Insecticidal effects of essential oils from various plants against larvae of pine processionary moth (Thaumetopoea pityocampa Schiff) (Lepidoptera: Thaumetopoeidae)

Along with sulfate turpentine, the essential oils obtained by steam distillation from nine plant species naturally grown in Turkish forests were tested at three different concentrations to evaluate their effectiveness against the larvae of pine processionary moth (Thaumetopoea pityocampa Schiff). The results indicated that the essential oils from the nine species and sulfate turpentine were effective against the larvae of T pityocampa. The most effective essential oil in the control of the larvae was steam-distilled wood turpentine, followed by thyme herb oil, juniper berry oil, laurel leaf oil, lavender flower oil, eucalyptus leaf oil, lavender leaf oil, cypress berry oil, essential oil of styrax and sulfate turpentine, respectively, in terms of mean mortality time. It is therefore feasible to use these essential oils as environment-friendly insecticides in the control of T pityocampa.     

4种植物挥发油的化学成分分析及其对赤拟谷盗的生物活性

本试验采用水蒸气蒸馏法提取飞机草?假蒟?紫穗槐和毛麝香4种植物的挥发油, 以气相色谱-质谱联用(GC-MS)分析挥发油的化学成分组成, 采用触杀和驱避活性测试评价以上植物挥发油对赤拟谷盗的生物活性?结果表明, 从上述植物挥发油中共鉴定出100种成分, 其中, 飞机草轻油和飞机草重油主要含有肉豆蔻醚(34.32%, 46.58%)和β-石竹烯(22.35%, 17.98%), 假蒟挥发油中主要含有β-胡椒烯(18.23%)和β-石竹烯(14.60%), 紫穗槐挥发油主要含有α-蒎烯(26.31%), 毛麝香挥发油主要含有γ-松油烯(24.90%)和环葑莰烯(16.59%)?此外, 飞机草轻油和重油?假蒟?紫穗槐和毛麝香挥发油对赤拟谷盗具有一定的触杀活性, 其24 h的LD50分别为58.83?62.73?51.94?44.08 μg/头和51.69 μg/头, 其中, 紫穗槐挥发油的触杀活性最强?同时, 上述植物挥发油对赤拟谷盗均具有一定的驱避活性, 其相对关联度ri分别为0.340 6?0.647 4?0.561 2?0.523 5和0.657 2, 其中, 毛麝香挥发油的驱避活性最强(ri =0.657 2)?因此, 紫穗槐和毛麝香挥发油在仓储害虫防治方面具有很好的研究价值和开发潜力?     

Impact of defoliation by the pine processionary moth (<Emphasis Type="Italic">Thaumetopoea pityocampa</Emphasis>) on radial,height and volume growth of calabrian pine (<Emphasis Type="Italic">Pinus brutia</Emphasis>) trees in Turkey

An outbreak of the pine processionary moth (PPM),Thaumetopoea pityocampa Schiff. (Lepidoptera: Thaumetopoeidae), began in spring 1998 and lasted 5 years in aPinus brutia Ten. (Calabrian pine) stand. Tree volume and volume elements increments were examined throughout a PPM outbreak cycle from 1981 to 2003, for an even aged, pure, undisturbed, young Calabrian pine stand. Tree ring chronologies of ‘control’ Calabrian pine, which was not defoliated by PPM during the period of 1998–2003, were used to estimate potential growth characteristics in the ‘host’ Calabrian pine (moderate and high defoliation groups) for current and past outbreaks. Increment cores were collected from 70 host and 78 control dominant or co-dominant trees and annual radial growth indices from 1981–2003 were calculated for each defoliation group in a 41 point sampling. Growth functions were defined as the cumulative sum of radial, height, and volume increment, and graphically compared between host Calabrian pine (3 moderate and one high), four control Calabrian pine and one host Crimean pine (Pinus nigra Arnold) sample trees. At least three severe outbreak periods were identified (from 1981–86; 1992–97; and 1998–2003), much of the study area being severely affected by PPM. Tree ring evidence suggests that large scale (in 1981, 1992, 1998) and partial (in 1988) outbreaks occurred in the study area. Negative inflections of host radial growth curves relative to control height and volume indicated PPM activity. The periodic average diameter growth reductions (in %) in 1981, 1988, 1992 and 1998, respectively, were 0, 13, 5 and 0 for control, 12, 8, 7 and 2 for moderate, and 18, 5, 0 and 7 for high defoliation groups. Outbreaks appear to be associated with dry winter and spring weather prior to the autumn and winter in which feeding occurs. http://www.phytoparasitica.org posting Sept. 28, 2004.     

Results and perspectives in the use ofBacillus thuringiensis Berl. var.kurstaki and other pathogens againstThaumetopoea pityocampa (Den. et Schiff.) in Italy (Lep., Thaumetopoeidae)

The pine processionary caterpillar,Thaumetopoea pityocampa is the most important defoliator of both native and introduced pines throughout Italy and is especially damaging in young plantations and on ornamental trees. A number of microbial pathogens have been isolated from larvae and pupae over the last 30 years. Some of them have been evaluated as biological control agents, and have provided encouraging results. However, onlyBacillus thuringiensis var.kurstaki (Btk) has passed the experimental screening and is now available for routine treatments, although its application by air is subjected to strict regulation by the government. The erratic performance of a single application ofBtk againstT. pityocampa that has been observed in the field (20–85% mortality) is related to a great variability in both the application dose and some population parameters ofT. pityocampa. The emergence period of adults varies from July (Alps) to October (South) and its duration is related to the spreading of the cohorts (individuals with different length of prolonged diapause) over time. In addition, embryonic development takes from 20 to 45 days, depending strictly on the temperatures recorded in the egg masses. As a result, the most vulnerable larval instars (L1 and L2) are never thoroughly reached by one application only, as the persistence of the bacteria on the needles is usually limited. Two applications are requested to control the pest in stands where the egg hatching occurs over more than one month. Another possibility consists of a single winter application against L3−L4 with a higher dose, to be performed where a certain amount of damage is tolerated.