Reproduction,adult survival and intrinsic rate of growth ofUrolepis rufipes [Hymenoptera: Pteromalidae], a pupal parasitoid of house flies,Musca domestica

Urolepis rufipes Ashmead, a recently discovered parasitoid of house flies at New York dairies, was reared at 15, 20, 25, 30 and 34°C to measure daily fertility, fecundity and adult survivorship. Little reproduction occurred at 15°C, and only a few ♀ successfully emerged at 34°C. The intrinsic rate of growth was fastest at 30°C (0.282 ♀/day), but fecundity was highest at 25°C (165.5 hosts attacked, producing 124.5 progeny). Some reproductive statistics at 25°C were: net reproductive rate (R₀=72.1 ♀/♀, generation time =18.7 days, intrinsic rate of increase (r_m)=0.228, finite rate of increase (λ)=1.26, daily birth rate =0.302, daily death rate =0.021 and Fisher's reproductive value =418. Sex ratio (average =75.9%) did not vary significantly with temperature (between 20–30°C) nor with mother's age.      

Effect of temperature on the development, fecundity, progeny sex ratio and life-table of Campoletis chlorideae, an endolarval parasitoid of the pod borer, Helicoverpa armigera

Development, survival, fecundity, progeny sex ratio (PSR) and age-specific life-table parameters of the parasitoid Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) were examined at six different constant temperatures (12, 17, 22, 27, 32 and 37°C) in the laboratory [70 ± 10% RH and 10:14 h (light:dark) photoperiod]. Second instar larvae of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) were reared on chickpea (Cicer arietinum L.) and used as the host. Development times shortened as the temperature increased from 12 to 37°C. The estimated lower developmental threshold (tL) was 3.4°C. The thermal summation for total immature stages was 379.97 degree-days. A reciprocal relationship between temperature and longevity was observed in the range of 12–17°C. The maximum mortality of pupae (71.8%) occurred at 37°C. At 22°C, the yield of a female parasitoid averaged 137.3 ± 14.7 (mean ± SD) progeny, of which 89.6 ± 7.6 were daughters. The number of daughters produced decreased when the females were kept either above or below 22°C, although the PSR was female biased in the range of 17–27°C. The analyses of life-table parameters, developmental rates, reproduction, mortality and PSR suggest that maximum population growth (r _m ) is near 27°C. There was little variation observed in most of the desired qualities of C. chlorideae in the range of 17–27°C, and it appears that the parasitoid is adapted to a wide range of temperatures. We suggest that for maximum production the parasitoid should be reared at 22 ± 4°C and be released in areas where the temperature ranges between 17° and 27°C, as in the plains of northern India.     

Temperature influences the performance and effectiveness of field and laboratory strains of the ichneumonid parasitoid, <Emphasis Type="Italic">Campoletis chlorideae</Emphasis>

To understand the influence of temperature on host–parasitoid interactions as a consequence of climatic change, we studied development, survival, and fecundity of field and laboratory strains of the Helicoverpa armigera larval endoparasitoid, Campoletis chlorideae at five different temperatures under laboratory conditions. Post-embryonic development period and degree-days required for completing the life cycle by both the strains decreased by 2.5 and 1.5 folds at 27°C compared to 18°C. Post embryonic development period showed a negative (r = −0.99, P < 0.001) and the development rate a positive (r = 0.99, P < 0.001) association with an increase in temperature. However, no parasitoid larvae survived in H. armigera larvae reared at 12 and 35°C after parasitization, suggesting that temperatures ≥35°C as a result of global warming will be lethal for development and survival of immature stages of C. chlorideae. Adult longevity was negatively associated (r = −0.91 to −0.96, P < 0.001) with temperatures between 12 and 35°C. The parasitoid adults stored at 12°C survived for longer period and exhibited higher fecundity than those kept at 27°C, but the efficiency of parasitism and adult emergence were quite low. Sex ratio of the progeny at 12°C was highly male-biased than the insects kept at 27°C. Laboratory strain of the parasitoid exhibited better survival, and the adults lived longer than the field strain at 18°C than at 27°C. Therefore, C. chlorideae adults stored at 18°C could be used for parasitism, while the immature stages should be reared at 27°C for mass production of the parasitoid for biological control of H. armigera.     

