Effects of leaf nitrogen content on oviposition site selection, offspring performance, and intraspecific interactions in an omnivorous bug

Abstract.  1. Oviposition site preference and its relation to offspring performance have received much attention in studies of herbivorous insects. Although this relationship is of great ecological significance, its presence in predacious and omnivorous insects has hardly been explored. When selecting an oviposition site, omnivores are expected to respond to both prey availability and, even more strongly, to plant traits that affect both females and their offspring.
2. In this study, females of Orius albidipennis (Heteroptera: Anthocoridae) showed a strong preference for oviposition at the vein origin site of cotton leaves. It appears that this site is a limited resource for ovipositing females, because they defend it against conspecific intruders. This defensive behaviour was significantly more pronounced on nitrogen-rich than nitrogen-poor plants.
3. The females' defensive behaviour on nitrogen-rich leaves corresponds with offspring performance; the nymphs developed faster and enjoyed higher survival on nitrogen-rich than on nitrogen-poor leaves. At the between-plant level, oviposition preference was not significantly correlated with offspring performance, and egg hatching rate did not differ significantly between nitrogen treatments.
4. Oviposition site selection by this omnivorous bug appears, however, to be correlated positively with offspring performance at the within-leaf level. This is supported by the significantly higher hatching success of eggs deposited at the preferred vein origin site as compared with those deposited on other parts of the leaf.     

Effect of the canopy complexity of trees on the rate of predation of insects

The effect of the complexity of tree canopies on the effectiveness of biological control of tree‐dwelling insect herbivores by predators has been neglected. A complex canopy provides a greater variety of resources than a simple canopy, which may result in an increase in the abundance of both herbivores and predators in complex canopies and a higher predation rate. On the other hand, it may be more difficult to locate prey in trees with a complex canopy, which may lower the predation rate. The main aim of this study is to determine the relationship between predation rate and canopy complexity. We have used a system consisting of lime trees, larvae of blowflies as prey and naturally occurring predators (mainly birds and ants). The complexity of the canopy of 12 of the lime trees was reduced by pruning, and the predation rate was determined by recording the fate of prey pinned on each of the trees for 30 min several times during the course of a year. The predation rate was negatively associated with canopy complexity. We compare these results with those reported in the literature and contrary to the widely held view conclude that a negative relationship between predation rate and canopy complexity is a common phenomenon and can be expected to be reported in studies not only on ambush but also on predators that actively search for prey.     

Intraspecific competition as a regulating factor limiting the number of transconjugants in soil

A laboratory study was carried out to determine survival of transconjugant cells ofPseudomonas fluorescens intro duced into sterile soil. The transconjugant survived significantly better when it was the only strain inoculated into the soil; when introduced into soil pre-colonized by the recipient strain, the transconjugant was undetectable. These results indicate that intraspecific competition is a regulating factor limiting the number of transconjugants in soil.     

不同产地白蜡虫(Ericerus pela Chavannes)产卵期天敌的种类及其群落结构研究

白蜡虫雌虫产卵期是白蜡种虫生产的关键时期,在我国白蜡主产地区,选择有代表性的4个种虫产地,2个白蜡产地和4个虫蜡混产地,调查群落中白蜡虫天敌的物种组成和数量变化,并进行聚类分析和排序,在10个白蜡主产地内,共收集到各种天敌15种,分属于6科11属,各群落的物种组成变化较小,优势种为白蜡虫花翅跳小蜂Microterys ericeri Ishii、中华花翅跳小蜂M.sinicus Jiang、白蜡虫啮小蜂Tetrastichus kodaikanalensis Saraswat、白蜡蚧长角象Anthribus la-jievorus Chao和黑缘红瓢虫Chilocorus rubidus Hope。群落的优势集中指数较小,多样性指数和均匀性指数较高,群落相似性系数最高达97.46%,最低为75.92%。影响群落相似性的主要因子为白蜡产区不同、生态环境差异和优势种天敌的数量变化,根据聚类分析和排序,将10个不同产地白蜡虫天敌群落分为3类;第1类为种虫产地,优势种天敌发生和危害较轻;第2类为白蜡产地,白蜡虫天敌发生和危害极为严重,其种群数量为第1类的3.36倍,第3类虫蜡皆产,其天敌数量介于第1、2类之间,中华花翅跳小蜂种群数量在第1、3类群落中大致相等,第2类发生较较重,白蜡虫天敌的严重危害是造成蜡区不产种虫的主要原因之一。     

