Search

Oviposition behaviour of Callosobruchus chinensis was tested on six varieties of horse gram seeds (ANK Black, AK 42, AK 21, BK 1, Urmi and Paiyur 1) to identify the resistance variety. In no choice test, females of C. chinensis laid lesser eggs within 24 h of mating on whole seeds of Urmi variety (11.6 ± 0.41) than the other varieties tested. However, females did not lay eggs when seed coat was removed from the above six varieties of horse gram. In choice test, females laid the lowest number of eggs within 24 h of mating on Urmi (1.11 ± 0.23) than the other varieties. The scanning electron micrograph (SEM) study revealed that there were morphological differences on the seed coat texture of the six horse gram varieties. The seed coat texture of Urmi variety is heterobrochate with some nearly bi-reticulate patches and few unevenly depressed muri, which partially inhibited oviposition on Urmi seeds. Urmi is the less preferred variety for oviposition.

Larvae of Diaphania indica (Saunders) (Lepidoptera: Crambidae) feed on flowers of Trichosanthes anguina L., and reduce crop production. Therefore, we have tried to find whether flower surface wax chemicals (alkanes and free fatty acids) of three T. anguina cultivars [MNSR-1 (MNS), Baruipur Long (BAR), and Polo No. 1 (POLO)] could act as short-range attractants and oviposition stimulants in females of D. indica. One mg flower surface wax of these cultivars acted as attractants in short Y-tube olfactometer bioassays and stimulated oviposition in females. A synthetic blend of nonadecane, pentacosane, and palmitoleic acid, a synthetic blend of pentacosane and palmitoleic acid, and a synthetic blend of pentacosane and oleic acid in amounts comparable to those present in 1 mg flower surface wax of MNS, BAR, and POLO cultivars, respectively, served as short-range attractants and oviposition stimulants in D. indica. Females exhibited equal egg-laying behavior towards these three synthetic blends when these blends were tested against one another, and hence, these blends could be used as lures in developing baits for traps in pest management strategies.

Two Polygonaceae weeds, Rumex dentatus L. and Polygonum glabrum Willd. are abundant in wheat- and rice-fields, respectively, in India. Galerucella placida Baly (Coleoptera: Chrysomelidae) is a biocontrol agent of these two weeds. The importance of long-chain alkanes and free fatty acids present in leaf surface waxes of these weeds was assessed as short-range attractant and ovipositional stimulant in G. placida females. Extraction, TLC, GC-MS and GC-FID analyses demonstrated 19 n-alkanes from n-C14 to n-C35 and 14 free fatty acids from C12:0 to C22:0 in leaf surface waxes. Hentriacontane was predominant among alkanes in both weeds, while oleic acid and docosanoic acid were predominant among free fatty acids in R. dentatus and P. glabrum, respectively. Females of G. placida were attracted toward one leaf equivalent surface wax of both weeds against the control solvent (petroleum ether) in a short Y-tube olfactometer bioassay. But, the insect could not differentiate between one leaf equivalent surface wax of R. dentatus and P. glabrum, indicating that both weed leaves were equally attractive in females. A synthetic blend of either 2.44, 35.57 and 23.58 μg ml−1 of octadecane, heptacosane and nonacosane, respectively, resembling the amounts present in one leaf equivalent surface wax of R. dentatus or 4.08, 19.54 and 23.58 μg ml−1 of octadecane, palmitoleic acid and docosanoic acid, respectively, resembling the amounts present in one leaf equivalent surface wax of P. glabrum acted as short-range attractant and ovipositional stimulant in G. placida. These results could be a basis for host plant specificity of the biocontrol agent.

East Calcutta Wetlands (ECW) located at the eastern fringe of Kolkata metropolitan, India designated as a Ramsar Site (No. 1208). ECW receives municipal solid wastes and composite wastewater from the city and local artisans use this for horticulture, agriculture and pisciculture practices. Horticulture designated as ‘green industry’ sequester significant amount of carbon (C) in plant biomass and in soil, therefore, helps to mitigate greenhouse gases and combat against global climate change. Six horticultural plant species commonly cultivated in ECW ecosystems were selected for present study. C sequestration potential of horticultural plants depends on plant biomass and plant density in cultivation fields. Highest amount of C was sequestered (40.76±6.73 ton ha-1) by ixora, a perennial plant in plant biomass. In case of basil, also a perennial plant, significant portion of the living plant biomass was exported from ECW as economically important parts which constitute 5.79±0.96 ton ha-1 C. Highest amount of soil organic carbon (SOC) was recorded from marigold fields (50.36±24.88 ton ha-1) which also constitute highest amount of C (34.37±5.67 ton ha-1) in residual parts (RP). Horticulture practices can sequester more amount of C in the ecosystem either by residual parts or remaining living plant biomass than agricultural practices.

Larvae of Spilosoma obliqua Walker (Lepidoptera: Arctiidae) feed on the leaves and flowers of green gram [Vigna radiata (L.) Wilczek] and reduce seed yield. Therefore, it is interesting to observe whether undamaged (UD) and insect-damaged (ID, plants after feeding by S. obliqua larvae) plants cause attraction of conspecific adult moths. Females showed attraction towards volatile blends of UD, ID and mechanically-damaged (MD) plants of three green gram cultivars [PDM 54 (PDM), Pusa Baisakhi (PUSA) and Samrat (SAM)] in Y-tube olfactometer bioassays. Females were more attracted towards volatile blends of ID plants of a particular cultivar than UD plants of the same cultivar. Total amount of volatiles was higher in ID plants than UD plants. Some herbivore-induced plant volatiles − 3Z-hexenal, 1-hexanol, 3Z-hexenyl acetate, 2-octanol and ocimene were attractive to the insect. Females were attracted towards three synthetic blends (µg in 25 µl CH2Cl2) comprised − 2.97 µg 3Z-hexenal, 4.92 µg 1-hexanol, 5.56 µg benzaldehyde, 9.76 µg 3Z-hexenyl acetate, 7.27 µg 2-octanol, 7.97 µg ocimene and 5.71 µg acetophenone resembling PDM, 4.68 µg 3Z-hexenal, 8.38 µg benzaldehyde, 7.66 µg 3Z-hexenyl acetate, 5.96 µg ocimene and 7.60 µg acetophenone resembling PUSA, and 3.39 µg 3Z-hexenal, 6.29 µg benzaldehyde, 8.74 µg 3Z-hexenyl acetate, 6.17 µg ocimene and 3.69 µg acetophenone resembling SAM in olfactometer and wind tunnel bioassays. Females could not distinguish between these three synthetic blends in olfactometer and wind tunnel bioassays, suggesting that these three synthetic blends could be used as lures in developing baited traps in integrated pest management strategies.