Reproduction and population parameters of the Nearctic predator Geocoris punctipes at constant and varying temperature regimes

The heteropteran predator Geocoris punctipes (Say) has been used in augmentative biological control since 2000 to control Lepidoptera. However, surprisingly, few data are available about the influence of temperature on its population development, which is of key importance to plan the number and moment of releases to obtain sufficient pest reduction. The objective of this study was to evaluate daily and total fecundity, longevity and life table parameters (m_x, l_x, r_m, R, λ, T and TD) of G. punctipes at constant (16.8°C, 21.5°C, 24.5°C and 28.3°C) and corresponding varying (day/night) (21/11°C, 24/18°C, 27/21°C and 30/26°C) temperatures. Pairs of adult predators aged 24 h and originating from nymphs exposed to the same temperature regimes were kept at the above‐mentioned temperature regimes in Petri dishes containing Anagasta kuehniella (Zeller) eggs and an oviposition substrate. Tests were conducted in climatic chambers at the different temperature regimes and a RH 70 ± 10% and a 14L: 10D photoperiod. Reproduction, longevity and life table parameters were significantly affected by temperature, with clear differences between treatments at low (16.8°C, 21/11°C, 21.5°C, 24/18°C) or a high (24.5°C, 27/21°C, 28.3°C, 30/26°C) temperature regimes. Highest reproduction and fastest population growth of G. punctipes took place at average temperatures ranging from 24.5°C to 30°C, and neither reproduction nor population growth was negatively influenced by varying temperatures at any of the temperature regimes.     

Multiple generation effects of high temperature on the development and fecundity of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B

Insects are ectotherms and their ability to resist temperature stress is limited. The immediate effects of sub‐lethal heat stress on insects are well documented, but longer‐term effects of such stresses are rarely reported. In this study, survival, development and reproduction of the whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B, were compared over five consecutive generations at 27, 31 and 35 °C and for one generation at 37 °C. Both temperature and generation significantly affected the fitness of the whitefly. These impacts were more dramatic with increasing generations and temperatures. Among the experimental temperatures, the most favorable for development and reproduction were 27 °C and 31 °C. At 27 °C, survival, development and fecundity were all stable over these five generations. At 31 °C, immature survival rate was the highest in the fifth generation, but female fecundities decreased in the fourth and fifth generations. At 35 °C, egg hatching rate, immature survival rate and female fecundity decreased significantly in the fourth and fifth generations. At 37 °C, survival of B. tabaci was not adversely affected, but female fecundity at 37 °C was less than 10% of that at 27 °C or 31 °C. These results demonstrate that the lethal high temperature for B. tabaci is over 37 °C, and the whitefly population continued expanding in the five generations at 35 °C. The ability of B. tabaci biotype B to survive high temperature stress will play an important role in its population extension under global warming.     

Effect of temperature on the reproductive biology of Peristenus spretus (Hymenoptera: Braconidae), a biological control agent of the plant bug Apolygus lucorum (Hemiptera: Miridae)

Peristenus spretus Chen et van Achterberg (Hymenoptera: Braconidae), a parasitoid of the plant bug Apolygus lucorum (Hemiptera: Miridae), has been studied for use in augmentative biological control in China. Under laboratory conditions, we explored the development, survival, age-specific and potential lifetime fecundity, oviposition period and progeny sex ratio of P. spretus reared at six constant temperatures (15°C, 19°C, 23°C, 27°C, 31°C, 35°C) on the second instar nymphs of A. lucorum. At 15°C, male and female P. spretus took 48.7 ± 0.3 and 52.5 ± 0.3 days to complete their immature development, while developmental time was reduced by more than half at 23°C and 27°C. The parasitoid can only develop to the larval stage at 31°C and neither larva nor pupa survived at 35°C. The estimated lower developmental threshold of the immature stage was 7.3°C. When parasitoid adults were exposed at 15°C, females laid 90% of their eggs at first 19 days of oviposition and had an extended reproductive life. In contrast, females held at 27°C laid most of their eggs (90%) in their first of 10 days of oviposition and had shorter longevity. The highest potential lifetime fecundity of P. spretus was 671.2 ± 34.7 SE eggs produced over 23.4 ± 1.4 SE days at 23°C. At 15°C, 19°C and 23°C, sex ratios of reared parasitoids were male-biased, but at 27°C there was no male bias.     

