Maximum Parasitism Research Articles

Population Fluctuations of Plassey Borer, Chilo tumidicostalis Hampson and its Parasitoid, Cotesia flavipes Cameron in Sugarcane Crop in Assam

Seasonal incidence of Plassey borer, Chilo tumidicostalis Hampson, and its larval parasitoid, Cotesia flavipes Cameron, was studied at Shillogani, Nagaon, Assam, during 2006-07. Population of C. tumidicostalis first appeared in the early part of May and peaked in the second fortnight of September in both the cropping seasons. Later it showed a declining trend till harvest. The activity of C. flavipes commenced from the first fortnight of June in both the cropping seasons and continued till the end of November, 2006 and early part of December, 2007. The extent of natural parasitism by C. flavipes varied from 2.10 to 39.43 per cent in 2006 and 1.33 to 48.30 per cent in 2007. Maximum parasitism (39.43 and 48.30 per cent) occurred during the first fortnight of October, 2006 and the second fortnight of September, 2007 in the two study years. The parasitism increased with the increase in incidence of C. tumidicostalis larvae and fairly synchronized with the latter's maximum incidence. The extent of parasitism had significant positive correlations with the incidence of host larval population and relative humidity, but showed non-significant correlations with temperature, total rainfall and sunshine in both the cropping seasons.

Influence of Parasitoid-Host Density on the Behaviour Ecology of Goniozus nephantidis (Muesebeck) (Hymenoptera: Bethylidae), a Parasitoid of Opisina arenosella Walker

Since Goniozus nephantidis (Muesebeck) is found to have strong parental care for its progeny, the influence of different densities of G. nephantidis and its host, Corcyra cephalonica (Stainton) on the behaviour ecology of the parasitoid was studied. Interaction between different densities of the host and parasitoid revealed that a ratio of 1:1 was significantly superior to all other ratios resulting in maximum parasitism (9.0 larvae / female), fecundity (93.2/female) and number of progenies (75.2/female). Exposing more than one C. cephalonica larva did not significantly increase the parasitizing efficiency, fecundity and progeny produced. Conversely, exposing a single C. cephalonica larva to several female parasitoids adversely affected the biological attributes of the parasitoid. Increasing the densities of either host insects or parasitoids had an inverse relationship with oviposition behaviour, parasitism efficiency and progeny production of the parasitoid establishing the important and significant role played by host-parasitoid density.

Influence of Parasitoid-Host Density on the Behaviour Ecology of Goniozus nephantidis (Muesebeck) (Hymenoptera: Bethylidae), a Parasitoid of Opisina arenosella Walker

Since Goniozus nephantidis (Muesebeck) is found to have strong parental care for its progeny, the influence of different densities of G. nephantidis and its host, Corcyra cephalonica (Stainton) on the behaviour ecology of the parasitoid was studied. Interaction between different densities of the host and parasitoid revealed that a ratio of 1:1 was significantly superior to all other ratios resulting in maximum parasitism (9.0 larvae / female), fecundity (93.2/female) and number of progenies (75.2/female). Exposing more than one C. cephalonica larva did not significantly increase the parasitizing efficiency, fecundity and progeny produced. Conversely, exposing a single C. cephalonica larva to several female parasitoids adversely affected the biological attributes of the parasitoid. Increasing the densities of either host insects or parasitoids had an inverse relationship with oviposition behaviour, parasitism efficiency and progeny production of the parasitoid establishing the important and significant role played by host-parasitoid density.

Potentiality of Plastanoxus westwoodi (Kieffer) (Hymenoptera: Bethylidae) against Flat Grain Beetle, Cryptolestes pusillus (Schoenherr) (Coleoptera: Cucujidae)

Plastanoxus westwoodi (Kieffer), an ectoparasitoid of the larvae and pupae of flat grain beetle, Cryptolestes pusillus (Schoenherr), was evaluated experimentally by infesting 625g kibbled wheat in a plastic container with 100 pairs of the beetles and at 35 days after introducing 0, 5, 10, 20, 30, 40 and 50 mated females of the parasitoids. Samples taken 180 days after the parasitoid was introduced showed P. westwoodi had reduced the population growth of the beetle by at least 43.08% even when only 5 mated females were introduced and by 81.31% when 50 mated females were introduced. The pest emergence was very high in the control container. Minimum pest emergence and maximum parasitism were achieved by introducing 50 mated females per container.