Aulacophora foveicollis Lucas, commonly known as red pumpkin beetle, is an important pest of many cucurbitaceous plants in India. To develop the mass rearing facilities, this research was conducted on the effects of photoperiods on larval and adult development of A. foveicollis on roots and leaves of Solena amplexicaulis (Lam.) Gandhi, commonly known as creeping cucumber, respectively, at five different photoperiods, 8 L:16D, 10 L:14D, 12 L:12D, 14 L:10D and 16 L:8D at 30 ± 1 °C and 75 ± 5% RH under laboratory conditions. The shortest total development time (egg to adult emergence) of A. foveicollis was 41.10 days at 14 L:10D. The longevity of females was the highest at 14 L:10D (61.00 days) and the shortest at 8 L:16D (39.87 days). The fecundity was the highest at 14 L:10D (188.08) and the lowest at 8 L:16D (101.40). The net reproduction rate (R0) ranged from 5.32 to 24.45 offspring, which was higher at 12 L:12D and 14 L:10D. The intrinsic rate of increase (r) varied from 0.0251 to 0.0520 day−1, and it was higher at 12 L:12D and 14 L:10D. The finite rate of increase (λ) was also higher at 12 L:12D and 14 L:10D. Mean generation time (T) was the fastest at 14 L:10D (61.52 days) and the longest at 8 L:16D (69.33 days). Population projection revealed that total A. foveicollis population growth was the fastest at 14 L:10D. These results suggested that 14 L:10D was the most suitable for development and reproduction of A. foveicollis than other photoperiod regimes tested in this study, and this information will be helpful for running successful bioassays in integrated pest management programme.

BACKGROUND The viviparous aphid Aphis craccivora Koch (Hemiptera: Aphididae) is a serious threat to the crop yield of Lathyrus sativus L. (Fabaceae), commonly known as grass pea. The synthetic insecticides applied to control this insect pest are not safe for the environment. Hence, it is necessary to find volatile organic compounds (VOCs) from two cultivars [BIO L 212 Ratan (BIO) and Nirmal B-1 (NIR)] of L. sativus plants causing behavioral preference of A. craccivora. RESULTS The VOCs from undamaged (UD), insect-damaged (ID) [plants on which 50 or 100 adults of A. craccivora were fed for 4 h (ID 50 or ID 100)], and mechanically damaged (MD) plants were identified and quantified by gas chromatography-mass spectrometry and gas chromatography-flame ionization detection analyses, respectively. Total VOCs were higher in ID plants compared to UD plants of each cultivar. However, total VOCs were higher in NIR cultivar compared to BIO cultivar for both UD and ID plants. Benzyl alcohol was predominant in volatile extracts of all treatments. In Y-tube olfactometer bioassays, females showed preference towards volatile extracts of UD, ID, and MD plants of each cultivar compared to the control solvent (CH2 Cl2 ). Insects preferred certain synthetic blends comparable to volatile extracts of UD, ID, and MD plants of each L. sativus cultivar against the control solvent. CONCLUSION Females preferred a synthetic blend of benzyl alcohol, 1,3-diethylbenzene, thymol, and 1-hexadecene at ratios of 142.49: 62.03:1.18:1 dissolved in 25 μL of CH2 Cl2 in olfactometer bioassays, which could be used in developing lures to control this insect pest.

Diaphania indica(Saunders) (Lepidoptera: Crambidae) is an important phytophagous pest ofTrichosanthes anguinaL. in India. We studied life table parameters by age-stage, two-sex, amylolytic and proteolytic activities, and food utilization parameters ofD. indicaon the leaves of threeT. anguinacultivars (Baruipur Long, Polo No. 1 and MNSR-1). Further, nutrients (total carbohydrates, proteins, lipids, amino acids and nitrogen) and antinutrients (total phenols, flavonols and tannins) in leaves were determined. The development time (egg to adult emergence) was the shortest on MNSR-1 (19.79 d) and the longest on Polo No. 1 (25.72 d). Fecundity was the highest and lowest on MNSR-1 (259 eggs) and Polo No. 1 (151.22 eggs), respectively. The lowest intrinsic rate of increase (rm) and net reproductive rate (R0) ofD. indicaon Polo No. 1 were 0.1112 d−1and 27.22 offspring individual−1, respectively. The mean generation time (T) was the shortest on MNSR-1 (23.99 days) and the longest on Polo No. 1 (29.70 d). The larvae ofD. indicafed with MNSR-1 had the highest level of amylolytic and proteolytic activities, and the lowest activities were in the larvae fed with Polo No. 1. The fifth-instar larvae fed with Polo No. 1 had the lowest consumption index and growth rate. The higher larval development time and lower fecundity ofD. indicaon Polo No. 1 were due to the lower level of nutrients and a higher level of antinutrients than other cultivars. Our results concluded that Polo No. 1 cultivar could be suggested for cultivation.

Altica cyanea (Weber, 1801) (Coleoptera: Chrysomelidae) is a biocontrol agent of Onagraceae rice-field weeds, Ludwigia adscendens (L.) Hara, L. parviflora Roxb. and L. octovalvis (Jacq.) Raven in India. Hence, it is relevant to study the life history traits and population growth of A. cyanea on three Ludwigia species using age-stage, two-sex life table. The nutritional and antinutritional contents from leaves of the Ludwigia species were measured to comment on the role of nutrients and antinutrients on growth, development and fecundity of A. cyanea. Total larval developmental time was the shortest on L. adscendens (17.78 ± 0.22 days), intermediate on L. parviflora (20.35 ± 0.24 days) and the longest on L. octovalvis (21.98 ± 0.24 days). Total fecundity was the highest on L. adscendens (147.22 ± 4.74 eggs/female) followed by L. parviflora (119.28 ± 4.70 eggs/female) and the lowest on L. octovalvis (89.62 ± 3.45 eggs/female). The intrinsic rate of increase (r) ranged from 0.0639 to 0.0875 d− 1, which was the lowest on L. octovalvis and the highest on L. adscendens. Population projection indicates that the population growth would be the fastest on L. adscendens and the slowest on L. octovalvis. The nutrients (lipids, amino acids and nitrogen) and antinutrients (tannins) were higher and lower, respectively, in L. adscendens than the other two Ludwigia species, which influenced faster larval development, higher adult longevity and greater fecundity of A. cyanea on L. adscendens. This study suggested that mass release of A. cyanea could be applied in biocontol program of these three Ludwigia weeds.

Lathyrus sativus L. (Fabaceae) is an important pulse crop of Asia, Europe, and Africa. Infestation by the aphid, Aphis craccivora Koch (Hemiptera: Aphididae) causes stunted growth of plants and reduces seed production. Females lay nymphs on the leaves and flowers of L. sativus. Hence, it is relevant to study the importance of leaf wax compounds (long-chain alkanes and free fatty acids) from two cultivars [BIO L 212 Ratan (BIO) and Nirmal B-1 (NIR)] of L. sativus as short-range attractant and stimulant for nymph laying in the aphid. The TLC, GC-MS and GC-FID analyses of n-hexane extracts from leaves of two cultivars revealed 18 n-alkanes from n-C15 to n-C36 and 14 free fatty acids from C12:0 to C22:0. Pentadecane was predominant among n-alkanes in both cultivars. Palmitoleic acid and pentadecanoic acid were predominant free fatty acids in leaf waxes of BIO and NIR, respectively. Females were attracted towards leaf waxes of both cultivars compared to the control solvent (n-hexane) in Y-tube olfactometer bioassays. A synthetic blend of either pentadecane, tridecanoic acid, and linoleic acid at similar amounts present in one leaf equivalent wax of BIO, or pentadecane, docosane, pentacosane, heptacosane, tritriacontane, and linoleic acid at similar amounts present in one leaf equivalent wax of NIR acted as short-range attractant and stimulated females to lay nymphs. But, the latter blend was more attractive and stimulated females to lay more nymphs than the former blend, and hence, this latter blend could be employed in the development of baited traps in pest management strategies.

