Cent Adult Emergence Research Articles

Effect of storage period on trichocards parasitized by Trichogramma chilonis Ishii under laboratory conditions

The present study aimed to find the suitable storage duration for parasitized trichocards without affecting much the biological parameters of T. chilonis adults such as adult emergence, adult longevity and egg parasitization. The results revealed that biological parameters viz., adult emergence, adult longevity and egg parasitization were inversely proportional to the storage period. Maximum adult emergence (87.63%), female longevity (5.57 days), male longevity (4.53 days) and egg parasitization (85.67%) were observed at 5 days storage period. Further, adult emergence declines to 56.13 per cent when trichocards are stored for 25 days. Whereas, less than 50 per cent egg parasitization in F1 generation was observed when trichocards were stored for 35 days. However, there was no egg parasitization by a female in the F1 generation noticed for 45 and 50 days storage period this might be due to short adult female longevity and lowest adult emergence. Hence, it can be concluded that trichocard could be effectively stored for up to 25 days at low temperatures under refrigerator conditions(4°C temperature and 50-60% relative humidity) by considering at least 50 per cent adult emergence with 4.13 days of female longevity as well as 63.00 per cent egg parasitization during the mass production program. Therefore, effective and right time augmentation of T. chilonis could be achieved under field conditions.

Temperature Tolerance in the Five Field Strains of Trichogramma chilonis from Northern Districts of Tamil Nadu, India

The egg parasitoid, Trichogramma chilonis is a potential egg parasitoid in the agricultural ecosystem, reducing many lepidopteran pest incidences. The laboratory strains of T. chilonis was significantly inferior to the ecotypes collected from fields in their parasitisation potential and tolerance to temperature due to continuous exposure to temperature extremes in the field. Hence, a study was undertaken to evaluate the laboratory reared strain of T. chilonis with that of other ecotypes to identify a temperature tolerant ecotype for use in pest management programme. Five ecotypes of T. chilonis were collected from farmer's fields on sugarcane and citrus using sentinel egg technique by exposing egg cards of Corcyra cephalonica, mass reared on C. cephalonica for three successive generations and tested for their relative tolerance to temperature in comparison with the laboratory population. The emergence percentage of the parasitoid varied with the ecotypes tested and all the field collected ecotypes recorded increased emergence compared to the laboratory population. At 150 C, the emergence was significantly higher in Chitteri ecotype (83.44%) followed by Arungunam and Amirthapuram ecotype (78.65 and 75.57%). The performance of all the ecotypes were best at 200 C and Chitteri ecotype performed significantly better compared to other ecotypes and the laboratory population with an adult emergence of 95.66 per cent. It was followed by Arungunam ecotype (88.65%) at 200 C. While the laboratory population and other ecotypes failed to develop at 350 C, Chitteri and Arungunam ecotypes were able to develop with 9.66 and 7.25 per cent adult emergence from the parasitised eggs.

Pesticide Tolerance in the Five Field Strains of Trichogramma chilonis from Northern Districts of Tamil Nadu, India

The egg parasitoid, Trichogramma chilonis is a potential egg parasitoid in the sugarcane, reducing early shoot borer and internode borer population. The laboratory strains of T. chilonis was significantly inferior to the ecotypes collected from fields in their tolerance to insecticide due to continuous exposure to insecticides in the field. Hence, a study was undertaken to evaluate the laboratory reared strain of T. chilonis with that of other ecotypes to identify a pesticide tolerant ecotype for use in pest management by augmentative release. Five ecotypes of T. chilonis were collected from farmer's fields on sugarcane and citrus using sentinel egg technique by exposing egg cards of Corcyra cephalonica, mass reared on C. cephalonica for three successive generations and tested for their relative tolerance to insecticides in comparison with the laboratory strain. Significantly higher level of parasitisation (50.59, 45.32 and 60.45 %) by Arungunam ecotype was observed on eggs sprayed with Imidacloprid 70 WS, Thiomethoxam 75 SG and Flubendiamide 20% WG respectively before exposing to the parasitoid. The Chitteri ecotype was found next in order of tolerance to the insecticides Imidacloprid 70 WS, Thiomethoxam 75 SG and Flubendiamide 20% WG (45.00, 41.23 and 58.23 % respectively). The adult emergence was not found to be affected much by the insecticides sprayed before parasitisation. Varying degrees of insecticide toxicity against different ecotypes of T. chilonis inside host eggs was observed and Arungunam ecotype showed more tolerance to the insecticides tested with,71.28, 53.46 and 81.67 per cent adult emergence respectively from parasitised eggs sprayed with Imidacloprid 70 WS, Thiomethoxam 75 SG and Flubendiamide 20% WG. Among the insecticide tested, Flubendiamide was least toxic to the parasitoid developing with in the host egg and Thiomethoxam was found to be more toxic with nearly 50 per cent reduction in the adult emergence.