Assessment of the tachinid Sturmiopsis inferens as a natural and applied biological control agent of sugarcane shoot borer (Chilo infuscatellus) in southern India

In field studies during 2000–2005, seasonal dynamics of sugarcane shoot borer Chilo infuscatellus Snellen (Lepidoptera: Crambidae) and its parasitoid Sturmiopsis inferens Tns. (Diptera: Tachinidae) were examined and augmentative releases of the parasitoid against the borer were evaluated at Coimbatore, India. The borer was active throughout the study period with the overall range of 0.3–28.6% fortnightly deadheart incidence. With considerable year-to-year variation, the borer peaked during July–August in high incidence years but showed indistinct peak activity periods in low attack years. Sturmiopsis inferens was found in all the study years with zero activity in some fortnights and overall maximum parasitism rates of 23.3 and 21.0% in 2000 and 2001, respectively; parasitoid activity dropped drastically in 2002 and the decline continued thereafter. The high parasitism years witnessed distinct peak activity in March and somewhat higher activity in July–August. Simple and multiple correlation analyses showed inconsistent influence of weather parameters on borer and parasitoid activity. Shoot borer activity was weakly related to St. inferens activity either in individual years or in the entire five-year period. Augmentative releases of St. inferens gravid females at dosages of 25–95 females/ha enhanced parasitism rates and reduced borer incidence in some trials but produced variable effects in some other trials. Dosage of parasitoid was not related to post-release parasitism rates in release plots. The results of the field trials and their implications are discussed.

Seasonal parasitism of Riptortus clavatus Thunberg (Heteroptera: Alydidae) by Dionaea magnifrons (Herting) (Diptera: Tachinidae)

Seasonal parasitism of adult Riptortus clavatus (Thunberg) (Heteroptera: Alydidae) by the tachinid fly parasitoid, Dionaea magnifrons (Herting), was monitored at three sites in Korea, 2006 by using the aggregation pheromone traps of R. clavatus. Basic developmental characteristics of the parasitoid were also examined. Annual parasitism of R. clavatus female and male adults was 6.8 and 11.6%, respectively. Parasitism of females and males of the over-wintering (Oct. to Jun.) generation (10.6 and 16.5%, respectively) was higher than the summer (Jul. to Sep.) generation (2.1 and 2.5%). Maximum parasitism for males was recorded during spring or autumn, reaching 35.6, 25.0, and 26.9% at the university campus, and pear and sweet persimmon orchards, respectively. Sex ratio of all the D. magnifrons was slightly male-dominated (62.2%). The pupal period of D. magnifrons was 9.2 days for both sexes in room temperature conditions. D. magnifrons larvae escaped from R. clavatus in 8.0 ± 3.4 days after host bug collection from the field during April to September, whereas in October and November they emerged in 15.1 ± 3.8 days. This parasitoid fly should be studied further to determine its effectiveness as a biological control agent complementary to existing strategies in the management of bean bug.

HOST AND NON-HOST PLANT VOLATILES ON OVIPOSITION AND ORIENTATION BEHAVIOUR OF TRICHOGRAMMA CHILONIS ISHII.

ABSTRACT In the process of host location and selection several cues associated with host’s play a major role. Volatile compounds emitted by plants as a consequence of herbivore activities are often attractive to insect natural enemies including the Hymenopteran egg parasitoids, Trichogramma species. We studied the plant - parasitoid interactions where the plant surface chemicals act as infochemicals that attract or arrest the parasitoids for egg parasitization and strategically help in preventing the pest infestation. The leaf surface chemicals of R. communis, damaged due to the feeding of the host, Achaea janata (L) (castor semilooper) (Lepidoptera: Noctuiidae), and a non – host, Serpentine leaf miner Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) were evaluated for their influence on host location, host acceptance and ovipositional behavior against the egg parasitoid, T. chilonis in laboratory bioassays. The A. janata damaged leaf emissions had synomonal effects on the parasitoid and induced orientation and oviposition, whereas, the surface chemicals from the plant infested with non-host L. trifolii ceased to produce any such effects. The maximum egg parasitization was observed in A. janata infested castor leaf extracts compared to the leaf miner infested or normal healthy castor leaf extracts. The results are interesting in the context of tritrophic interactions between the pest, parasite and the host plant and are useful in biological control of insect pests.