Ludwigia adscendens (L.) Hara, Ludwigia parviflora Roxb., and Ludwigia octovalvis (Jacq.) Raven (Onagraceae) are abundant weeds in rice fields in India. These weeds compete with rice for resources in fields and this results in reduction of grain yield. Altica cyanea (Weber) (Coleoptera: Chrysomelidae) is a biocontrol agent of the three rice‐field weeds. Hence, it is relevant to study host preference of A. cyanea using volatile cues of these three weeds. Therefore, we attempted to identify volatiles from leaves of the three Ludwigia species attracting A. cyanea, which could be used as an attractant during early emergence of the weeds in rice fields. In Y‐tube olfactometer assays, A. cyanea females were more attracted to natural volatiles of plants after 48 h of feeding by adults than to volatiles of undamaged plants. The volatile organic compounds from undamaged plants, and plants after 6 and 48 h of feeding by A. cyanea were identified and quantified by gas chromatography and mass spectrometry (GC–MS) and GC‐flame ionization detection (FID), respectively. In total, 25, 29, and 29 volatile compounds were detected in headspaces of undamaged L. adscendens, L. parviflora, and L. octovalvis, respectively, whereas 32, 35, and 34 compounds, respectively, were detected after 48 h of feeding by A. cyanea. Methyl jasmonate predominated among the volatile compounds in all treatments, but this compound was not attractive to A. cyanea. Females were attracted by synthetic blends of 3‐hexanol, α‐pinene, linalool oxide, and phytol in amounts mimicking those in each of the three Ludwigia species after 48 h of feeding by A. cyanea. The blends mimicking L. adscendens and L. parviflora included geraniol, whereas the blend mimicking L. parviflora also included 1‐tridecanol. These synthetic blends may be helpful to monitor A. cyanea in biocontrol programmes.

Rumex dentatus L. and Polygonum glabrum Willd. (Polygonaceae) are important weeds of wheat and rice fields, respectively, in India and Pakistan. Adults and larvae of Galerucella placida Baly (Coleoptera: Chrysomelidae) feed both weeds. Therefore, we studied the biology of G. placida on two weed leaves using age-stage, two-sex life table at 21 °C, 65 ± 5% r.h. and 12L: 12D. We also studied food utilization indices of G. placida on these leaves. Further, we investigated the quantities of nutrients (total carbohydrates, proteins, lipids, amino acids and nitrogen) and antinutrients (total phenols, flavonols and tannins) of the leaves. Correlation analysis suggested that fecundity and the intrinsic rate of increase (rm) of G. placida were positively correlated with nutrients of leaves, while negatively correlated with antinutrients. Faster larval development, higher longevity of adults and greater fecundity of G. placida were recorded on R. dentatus than P. glabrum. The rm was higher on R. dentatus than P. glabrum. The nutrients were greater in R. dentatus than P. glabrum, while antinutrients were lower in R. dentatus than P. glabrum. The growth rate and consumption index were greater on R. dentatus than P. glabrum. The above results suggested that better nutritional quality of R. dentatus than P. glabrum influenced faster larval development, higher longevity of adults and greater fecundity of G. placida on R. dentatus. This study concluded that R. dentatus could be used for mass rearing of G. placida in biocontol program prior to release in fields for control of both these weeds.

Objectives Altica cyanea (Weber) (Coleoptera: Chrysomelidae) is a potential biocontrol agent of rice-field weeds, Ludwigia adscendens (L.) Hara, L. parviflora Roxb., and L. octovalvis (Jacq.) Raven (Onagraceae) in India. Damage on leaf tissue causes stress on plants. Hence, this study aims to observe how the three Ludwigia species are trying to cope with the stress caused by feeding of A. cyanea adults at different time intervals. Materials Uninfested L. adscendens, L. parviflora, and L. octovalvis, and each Ludwigia species on which 5 adult A. cyanea females had fed on continuously for 6 h or 48 h were used for collection of leaf tissues. The amounts of total ROS, H2O2, activity of enzymatic antioxidants [superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), activity of peroxidases towards phenolic substances {guaiacol peroxidase (GPX) and pyrogallol peroxidase (PPX)}, and ascorbate peroxidase (APOX)] and non-enzymatic antioxidants (phenolics and thiols) were estimated from leaf tissues of undamaged and insect damaged Ludwigia species using standard protocols. Results The amounts of total ROS and H2O2 were higher in each Ludwigia species after 48 h feeding by A. cyanea followed by plants after 6 h feeding by A. cyanea and undamaged plants. The activities of antioxidant enzymes such as CAT, SOD, GST, APOX, PPX, and GPX were higher in each Ludwigia species after 48 h feeding by A. cyanea compared to undamaged plants. Total proteins and thiols were higher in each undamaged Ludwigia species compared to insect damaged plants; whereas total phenols were higher in each insect damaged Ludwigia species compared to undamaged plants. Conclusions Higher amounts of total ROS and H2O2 in each insect damaged Ludwigia species compared to undamaged plants suggested that A. cyanea feeding resulted stress in the insect damaged plants. Higher amounts of CAT, SOD, GST, and APOX in insect damaged Ludwigia species compared to undamaged plants suggested that these four enzymes were acting as antioxidants to reduce the stress created in plants due to insect herbivory.

Aphis craccivora Koch (Hemiptera: Aphididae) is an important pest of Lathyrus sativus L. plants, and causes retarded plant growth and loss of seed production. The insect sucks cell sap from flowers and lays nymphs on flowers. Hence, an attempt has been made to observe whether flower surface wax compounds (alkanes and free fatty acids) from two cultivars (BIO L 212 Ratan and Nirmal B-1) of L. sativus could act as short-range attractant and stimulant for nymph laying by adult viviparous females. The n-hexane extracts of flower surface waxes were analyzed by TLC, GC-MS and GC-FID analyses. Twenty one and 22 n-alkanes between n-C12 and n-C36 were detected in BIO L 212 Ratan and Nirmal B-1, respectively; whereas 12 free fatty acids between C12:0 and C22:0 were identified in both cultivars. Pentadecane and tridecanoic acid were predominant n-alkane and free fatty acid, respectively. One flower equivalent surface wax of both cultivars served as short-range attractant and stimulant for nymph laying through Y-tube choice experiments and I-tube viviparity assays, respectively, by adult viviparous females. A synthetic blend of nonacosane, tridecanoic acid and linoleic acid, and a synthetic blend of tetradecane, pentadecane, nonacosane, tridecanoic acid and linoleic acid resembling in amounts as present in one flower equivalent surface wax of BIO L 212 Ratan and Nirmal B-1, respectively, served as short-range attractant and stimulant for nymph laying by adult viviparous females. This study suggests that both these blends could be used in lures in the development of baited traps in pest management programmes.