Parasitism of <Emphasis Type="Italic">Spodoptera litura</Emphasis> (Lepidoptera: Noctuidae) by <Emphasis Type="Italic">Microplitis prodeniae</Emphasis> (Hymenoptera: Braconidae)

Spodoptera litura Fabricius is a major vegetable pest that is widely distributed throughout tropical, subtropical and temperate regions. Microplitis prodeniae Rao and Chandry is a solitary endoparasitoid of S. litura. To assess the potential use of this parasitoid as a biological control agent, the reproductive schedule, fecundity and functional response of M. prodeniae were investigated under conditions of 28 ± 1°C and 70 ± 10% relative humidity with a 14:10-h L:D photoperiod. The parasitoid’s average lifetime fecundity was 171.0 ± 10.4 eggs, of which approximately 50% were laid within the first 3 days. Additionally, M. prodeniae exhibited a Holling type II functional response, and the estimated maximum numbers of the 1st, 2nd and 3rd instar larvae that were parasitized by a single M. prodeniae female were 71.6, 78.4 and 41.5 larvae over a 24-h period, respectively. The results of this study suggest that M. prodeniae has great potential as a candidate for controlling S. litura and can guide efforts in its mass production.     

Effects of food and temperature on development,fecundity and life‐table parameters of Adalia bipunctata (Coleoptera: Coccinellidae)

Development, reproduction and life tables of Adalia bipunctata (L.) were studied at three temperatures (19, 23 and 27°C) on a mixture of frozen pollen and Ephestia kuehniella Zeller eggs as a factitious food and on the aphids Myzus persicae (Sulzer) and Acyrthosiphon pisum (Harris) as natural foods. Development time of A. bipunctata on all tested diets decreased with increasing temperature. Mortality was lowest at 23°C, averaging 44.5%, 42.6% and 24.3% on factitious food, A. pisum and M. persicae respectively. The shortest developmental time from egg to adult at this temperature was observed on factitious food (18.55 days). However, the factitious food was inferior to the aphid diets in terms of reproduction, yielding the longest pre‐oviposition period, shortest oviposition period and lowest fecundity. The mean oviposition rate at 23°C varied from 19.94 to 25.03 eggs day^?1 on factitious food and M. persicae respectively. The intrinsic rate of increase (r_m) on different foods increased with increasing temperature and ranged from a minimum of 0.08 females/female/day on factitious food (19°C) to a maximum of 0.18 females/female/day on A. pisum (27°C). The results suggest that a mixture of E. kuehniella eggs and pollen fully support development of A. bipunctata larvae and can be used as an alternative to live aphids in the mass rearing of the pre‐imaginal stages of the predator. However, reproductive performance of a laboratory population may be better on aphids than on the factitious food.     

Effects of pattern and timing of high temperature exposure on reproduction of the rose grain aphid, Metopolophium dirhodum

Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) is one of the three most important cereal aphid species in Germany and central European countries. High temperature is known to play a detrimental role in the reproduction and survival of aphids. Detailed experiments were conducted to assess the effects of high temperatures (27, 29, 31, and 33 °C), exposure pattern (8 h day^?1 for 1, 2, 4, and 6 days), and exposure development stage (2nd, 3rd, 4th instar larvae, and adult) on the reproduction and longevity of M. dirhodum. All three factors have a significant influence on the aphids. Increasing the temperature to over 29 °C significantly decreases their lifetime fecundity and longevity. Mature aphids are more sensitive to high temperatures than younger ones. A high temperature pulse to treat aphids older than 3rd instar larvae greatly shortened their longevity and lessened their lifetime fecundity. Lifetime fecundity and longevity was found to be inversely related to exposure pattern. A high temperature pulse lasting longer than 1 week greatly reduced the lifetime fecundity and longevity. The limitation of the data collected from experiments at constant temperatures for aphid forecasting is discussed.     