Effect of Cold Storage of Trichocard on Adult Emergence and Parasitization of Trichogramma chilonis

The present study was carried out to identify the ideal temperature for proper storage of trichocards prepared from host egg Corcyra cephalonica parasitized by T. chilonis (Ishii). The effect of differential temperature on adult emergence of T. chilonis and parasitization on stored Corcyra eggs was assessed. Parasitized trichocards as well as non-irradiated eggs of C. cephalonica were maintained at 4±1°C, 8±1°C, 10±1°C and 12±1°C. The trichocards maintained at 10±1°C for 15 days resulted in highest per cent adult emergence of 73 percent which declined to 57.5 percent by 35 days of storage. By 45 days of storage, the temperatures of 4±1°C and 8±1°C recorded the highest adult emergence of 50.50 and 51.80 per cent respectively. Highest efficiency of parasitization (92.3%) was achieved by the parasitoids emerged from trichocards maintained at 4±1°C which significantly decreased with increase in temperature and duration of storage. Influence of storage of C. cephalonica eggs was observed to be significant with highest per cent parasitization on Corcyra eggs stored at 4±1 for 15 days which declined thereafter. The temperatures of 4±1°C and 10±1°C were found conducive for storage of parasitoid trichocard and eggs of C. cephalonica.

Host Plant Resistance and Analysis of Chemical Compounds Responsible for Bruchid Resistance in Greengram Vigna radiata (L.) Wilczek

Background: Greengram Vigna radiata (L.) Wilczek, is an important legume crop that serves as a low-cost source of protein. The bruchid (Callosobruchus spp.) is a serious storage pest affecting greengram and other pulse crops. Thus, a study was designed to investigate bruchid resistance (Callosobruchus chinensis) in inter sub-specific derived lines of greengram and to identify chemical compounds responsible for resistance. Methods: The experimental material comprised of 200 inter sub-specific derived lines of F9 generation of VBN (Gg) 2 (susceptible to bruchid) × Vigna radiata var. sublobata/2 (resistant to bruchid) and a susceptible check variety. The bruchid screening experiment was carried out in completely randomized design and replicated twice with 50 seeds in each replication by adopting no choice test. Out of 200 lines evaluated for bruchid screening, seed damage due to bruchid was less than 20 per cent in 11 lines, identified as resistant. However, three resistant lines viz., GGISC 124, GGISC 140 and GGISC 150 were taken for further confirmation for bruchid resistance and GC-MS analysis to discover the chemical compounds conferring resistance (Clarus SQ 8C, Perkin Elmer). Result: In confirmation screening, seed damage due to bruchid (Callosobruchus chinensis) on 30th day was less than 20 per cent in three inter sub-specific lines viz., GGISC 124, GGISC 150 (17.00%) and GGISC 140 (18.00%), whereas the susceptible check [VBN (Gg) 2] reached 100 per cent adult emergence. The three inter sub-specific lines recorded susceptibility index of 0.046 (GGISC 124), 0.047 (GGISC 140) and 0.048 (GGISC 150) and classified as resistant. The susceptible check [VBN (Gg) 2] recorded the susceptibility index of 0.085. GC-MS study was carried out in resistant lines GGISC 124, GGISC 140, GGISC 150 and susceptible check VBN (Gg) 2. The results revealed that the existence of three compounds viz., 9,12-octadecadienoic acid, methyl ester; Hexadecanoic acid, 1-(hydroxymethyl)-1, 2-ethanediyl ester and Hexadecanoic acid, 2-oxiranyl methyl ester in resistant lines conferred resistance against C. chinensis in greengram.