The effect of three green gram cultivars (PDM 54, PUSA BAISAKHI and SAMRAT) on the biology ofSpilosoma obliquaWalker (Lepidoptera: Arctiidae) was studied using age-stage, two-sex life table. We also studied food utilization efficiency measures of larvae on green gram cultivars. The nutritional and antinutritional factors of leaves of green gram cultivars were determined. The preadult development time ofS. obliquawas shortest on PDM 54 (35.54 days) and longest on SAMRAT (39.29 days). The fecundity was highest on PDM 54 (318.32) and lowest on SAMRAT (250.20). The net reproductive rate (R0) ranged from 37.53 on SAMRAT to 79.58 on PDM 54. The intrinsic rate of increase (r) was higher on PDM 54 (0.1148 day−1) and PUSA BAISAKHI (0.1018 day−1) than SAMRAT (0.0875 day−1). The finite rate of increase (λ) was lowest on SAMRAT (1.0915 day−1). Mean generation time (T) was shortest on PDM 54 (38.12 days) and longest on SAMRAT (41.42 days). Population projection revealed that the population growth was slowest on SAMRAT. The growth rate of sixth instar larvae was highest on PDM 54 and lowest on SAMRAT. The lower level of nutritional factors such as total carbohydrates, proteins, lipids, amino acids and nitrogen content, and a higher level of antinutritional factors such as total phenols, flavonols and tannins influenced higher development time and lower fecundity ofS. obliquaon SAMRAT than other cultivars. These findings suggested that SAMRAT is a less suitable cultivar toS. obliquathan other cultivars, and this cultivar can be promoted for cultivation.

The importance of long-chain alkanes and free fatty acids present in leaf surface waxes of two Commelinaceae rice-field weeds, Commelina benghalensis L. and Murdannia nudiflora (L.) Brenan, was evaluated as short-range attractant and oviposition stimulant in the Lema praeusta (Fab.) (Coleoptera: Chrysomelidae). Surface waxes were extracted by dipping leaves in n-hexane for 1 min at 27 ± 1 °C. Thin-layer chromatography, gas chromatography–mass spectrometry, and gas chromatography–flame ionization detection analyses of n-hexane extracts revealed 20 n-alkanes from C14 to C36 and 13 free fatty acids from C12:0 to C22:0. Pentacosane and palmitoleic acid were predominant among n-alkanes and free fatty acids, respectively. Females showed attraction to one leaf equivalent surface wax of both weeds against the control solvent (petroleum ether) in Y-tube olfactometer bioassays. However, the insect could not discriminate between one leaf equivalent surface waxes of two weeds, suggesting that both weeds were equally attractive to females. Among all identified alkanes and fatty acids, females showed attraction towards individual docosane, tricosane, pentacosane and heptacosane, and tridecanoic acid, palmitoleic acid, linoleic acid, and arachidic acid, resembling in amounts as present in one leaf equivalent surface wax of C. benghalensis and M. nudiflora, respectively. A synthetic blend of either docosane, tricosane, pentacosane, and heptacosane, resembling in amounts as present in one leaf equivalent surface wax of C. benghalensis, or tridecanoic acid, palmitoleic acid, linoleic acid, and arachidic acid, resembling in amounts as present in one leaf equivalent surface wax of M. nudiflora, served as short-range attractant and oviposition stimulant in L. praeusta.

Two Polygonaceae weeds, Rumex dentatus L. and Polygonum glabrum Willd. are abundant in wheat- and rice-fields, respectively, in India. Galerucella placida Baly (Coleoptera: Chrysomelidae) is a biocontrol agent of these two weeds. The importance of long-chain alkanes and free fatty acids present in leaf surface waxes of these weeds was assessed as short-range attractant and ovipositional stimulant in G. placida females. Extraction, TLC, GC-MS and GC-FID analyses demonstrated 19 n-alkanes from n-C14 to n-C35 and 14 free fatty acids from C12:0 to C22:0 in leaf surface waxes. Hentriacontane was predominant among alkanes in both weeds, while oleic acid and docosanoic acid were predominant among free fatty acids in R. dentatus and P. glabrum, respectively. Females of G. placida were attracted toward one leaf equivalent surface wax of both weeds against the control solvent (petroleum ether) in a short Y-tube olfactometer bioassay. But, the insect could not differentiate between one leaf equivalent surface wax of R. dentatus and P. glabrum, indicating that both weed leaves were equally attractive in females. A synthetic blend of either 2.44, 35.57 and 23.58 μg ml-1 of octadecane, heptacosane and nonacosane, respectively, resembling the amounts present in one leaf equivalent surface wax of R. dentatus or 4.08, 19.54 and 23.58 μg ml-1 of octadecane, palmitoleic acid and docosanoic acid, respectively, resembling the amounts present in one leaf equivalent surface wax of P. glabrum acted as short-range attractant and ovipositional stimulant in G. placida. These results could be a basis for host plant specificity of the biocontrol agent.

The Polygonaceae weed, Rumex dentatus L. grows in association with wheat, mustard and potato, while Polygonum glabrum Willd. grows in association with rice in India. Both larvae and adults of Galerucella placida Baly (Coleoptera: Chrysomelidae) voraciously consume these weeds. Applications of synthetic herbicides to control weeds are harmful to the environment including beneficial organisms. We propose to find volatile organic compounds (VOCs) from both weeds causing attraction of the biocontrol agent, G. placida, in order to attempt to use the insect as a biological weed control. Behavioral responses of G. placida towards volatile blends characteristic of undamaged (UD), insect-damaged (ID), jasmonic acid-treated (JA) or mechanically-damaged (MD) plants were conducted by Y-tube olfactometer bioassays. Cuminaldehyde was predominant in VOCs of UD R. dentatus, ID P. glabrum, and both JA and MD R. dentatus and P. glabrum. Geraniol was predominant in VOCs of UD P. glabrum, while 1,3-diethylbenzene predominated in VOCs of ID R. dentatus. Females were more attracted towards volatile blends of ID plants compared to UD or JA plants. Females did not show attraction towards volatile blends of JA plants. We identified two bioactive synthetics blends, one comprised of seven compounds - 16.65 µg 1,3-diethylbenzene, 10.72 µg acetophenone, 6.52 µg 2,6-(E,Z)-nonadienal, 2.46 µg 1-nonanol, 4.19 µg decanal, 9.86 µg 4-ethylacetophenone and 3.34 µg 1-hexadecene dissolved in 25 µl CH

Supplementary material with raw data set

Larval Diaphania indica (Saunders) (Lepidoptera: Crambidae) cause complete defoliation of Trichosanthes anguina L. and reduce crop yield in India. Females lay eggs on the leaf surface, and therefore leaf surface waxes are potentially involved in host selection. Alkanes and free fatty acids are the major constituents of leaf surface waxes, so a study was conducted to determine whether these wax constituents from three T. anguina cultivars (MNSR-1, Baruipur Long, and Polo No.1) could act as short-range attractants and oviposition stimulants in D. indica females. Twenty n-alkanes from n-C14 to n-C36 and 13 free fatty acids from C12:0 to C21:0 were detected in the leaf surface waxes of these cultivars. Heptadecane and stearic acid were predominant among n-alkanes and free fatty acids, respectively, in these cultivars. Females showed attraction towards one leaf equivalent surface wax of each of these cultivars against solvent controls (petroleum ether) in Y-tube olfactometer bioassays. A synthetic blend of heptadecane, eicosane, hexacosane, and stearic acid, a synthetic blend of hexacosane and stearic acid, and a synthetic blend of pentadecane and stearic acid comparable to amounts present in one leaf equivalent surface wax of MNSR-1, Baruipur Long, and Polo No.1, respectively, were short-range attractants and oviposition stimulants in D. indica. Female egg laying responses were similar to each of these blends, providing information that could be used to developing baited traps in integrated pest management (IPM) programs.