Parasitism and Development of <I>Conura acuta</I> (Hymenoptera: Chalcididae) on Sugarcane Stalkborers (Lepidoptera: Crambidae) in Mexico

Abstract A 10-yr study was conducted in the Los Mochis sugarcane area in western Mexico to determine rates of parasitism by Conura acuta (F.), an indigenous pupal parasitoid of the stalkborers Diatraea considerata Heinrich and D. grandiosella Dyar. Parasitism by C. acuta was practically zero in 1993, progressively increased soon after chemical insecticide applications were discontinued in the sugarcane area, peaked at a yearly average of 3.2% in 1997, and stabilized thereafter at 2–3%, except in 2000 and 2002, probably because of drought. Seasonal parasitism by C. acuta was density-dependent, with maximum parasitism occurring during summer, when hosts were more abundant. Maximum parasitism by C. acuta occurred during mid-September 1996 with 43.3%. Although parasitism by C. acuta was generally low throughout the study, its impact may be important in terms of indispensable mortality, late in the life history of stalkborers. No field parasitism by C. acuta was observed on Eoreuma loftini (Dyar), a concurrent...

Parasitism and Development ofConura acuta(Hymenoptera: Chalcididae) on Sugarcane Stalkborers (Lepidoptera: Crambidae) in Mexico

A 10-yr study was conducted in the Los Mochis sugarcane area in western Mexico to determine rates of parasitism by Conura acuta (F.), an indigenous pupal parasitoid of the stalkborers Diatraea considerata Heinrich and D. grandiosella Dyar. Parasitism by C. acuta was practically zero in 1993, progressively increased soon after chemical insecticide applications were discontinued in the sugarcane area, peaked at a yearly average of 3.2% in 1997, and stabilized thereafter at 2–3%, except in 2000 and 2002, probably because of drought. Seasonal parasitism by C. acuta was density-dependent, with maximum parasitism occurring during summer, when hosts were more abundant. Maximum parasitism by C. acuta occurred during mid-September 1996 with 43.3%. Although parasitism by C. acuta was generally low throughout the study, its impact may be important in terms of indispensable mortality, late in the life history of stalkborers. No field parasitism by C. acuta was observed on Eoreuma loftini (Dyar), a concurrent sugarcane stalkborer in this area. In the laboratory, the most preferred hosts by C. acuta were D. grandiosella and D. considerata with 60% parasitism, whereas E. loftini, D. saccharalis (F.), and Spodoptera frugiperda (J. E. Smith) were poorly accepted (<5%). Parasitism was highest in the youngest pupae (1 d old) and decreased progressively with host age. Late-instar larvae and prepupae were not accepted, showing that C. acuta is a true pupal parasitoid (idiobiont). Attraction and parasitism by C. acuta were higher when pupae were exposed with larval frass compared with clean pupae, suggesting the presence of a kairomone in the process of host finding and acceptance. Developmental time of C. acuta was 10 d longer on D. considerata than on D. grandiosella, with no difference between parasitoid sexes within hosts. In contrast, C. acuta longevity did not differ after emerging from either host species, with females living >20 d longer than males. Opportunities for using C. acuta, the only known pupal parasitoid of sugarcane stalkborers in Mexico, as a biological control agent are discussed.

Importation, colonization and establishment of Coccophagus cowperi Gir. (Hymenoptera: Aphelinidae) on Saissetia coffeae (Walk.)(Homoptera: Coccidae) in Egypt

The hemispherical soft scale, Saissetia coffeae (Walker) (Homoptera: Coccidae), is one of the most important pests attacking olive trees in Egypt. During the period 2001–2003, a total of about 300,000 individuals of the parasitoid Coccophagus cowperi Girault (Hymenoptera: Aphelinidae), obtained from India, was released at 35 sites for the biological control of S.coffeae on olive trees in Egypt. The maximum parasitism rates reached 53 and 62%, while average parasitism rates were 17.2 and 30.8% in the Marsy Mattrouh and El-Arish locations, respectively. These results indicate establishment of this parasitoid on this important economic plant in Egypt.

