Feeding responses to selected alkaloids by gypsy moth larvae, Lymantria dispar (L.)

Deterrent compounds are important in influencing the food selection of many phytophagous insects. Plants containing deterrents, such as alkaloids, are generally unfavored and typically avoided by many polyphagous lepidopteran species, including the gypsy moth Lymantria dispar (L.) (Lepidoptera: Lymantriidae). We tested the deterrent effects of eight alkaloids using two-choice feeding bioassays. Each alkaloid was applied at biologically relevant concentrations to glass fiber disks and leaf disks from red oak trees (Quercus rubra) (L.), a plant species highly favored by these larvae. All eight alkaloids tested on glass fiber disks were deterrent to varying degrees. When these alkaloids were applied to leaf disks, only seven were still deterrent. Of these seven, five were less deterrent on leaf disks compared with glass fiber disks, indicating that their potency was dramatically reduced when they were applied to leaf disks. The reduction in deterrency may be attributed to the phagostimulatory effect of red oak leaves in suppressing the negative deterrent effect of these alkaloids, suggesting that individual alkaloids may confer context-dependent deterrent effects in plants in which they occur. This study provides novel insights into the feeding behavioral responses of insect larvae, such as L. dispar, to selected deterrent alkaloids when applied to natural vs artificial substrates and has the potential to suggest deterrent alkaloids as possible candidates for agricultural use.     

Disulfide connectivity and reduction in pheromone-binding proteins of the gypsy moth, Lymantria dispar

Males of the gypsy moth, Lymantria dispar, are attracted by a pheromone released by females. Pheromones are detected by olfactory neurons housed in specialized sensory hairs located on the antennae of the male moth. Once pheromone molecules enter the sensilla lymph, a highly abundant pheromone-binding protein (PBP) transports the molecule to the sensory neuron. The PBPs are members of the insect odorant-binding protein family, with six conserved cysteine residues. In this study, the disulfide bond connectivities of the pheromone-binding proteins PBP1 and PBP2 from the gypsy moth were found to be cysteines 19–54, 50–109, and 97–118 for PBP1, and cysteines 19–54, 50–110, and 97–119 for PBP2, as determined by cyanylation reactions and cyanogen bromide chemical cleavage. We have discovered that the second disulfide linkage is the most easily reduced of the three, and this same linkage is missing among four cysteine-containing insect odorant-binding proteins (OBPs). We are the first to identify the unique steric and electronic properties of this second disulfide linkage. Electronic Supplementary Material  Supplementary material is available for this article at

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Evaluation of Steinernema feltiae and S. bibionis (Rhabditida: Steinernematidae) for suppression of Lymantria dispar (Lepidoptera: Lymantriidae) in Pennsylvania,U.S.A.

Lymantria dispar L. larvae exposed to the entomogenous nematodes Steinernema feltiae Filipjev and S. bibionis (Bovien) for ⩾ 16 h in laboratory petri dish tests averaged 93 and 91% mortality, respectively. Nylon pack cloth bands, lined with Pellon fleece or terry cloth, placed around oak tree boles were treated with nematode suspensions in central Pennsylvania. Fifth and 6th stage host larvae collected from beneath these bands after nematode treatment averaged 28% mortality.     

2,3-Dimethyl-5-(2-methylpropyl)pyrazine, a trail pheromone component of Eutetramorium mocquerysi Emery (1899) (Hymenoptera: Formicidae)

 The ant Eutetramorium mocquerysi (Myrmicinae) is endemic to the island of Madagascar. During foraging and nest emigration the ants lay recruitment trails with secretions from the poison gland. We identified three pyrazine compounds in the poison gland secretion: 2,3-dimethyl-5-(2-methylpropyl)pyrazine 1, 2,3-dimethyl-5-(3-methylbutyl)pyrazine 3, 2,3-dimethyl-5-(2-methylbutyl)pyrazine 4. Only the first component elicited trail-following behavior in the ants. We were unable to investigate whether the other pyrazine components have a synergistic function. Received: 21 February 2000 / Accepted in revised form: 27 June 2000     

狐尾藻降解双酚A内生菌的分离鉴定及降解特性

该研究从沉水植物狐尾藻中分离筛选到1株可降解环境内分泌干扰物双酚A(BPA)的内生细菌Hu32。通过摇瓶实验进行了菌株降解条件的优化和降解特性的探索,发现菌株降解初始浓度为10 mg/L,BPA的最佳条件为接种量为1%,初始pH值为6.0,温度为25℃。在该条件下,菌株最大生长浓度OD_(600)达到0.22,3 d对10 mg/L,BPA的降解率达到(47.17±1.22)%。经过对其形态特征和16S rRNA基因同源性序列分析,该菌株初步鉴定为类芽孢杆菌属(Paenibacillus sp.)。这是首次从沉水植物中分离到新型可降解BPA的内生菌,有助于了解水生植物对BPA污染水体的修复机制,为进一步阐明水体中BPA的生态归趋奠定基础。     

A ton is not always a ton: A road-test of landfill,manure, and afforestation/reforestation offset protocols in the U.S. carbon market

The outcome of recent international climate negotiations suggests we are headed toward a more fragmented carbon market, with multiple emission trading and offset programs operating in parallel. To effectively harmonize and link across programs, it will be important to ensure that across offset programs and protocols that a “ton is a ton”. In this article, we consider how sample offsets projects in the U.S. carbon market are treated across protocols from five programs: the Clean Development Mechanism, Climate Action Reserve, Chicago Climate Exchange, Regional Greenhouse Gas Initiative, and the U.S. EPA's former program, Climate Leaders. We find that differences among protocols for landfill methane, manure management, and afforestation/reforestation project types in accounting boundary definitions, baseline setting methods, measurement rules, emission factors, and discounts lead to differences in offsets credited that are often significant (e.g. greater than 50%). We suggest opportunities for modification and harmonization of protocols that can improve offset quality and credibility and enhance prospects for future linking of trading units and systems.