We examined previous reports of Lema praeusta (Fab.) (Coleoptera: Chrysomelidae) as a minor pest of turmeric, eggplant, bottle gourd and pumpkin leaves, but no feeding damage by larvae and adults of L. praeusta were recorded by us on these leaves. We observed feeding by the larvae and adults of L. praeusta on ten species of Commelinaceae plants in no-choice tests. The biology, fecundity and life table parameters of L. praeusta on two Commelinaceae weeds, Commelina benghalensis L. and Murdannia nudiflora (L.) Brenan were determined under laboratory conditions (27 ± 1°C, 65 ± 5% RH and 12L:12D). Total larval development times of L. praeusta were 6.36 ± 0.07 and 7.28 ± 0.11 days (mean ± SE) on C. benghalensis and M. nudiflora, respectively. Adult females lived 106.25 ± 1.17 and 77.65 ± 0.91 days (mean ± SE) on C. benghalensis and M. nudiflora, respectively. Each female laid 272.95 ± 2.39 and 224 ± 1.74 eggs (mean ± SE) during a lifetime on C. benghalensis and M. nudiflora, respectively. The net reproductive rate (Ro), intrinsic rate of increase (rm), generation time (Tc), doubling time (DT) and finite rate of increase (λ) were 136.48, 0.14, 36.17, 5.10 and 1.41 on C. benghalensis, respectively, whereas Ro, rm, Tc, DT and λ were 112, 0.20, 23.64, 3.47 and 1.51 on M. nudiflora, respectively, suggesting that L. praeusta could be a potential biocontrol agent against C. benghalensis and M. nudiflora in the fields of rice, maize, sorghum, soybean, mung bean, peanut and cotton.

Galerucella placidaBaly feeds on the rice-field weedPolygonum orientaleL. (Polygonaceae) in India and Bangladesh during autumn and winter seasons. The insect is widely available during the winter season when the temperature fluctuates between 9 and 24 °C. Hence, it is of considerable interest to study how the adults cope with the stress resulting due to temperature fluctuations. Consequently, we analysed the levels of H2O2, antioxidant enzymes [catalase (CAT), superoxide dismutase (SOD), peroxidases (POD), guaiacol peroxidase (GPX), pyrogallol peroxidases (PPX), ascorbate peroxidases (APOX) and glutathione-S-transferases (GST)] and malondialdehyde (MDA) at 9, 12, 15, 18, 21 and 24 °C in adultG. placida. H2O2was highest at 24 °C followed by 9 °C and lowest at 18 and 21°C. CAT and SOD were highest at 9 °C followed by 24 °C, while POD was highest at 24 °C followed by 9 °C. CAT and POD were lowest at 18 and 21 °C, but SOD was the lowest at 21 °C. APOX were three-fold higher at 9 °C compared to 12 °C, which was the lowest at 18 and 21 °C, implying that APOX had strong detoxification function at 9 °C. GST was highest and lowest at 9 and 21 °C, respectively. MDA was highest at 9 °C and lowest at 18 and 21 °C, which did not differ significantly at 15 and 24 °C, suggesting that lower and higher temperature stress was accompanied by lipid peroxidation. This finding provides useful information for mass rearing ofG. placidafor predicting population dynamics and understanding the potential forG. placidaas biocontrol agent under varying environmental conditions.

Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) is an important herbivore pest of cucurbitaceae, which is currently controlled by insecticides in southeast Asia. The insect cuticle is the first line of defence against insecticides. So, we investigated the variations in the composition of n-alkanes and free fatty acids (FFAs) in cuticular and internal lipids of A. foveicollis males and females exposed to monocrotophos compared to untreated adults. Both sexes of A. foveicollis adults were dipped in petroleum ether for 1 min at room temperature for extraction of surface waxes, and the insects were further kept in dichloromethane for 15 days for extraction of internal lipids. n-Alkanes and FFAs of cuticular and internal lipids were identified and quantified by GC–MS and GC–FID analyses. Higher quantities of cuticular lipids were observed in males and females exposed to monocrotophos than untreated males and females. Twenty n-alkanes were identified between n-C15 and n-C36 in cuticular lipids of untreated A. foveicollis adults; whereas 21 n-alkanes were detected in cuticular lipids of treated adults. Nineteen FFAs were recorded between C10:0 and C22:0 in cuticular lipids of untreated adults; whereas 21 and 19 FFAs were recorded in cuticular lipids of treated males and females, respectively. Hentriacontane and palmitoleic acid were the predominant n-alkane and FFA in the cuticular lipids of treated males and females, respectively. This study revealed that change of alkanes and FFAs in cuticular lipids of A. foveicollis males and females are linked to exposure to monocrtophos, which might result in increasing resistance of A. foveicollis.

Solena amplexicaulis (Lam.) Gandhi (Cucurbitaceae) is a promising vegetable in Southeast Asia. Infestation of Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) adults on leaves of the crop plant causes death of the plant and reduces crop production. Currently, growers are applying insecticides to control this pest, which are harmful to health and environment. Hence, an attempt has been made to find out allelochemicals from leaves attracting the insect, which might be used for ecofriendly pest management program. The emission of volatiles was detected from undamaged leaves of herbivore-induced plants after 24 h and 120 h of continuous females feeding on lower leaves of the same plants by GC-MS and GC-FID analysis. The insect showed attraction to systemically released volatiles from herbivore-induced plants against unharmed plants in Y-shaped glass tube olfactometer bioassays. The insect was attracted to a synthetic blend of 1.2 µg linalool oxide + 3.2 µg nonanal + 1.5 µg trans-2-nonenal dissolved in 20 µL CH2Cl2 in olfactometer and wind tunnel bioassays, and hence, this blend could be used in development of baited traps in pest management strategies.