Effects of variation among plant species on the interaction between a herbivore and its parasitoid

Abstract. 1. Previous studies have demonstrated that phenotypic traits of plants have the potential to affect interactions between herbivores and their natural enemies. Consequently, the impact of natural enemies on herbivore vital rates and population dynamics may vary among plant species. This study was designed to investigate the potential for density‐dependent parasitism of an aphid herbivore feeding on six different host plant species.2. Population densities of the aphid Aphis nerii B de F (Homoptera: Aphididae) and its parasitoid Lysiphlebus testaceipes Cresson (Hymenoptera: Braconidae) were recorded within a single growing season on six different species of milkweed in the genus Asclepias L. (Asclepiadaceae). Asclepias species are known to vary in their quality as food for herbivores. Although data on plant quality were not available in this study, population data were analysed to determine the effects of different Asclepias species on rates of parasitism and aphid population growth.3. Parasitism rates of A. nerii varied among Asclepias species but were temporally density dependent over at least some range of aphid density on all plant species. Aphid population growth rates also varied among Asclepias species, and declined with an increase in the maximum parasitism rates among plant species; however, in no case was density‐dependent parasitism sufficient to prevent exponential population growth of aphids within the growing season. The results serve to emphasise that, if natural enemies are to regulate herbivore populations, density‐dependent mortality is a necessary, but not sufficient, condition for regulation.

Kairomonal effect of some saturated hydrocarbons on the egg parasitoids, Trichogramma brasiliensis (Ashmead) and Trichogramma exiguum, Pinto, Platner and Oatman (Hym., Trichogrammatidae)

Abstract: Bioassay studies carried out on the egg parasitoids Trichogramma brasiliensis and T. exiguum with 11 straight chain‐saturated hydrocarbons, revealed that pentacosane and hexacosane recorded very high parasitoid activity index (PAI) and parasitism for both the parasitoids indicating high kairomonal activity. These were followed by docosane, tricosane, heneicosane, hexatriacontane and tetracosane, which may be grouped as favourable hydrocarbons showing varying levels of kairomonal activity for T. brasiliensis, as compared to eicosane, pentadecane, octacosane and heptadecane, which can be grouped as non‐favourable hydrocarbons. In the case of T. exiguum, pentacosane‐treated egg cards showed maximum parasitism followed by hexacosane, pentadecane, hexatriacontane, tricosane and docosane thereby indicating their kairomonal activity in comparison with heptadecane, tetracosane, eicosane, heneiocosane and octacosane which recorded low levels of parasitism. In the case of T. brasiliesnsis, tetracosane recorded the highest response at the lowest concentration, C1 (62.5 ng/cm2), which decreased as the concentration increased. Eicosane, heneicosane and docosane recorded the highest parasitism at C2 (125 ng/cm2). In heptadecane, tricosane, pentacosane and hexatriacontane the highest parasitism was recorded at the medium concentration, C3 (250 ng/cm2). Octacosane recorded the highest response at C4 (375 ng/cm2). Pentadecane and hexacosane‐treated egg cards showed their highest response at C5 (500 ng/cm2). In the case of T. exiguum, the lowest concentration, C1 evoked the highest response in hexacosane, whereas heptacosane, heneiocosane, docosane and tetracosane recorded the highest parasitism at C2. Eicosane, pentacosane and octacosane recorded maximum parasitism, at C3, whereas tricosane and hexatriacontane showed maximum parasitism at C4 and pentadecane at C5. These concentrations can be taken as the optimum concentration to increase parasitization by these parasitoids. The favourable hydrocarbons at their optimum concentration can be used for efficient management of these parasitoids in field releases.

THE ROLE OF COCCOPHAGUS SCUTELLARIS (HYMENOPTERA: APHELINIDAE) IN THE BIOLOGICAL CONTROL OF SOFT SCALE INSECTS (HOMOPTERA: COCCIDAE) IN EGYPT

Abstract Coccophagus scutellaris (Dalman) is one of the specific parasitoids that attack soft scale insects in Egypt. In the present study, C. scutellaris was reared from 6 species of soft scale insects. These are Ceroplastes flori‐densis Comstock, Coccus hesperidum L., Pulvinaria floccgera (Westwood), P. psidii Maskell, Saissetia coffeae (Walker) and S. oleae (Oliver). The abundance of C. scutellaris was monitored from July to Nov. 1999–2000 in five localities in Egypt, the Beni‐Suef, Cairo, Giza, Gharbiya and the Northern coast. C. scutellaris is considered an effective parasitoid of S. coffeae and S. oleae with maximum parasitism rates reaching 26% and 22% in Nov. and Aug. 1999, respectively.