Functional response and life history parameters of <Emphasis Type="Italic">Apanteles taragamae</Emphasis>, a larval parasitoid of <Emphasis Type="Italic">Maruca vitrata</Emphasis>

The legume pod borer Maruca vitrata Fabricius (Lepidoptera: Crambidae) is a serious pest of cowpea in West-Africa. The parasitoid Apanteles taragamae Viereck (Hymenoptera: Braconidae) that originates from Taiwan is a potential candidate for biological control of M. vitrata. We investigated under laboratory conditions the functional response of the parasitoid by offering each experienced female 10, 20, 30 and 40 larvae of M. vitrata. We studied the influence of different host larval ages on the development, longevity, sex ratio, lifetime fecundity and parasitization rate of the wasp. In a comparative study, we also investigated the life history of A. taragamae and M. vitrata at different temperatures in the range of 20–30°C. The parasitoid successfully parasitized two- and three-day-old host larvae (first and second instars). Younger larvae (one-day-old) were parasitized to a lesser extent, and only males developed in them. Older larvae were not parasitized, partly because of defensive host behaviour. The success of parasitization was positively correlated with the density of two-day-old M. vitrata larvae. Parasitoid developmental time and longevity decreased with increasing temperature. The intrinsic rate of population increase (r _m ) exhibited an optimum curve with a maximum at 24–28°C. For the host M. vitrata, r _m was maximal at temperatures of 26–30°C. The data are discussed in the context of the potential of A. taragamae for biological control of M. vitrata.     

Temperature response of root‐lesion nematode (Pratylenchus thornei) reproduction on wheat cultivars has implications for resistance screening and wheat production

The root‐lesion nematode Pratylenchus thornei is a major pathogen of wheat and other field crops, particularly in the northern grain region of sub‐tropical eastern Australia. Research was conducted into the temperature requirements of P. thornei for reproduction on wheat to increase the reliability of selection in resistance tests for wheat breeding. Final population densities (P_f) of P. thornei were determined on four wheat cultivars (Gatcher, GS50a, Potam and Suneca) at fortnightly intervals from 8 to 18 weeks at a range of six soil temperatures (15°C, 20°C, 22.5°C, 25°C, 27.5°C and 30°C) in a glasshouse experiment. Pratylenchus thornei had the highest P_f in the temperature range of 20–25°C on all wheat cultivars at all growth times after sowing, with no nematode reproduction measured at 30°C and very little at 15°C. The wheat cv. GS50a consistently produced lower P_f than cvs Gatcher, Potam and Suneca in the optimum temperature range of 20–25°C. In carrot disc cultures, P. thornei had an optimum temperature of 25°C with little reproduction at 17.5°C and none detectable at 30°C. A standard soil temperature of 23°C was chosen to maximise differences in nematode reproduction between resistant and susceptible wheat genotypes for selection in wheat breeding, and to improve reproducibility among successive experiments. The relationships derived from these experiments will be valuable for simulation of P. thornei reproduction in crop growth models. They also indicate that early sowing of wheat into cool soil (≤15°C) in farmers' fields of the northern grain region should favour wheat growth over nematode reproduction and increase grain yield.     

Development,survival and reproduction of Orius niger (Hemiptera:Anthocoridae) under different photoperiod and temperature regimes

The successful use of the predatory bug Orius spp. (Hemiptera:Anthocoridae) for the biological control of pests, namely western flower thrips Frankliniella occidentalis (Pergande), in greenhouses during winter depends on overcoming the obstacles of short photoperiods and low temperatures which limit the efficacy of the predators through diapause induction, slowed development, reduced survival and reproduction. Thus, research has focused on determining the insect species least vulnerable to these problems. This study investigated the effect of varying day-lengths (9, 11, 13 and 16 h) at 26°C as well as constant (18, 22, 26 and 30°C) and fluctuating (10/22°C) temperatures on biological characteristics of Orius niger (Wolff). Photoperiod did not induce reproductive diapause and did not significantly affect development, survival of eggs and nymphs, longevity, fecundity or sex ratio; with the exception of the 16 h day-length which led to a shorter duration of nymphal development. Fluctuating temperatures and a constant temperature of 18°C increased the incubation period, duration of nymphal development, total developmental time, generation time and longevity, compared to the constant temperatures of 22, 26 and 30°C, but decreased fecundity compared to 22 and 26°C. On the other hand, sex ratio was not influenced by 10/22 and 18°C. Egg hatch rate and nymph survival differed significantly between temperature regimes, being lower at 18 and 10/22°C. These results suggest that O. niger would be able to survive and reproduce under winter conditions in unheated Mediterranean greenhouses and is a candidate for use in the biological control of pests.     