Gas Chromatography-Mass Spectrometry (GC-MS) based Metabolomics of Promising Chickpea Genotypes against Callosobruchus chinensis (L.)

Background: The pulse beetle, Callosobruchus chinensis L. is one of the main biotic threats to chickpea in both field and storage in the world. The evaluation of chickpea genotypes for pulse beetle resistance has increased motivation for the identification and application of host plant resistance as a critical component of pest management. Methods: In the present study, different chickpea genotypes were evaluated under laboratory conditions to identify the antixenosis, antibiosis and GC-MS based untargeted metabolomics of promising chickpea genotypes to the C. chinensis. Result: Genotype NBeG1004 (36.61 eggs/100 seeds) was less prone to egg laying, while ICCV14872 (180.45 eggs/100 seeds) was the most preferred. However, maximal developmental periods, minimum per cent adult emergence and growth index was observed in ICCV92944 Genotype HC1 showed substantial resistance with maximum phenolic, flavonoid and protease inhibitors content. The results revealed that presence of 9-Octadecenoic acid (Z) in HC1 conferred resistance to C. chinensis. These results show assurance for incorporation into an IPM program against C. chinensis.

Screening the seeds of different chickpea genotypes against pulse beetle C. chinensis L. in laboratory condition.

This study was conducted to evaluate the resistance/ tolerance of 15 chickpea cultivars viz., BDNG 797, VIKRAM, BDNG 804, BDNG 801, PG 805-17-5, AKG 1303 JAKI 9218, BDNG 2010-1, PG 13107, AKG 1109, SAKI 9516, PG 0819-43, AKG 1401, ICCV 3137 and ICCV 86111 against pulse beetle. Chickpea genotypes/ varieties viz. ICCV 86111, AKG 1303, PG 805-17-5, BDNG 801 and Vikram were found least preferred against C. chinensis in which lowest numbers of eggs laid by pulse beetle, least adult emergence, developmental periods and seed infestation and weight loss. Based on ovipositional preference, significantly lowest number of eggs (16.67 eggs / 100 seeds) were laid on variety ICCV - 86111 which was found at par with the genotypes AKG – 1303 (17.00 eggs / 100 seeds) followed by PG-805-17-5 (17.33eggs/100seeds) and Vikram (18.33 eggs/ 100 seeds). The significantly highest per cent adult emergence was recorded in ICCV-3137 (82.33 per cent) followed by Jaki -9218 (81.00 per cent), Saki -9516 (80.00%), PG 13107 (78.33 per cent), AKG 1401 (76.67 per cent), BDNG 804 (76.67 per cent) and BDNG 2010-1 (76.67 per cent) which was found at par with each other. On an average the shortest beetle completed its developmental period was found significantly 27.50 days in ICCV 86111 which was at par with PG-805-17-5 (27.51 days) followed by AKG-1303 (27.65days), Vikram (28.09 days) and BDNG 797 (28.76 days), respectively. The variety ICCV 3137, SAKI 9516 and BDNG 804 was most susceptible on the basis of above parameter.

Biology of Spodoptera litura (Fabricius) on different crop plants

Biology of Spodoptera litura (Fabricius) was carried out on different crop plants, viz., tomato, cabbage, cauliflower and black gram. The total life cycle on cabbage, cauliflower, tomato and black gram was 33.95, 35.23, 37.60 and 43.14 days respectively. Spodoptera litura (Fabricius) completed its life cycle within a shorter period and consumed more food on cabbage as compared to other host plants. The sex ratio on cabbage, cauliflower, tomato and black gram was 1: 2, 1: 1.6, 1: 1.6 and 1: 1.3 respectively. The incubation period of the eggs on cabbage and cauliflower was 3 days. The percent viability of eggs was highest on cabbage (92%). The shortest larval period (22.4 days) and least pupal duration (4.8 days) was also recorded on cabbage, while longest pupal period (9.6 days) was found on black gram. The weight of larva and pupa on cabbage was 1064.4 mg and 387 mg respectively and per cent adult emergence was highest on cabbage (90%).