Herbivorous insects employ host plant volatile blends as cue for host recognition. Adults of Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) feed on leaves, flowers, and fruits of Solena amplexicaulis (Lam.) Gandhi (syn: Melothria heterophylla) (Cucurbitaceae), commonly known as creeping cucumber. Currently, this pest is controlled by insecticides application. Hence, it is necessary to find out volatile components from fruits attracting the insect, which might be used for eco-friendly pest management program. behavioral responses of females were measured by Y-tube olfactometer bioassays towards volatile blends from undamaged (UD), insect-damaged (ID), and mechanically damaged (MD) fruits with the aim to identify the compounds responsible for host fruit location. Volatile organic compounds were identified and quantified by GC-MS and GC-FID analyses, respectively. Nonanal was predominant in volatile blends of UD, ID, and MD fruits. 1-Octen-3-ol, 3-octanone, 2-octanol, heptadienal (2E,4E), 1-pentadecanol, and 1-hexadecanol were present in volatile blends of ID and MD fruits, but females did not show response to these six compounds. 1-Octanol and 1-heptadecanol were unique in volatile blends of UD fruits after 4 hr of damage, but females did not show response to these compounds. Females were more attracted to volatile blends from UD fruits after 4 hr of damage in comparison to volatile blends released by UD fruits, due to increased emissions of (E,Z)-2,6-nonadienal and 2E-nonenal. A synthetic blend of 3.35 μg (E,Z)-2,6-nonadienal and 1.72 μg 2E-nonenal dissolved in 25 μl CH2Cl2 could be used for the development of baited traps to control this insect pest in integrated pest management strategies.

Aphis craccivora Koch (Hemiptera: Aphididae) is an important pest of Lathyrus sativus L. plants, and causes retarded plant growth and loss of seed production. The insect sucks cell sap from flowers and lays nymphs on flowers. Hence, an attempt has been made to observe whether flower surface wax compounds (alkanes and free fatty acids) from two cultivars (BIO L 212 Ratan and Nirmal B-1) of L. sativus could act as short-range attractant and stimulant for nymph laying by adult viviparous females. The n-hexane extracts of flower surface waxes were analyzed by TLC, GC-MS and GC-FID analyses. Twenty one and 22 n-alkanes between n-C12 and n-C36 were detected in BIO L 212 Ratan and Nirmal B-1, respectively; whereas 12 free fatty acids between C12:0 and C22:0 were identified in both cultivars. Pentadecane and tridecanoic acid were predominant n-alkane and free fatty acid, respectively. One flower equivalent surface wax of both cultivars served as short-range attractant and stimulant for nymph laying through Y-tube choice experiments and I-tube viviparity assays, respectively, by adult viviparous females. A synthetic blend of nonacosane, tridecanoic acid and linoleic acid, and a synthetic blend of tetradecane, pentadecane, nonacosane, tridecanoic acid and linoleic acid resembling in amounts as present in one flower equivalent surface wax of BIO L 212 Ratan and Nirmal B-1, respectively, served as short-range attractant and stimulant for nymph laying by adult viviparous females. This study suggests that both these blends could be used in lures in the development of baited traps in pest management programmes.

Extraction, thin layer chromatography and gas chromatography–mass spectrometry of Solena amplexicaulis (Lam.) Gandhi, commonly known as creeping cucumber, (Cucurbitaceae) leaves revealed 21 long-chain primary alcohols, and 100 g leaves indicated presence of 3651.59 ± 327.18 SE µg long-chain primary alcohols. 1-Heptadecanol and 1-triacontanol were the predominant and least abundant primary alcohols, representing for 780.44 ± 42.59 and 3.28 ± 0.55 SE μg, respectively. Antibacterial property of the complete synthetic blend (0.1%), comparable to long-chain alcohols as detected by GC-FID of 100 g S. amplexicaulis leaf extracts was evaluated on the pathogenic bacteria Salmonella gallinarum by agar well diffusion method, and exhibited 20.4, 26.7 and 38.2 mm zone of inhibition at 25, 50 and 100 μl doses, respectively. One hundred µl dose of 6 individual pure synthetic compounds, 1-tridecanol, 1-pentadecanol, 1-heptadecanol, 1-nonadecanol, 1-eicosanol and 1-tricosanol comparable to the amounts present in 0.1% solution of pure isolated alcohols from S. amplexicaulis leaves displayed 16.2, 17.7, 18.6, 22.8, 15.8 and 14.5 mm zone of inhibition against this bacterium, respectively. Hundred µl dose from a synthetic blend of above 6 compounds (comparable to the proportions as present in 0.1% solution of pure isolated alcohols from 100 g S. amplexicaulis leaves) exhibited 38.1 mm zone of inhibition against this bacterium. Furthermore, 100 μl dose from a mixture (1:1) comprising of chloramphenicol (1 µg/ml) and a synthetic blend of above 6 compounds displayed 38.8 mm inhibition zone against S. gallinarum, and hence, this combination might be used against this pathogenic bacteria.

The importance of leaf surface wax compounds from the rice-field weed Ludwigia octovalvis (Jacq.) Raven (Onagraceae) was determined in the flea beetle Altica cyanea (Weber) (Coleoptera: Chrysomelidae). Extraction, thin layer chromatography and GC-MS and GC-FID analyses of surface waxes of young, mature and senescent leaves revealed 20, 19 and 19 n-alkanes between n-C15 and n-C35, respectively; whereas 14, 14 and 12 free fatty acids between C12:0 and C22:0 fatty acids were identified in young, mature and senescent leaves, respectively. Tricosane was predominant n-alkane in young and mature leaves, whilst eicosane predominated in senescent leaves. Heneicosanoic acid, palmitic acid and docosanoic acid were the most abundant free fatty acids in young, mature and senescent leaves, respectively. A. cyanea females showed attraction to 0.25 mature leaf equivalent surface waxes compared with young or senescent leaves in a short glass Y-tube olfactometer bioassay. The insects were attracted to a synthetic blend of 0.90, 1.86, 1.83, 1.95, 0.50 and 0.18 µg ml−1 petroleum ether of hexadecane, octadecane, eicosane, tricosane, palmitic acid and alpha-linolenic acid, respectively, comparable with the proportions as present in 0.25 mature leaf equivalent surface waxes. A. cyanea also laid eggs on a filter paper moistened with 0.25 mature leaf equivalent surface waxes or a synthetic blend of 0.90, 1.86, 1.83, 1.95, 0.50 and 0.18 µg ml−1 petroleum ether of hexadecane, octadecane, eicosane, tricosane, palmitic acid and alpha-linolenic acid, respectively. This finding could provide a basis for monitoring of the potential biocontrol agent in the field.

Galerucella placida Baly (Coleoptera: Chrysomelidae) is a promising biocontrol agent of the rice-field weed Polygonum orientale L. (Polygonaceae) in India and Bangladesh. The longevity of G. placida adults was related with nutrients and antinutrients of young, mature and senescent leaves of P. orientale. Mature leaves of P. orientale had higher level of nutrients (carbohydrates, proteins, lipids, nitrogen and amino acids) and lower level of antinutrients (phenols and flavonols) compared to young and senescent leaves. Higher level of carbohydrates, proteins, lipids, nitrogen, amino acids including water content, and lower phenol and flavonol content of mature leaves had influenced higher survival of G. placida. Total larval developmental and pupal periods were 26.27 ± 0.45 SE and 7.06 ± 0.17 SE days on mature weed leaves, respectively; whilst adult males and females lived for 52.15 ± 0.33 SE and 58.0 ± 0.38 SE days on mature leaves, respectively. Fecundity of individual G. placida was 133.3 ± 3.2 SE eggs during life time. The net reproductive rate, generation time, intrinsic rate of increase, finite rate of increase and doubling time were 66.675, 27.5376, 0.1525, 1.2502 and 4.5452 days, respectively, under laboratory conditions (27 ± 0.5 °C, 12L:12D photoperiod, 65 ± 5% RH).