Pathogenicity of Selected Antagonistic Soil Fungi on Meloidogyne incognita (Kofoid & White) Eggs and Egg Masses under in Vitro and in Vivo Conditions

Four indigenous antagonistic fungi belonging to 3 species, Gliocladium virens Miller Giddens & Foster, Paecilomyces lilacinus (Thon) Samson, Trichoderina harzianum Rifai and T. viride Pers. Ex S. F. Gray evaluated for their pathogenicity to eggs and egg masses of Meloidogyne incognita , in vitro through the Petri-dish assay and in vivo under glasshouse conditions were found pathogenic. Under both the conditions, maximum egg mass and egg parasitization was observed to be by P. lilacinus followed by T. viride , G. virens and T. harizianum . There was a general decline in parasitization by these fungi, under in vivo conditions compared to that under in vitro conditions. Fungal colonization in galled roots was higher than in healthy roots. Comparatively T. viride and G. virens recorded higher root colonization closely followed by P. lilacinus . Among the four fungi , P. lilacinus recorded consistently higher pathogenicity against root-knot nematodes both in vitro and in vivo conditions, indicating that P. lilacinus was more efficient against root-knot nematodes compared to other species.

Host searching capacity of laboratory reared and field collected populations of Trichogramma chilonis Ishii.

In cotton field Trichogramma chilonis could disperse as far as 9 metres to search its host, but the maximum parasitization was observed up to 2 metres. The performance of the Muktsar population was better than all other populations. The laboratory reared population was significantly inferior to all field collected populations.

Biological Suppression of Potato Tubermoth, Phthorimaea operculella (Zeller) with Exotic Parasitoids and Microbial Agents under Field and Storage Conditions

Investigations on bioefficacy of parasitoids and microbial agents against potato tubermoth (PTM), Phthorimaea operculella (Zeller) (Lepidoptcra: Gelechiidae) were carried out under field and storage conditions of potato during 1996-1997. The results showed that three sprays of endosulfan 0.05 per cent at 10 days interval proved to be the most effective and on par with four releases of Chelonus blackburni Cameron @ 15000 adults/ha/release at weekly interval, Copidosoma koehleri Blanchard @ 50000 adults/ha/lrelcase and Trichogramma chilonis Ishii @ 50000 adults/ha/releasc at weekly interval, and three sprays of Bacillus Thuringiensis Berliner @ 1 kg/ha at 10 days interval. Amongst the parasitoids, maximum parasitism was recovered through retrieval with C. blackburni (71.78 %), followed bye C. koehleri (69.39%) and T. chilonis (61.33%). Under storage conditions ( Arnies ), initial release of C. blackburni @ 2 adults/kg tubers recorded minimum tuber infestation (7.21 %) after 60 days.

Ecdysteroid and free amino acid content of eggs of the Colorado potato beetle, Leptinotarsa decemlineata.

In order to identify components of the Colorado potato beetle (CPB) egg that may be required by Edovum puttleri, a parasitic wasp that parasitizes the CPB egg, to complete development, ecdysteroid and free amino acid content of CPB eggs were analyzed by reversed phase high pressure liquid chromatography followed by radioimmunoassay to identify ecdysteroids. Ecdysteroid titers were relatively low (<300 pg/egg) through day 2 post-oviposition and then increased sharply, reaching concentrations >2,500 pg/egg on day 3 post-oviposition. Ecdysone (E), 20-hydroxyecdysone (20E), and polar conjugates of E were prominent ecdysteroids present in eggs sampled on days 0 and 1 post-ecdysis, and E, 20E, three peaks containing more polar ecdysteroids (metabolic inactivation products), and polar conjugates of E were present in eggs sampled on day 2. Thus, at a time when parasitization of CPB eggs by E. puttleri is relatively high (0-48 h), physiologically-active ecdysteroids (20E and perhaps E are physiologically active) are present at concentrations between 50 and 200 pg/egg. Ecdysone and 20E reached their highest levels in day-3 eggs, indicating that ecdysteroid may direct physiological processes associated with the completion of CPB embryonic development. In day-4 eggs, the concentration of E and 20E fall dramatically and polar metabolites of E and/or 20E are now responsible for the high ecdysteroid content of the eggs. Interestingly, conjugates of E decrease to relatively low levels in day-3 eggs and are absent in day-4 eggs. Therefore, it is likely that the increase in E in day-3 eggs is due, in part, to the breakdown of polar conjugates of E. Nine amino acids were present in significant quantities in eggs sampled at various times between 0 and 48 h post-oviposition. These include histidine, glutamine, proline, asparagine, serine, glutamic acid, threonine, lysine, and tyrosine. The first three amino acids were present at concentrations that were approximately 2 to 6 times greater than the concentrations of the last six amino acids. Amounts of most of the free amino acids varied with the age of the eggs from which the extract was prepared, but in general, there was no correlation between the levels at times of maximum parasitization (0 and 30 h) and the levels at the less favored times of parasitization (16 and 48 h). This information should facilitate the development of diets for both parasites and predators of pest species of beetles. Arch. Insect Biochem. Physiol. 44:172-182, 2000. Published 2000 Wiley-Liss, Inc.