Studies on the antibiosis mechanism of resistance in different rice accessions against yellow stem borer, Scirpophaga incertulas (Walker)

The effect of antibiosis on survival and growth of yellow stem borer, Scirpophaga incertulas feeding on different rice accession was studied to identify the rice donors. Among the 16 accessions, developmental characteristics viz., minimum per cent larval entry, per cent larval survival, larval weight, per cent pupal survival, pupal weight, per cent adult emergence, adult weights and maximum larval and pupal period were observed in TKM 6, IR 20, IET 23715 and IET 23710 and vice versa in TN1, IET 23673 and IET 23681.

Effect of different insecticides on adult emergence of Trichogramma chilonis (Ishii)

The present investigations were undertaken on laboratory studies of Trichogramma chilonis (Ishii) during the year 2013-2014 in the Bio-control laboratory, Department of Agricultural Entomology, College of Agriculture, Dapoli (Maharashtra).The results of effect of different insecticides on adult emergence of T. chilonis revealed that insecticides viz., oxydemeton methyl can be safely used in the field after release of T. chilonis . However, insecticides viz., cypermethrin, dimethoate, indoxacarb and emamectin benzoate can be wisely used in the field 4-5 days after release of T. chilonis , while malathion and dichlorvos should strictly be retrained from their use as they reduce the per cent adult emergence.

Biology of <I>Cryptolaemus montrouzieri</I> (Mulsant) on <I>Maconellicoccus hirsutus</I> (Green) at different temperature levels

Laboratory experiments were conducted on the biology of C. montrouzieri at different temperature levels viz. , 20°C, 25°C, 30°C and 35°C at the Department of Agricultural Entomology, College of Agriculture. Later during 2014-2015. The incubation period, mean larval duration, growth index, pupal duration and per cent adult emergence of C. montrouzieri was observed to be 14.89, 5.89, 4.20 and 2.17 days, 83.81, 27.8, 24.38 and 11.45 days, 0.39, 3.23, 2.53 and 5.31, 26.25, 8.76, 6.94 and 4.20 days and 92.00, 94.97, 88.00 and 69.34 per cent at 20°C, 25°C, 30°C and 35°C respectively. Longevity of male and female beetles of C. montrouzieri was found to be 87.00 and 96.01 days, 65.61 and 80.78 days, 36.80 and 48.31 days and 24.91 and 35.05 days at 20°C, 25°C, 30°C and 35°C respectively, while the Pre-oviposition and oviposition period of C. montrouzieri to the tune 29.00, 15.20, 13.40 and 9.8 days and 30.80, 32.30, 28.00 and 19.60 days at 20°C, 25°C, 30°C and 35°C temperature respectively.

Biology of <I>Cryptolaemus montrouzieri</I> (Mulsant) on <I>Maconellicoccus hirsutus</I> (Green) at different temperature levels

Laboratory experiments were conducted on the biology of <em>C. montrouzieri</em> at different temperature levels <em>viz.</em>, 20°C, 25°C, 30°C and 35°C at the Department of Agricultural Entomology, College of Agriculture. Later during 2014-2015. The incubation period, mean larval duration, growth index, pupal duration and per cent adult emergence of <em>C. montrouzieri</em> was observed to be 14.89, 5.89, 4.20 and 2.17 days, 83.81, 27.8, 24.38 and 11.45 days, 0.39, 3.23, 2.53 and 5.31, 26.25, 8.76, 6.94 and 4.20 days and 92.00, 94.97, 88.00 and 69.34 per cent at 20°C, 25°C, 30°C and 35°C respectively. Longevity of male and female beetles of <em>C. montrouzieri</em> was found to be 87.00 and 96.01 days, 65.61 and 80.78 days, 36.80 and 48.31 days and 24.91 and 35.05 days at 20°C, 25°C, 30°C and 35°C respectively, while the Pre-oviposition and oviposition period of <em>C. montrouzieri</em> to the tune 29.00, 15.20, 13.40 and 9.8 days and 30.80, 32.30, 28.00 and 19.60 days at 20°C, 25°C, 30°C and 35°C temperature respectively.

