Population Characteristics of Dendrolims Superans in Daxing'an Mountains

CollectionofdataFiveI1tlndredf1eadsofD..`IIl,L;l-I;(Ilt`crecoIlectedilltIletbrest.oraroul1dtbrestarcadtIril1gtl1epeakofap-pearancetYol11I99lloI992.TI1el1tlInberoftb111aIca11dlllaIeaduItst`ererecorded.T``/ostal1dardpIotsucrecI10seninYol1gqingandHa[1jiayuan…     

Effects of gamma radiation on life stages of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

We report the results of experiments conducted with Ephestia kuehniella Zeller to determine the effects of gamma radiation on life stages. Eggs, larvae, pupae and adults were irradiated with increasing doses of gamma radiation (seven dose levels between 50 and 400 Gy for eggs and larvae, six dose levels between 50 and 350 Gy for pupae and four dose levels between 250 and 550 Gy for adults). All the experiments were conducted in a growth chamber maintained at 27 ± 1°C, 65 ± 5% r.h., and alternating 14 h light:10 h dark cycles. The number of adults that developed from irradiated eggs and larvae was lower than the untreated control. Doses of 200 Gy and above prevented adult emergence from irradiated eggs. Although a dose of 200 Gy was enough to prevent adult emergence from young larvae, 250 Gy should be used to prevent adult emergence completely from last instar larvae. Delayed developmental periods were observed for the treated eggs and larvae. Fecundity and egg hatchability were decreased depending on the doses applied. Decreased fecundity and egg hatchability were more prevalent when both the male and female pupae were treated compared to the treatment of female pupae only. There was no significant decrease in the fecundity of irradiated adults except 550 Gy, and no eggs hatched at doses of 300 Gy and above.     

Population dynamics of Dasiops inedulis (Diptera: Lonchaeidae) and its biotic and abiotic mortality factors in Colombian sweet passionfruit orchards

Throughout South America, the lonchaeid flies Dasiops spp. are important herbivores of passionfruit crops. However, little is known on the biology and ecology of these insects, resulting in inadequate pest management schemes. In this study, we describe Dasiops inedulis population dynamics in Colombian sweet passionfruit (SP; Passiflora ligularis Juss.) and elucidate biotic mortality factors at different fly developmental stages. From August 2009 to July 2010, D. inedulis and Dasiops spp. abundance was assessed through monthly McPhail bait trapping and collection of SP flower buds, flowers, and immature fruits. Mortality levels of D. inedulis were determined for early instar larvae by ovary dissection and for late-instar larvae or pupae by prey removal trials. Maximum infestation reached 80 % in fruits and flower buds, and bud infestation correlated with precipitation during the previous month. Two days after oviposition, 8.2 ± 2.3 (mean ± SD) Dasiops sp. eggs were found in SP ovaries and 4.4 ± 1.2 late-instar larvae were recovered from immature fruits at day 14. Upon larval drop on the orchard soil, 74.8 % larvae burrowed within the soil within 9 min, while 12.5 % larvae were attacked by ants. In-field mortality of young pupae amounted to 75.3 ± 7.0 %, with vertebrate predators likely causing 12.1 ± 6.0 % mortality. Late-instar larvae and pupae appear highly vulnerable to natural enemy action, with the ground-foraging predator community mainly composed of ants (80.37 %) and ground beetles (9.17 %). Our findings should help develop integrated pest management (IPM) tactics for SP crops.     

Evaluation of two Neem seed kernel extracts againstLiriomyza trifolii (Burg.) (Dipt. Agromyzidae)

Laboratory evaluation of Neem Azal-S and Margosan-O was carried out against the adult and larvae ofLiriomyza trifolii Burgess. The feeding deterrent activity of both compounds was significantly realized against the adults particularly at high concentrations which lasted for 5 days after treatment. Both formulations also deterred the females from laying eggs and the percentage of oviposition deterrent index (ODI) reached 80.7 and 52.6 for Neem Azal-S and Margosan-O (2%), respectively.Post infestation treatment of bean seedlings containing 3rd instar larvae indicated that the toxic action of the tested extracts was quite limited. However, different percentages of malformed pupae were obtained. The sex ratio between the resulting adults was nearly unaffected with the exception of individuals whose larvae were treated with 2% Neem Azal-S where all the resulting progenies were females.With 2 tables     