Intraspecific heritable variation in life-history traits can alter the outcome of interspecific competition among insect herbivores

Competition is one of the most important biotic factors determining the structure of ecological communities. In this study, we show that there is variation in competitive ability between two clones of the pea aphid, Acyrthosiphon pisum, both of which out-compete a clone of the vetch aphid, Megoura viciae, in the laboratory. We tested whether this variation in competitive ability would alter the outcome of interspecific competition in the field. While one pea aphid clone followed the pattern set in the laboratory, out-competing the Megoura viciae clone, another showed the reverse effect with Megoura viciae dominating. These differences appear to be the result of variation in early population growth rate between the pea aphid clones, rather than predation, although predation did lead to the eventual extinction of colonies. We also questioned whether intra- and interspecific differences in predator escape behaviour could affect the outcome of competition in the field. All three clones responded similarly to the presence of foraging hoverfly larvae (Episyrphus balteatus), but the Megoura viciae clone dropped from the plant significantly less often in response to the presence of a foraging two-spot ladybird (Adalia bipunctata). This work provides evidence that intraspecific variation in competitive ability can alter the outcome of interspecific competitive interactions in nature and suggests that species–specific behavioural traits may have the potential to modify the outcome of these interactions.     

Competition as a factor underlying the abundance of an uncommon phytophagous insect, the salt-marsh planthopper Delphacodes penedetecta

Abstract. 1. Recent reviews of experimental studies provide compelling evidence that competition should be retained as a potential factor influencing the success of phytophagous insects. In this context, the objective of the study was to determine the role of interspecific and intraspecific competition, both contemporaneous and plant mediated (feeding‐induced resistance), in limiting the population density of a consistently rare insect in a guild of abundant potential competitors. 2. Competitive interactions were assessed experimentally between two phloem‐feeding planthoppers, the abundant Prokelisia dolus and the rare Delphacodes penedetecta (Hemiptera: Delphacidae). Both species are monophagous on the cordgrass Spartina alterniflora and overlap broadly in their use of habitats in the intertidal salt marshes along the Atlantic coast of North America. 3. The two planthoppers partition their cordgrass host plant, with D. penedetecta feeding more on the basal stems (particularly females) and P. dolus occurring most often on the canopy leaves. Notably, there was no evidence for niche shifting in D. penedetecta because its distribution on the plant did not change in the presence or absence of P. dolus. 4. Interspecific interactions with P. dolus had very little effect on the performance (development time and body size) and survival of D. penedetecta, a result demonstrated in both the laboratory and field. This result occurred both in contemporaneous interactions and on plants fed on previously by P. dolus. Only the males of D. penedetecta experienced weak competitive effects from P. dolus, as evidenced by reduced body size and slightly protracted development. 5. By contrast, there were strong adverse effects of intraspecific crowding (both from contemporaneous interactions and on plants fed on previously by conspecifics), whereby the survival, development time, and body size of D. penedetecta were affected very adversely. 6. These results suggest that interspecific competition is a weak force influencing the abundance of D. penedetecta in the field. Rather, strong intraspecific competition, a high requirement for plant nitrogen, and intrinsically low lifetime fecundity combine to explain the rarity of D. penedetecta.     