Biosafety of Nanoemulsion of Hexanal to Honey Bees and Natural Enemies

One of the main drawbacks of mango is its post harvest losses. Hexanal, a volatile plant component inhibits Phospholipase D (PLD), the key enzyme involved in the initiation of plasma membrane deterioration to induce the ripening of fruits. Nanoemulsion of hexanal would be more effective than the conventional form of treatment owing to its smaller droplet size. Studies were conducted to develop nanoemulsion of hexanal and its biosafety to pollinators and natural enemies in mango ecosystem. Combination of hexanal, Tween 20, ethanol at 1:10:10, was found to have good emulsion. The average droplet size was 9.9 nm with the zeta potential of -20.0 mV. This combination was used for the biosafety studies on honey bees Apis cerana indica F., egg parasitoid Trichogramma chilonis Ishii and predator Chrysoperla carnea Stephens. Nanoemulsion of hexanal on honey bees and exposure of bees to hexanal treated mango varieties had no adverse effect on honey bees (0% mortality). Nanoemulsion at recommended field dose (0.04%) showed 96.53% parasitization and 96.61 per cent adult emergence of the egg parasitoid and recorded 85.05 per cent emergence in the predator. When the grubs were fed with hexanal sprayed Corcyra eggs as well as by direct spraying of hexanal nanoemulsion on the grubs, there was 100 per cent pupation and adult emergence.

Screening for Resistance Against Pulse Beetle, Callosobruchus analis (F.) in Greengram (Vigna radiata (L.) Wilczek) Accessions

The susceptibility of eighty five green gram accessions were evaluated against pulse beetle, Callosobruchus analis (F.) under laboratory conditions. Accessions which exhibited lesser susceptibility index during the preliminary free choice tests were further subjected to ‘force choice’ test for confirmation of bruchid resistance. No green gram accession was found immune to bruchid infestation and showed significant difference in terms of oviposition, developmental period, adult emergence and seed weight loss. Two accessions viz, Km-12-5 and P-S-16 revealed lesser per cent adult emergence of 12.22 and 14.29, respectively. Prolonged developmental period (25.67 and 26.00 days, respectively) and lesser susceptibility index (0.042 and 0.044 respectively) in comparison to highly susceptible Ganga 8, which exhibited a survival of 71.67 %, developmental period of 20.67 days and susceptibility index of 0.09. Correlation between GI and other growth parameters of pulse beetle on different accessions indicated that GI had negative relationship with mean developmental period (−0.924) and significant positive relationship with adult emergence (0.931), weigh loss (0.952) and eggs laid (0.734). Hence, these accessions can be effectively used as promising donors for developing bruchid resistant varieties which would ensure food security by reducing postharvest losses under storage conditions.

Laboratory Evaluation of Transgenic Bt Cotton (cry1Ac +cry2Ab genes) and Non-Bt Cotton against Neonates, First and Second Instar Larvae of Spodoptera litura Fab.