Age-Dependent Parasitism ofCulicoides variipennis sonorensis(Diptera: Ceratopogonidae) byHeleidomermis magnapapula(Nematoda: Mermithidae) and Considerations for Assessing Parasite Impact

Laboratory and field studies were conducted to determine whether all larval stages ofCulicoides variipennis sonorensisWirth and Jones were susceptible to parasitism byHeleidomermis magnapapulaPoinar and Mullens. All four larval instars (L1–L4) were readily attacked in the laboratory, although parasites took significantly longer to enter older hosts (average of 119 s for L1 to 199 s for L4). Field studies indicated that free-living adult nematodes, and presumably the preparasitic (infective) stages, were distributed above the waterline, where early-stage host larvae (L1 and L2) were most common. Dissection of field-collected hosts over a full host generation showed maximum parasitism was lower in L4 (40%) than in L1 (71%), L2 (64%), and L3 (64%) hosts. Second stage parasites were found only in L1 and L2 hosts. Absence of second stage parasites in L3 and L4 hosts showed that older larvae were seldom attacked in nature. The mature parasites emerge primarily from L4 hosts. Collecting L4 hosts in the field can significantly underestimate parasitism due to emergence ofH. magnapapulafrom L4 hosts prior to sampling or premature host mortality due to parasitism. Dissection of L3 hosts should result in the most accurate parasitism estimates, but these estimates still ignore some parasite-induced mortality in the early host stages.

IMPACT OF Apanteles creatonoti (HYMENOPTERA: BRACONIDAE ON THE POPULATION OF Spilosoma obliqua

Apanteles creatonoti Viereck (Braconidae) is an important larval parasitoid ofSpilosuma obliqua (WIK). The pest mortality due to this parasitoid was 38 per cent in the fields of Maharashtra. In the laboratory (25±1°C temp., 55-60 per cent R.H., 12 h photoperiod) the parasitism reached upto 45.60 per cent. The parasitoid attacks five-day-old host larvae mostly. The optimum host density for maximum parasitism was 50. The progeny production ranged from 57 to 96 (average 84.1) with an average sex ratio (1:1:679. The innate capacity for increase was found to be 0.181 per female per day on the five-day-old hosts and population multiplied to 50.25 times in a mean generation time of 21.64 days.

Biology of an egg parasite of Callosobruchus maculatus (Fab.) (Coleoptera: Bruchidae)

Uscana mukerjii (Mani) (Chalcidoidea, Trichogrammatidae) parasitizes eggs of Callosobruchus maculatus. Mated adult U. mukerjii lived for 5.0 ± 0.8 and 4.7 ± 0.9 days (males and females, respectively) at 27 °C. The female copulated only once, whereas males did so up to 4 times. The maximum parasitization of host eggs took place within the first 24 hours of egg laying and declined thereafter. The parasite completed its development inside the host egg in 7.2 days at 27 °C and 60–63% r.h. and emerged after cutting a circular hole in the chorion of the host egg. Mated and unmated females laid 35.4 ± 1.4 and 36.0 ± 2.2 eggs in their life time of which 27.3 ± 1.8 and 23.2 ± 2.8, hatched respectively. Parasitized host eggs did not hatch and were ultimately destroyed. The degree of parasitization varied with the pulses on which the host eggs were laid. This egg parasite may be useful in controlling the populations of C. maculatus and thus help in reducing the damage caused.