Population characteristics ofDendrolims superans in Daxing’an Mountains

Dendrolims superans produced one generation every two years. Large larvae and small larvae exist at the same time. It broke out in Daxiang an Mountains in 1990, and seriously destroyed growth ofLarix gmelini Rupr. In order to controlD superans, the population properties ofD superans were studied from 1991 to 1992, including sexratio, age distribution, pattern etc.. The sex ratio ofD. superans population is ♀∶♂ − 1.06:L. The larvae age distribution indicates that larvae over 5 instar is less than younger larvae under 4 instar in Yongqing forest farm, but the younger larvae under 4 instar is more than larvae over 5 instar in Hanjiayuanzi Forest Farm. The population ofD. superans in Yongqing Farm has been declining. and mereasing in Hanjiayuanzi. Pupae and eggs are mainly distributed in middle and lower crowns layer of trees respeetively account for 66% and 59.5% of total individuals. The pupae in higher crown layer is lightly regular distribution and clumping distribution middle and lower crowns layer of trees. The eggs in higher crown is light clumping distribution and random in middle and low crown of tree. (Responsible Editor: Zhu Hong)     

Ants and birds reduce western spruce budworm feeding injury to small Douglas-fir and western larch in Montana

Western spruce budworm, Choristoneura occidentalis Freeman, larvae on small Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) and western larch (Larix occidentalis Nutt.) trees were protected from ant and bird predation during fourth instar to pupation. Significantly greater budworm densities were found on protected trees than on the controls at the end of the experiment, and significantly greater feeding injury was associated with increased budworm densities on fir. It is concluded that ants and birds remove budworm larvae feeding on small conifer trees and reduce injury up to 50%.     

泰加大树蜂生物学特性的研究

泰加大树蜂Urocerus gigas taiganus Benson是落叶松、云杉、冷杉的蛀干害虫。主要危害林中的濒死木、枯立木及新伐倒的原木、伐根。该虫在辽宁抚顺地区1年1代，以2—5龄幼虫在木质部蛀道内越冬，第2年5月上旬老熟幼虫开始化蛹，成虫5月下旬开始羽化并产卵，6月中旬出现初孵幼虫。     

珍珠梅纽扁叶蜂生物学特性及防治技术研究

珍珠梅纽扁叶蜂Neurotoma sibirica Gussakovskij在海城1 a发生1代,以预蛹在土壤中越夏、越冬,翌年4月上旬化蛹。4月下旬成虫开始羽化至6月上旬,5月中、下旬为盛期。卵出现于4月下旬,于5月中旬开始孵化,孵化盛期为5月下旬。老熟幼虫于6月中旬下树入土。珍珠梅纽扁叶蜂有13种天敌,其中显背臀姬蜂Notopygus insignis Kriechbaumer为中国新纪录属、种,异色瓢虫Harmonia axyridis(Pallas)是优势种。利用3种农药对珍珠梅纽扁叶蜂3龄幼虫进行防治试验,效果达93%以上。     

Development and feeding potential of the green lacewingChrysoperla carnea Steph. (Neur. Chrysopidae) on different insect pests of cotton

Results of laboratory experiments revealed that the total development period (egg to adult emergence) of the common green lacewing Chrysoperla carnea lasted for 19.15, 19.35, 19.95, 20.15, 20.60 and 22.50 days when the larvae were fed with Bemisia tabaci, eggs of Corcyra cephalonica, Heliothis armigera, Aphis gossypii, Amrasca biguttula and neonates of Heliothis armigera respectively. Larval development was rapid on eggs of C. cephalonica (8.20 days) and prolonged on neonates of H. armigera (11.10 days). Pupal development period was quicker on B. tabaci and A. biguttula (7.40 days) and prolonged on neonates of H. armigera (8.40 days).During development each larva of C. carnea consumed an average of 732.35 eggs of C. cephalonica, 662.53 eggs of H. armigera, 419,18 A. gossypii, 409.55 neonates of H. armigera 329.70 pupae of B. tabaci and 288.45 nymphs of A. biguttula. In all the cases, the third instar larvae consumed the major portion of the total number consumed (60–80%). The most suitable preys, resulting in rapid development, for C. carnea were pupae of B. tabaci and eggs of C. cephalonica.With 2 tables     

枣镰翅小卷蛾自然种群生命表的研究

１９８９－１９９３年在山西太谷枣区对枣镰翅小卷蛾的自然种群进行了系统调查，编制了１－３代５年的生命表及平均生命表。分析得出，第１代的卵和１－２龄幼虫是其世代及年度的薄弱环节；１－２代，２－３代，３代－翌年１代的种群趋势指数分别为２．４５、２．７和０．２１，在年份间种群由上升到平衡；第１代的风雨致死，第２代的４－５龄幼虫及蛹的虫寄生，越冬代（即第３代）的打枣致死、蛹期天敌取食及冬季消亡对种群的控制作用较大；用灰色关联度分析关键因子是作者提出的新方法，文中给出了详细的分析步骤，关键因子：第１代为４－５龄幼虫天敌取食，第２代为蛹期虫寄生，越冬代为４－５龄菌寄生和蛹冬季消亡。