On the role of sinigrin (mustard oil) in a tritrophic context: plant–aphid–aphidophagous hoverfly

1. Plant secondary metabolites can govern prey–predator interactions by altering the diet breadth of predators and sometimes provide an ecological refuge to prey. Brassicaceae plants and their specialist pests can be used as a model system for understanding the role of chemically mediated effects restricting the diet breadth of natural enemies, and consequently the occurrence of enemy‐free space for the specialist pest. 2. The objective of the present study was to test the performance of the generalist predator Episyrphus balteatus De Geer (Diptera: Syrphidae) fed on the specialist herbivore Brevicoryne brassicae L.(Homoptera: Aphididae), reared on two different brassica species: black mustard (Brassica nigra), a wild species with high levels of sinigrin; and canola (Brassica napus), a cultivated species without sinigrin. 3. The preference and performance of the predator and the performance of the prey were measured. Sinigrin was quantified by high‐performance liquid chromatography in both leaf samples and aphids reared on the two host plants. 4. The cabbage aphid performed better on canola than on black mustard. The performance of the predator on this aphid when reared on canola was clearly better than when reared on black mustard. Females had a higher overall preference for cabbage aphids reared on canola than on black mustard. 5. The ability of aphids reared on plants with high glucosinolate content to reduce the performance of their generalist predators indicates that the presence of B. nigra may provide enemy‐free space for the cabbage aphid from its predator, a concept that has useful application in the context of biological control for agricultural systems.     

Soil nutrient effects on oviposition preference,larval performance,and chemical defense of a specialist insect herbivore

This study examined the effects of increased leaf nitrogen in natural host-plants (Plantago spp.) on female oviposition preference, larval performance, and larval chemical defense of the butterfly Junonia coenia. Increased availability of soil nutrients caused the host-plant’s foliar nitrogen to increase and its chemical defense to decrease. Larval performance did not correlate with increases in foliar nitrogen. Larval growth rate and survival were equivalent across host-plant treatments. However, larvae raised on fertilized host-plants showed concomitant decreases in chemical defense as compared to larvae reared on unfertilized host-plants. Since most butterfly larvae cannot move long distances during their first few instars and are forced to feed upon the plant on which they hatched, J. coenia larval chemical defense is determined, in large part, by female oviposition choice. Female butterflies preferred host-plants with high nitrogen over host-plants with low nitrogen; however, this preference was also mediated by plant chemical defense. Female butterflies preferred more chemically defended host-plants when foliar nitrogen was equivalent between host-plants. J. coenia larvae experience intense predation in the field, especially when larvae are not chemically well defended. Any qualitative or quantitative variation in plant allelochemical defense has fitness consequences on these larvae. Thus, these results indicate that females may be making sub-optimal oviposition decisions under a nutrient-enriched regime, when predators are present. Given the recent increase in fertilizer application and nitrogen deposition on the terrestrial landscape, these interactions between female preference, larval performance, and larval chemical defense may result in long-term changes in population dynamics and persistence of specialist insects.     

The effects of host plant species on adult oviposition and larval performance of the aphid predator Aphidoletes aphidimyza

1. Although preference–performance relationships in insects are typically studied in a bi-trophic context, it is well known that host plants can affect both the preference and performance of natural enemies of herbivorous insects. 2. This study presents evidence from field and laboratory studies that two species of milkweeds, the putatively less defended Asclepias incarnata and the putatively more defended Asclepias syriaca, differentially affect adult oviposition and larval performance in Aphidoletes aphidimyza, an aphid-feeding predatory midge, independent of aphid density. 3. Host plant species affected predatory fly larvae abundance by a factor of 50 in the field and a factor of 8 in the laboratory. Larval and adult emergence rates in our laboratory studies provided strong evidence for reduced performance on A. syriaca. Oviposition in choice and no-choice settings provided some evidence for preference for A. incarnata, and a potentially suppressive effect of A. syriaca. 4. The results provide limited support for the hypothesis that natural selection can lead to positive correlations between adult oviposition preferences and larval performance upon various food sources, even when predatory insects oviposit onto host plants of their herbivorous prey. 5. Preference and performance are not perfectly aligned in this system, however, because ovipositing females do not reject A. syriaca entirely. Potential explanations for mismatches between preference and performance in this system include the neural constraints associated with being a generalist, adaptive time-limited foraging strategies, and unique evolutionary histories of laboratory colonies compared with wild insects.     

