DETERMINATION OF OPTIMUM ADULTPOPULATION DENSITY IN CAGES FOR REARING OFCHRYSOPERLA CARNEA (STEPHENS) (NEUROPTERA:CHRYSOPIDAE)MUZAMMIL SATTAR, MUHAMMAD HAMED, SAJIDNADEEM AND MUHAMMAD AFZAL MURTAZAPlant Protection Division, Nuclear Institute forAgriculture and Biology (NIAB). P.O.Box 128, JhangRoad, Faisalabad
•Cotton is indigenous and predominant cash crop of Pakistan. It is being cultivatedon 3 million plus hectares annually and covers 14% of the total cropped area ofPakistan.•Cotton lint is the source of raw material to textile industry and spelled outapproximately 11 million bales under home consumptions. Provides 71% ofdomestic edible oil production.•The foreign exchange earning is contributed to 65% from raw cotton, yarn, clothand it’s made up constitutes. It accounts for 11.7 % value added income toAgriculture and 2.9 % of the GDP to country. Thus cotton is an occupation of 1.5million farming community and provides job to 50-54 % of the labour force.•During the past decade (1995-96 to 2005-06) cotton production of our countryhas risen at 2.67 % per annum due to 0.14 % annual expansion in area and 2.53 %improvement in yield.• The positive significant increase in production with horizontal and verticalapproaches obviously well lead our country to higher values in second decadeending by 2015.
Integrated Pest Management (IPM) is the coordinated use of pest andenvironmental information to design and implement pest controlmethods that are economically, environmentally and socially sound.•IPM promotes prevention over remediation and advocates integration ofmultiple control strategies to achieve long-term pest managementsolutions.IPM consists of gathering information, interpreting data, creating aflexible management plan, making timely decisions and taking the properaction.Information gathering and decision-making techniques include: accuratepest identification, learning about the weak link in a pests life-cycle orbiology, scouting and monitoring crops in fields and greenhouses, usingaction thresholds to minimize spraying, and keeping records of findingsto assess the effectiveness of management decisions.
INTRODUCTIONBiological control is a living weapon overchemical control, which is modern andwidely accepted technique in the world.The term “Biological control” was firstused by Smith (1919) to signify the useof natural enemies to control insect pests(Clarke, 1993).
NEUROPTERA• This order consists of a group of insects withrather soft bodies, biting mouthparts and twopairs of very similar membranous wings whichare usually held roof-like along the abdomen atrest.• Order Neuroptera consists of the lacewings, antlions and their relatives.• One family consists of parasitoids.• Their agricultural importance lies in theircarnivorous habits.• The larvae are all predators, some areterrestrial, feeding on jassids, psyllids, aphids,coccids, mites, mealy bugs etc. and others areaquatic.• No doubt that they play an important role in thenatural control of many small homopterouspests.
ADULTSThe adult green lacewings have a soft, slender, pale green delicate body, they havelarge transparent, pale green membranous wings with green veins, long hair-likeantennae and have bright, golden or copper-coloured eyes. The overall bodylength including wings is about 1 inch; these are active fliers particularly duringthe evening and night and have a characteristic, fluttering flight, sometimes thisinsect comes to light at night. And have a strong flight urge, may fly for 3 to 4hours, feed on pollen, nectar and aphid honeydew.
EGGSThe Oval shaped green eggs are protectively laid singly at the end/tip of hair likelong silken stalks about an inch high, fifth day of adult emergence, resemblingminiature cattails growing from the plant foliage are pale green, turning greenishto white colour after 2-3 days than small larvae hatched out.
LARVAThe larvae which are very active, somewhat elongate, has three instars,up to about a inch long when fully grown, broadest in the middle andtapered toward the rear, gray or brownish and alligator-like with well-developed legs and large pincers have sickle-shaped mouthparts, withwhich they suck the body fluids from the prey, feed on many types of softbodied insects, including aphids, mealy bugs, scale insects, leafhoppers,thrips, and even small caterpillars. They grow from 1mm to 6-8 mm. Theycan detect the larvae of leaf miners actually within the mines, and willpierce the leaves in order to feed on the miners within. They also goodpredators of spider mites.
PUPAMature third instars larvae spin round, pupate within spherical,parchment-like silken cocoons, usually in hidden places in plants.Adults emerge out after 8-10 days. Again the life cycle will start.
INTRODUCTION• Among other Neuropterans, Green lacewings are importantand widely distributed predators, reared in controlledtemperature.• For culturing it is necessary to modify the technology.• Green lacewings, adult reared in different types of cages.• Better ovipositor, good health and long life requires a properfood and space with maintained temperature in laboratoryconditions.• Bulk production of insects requires proper rearing cages,natural/ artificial food, temperature and humidity conditions.