The influence of young, mature and senescent leaves of bitter gourd Momordica charantia L. (Cucurbitaceae) on the feeding, growth and reproduction of Epilachna dodecastigma (Weid.) (Coleoptera: Coccinellidae) were studied under laboratory conditions (27 ± 0.5 °C, 12 h light: 12 h dark photoperiod, 65 ± 5% RH). Larval developmental time of E. dodecastigma was longest on senescent leaves followed by young and mature leaves, whereas the pupal period was shortest on young and mature leaves. The longevity of females was generally higher than males. Male and female longevity were highest on mature leaves and lowest on senescent leaves. Fecundity was highest on mature leaves followed by young and senescent leaves. The growth and development of E. dodecastigma were related with nutrient and phenol content of three types of bitter gourd leaves. Carbohydrate content was higher in young and mature leaves, whereas protein, nitrogen, amino acid and lipid content were in greater quantities in mature leaves followed by young and senescent leaves. Phenol content was greatest in senescent leaves and least in mature leaves. Higher level of carbohydrates, proteins, lipids, nitrogen and amino acids including water content and lower phenol content of mature leaves had influenced higher growth rate and fecundity of E. dodecastigma.

Epilachna dodecastigma (Wied.) (Coleoptera: Coccinellidae) causes economic losses to bitter gourd, Momordica charantia L. (Cucurbitaceae) production in India and Bangladesh because adults feed on the leaves and flowers resulting death of the plant. This insect is currently controlled by insecticides, which are harmful to human health and environment. We studied the behavioral responses of E. dodecastigma females to floral volatiles and synthetic compounds comparable to floral volatiles in a Y-tube olfactometer to determine their potential for monitoring this pest. The gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID) analyses of M. charantia floral volatiles revealed the presence of 20 compounds. Myrcene was predominant followed by methyl jasmonate and 1-octadecanol in floral volatiles. Epilachna dodecastigma females were attracted to floral volatiles by a Y-tube olfactometer bioassay. Females were attracted to individual synthetic 1-heptanol, s...

Epilachna vigintioctopunctata Fabr. (Coleoptera: Coccinellidae) and Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) are important pests of Solena amplexicaulis (Lam.) Gandhi (Cucurbitaceae), commonly known as creeping cucumber. The profiles of volatile organic compounds from undamaged plants, plants after 48 hr continuous feeding of adult females of either E. vigintioctopunctata or A. foveicollis, by adults of both species, and after mechanical damaging were identified and quantified by GC-MS and GC-FID analyses. Thirty two compounds were detected in volatiles of all treatments. In all plants, methyl jasmonate was the major compound. In Y-shaped glass tube olfactometer bioassays under laboratory conditions, both insect species showed a significant preference for complete volatile blends from insect damaged plants, compared to those of undamaged plants. Neither E. vigintioctopunctata nor A. foveicollis showed any preference for volatiles released by heterospecifically damaged plants vs. conspecifically damaged plants or plants attacked by both species. Epilachna vigintioctopunctata and A. foveicollis showed attraction to three different synthetic compounds, linalool oxide, nonanal, and E-2-nonenal in proportions present in volatiles of insect damaged plants. Both species were attracted by a synthetic blend of 1.64 μg linalool oxide + 3.86 μg nonanal + 2.23 μg E-2-nonenal, dissolved in 20 μl methylene chloride. This combination might be used as trapping tools in pest management strategies.

Lathyrus sativus L. (Leguminosae) seed, commonly known as khesari, is an important legume in India, Pakistan, Bangladesh, China, and Ethiopia. Ten free fatty acids were identified in seed coat waxes of four varieties of L. sativus with total fatty acids accounting for between 10.5 and 17.4 mg per 100 g of seed depending on the variety. Palmitoleic acid (C16:1) was the predominant free fatty acid in two of the varieties; whereas palmitic (C16:0) and lauric (C12:0) acids were the predominant free fatty acids in the two other varieties. Attraction of free fatty acids from seed coat waxes of the four varieties were tested for attractiveness to females of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) at 2–8, 2–8, 4–8, and 4–8 μg concentrations, respectively, in Y-tube olfactometer bioassays. The attractiveness of synthetic mixtures comparable to the fatty acid compositions of the four varieties were also tested. Individual synthetic myristic, palmitic, palmitoleic, and stearic acids at 0.66, 1.18, 1.36, and 1.18 μg, respectively, elicited attraction of the insect. A synthetic blend of 0.93, 1.68, 1.82, and 1.18 μg of myristic, palmitic, palmitoleic, and stearic acids, respectively, was most attractive to the insect. At present, C. maculatus are controlled with insecticides, which are harmful to human health and environment. Hence, the above mentioned combination of four fatty acids might be used for insect pest management such as baited traps.

The effect of five constant temperatures of 21, 24, 27, 30 and 33 °C on adult life span, reproduction, oviposition behavior and larval developmental time of a bitter gourd inhabited coleopteran insect Epilachna dodecastigma (Wied.) (Coccinellidae) was determined in laboratory conditions under 70 ± 5 % relative humidity and a photoperiod of 12 L : 12 D. Larval developmental time of E. dodecastigma decreased as temperature increased from 21 to 33 °C. Life table data revealed that overall mortality was lowest at 27 °C and highest at 21 °C. Females lived longer than males at all temperatures; but longevity decreased with increase in temperature. Pre-oviposition period decreased significantly with increase in temperature up to 27 °C and thereafter increased at a slower rate; whereas oviposition period decreased significantly with increase in temperature. Fecundity and egg viability increased significantly with an increase in temperature up to 27 °C and thereafter decreased at a slower rate. The intrinsic rate of increase (r m ) was 0.1703, 0.1984, 0.2235, 0.2227 and 0.2181 day−1 at 21, 24, 27, 30 and 33 °C, respectively. The net reproductive rate and finite rate of increase was highest at 27 °C (R o = 112.05; λ = 1.4233) and lowest at 21 °C (R o = 51.23; λ = 1.2581).