Combined effects of climate and biotic interactions on the elevational range of a phytophagous insect

1. The ranges of many species have expanded in cool regions but contracted at warm margins in response to recent climate warming, but the mechanisms behind such changes remain unclear. Particular debate concerns the roles of direct climatic limitation vs. the effects of interacting species in explaining the location of low latitude or low elevation range margins. 2. The mountains of the Sierra de Guadarrama (central Spain) include both cool and warm range margins for the black-veined white butterfly, Aporia crataegi, which has disappeared from low elevations since the 1970s without colonizing the highest elevations. 3. We found that the current upper elevation limit to A. crataegi's distribution coincided closely with that of its host plants, but that the species was absent from elevations below 900 m, even where host plants were present. The density of A. crataegi per host plant increased with elevation, but overall abundance of the species declined at high elevations where host plants were rare. 4. The flight period of A. crataegi was later at higher elevations, meaning that butterflies in higher populations flew at hotter times of year; nevertheless, daytime temperatures for the month of peak flight decreased by 6.2 degrees C per 1 km increase in elevation. 5. At higher elevations A. crataegi eggs were laid on the south side of host plants (expected to correspond to hotter microclimates), whereas at lower sites the (cooler) north side of plants was selected. Field transplant experiments showed that egg survival increased with elevation. 6. Climatic limitation is the most likely explanation for the low elevation range margin of A. crataegi, whereas the absence of host plants from high elevations sets the upper limit. This contrasts with the frequent assumption that biotic interactions typically determine warm range margins, and thermal limitation cool margins. 7. Studies that have modelled distribution changes in response to climate change may have underestimated declines for many specialist species, because range contractions will be exacerbated by mismatch between the future distribution of suitable climate space and the availability of resources such as host plants.     

The structure of the phytophagous insect fauna on the introduced weed Solidago altissima in Switzerland

Solidago altissima L. was introduced into Europe as an ornamental plant from North America more than 100 years ago and the phytophagous insect fauna of it was recently examined in Switzerland where it has become an important weed in disturbed habitats. Rhizomes and aerial parts were examined and all insects collected in summer were tested in a no-choice feeding test. 18 out of 55 phytophagous insects were found feeding on S. altissima in Switzerland and for the remaining 37 the relation with the plant was not determined. The insects that have expanded their host range to feed on S. altissima since its introduction to Switzerland are almost solely opportunistic, unspecialized ectophages not closely attuned to the growth cycle of S. altissima. Only 4% of the insects were specialists and 9% endophagous. In contrast in North America S. altissima supports 25% specialists and 17% endophages. The native Solidago virgaurea L. in Switzerland supports many more specialists (28%) and endophages (23%) than S. altissima here. Possible reasons why almost none of these have switched to S. altissima are discussed. A comparison is made between the number of insects recruited by S. altissima in Switzerland with the number recruited by the exotic plants Heracleum mantegazzianum Som. & Lev. (Apiaceae) in Switzerland and Xanthium occidentale Bertol. (Asteraceae) in Australia. Reasons for different levels of insect recruitment are discussed. The high number of phytophagous insect species found on S. altissima in North America shows that there should be no shortage of possible control agents and any insects imported into Switzerland for the biological control of S. altissima would find largely unexploited food sources awaiting them.     