Transgenic Bt cotton BG II (cry1Ac +cry2Ab genes) in comparison with non-Bt cotton were evaluated for their effect on the development of Spodoptera litura in the IPM Laboratory of Department of Entomology, Punjab Agricultural University Ludhiana. The leaf and square of various Bt cotton cultivars viz. MRC 7017, BCHH 6488, BCHH 6588, Ankur 3028, NCS 855 and non-Bt cotton LH 2076 were fed to the neonates, first and second instars larvae of cotton leaf worm, S. litura. The neonates, 1st and 2nd instar larvae when fed on leaves of transgenic Bt cotton resulted in 100 per cent mortality as compared to non-Bt cotton (0.00). However, 2nd instar larvae fed on squares of Bt cotton resulted in 100 per cent mortality in most of the Bt cotton cultivars, MRC 7017, BCHH 6488, BCHH 6588 and Ankur 3028 except NCS 855 (82.16) and non-Bt (6.63). The developmental times of 2nd instar larvae of S. litura were different among Bt cotton cultivars and non-Bt cotton. The survived 3rd instar larvae fed on leaves in Ankur 3028 (11.11) followed by BCHH 6588 (7.14) and BCHH 6488 (7.4) continued to be 3rd instar even after 17 days, while those on non Bt cotton moulted to pupal stage (7.14). However, when larvae fed on squares of Bt cotton and non-Bt cotton, maximum pupation takes place in non Bt cotton cultivar, LH 2076 (93.33) followed by Bt cotton cultivar NCS 855 (17.85) after 24 days. The total developmental time of larvae in the Bt cotton was significantly longer than that of larvae on non-Bt squares. The higher weight of larvae fed on leaves was recorded in LH 2076 (19.72 mg). Similarly, after 10 days of release of S. litura on squares of different cotton cultivars higher weight of larvae was recorded in LH 2076 (25.671 mg) and lower in MRC 7017 (2.919 mg). The pupae that developed from the larvae that fed on non-Bt were heavier than those that developed from the larvae that fed on non-Bt cotton squares. After 27 days, 100 per cent adult emergence was recorded in non-Bt cotton cultivar, LH 2076 followed by single emergence in BG II cotton cultivar NCS 855. However, after 31 days, four adults were formed in case of NCS 855 but they were not able to survive for more than 2 days and all of them were males. It can be inferred that all BGII cotton cultivars were toxic to neonates, first and second instar larvae of S. litura under laboratory conditions.

Effect of Insecticides on Some Biological Parameters of Trichogramma chilonis Ishii (Hymenoptera: Trichogrammtidae)

Bioassay carried out to determine the toxicity of seven insecticides (viz. endosulfan 0.07%, imidacloprid 0.004%, spinosad 0.01%, triazophos 0.08%, thiodicarb 0.075%, novaluron 0.01% and azadirachtin @1ml/L) to Trichogramma chilonis showed that spinosad was the most toxic in all the studies followed by triazophos. Spinosad resulted in only 17.80 per cent parasitization and 3.97 per cent adult emergence from the host eggs, Corcyra cephalonica Stainton treated before parasitization. Novaluron was found to be the safest resulting in 58.93 per cent parasitization and 89.72 per cent adult emergence from the host eggs treated before parasitization. The parasitization in other insecticides ranged from 20.00 to 40.47 per cent. Spinosad was also found highly toxic to all the immature stages of T. chilonis resulting in only 0.46, 0.66 and 0.65 per cent adult emergence when the parasitoid was treated in the egg, larval and pupal stages, respectively. Novaluron was found to be safe to all the immature stages of the parasitoid resulting in 86.75, 87.84 and 87.46 per cent adult emergence when treated in egg, larval and pupal stages, respectively. The parasitoid adult emergence in other insecticides ranged from 57.95 to 88.63 per cent when treated in egg stage, 53.97 to 87.12 per cent when treated in larval stage and 61.46 to 87.15 per cent when treated in pupal stage.

Bioassay studies for bruchid (Callosobruchus chinensis) resistance in

The results of bioassay indicated that per cent adult emergence, mean time of adult emergence and per cent weight loss were most important parameters which helped in categorizing the genotypes into susceptible or resistant. Out of nine interspecific progenies, one of progeny UPAS120 × scarabaeiodes was found least susceptible for Callosobruchus chinensis, while other progenies in the descending order for resistance to bruchid were UPAS120 × cajanifolius, PA134 × C. scarabaeiodes, PA134 × C. acutifolius, ICPL84023 × C. cajanifolius and ICPL84023 × scarabaeiodes. Since genetic resistance is the cheapest source of resistance in managing the biotic stress, the resistant material found in this study will definitely useful in the pigeonpea improvement programme especially for bruchid resistance.