Aulacophora foveicollisLucas causes economic losses to creeping cucumber [Solena amplexicaulis(Lam.) Gandhi] growers in India and Bangladesh because adults feed on the leaves and flowers causing death of the plant. The insect is a generalist herbivore as it also causes damage to pumpkin, bottle gourd, sponge-gourd and gac fruit production by feeding on leaves and flowers of these plants. At present, insects are controlled with insecticides, which are harmful to human health and the environment. We studied the behavioural responses of adultA. foveicollisto flower surface waxes and synthetic compounds mimicking flower surface waxes to determine their potential for monitoring this pest. The gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID) analyses ofS. amplexicaulisflower (50 g) surface waxes indicated presence of 17.9 and 3.1 mg alkanes and free fatty acids, respectively. Seventeenn-alkanes fromn-C15ton-C34and 16 free fatty acids from C10:0 to C22:0 were detected in the flower surface waxes. Heptacosane was predominant amongn-alkanes representing 2748.1 µg; whereas, pentadecanoic acid was the major fatty acid accounting for 466.6 µg.Aulacophora foveicolliswere attracted to the flower surface waxes at concentrations of 4 to 8 μg/ml, as demonstrated by a Y-tube olfactometer bioassay. Using a dose response bioassay, the insect was shown to be attracted to individual synthetic pentadecane, heptacosane, nonacosane, undecanoic acid and nonadecanoic acid at 0.70, 0.70, 1.20, 1.60 and 1.40 µg/ml, respectively. The insect displayed highest attraction to a synthetic mixture of 0.70, 1.23, 0.77, 0.84, 0.94 and 0.74 µg/ml of pentadecane, heptacosane, nonacosane, undecanoic acid, lauric acid and nonadecanoic acid, respectively, and hence, this combination might be used for insect pest management such as in baited traps.

The effects of feeding on root by the larvae and three types of Momordica cochinchinensis Spreng (Cucubitaceae) leaves (young, mature and senescent) by the adults of Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) were studied under laboratory conditions. Total larval developmental time was 19.7 ± 0.2 days by feeding on young roots. Adult males lived for 28.4 ± 1, 65.7 ± 1.1 and 22.8 ± 1.3 days on young, mature and senescent leaves, respectively; whilst adult females lived for 34.3 ± 1.2, 68.5 ± 0.9 and 26.4 ± 1.4 days on young, mature and senescent leaves, respectively. Fecundity was highest in mature leaves fed insects (202.2 ± 10.6). Total carbohydrate, protein, lipid, nitrogen and amino acid were much higher in root followed by mature leaves than young and senescent leaves. Moisture content was highest in mature leaves than the roots, young and senescent leaves. Phenols were greatest in young leaves followed by mature leaves and least in senescent leaves and roots of the said plant. Flavonols were higher in young leaves and least in root. These results suggest that A. foveicollis adults perform better on mature leaves than young and senescent leaves for their nutrition.

Galerucella placida Baly (Coleoptera: Chrysomelidae) is a potential biocontrol agent of the rice-field weed Polygonum orientale L. (Polygonaceae). The volatile organic compound (VOC) profiles from undamaged and mechanically damaged plants, and from plants 12- and 36-h following continuous feeding of female G. placida adults and 2nd instar larvae were identified and quantified by GC–MS and GC-FID analyses. Twenty-four and 21 compounds were identified in volatiles of undamaged and insect feeding plants, respectively; whereas 22 compounds were detected in volatiles of mechanically damaged plants. Decanal and 1-dodecanol were unique to undamaged plants, and linalool was detected in volatiles of undamaged and mechanically damaged plants, but not in volatiles of insect damaged plants. However, the beetles are not attracted by none of these volatile components, when tested individually in Y-shaped glass tube olfactometer bioassays. In all plants, methyl jasmonate was predominant. 1-Undecanol was the least amount in undamaged plants, and plants 12-h after feeding by G. placida adults and larvae; whereas 1-tridecanol was the least abundant in plants 36-h after feeding by G. placida adults and larvae, and mechanically damaged plants. The beetles showed significant preference to the whole volatile blends from plants 12-h after feeding by larvae and plants 36-h after feeding by either larvae or adults compared to those of undamaged plants. Further, G. placida responded to individual synthetic compounds, 3-hexanol, 1-octen-3-ol, nonanal, and geraniol at 7, 1.38, 3.75 and 4.5 µg/25 µL CH2Cl2, respectively, and provide a basis for attraction of the potential biocontrol agent in the field.

The effect of four varieties ofLathyrus sativusLinnaeus (Fabaceae) seeds (Bio L 212 Ratan, Nirmal B-1, WBK-14-7, and WBK-13-1) on the bionomics ofCallosobruchus maculatus(Fabricius) (Coleoptera: Chrysomelidae: Bruchinae) was studied under laboratory conditions. Total larval developmental time was longer on WBK-13-1 than Bio L 212 Ratan. Adult emergence was highest on Bio L 212 Ratan followed by Nirmal B-1, WBK-14-7, and WBK-13-1. The development and fecundity were related with nutrient and antinutritional factors of khesari seeds. Total carbohydrates and proteins were highest in Bio L 212 Ratan and Nirmal B-1 while lipids and nitrogen were highest in Bio L 212 Ratan and least in WBK-13-1. Amino acids were higher in Nirmal B-1 and WBK-13-1. Phenols were greatest in Nirmal B-1 and least in Bio L 212 Ratan and WBK-14-7. β-ODAP was higher in Bio L 212 Ratan and Nirmal B-1. The lower levels of carbohydrates, proteins, lipids, nitrogen, water content, and higher trypsin inhibitor activity of WBK-14-7 and WBK-13-1 may explain the higher developmental time and lower fecundity ofC. maculatuson these varieties. These results suggest that infestations ofC. maculatusmay be easier to manage on WBK-14-7 and WBK-13-1 than on the other varieties of khesari seeds.

Extraction, thin layer chromatography and gas chromatography-mass spectrometry of leaf surface waxes of Polygonum orientale L. (Polygonaceae) weed revealed 11, 15 and 11 free fatty acids in young, mature and senescent stages. Oleic acid was the predominant in young leaves (5950 ± 111 µg); whereas palmitic acid was the predominant fatty acids, representing 4247.5 ± 23 and 6644 ± 110 µg in mature and senescent leaves, respectively. Both tridecanoic and heneicosanoic acids were not detected in young and senescent leaves, and myristic and heptadecanoic acids were not identified in young leaves; whereas lauric and nonadecanoic acids were not detected in senescent leaves. The free fatty acids from young, mature and senescent weed leaves, and the mixtures of synthetic fatty acids mimicking free fatty acids of three types of weed leaves attracted female Galerucella placida (Coleoptera: Chrysomelidae) at the minimal amounts of 2, 1 and 2 leaf equivalent free fatty acids, respectively, in Y-shaped glass tube olfact...

Momordica charantia L. (Cucurbitaceae) is an important vegetable in Asia and Africa. Larvae and adults of Epilachna dodecastigma (Wied.) (Coleoptera: Coccinellidae) consume M. charantia leaves and flowers and reduces crop production. Currently, this pest is controlled by insecticides application. Hence, it is necessary to find out allelochemicals from flowers attracting the insect, which might be used for environment friendly pest management program. Therefore, free fatty acid profile from flowers was characterized and then proposed use of a synthetic blend of fatty acids for development of baited traps. Extraction, thin layer chromatography and gas chromatography–mass spectrometry of M. charantia flowers revealed 14 free fatty acids. The free fatty acids from flowers and synthetic blends of fatty acids mimicking different concentrations of free fatty acids attracted female E. dodecastigma between 50–400 μg/mL concentrations in Y-shaped glass tube olfactometer bioassay. A synthetic blend of 112.61, 29.22,...