Materials And Methods• For mass rearing adults of C. carnea, labour intensive and time consuming activity is mostimportant thing.• Three types of cages were used, to test the better egg production, how much time wasrequired for egg harvesting, food provision, and the time spent on the sanitation of cagesfor maintaining the healthy culture.• Shifting of adults from one cage to another and particularly egg harvesting and cleaningwas difficult to perform.• In view of above difficulties, adult cages were designed with the objectives to avoid the useof anaesthesia or vacuum suckers to reduce labour involved in sanitation, feeding andharvesting of eggs and to ensure proper light and ventilation inside the cage.The following designs were tested:• Transparent Perspex Cages• Transparent Glass Cages• Wooden Cages
Adults’ RearingTransparent Perspex Cages• Adults of C. carnea were reared in these cages for testing the eggs laid onsubstrate and drifted and laid on other structures.• The cage was made of only three (5 mm width) sheets (16 x 16 inch); one inlower surface and two for side walls, the front side was made of plastic net withreplaceable top lid of wooden piece covered with black muslin cloth.• Only one rounded whole of 3 inches in diameter was made in front side for foodprovision and cleaning of cage, an iron rod was patched with glue (Smad bond®).• Which was covered and stitched with white muslin cloth sleeve; both the endsof sleeve were open for sanitation, provision of food and water and release ofnewly emerged insects.
Adults’ RearingTransparent Glass Cages• Shape of the cage resembled with Perspex cage, except that the cage wastransparent made of glass (16 x 16 inch), covered with black muslin cloth directlyas egg laying substrate at the ceiling of the cage without any use of woodensheet.• Pinned tightly with common paper pins from four ends which was easy tochange the cover, without any escape of adults’.• The front side had a hole for handling of insects which was covered by whitemuslin cloth sleeve.• Moisture was maintained by placing wet cotton wig in glass vials. There was noneed to shift the adults during food and water provision and for sanitation.
Adults’ RearingWooden Cages• These cages were made of wood (16 x 16 inch), with net on four sides; basewas wooden sheet while lid was replaceable wooden sheet, covered withblack muslin cloth.• A hole of 3 inch was made for sanitation, provision of food and water andrelease of newly emerged insects.• Water soaked cotton for maintaining moisture inside the cage in glass vialswas provided.
Adults’ RearingMaintenance of Culture(A) Food provision: Standard adults diet was provided twice daily in droplets onPerspex sheet strips with the help of fine camel hair brush.(B) Egg harvesting: Eggs were harvested from replaceable black muslin clothcover with the help of sharp razor blade. Some eggs were laid on otherstructures within cage such as cage walls, water containing vials etc., werealso harvested with razor.(C) Cleaning of cages: All the cages were cleaned with wet cotton wig after thatdried gently with the help of tissue paper.Time of food provision, egg harvesting and cleaning of cages was noted.
Table- 1 Handling time required for mass-rearing of C. carneaadults in different types of cages under laboratoryconditions Mean S.E).Cages Operation time (minutes)Food provision Egg harvesting CleaningPerspex 3.00 b 4.40 b 4.60 bGlass 2.40 b 3.80 b 3.70 bWooden 3.90 a 16.60 a 9.90 aFigures followed by same letter in a column are not significantly different from each other at 5%DMRT.
Table- 2 Egg-laying distribution of C. carnea in different types ofcages under laboratory conditions.Cages Mean S.E. Drifted eggs(%)On substrate DriftedPerspex cage 192.8 5.23 b 17.97 2.47 b 9.32Glass cage 273.42 14.46 a 13.45 1.39 c 3.71Wooden cage 167.55 14.49 c 38.27 5.71 a 18.46Figures followed by same letter in a column are not significantly different from each other at 5%DMRT.
CONCLUSIONSIt is concluded that for mass production of C. carnea under laboratoryconditions glass cages are the best for adult rearing .Further, experiment was conducted in controlled temperature and humidityconditions (26±2°C with 60±5% RH).For optimization of population density 50, 100, 150 and 200 randomlycollected, of equal size and age adults of green lacewings were released incages measuring 36 X 36 X 50 mm.Each treatment has eight replications. Density effect on different biologicalparameters of predator viz., number of eggs laid, size of eggs and mortalitywere recorded.The maximum egg laying 630.0±0.12 was recorded in cages having low density(50 adults) while the minimum of 410.0±0.01 eggs was recorded in cages ofhigh density (200 adults).The highest mortality of 88.63% was recorded in high density cages whereas;the minimum mortality of 10.0% was recorded in low density cages.
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