Effects of natal habitat odour, reinforced by adult experience, on choice of oviposition site in the mosquito Aedes aegypti

The effects of natal experience on the oviposition behaviour of adult female mosquitoes were investigated in the laboratory using Aedes aegypti (L.) (Diptera: Culicidae). 'Treatment' mosquitoes were exposed to a dilute repellent (inducing stimulus) in their breeding water (aquatic stages) and/or in the air (adults) during various combinations of life stages [larval only (L regime); larval and pupal (LP regime); larval, pupal and emergent adult (LPE regime); larval, pupal, emergent adult and adult (LPEA regime); pupal, emergent adult and adult (PEA regime); adult only (A regime)]. 'Control' mosquitoes were raised in an identical manner, but were not exposed to the inducing stimulus. The oviposition behaviour of treatment and control females was assessed in an oviposition assay that presented a choice of water with or without the inducing stimulus. Of the 435 mosquitoes tested in the experiment, 176 were non-distributors (i.e. laid all of their eggs in only one of the choices). Treatment females (distributors plus non-distributors) reared in the presence of the inducing stimulus throughout their lives (LPEA regime) showed a significant preference for the oviposition option containing the inducing stimulus (24/36 females) compared with corresponding controls (5/39 females). Distributors reared under the LPEA and PEA regimes also showed this preference (6/6 treatment vs. 2/29 control females, and 13/18 treatment vs. 7/23 control females, respectively). Females that had been exposed to the inducing stimulus as either immatures or adults only showed no preference for, and some showed an aversion to, the treatment oviposition option. This is interpreted as evidence for a natal habitat preference induction (NHPI) in this species, albeit one that requires extensive reinforcement in the adult stage. This adult experience-reinforced NHPI (AER-NHPI) is discussed in terms of its adaptive significance for container breeders, the possible timing mechanism and sensory basis of induction and potential practical consequences.     

Effects of specialist parasitoids on oviposition preference of phytophagous insects: encounter–dilution effects in a tritrophic interaction

Abstract.  1. Host plant preferences of the female diamondback moth Plutella xylostella were studied.
2. Female moths preferred conspecific-damaged cabbage plants over undamaged cabbage plants. The performance of P. xylostella larvae on conspecific-infested plants did not differ significantly from that of larvae on undamaged plants.
3.  Cotesia plutellae , the specialist parasitoid wasp of P. xylostella larvae, displayed equal preference for plants with differing levels of host-larvae damage, and the wasp attacked only one or two hosts on average before leaving an infested plant, irrespective of the number of hosts on the plant. It is hypothesised that the oviposition preferences of P. xylostella females for host plants already damaged by conspecific larvae demonstrate an encounter–dilution effect against C. plutellae .     

Defining core habitat of local populations of the gray treefrog (Hyla versicolor) based on choice of oviposition site

Concern over amphibian population declines and loss of terrestrial and aquatic habitat have emphasized the need to define habitat requirements for each stage in a species' life history. The realization that pond-breeding amphibians spend most of their lives in the terrestrial environment suggests the need to protect terrestrial as well as aquatic habitat. Many studies on amphibian populations have focused on emigration from breeding sites to define habitat use; however these studies do not typically elucidate terrestrial activities of adults within the breeding season. We measured colonization rates of artificial pools by gray treefrogs (Hyla versicolor) at multiple distances from natural breeding ponds. We found a non-random distribution of egg deposition among distances, with 95% of eggs deposited within 15 m of the breeding pond. Additionally, we found that the time to first colonization of artificial pools increased with respect to distance. Our results indicate that adult gray treefrogs may travel up to 200 m within a breeding season, and that multiple breeding ponds may be considered part of a single population. We suggest that a minimum core terrestrial habitat of 60 m surrounding breeding sites is appropriate for protection of local populations of gray treefrogs.     