Effects of host stages and temperature on population parameters of Oomyzus sokolowskii, a larval-pupal parasitoid of Plutella xylostella

Oomyzus sokolowskii is alarval-pupal parasitoid of diamondback moth, Plutella xylostella. In a host stage preference test, the parasitoid parasitised all larval and pupal stages, but exhibited a strong preference for larvaeover prepupae or pupae, and did not show a preference among the larval instars. At 25°C, the developmental time, number and sex ratio of offspring per host pupa, and successful parasitism did not differ significantly among parasitoids reared from host larvae of different instars, indicating similar host suitability between larvae of different instars. Mean developmental times from egg to adult at 20, 22.5, 25, 30, 32.5, and 35°C were 26.5,21.0, 16.0, 12.7, 11.9 and 13.4 days, respectively. The favourable temperature range for development, survival, and reproduction of the parasitoid was 20--30°C. However, wasps that developed and emerged at a favourable temperature could parasitise effectively at 32--35°C for 24 hours. Life-fertility table studies at 20, 25, and 30°C showed that each female wasp on average parasitised 3.1, 13.2, 6.8 larvae of diamondback moth and produced 20.5, 92.1, 50.4 offspring, respectively, during her lifetime. The highest intrinsic rate of natural increase (r _m) of 0.263 female/day was reached at 30°C as a result of the short mean generation time at this temperature compared to that at 20 and 25°C, suggesting that the parasitoid had the highest potential for population growth at relatively high temperatures. This revised version was published online in July 2006 with corrections to the Cover Date.     

Influence of post-treatment temperature, solvents and emulsifiers on the toxicity of cypermethrin to larvae of Spodoptera litura (Fab.)

Larvae of the tobacco caterpillar, Spodoptera litura (Fab.) were topically bioassayed with cypermethrin emulsion formulation and proprietary EC in combination with different solvents and emulsifiers for their toxicity at 16 ± 2°C and 27 ± 1°C. Among different solvents, the descending order of efficacy (with relative toxicity in parenthesis) against 9 ± 1 day old larvae of S. litura (Fab.) at 16 ± 2°C than 27 ± 1°C was: xylene (7.41), aromex (5.54), cyclohexane (4.93), C-IX (3.93), benzene (2.40) and toluene (2.26). With emulsifier, the order was: Triton X-100 (7.41), SN₄S (4.60), Teepol (2.90), Tween-80 (1.49), Swascofix DP-50 (1.28), SN₄R (1.10) and S₅₂B (1.07). However, the proprietary cypermethrin EC was 2.31 times more toxic at 16 ± 2°C than at 27 ± 1°C.     

Effect of temperature on the life history and demographic parameters of Spalgis epius (Lepidoptera: Lycaenidae), a candidate biological control agent of mealybugs (Hemiptera: Pseudococcidae)

Many species of mealybugs (Hemiptera: Pseudococcidae) are serious pests of economically important crops worldwide. We evaluated the influence of constant temperatures: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32 and 34°C on the life history and demographic parameters of Spalgis epius (Lepidoptera: Lycaenidae), a candidate biological control agent of various species of mealybugs. No eggs completed their development at 14 and 34°C. Egg-to-adult developmental time significantly decreased from 89.9 days at 16°C to 20.4 days at 32°C. The estimated lower temperature threshold of 10.2°C and 416.6 degree-days were required to complete egg-to-adult development. The mortality of immature stages was maximum at 16 and 32°C and minimum at 28°C. The highest lifetime fecundity was recorded at 28°C and it significantly decreased at 32°C. The longevity of adults was about three times more at 16°C than at 30 and 32°C. The net reproductive rate (R ₀) significantly increased with increased temperatures up to 28°C and significantly decreased at 32°C. The mean generation time (T) significantly decreased with increased temperature up to 30°C, but it significantly increased at 32°C. The intrinsic rate of population increase (r _m ) was highest at 30°C. The finite rate of increase (λ) was significantly greater at 30°C than at other temperatures. These data suggest that S. epius can develop, reproduce and survive in a wide range of temperatures and thus could be regarded a potential biological control agent of mealybugs.     