Impact of Chloronicotinyl Insecticide, Imidacloprid on Egg, Egg-Larval and Larval Parasitoids Under Laboratory Conditons

Laboratory studies were carried out to compare the toxicity of the chloronicotinyl insecticide, imidacloprid on parasitoids. The studies took place at the Tamil Nadu Agricultural University, Coimbatore from 2006-2007. Imidacloprid was tested against three beneficial insects viz., an egg parasitoid, egg larval parasitoid and a larval parasitoid representing two families of Hymenoptera: Trichogrammatidae (Trichogramma chilonis Ishii) and Braconidae (Chelonus blackburni Cameron; Bracon hebetor Say) that attack insect pests of cotton. The toxicity of imidacloprid was evaluated by treating the parasitized eggs using an atomizer in the case of T. chilonis and glass scintillation vial residue bioassay method for the adults of C. blackburni and B. hebetor. The toxicity of imidacloprid to parasit- oids was compared with another neonicotinoid, named thiamethoxam, and a standard check, methyl demeton. Imidacloprid 17.8 SL did not cause any adverse effects on the adult emergence and parasitization of T. chilonis. At the recommended dose of imidacloprid (25 g active substance (a.s.)/ha), 90.67 and 85.32 per cent adult emergence and parasitization was recorded, respectively. The recom- mended dose of imidacloprid caused 56 per cent mortality and was found to have moderate impact on the adults of C. blackburni. On the other hand, it was found to be toxic to the parasitoid B. hebetor, causing 70 per cent mortality at 48 hours after treatment (HAT). The data presented here will provide pest managers with specific information on the compatibility of selected insecticides with natural enemies attacking pests of cotton, Gossypium hirsutum L.

Evaluation of Quality of Trichogramma chilonis Ishii from Different Production Units in India

The post-shipment quality of parasitized egg cards of Trichogramma chilonis Ishii obtained from nine production units in South India was evaluated. Evaluations included the number of parasitized eggs per card, per cent parasitism, per cent adult emergence, sex-ratio and parasitizing efficiency on the target host. There was a lot of variation in the card size and the number of eggs per card. The parasitism was more than 90 per cent in the tricho-cards supplied by two units. The adult emergence and sex-ratio was as per the quality standards, Considering the recommendation of 1,50,000 parasitized eggs per hectare of cotton, only three units could reach the quality standards. The parasitizing efficiency of T. chilonis supplied by two units was less than 50 per cent and parasitism ranged between 60 and 73 per cent in the others. There is a need for regulatory agencies to periodically evaluate the quality of Trichogrammatids produced by insectaries based on simple and reliable methods. Trichogramma producers should reach a consensus with respect to the method of producing Tricho-cards and recommendations to be given to farmers. This would ensure the proper utility of Trichogrammatids in biocontrol programmes.

Safety of botanical and microbial pesticide mixtures to Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae).

Laboratory experiments were conducted to study the effects of botanical (neem, sweet-flag and pongamia) and microbial pesticide mixtures (HaNPV, Bacillus thuringiensis (=Spicturin) and spinosad) on adult mortality and adult emergence of the egg parasitoid, Trichogramma chilonis . In contact toxicity test, neem + sweet-flag and neem + sweet-flag + pongamia at 0.12 and 0.18 per cent concentrations registered up to 33.89 per cent mortality of adult parasitoids while the same concentrations had 79.58 to 81.00 per cent adult emergence. Experiments with mixtures of microbial pesticides revealed that spinosad at 75 g a. i./ha and its combination with HaNPV or Spicturin or with both registered cent per cent adult mortality in 24 hours. Also, spinosad or its combinations registered poor adult emergence of this parasitoid, which ranged from 13.08 to 13.83 while HaNPV and Spicturin registered adult emergence of 93.33 and 93.58 per cent. The possibilities of using the botanical mixtures or microbial pesticide mixtures along with this parasitoid are discussed.