Linkages between nectaring and oviposition preferences of Manduca sexta on two co‐blooming Datura species in the Sonoran Desert

1. The oviposition choices of phytophagous insects determine the environment that their offspring will experience, affecting both larval performance and host plant fitness. These choices, however, may be influenced by other activities, such as nectar foraging. 2. In the Sonoran Desert, Manduca sexta (Lepidoptera: Sphingidae) oviposits primarily on the perennial herb Datura wrightii. It has been reported to oviposit on the smaller‐flowered, co‐blooming, sympatric annual Datura discolor as well. Datura is also M. sexta's most important source of nectar in this region. Nectaring and oviposition decisions thus determine M. sexta's reproductive success, as well as the relative benefits (pollination) and costs (herbivory) that each Datura species derives from this interaction. 3. The nectaring and oviposition choices of adult M. sexta on these congeners were studied to investigate how nectar foraging influences oviposition. Larval performance on the two hosts was then assessed. 4. Nectaring and oviposition were behaviourally linked, with M. sexta preferring the perennial D. wrightii as both a nectar source and larval host when given a choice between the two species. This preference disappeared, however, when only D. discolor bore flowers. 5. In the laboratory, larvae developed at equal rates when fed D. wrightii or D. discolor leaves, but survival was higher on D. wrightii when larvae fed on intact plants. 6. These findings suggest that while female preferences match larval performance in most cases, the link between nectaring and oviposition may at times bias moths to lay eggs on inferior larval hosts.     

Effects of the light environment on oviposition preference and survival of a leaf-mining moth, Cameraria hamadryadella (Lepidoptera: Gracillariidae), on Quercus alba L.

Abstract.  1. Oviposition preference and the survival and mortality of larvae of Cameraria hamadryadella (Lepidoptera) on the foliage of Quercus alba L. (Fagaceae) in sun and shade were examined. To separate the effects of the environment of foliation from that of rearing, C. hamadryadella were allowed to oviposit on oak saplings that foliated either in the sun or shade. Subsequently, trees were placed into the sun or shade and larval survival was monitored.
2. Trees that foliated in the shade had leaves that were 30% longer than those that foliated in the sun. However, the density of leaf mines did not differ between trees that foliated in the sun or shade.
3. Larval survival was higher in the shade than in the sun, but no difference in survival due to the site of foliation was detected. Differences in larval survival between the sun and shade environments could not be attributed to differences in natural enemy mortality. However, 'death by other causes' was higher for larvae reared in the sun than in the shade. In sunny environments photochemical processes may reduce foliage quality, which results in lower survival of C. hamadryadella larvae.
4. Ovipositing C. hamadryadella do not appear to discriminate between foliage produced in the sun or shade. This lack of discrimination, coupled with the fact that ovipositing C. hamadryadella are active after dark, accounts for the absence of a difference in abundance between sun and shade.
5. The results presented here, combined with other published studies, argue that different patterns of insect herbivory and abundance in relation to the light level experienced by host-plant foliage might be expected for species that oviposit either in the night or in the day.     

Survival against the odds: ontogenetic changes in selective pressure mediate growth-mortality trade-offs in a marine fish

For organisms with complex life cycles, variation among individuals in traits associated with survival in one life-history stage can strongly affect the performance in subsequent stages with important repercussions on population dynamics. To identify which individual attributes are the most influential in determining patterns of survival in a cohort of reef fish, we compared the characteristics of Pomacentrus amboinensis surviving early juvenile stages on the reef with those of the cohort from which they originated. Individuals were collected at hatching, the end of the planktonic phase, and two, three, four, six and eight weeks post-settlement. Information stored in the otoliths of individual fish revealed strong carry-over effects of larval condition at hatching on juvenile survival, weeks after settlement (i.e. smaller-is-better). Among the traits examined, planktonic growth history was, by far, the most influential and long-lasting trait associated with juvenile persistence in reef habitats. However, otolith increments suggested that larval growth rate may not be maintained during early juvenile life, when selective mortality swiftly reverses its direction. These changes in selective pressure may mediate growth-mortality trade-offs between predation and starvation risks during early juvenile life. Ontogenetic changes in the shape of selectivity may be a mechanism maintaining phenotypic variation in growth rate and size within a population.     