Effect of Temperature on Development and Reproduction of <Emphasis Type="Italic">Epilachna dodecastigma</Emphasis> (Wied.) (Coleoptera: Coccinellidae)

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).     

Life tables and development of <Emphasis Type="Italic">Amblyseius swirskii</Emphasis> (Acari: Phytoseiidae) at different temperatures

Development time, reproduction, survival and sex ratio were determined for the omnivorous mite Amblyseius swirskii at nine constant temperatures (13, 15, 18, 20, 25, 30, 32, 34 and 36°C) on pepper leaf disks with cattail, Typha latifolia, pollen for food. These data were used to derive life table parameters at these constant temperatures. No development was observed at 13°C. The lower development threshold, based on the fit to the linear portion of the development curve, was 11.3°C. The upper development threshold was 37.4 ± 1.12°C, and the optimum temperature was calculated to be 31.5°C. Average lifetime fecundity ranged from a low of 1.3 ± 0.24 eggs/female at 15°C to a high of 16.1 ± 0.34 eggs/female at 25°C, and r _m was greatest at 32°C. Non-linear regression of the relationship between temperature and r _m produced an estimate of 15.49 ± 0.905°C for the lower threshold for population growth and 36.99 ± 0.816°C for the upper threshold for population growth, and an optimum temperature of 30.1°C. These values suggest that A. swiskii populations should grow quickly in response to food availability (pollen or prey) between 20 and 32°C, but that, especially below 20°C, population growth could be slow and impacts on prey populations should be monitored carefully.     

Recurrent warming to improve cold storage of Trichogrammatids (Hymenoptera: Trichogrammatidae)

Cold storage can be used to slow development, facilitate accumulation of the organisms and accommodate fluctuating demand for augmentative biological control agents. Previous research suggested the possibility of improving cold storage of Trichogrammatids by recurrent warming, so we subjected Trichogramma ostriniae juveniles within Ephestia kuehniella host eggs to either 2°C constant or to 2°C with twice-weekly recurrent warming for 3 h to 20°C. Parasitoid subsamples were allowed to mature for 1–9 days before placement in cold storage for up to 8 weeks. Parasitism by parentals, progeny emergence and fecundity and longevity of progeny were measured weekly for 8 weeks. Relative to constant 2°C, recurrent warming generally improved emergence, fecundity and longevity, and all the response variables were affected by the interaction of temperature regimen, parasitoid maturity class, and cold storage duration. This implies the utility of recurrent warming to improve egg parasitoid performance and for extending the duration of cold storage.     

Effect of ellagic acid on the larvae of Spodoptera litura (Lepidoptera:Noctuidae) and its parasitoid Bracon hebetor (Hymenoptera:Braconidae)

The present study was aimed at investigating the effect of plant based compound, ellagic acid on parasitoid Bracon hebetor (Say) through its host, the common cutworm, Spodoptera litura (Fabricius). The effect on S. litura was ascertained by feeding six days old larvae on artificial diet incorporated with different concentrations (5 ppm, 25 ppm, 125 ppm, 625 ppm, 3125 ppm) of ellagic acid and water as control. Its effect on B. hebetor was determined by allowing the adult B. hebetor to parasitize the treated host larvae. The mortality of S. litura larvae was increased whereas adult emergence declined with increasing concentration of ellagic acid. The developmental period was delayed significantly and all the nutritional indices were reduced with treatment. Ellagic acid at LC₃₀ (7.70 ppm) had not much influence on the growth of parasitoid B. hebetor but LC₅₀ (43.45 ppm) adversely influenced the development of the parasitoid, B. hebetor when reared on treated larvae of S. litura. This was evident from reduced parasitization, fecundity, egg laying, egg hatching, emergence, increased larval mortality, reduced pupation and prolonged development of the immature stages at LC₅₀. However, parasitization, egg hatching and larval mortality of the parasitoid were not significantly impacted at LC₃₀ indicating the possibility of its use in integrated pest management programmes.