larvae was more in the unopened flower buds (78.00 ± 3.35%) and mature pods (52.00 ± 3.35%).

Keywords

Maruca vitrata, Lablab purpureus var. typicus, incidecne, plant growth stages, unopened/ open flowers, mature/immature pods, single/multiple larvae/pod or bud.

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S. Sivaranjani ¹, V. Geethalakshmi ¹, S. Pazhanivelan ¹, J. S. Kennedy ¹, S. P. Ramanathan ¹, R. Gowtham ², K. Pugazenthi ¹

Affiliations
1 Tamil Nadu Agricultural University, Coimbatore 641 003, India., IN
2 Indian Farmers Fertilizers Cooperative Limited, Coimbatore 641 003, India., IN

Abstract

Hyperspectral remote sensing captures images in multiple wavelengths and is widely used to detect plant stress in agriculture. A study was conducted on brown planthopper (BPH) infestation in rice at various temperature regimes (15°C, 20°C, 25°C, 30°C and 35°C). The experimentation was done in the Environmental Control Chamber, Tamil Nadu Agricultural University, Coimbatore, India. The field spectroradiometer and vegetation indices were used to study the early and late infestations of BPH in rice. The results reveal that reflectance at certain wavelengths (550, 670 and 700 nm) indicates plant stress. Among the vegetation indices, MCARI performed better than NDVI, PRI, NDRE and SR for the detection of early and late infestation of BPH. Hence, hyperspectral reflectance from rice has been used to detect pest damage and improve management policies.

Keywords

Brown planthopper, hyperspectral sensor, Plant stress, rice, vegetation indices.

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