The choice of oviposition site and the effects of density and oviposition timing on survivorship in<Emphasis Type="Italic"> Rana japonica</Emphasis>

In species that lack parental care and whose larvae are restricted to a given space throughout development, choice of egg-laying or reproductive sites often greatly influences fitness. Furthermore, reproductive success of individuals may be affected not only by conditions of the breeding area but also by the time when they start to breed, because intraspecific variation in the timing of breeding may result in asymmetric competition between larvae. We addressed these issues in an experimental and field study of the Japanese brown frog, Rana japonica. We tested whether the survival success of larvae decreased with an increase in the number of deposited egg masses and with a greater delay in oviposition. We found that the number of egg masses and timing of oviposition together significantly predicted larval survival per clutch. Moreover, we observed the natural oviposition of R. japonica to examine the prediction that if the density of larvae and the timing of oviposition affect survivorship of larvae, R. japonica will avoid depositing eggs in pools in which egg masses have already been deposited. We found that for small pools only, R. japonica tended to favor oviposition at unoccupied pools (those lacking egg masses and larvae) in the spawning season. For large pools, however, adults favored those already occupied by egg masses in the spawning period. The density of egg masses and tadpoles or the timing of oviposition may have less effect on spawning or the survival of tadpoles in large pools than in small pools.     

S-Sulfocysteine as a Source of the Sulfur Atom of Cephalosporin C

S. lignicolum acid proteinases A-1, A-2, and B (S-PI-insensitive) were examined for the structure of the active sites by the method of Nakatani using PAD as a probe. We attempted to screen for substances that release zinc(II)-PAD from the complex of zinc(II)-PAD-S-PI-insensitive acid proteinases. Angiotensin I released zinc(II)-PAD from the complex as well as from the complex of S-PI-sensitive acid proteinases. Angiotensin I is a good substrate for these enzymes regardless of S-PI-sensitivity. These results suggest that the two carboxyl groups capable of binding to zinc(II)-PAD are at the active site regions of S. lignicolum enzymes and that they are involved in their catalytic actions.     

The importance of leaf surface wax as short-range attractant and oviposition stimulant in a generalist Lepidoptera

Green gram, Vigna radiata (L.) Wilczek, is an important pulse crop of Asia. Severe attack by the larvae of Spilosoma obliqua Walker (Lepidoptera: Arctiidae) causes defoliation of green gram and reduces seed yield. Females lay eggs on the leaf surface, and therefore, surface wax plays an important role as short-range attractant and oviposition stimulant. So, we have attempted to find out whether leaf surface wax compounds (alkanes and free fatty acids) from three green gram cultivars (PDM 54, PUSA BAISAKHI and SAMRAT) could act as short-range attractant and oviposition stimulant in females. The TLC, GC-MS and GC-FID analyses of n-hexane extracts revealed 20 n-alkanes from n-C₁₅ to n-C₃₆ and 13 free fatty acids from C12:0 to C21:0, whilst linoleic acid was unique in SAMRAT. Pentacosane was the predominant amongst n-alkanes in the leaf surface waxes of three cultivars. Heneicosanoic acid and palmitoleic acid were the predominant free fatty acids in the leaf surface waxes of PDM 54, and PUSA BAISAKHI and SAMRAT, respectively. Females were attracted towards one leaf equivalent surface wax of three green gram cultivars against solvent controls (n-hexane) in Y-tube olfactometer bioassays. A synthetic blend of pentacosane, heptacosane, nonacosane, hexatriacontane, palmitoleic acid, linolenic acid and stearic acid, a synthetic blend of pentacosane, hexatriacontane and stearic acid, and a synthetic blend of hexatriacontane, linolenic acid and stearic acid resembling in amounts present in one leaf equivalent surface wax of PDM 54, PUSA BAISAKHI and SAMRAT, respectively, served as short-range attractant and oviposition stimulant in females. Females showed equal preference for egg laying towards the above three synthetic blends when these blends were tested against each other, and hence, these blends could be employed in development of baited traps in pest management strategies.