\u3ci\u3eAgonopterix Alstroemeriana\u3c/i\u3e (Oecophoridae) and Other Lepidopteran Associates of Poison Hemlock \u3ci\u3e(Conium Maculatum)\u3c/i\u3e in East Central Illinois

Poison hemlock (Conium maculatum) (Apiaceae), a noxious Eurasian weed extensively naturalized throughout North America, is characteristically attacked by few insects. Over the past two decades, an introduced oecophorid caterpillar, Agonopterix alstroemeriana, has been reported infesting poison hemlock, its sole host in its area of indigeneity, in parts of the northeastern and western United States. We report for the first time evidence of established midwestern populations of this species. We also report poison hemlock as a host plant for the polyphagous lepidopterans Eupithecia miserulata, Trichoplusia ni, and Spilosoma virginica

A Native Hymenopteran Predator of \u3ci\u3eAgonopterix Alstroemeriana\u3c/i\u3e (Lepidoptera: Oecophoridae) in East-Central Illinois

Agonopterix alstroemeriana is a European oecophorid moth that defoliates poison hemlock (Conium maculatum), a noxious Eurasian weed extensively naturalized throughout temperate Australia, New Zealand, North America, and South America. Throughout western North America, and increasingly in the Midwest and Northeast, A. alstroemeriana has been utilized in poison hemlock eradication programs. We report, for the first time, predation on A. alstroemeriana by Euodynerus foraminatus (Hymenoptera: Eumenidae), a native solitary wasp that paralyzes these and other lepidopteran larvae and uses them to provision its nests. The presence of an effective predator may reduce the impact of A. alstroemeriana in biological control programs

A Native Hymenopteran Predator of \u3ci\u3eAgonopterix Alstroemeriana\u3c/i\u3e (Lepidoptera: Oecophoridae) in East-Central Illinois

Agonopterix alstroemeriana is a European oecophorid moth that defoliates poison hemlock (Conium maculatum), a noxious Eurasian weed extensively naturalized throughout temperate Australia, New Zealand, North America, and South America. Throughout western North America, and increasingly in the Midwest and Northeast, A. alstroemeriana has been utilized in poison hemlock eradication programs. We report, for the first time, predation on A. alstroemeriana by Euodynerus foraminatus (Hymenoptera: Eumenidae), a native solitary wasp that paralyzes these and other lepidopteran larvae and uses them to provision its nests. The presence of an effective predator may reduce the impact of A. alstroemeriana in biological control programs

Comparative CYP-omic analysis between the DDT-susceptible and -resistant Drosophila melanogaster strains 91-C and 91-R

BACKGROUND: Cytochrome P450 monooxygenases (P450s) are involved in the biosynthesis of endogenous intracellular compounds and the metabolism of xenobiotics, including chemical insecticides.We investigated the structural and expression level variance across all P450 geneswith respect to the evolution of insecticide resistance under multigenerational dichlorodiphenyltrichloroethane (DDT) selection. RESULTS: RNA-sequencing (RNA-seq) and reverse transcriptase–quantitative polymerase chain reaction (RT-qPCR) indicated that the transcript levels of seven P450 genes were significantly up-regulated and three P450 genes were down-regulated in the DDT-resistant strain 91-R, as compared to the control strain 91-C. The overexpression of Cyp6g1 was associated with the presence of an Accord and an HMS-Beagle element insertion in the 5′ upstreamregion in conjunction with copy number variation in the 91-R strain, but not in the 91-C strain. A total of 122 (50.2%) fixed nonsynonymous (amino acid-changing) mutationswere found between 91-C and 91-R, and 20 (8.2%) resulted in amino acid changes within functional domains. Three P450 proteins were truncated as a result of premature stop codons and fixed between strains. CONCLUSION: Our results demonstrate that a combination of changes in P450 protein-coding regions and transcript levels are possibly associated with DDT resistance, and thereby suggest that selection for variant function may occur within this gene family in response to chronic DDT exposure

Ecologically Appropriate Xenobiotics Induce Cytochrome P450s in Apis mellifera

BACKGROUND: Honey bees are exposed to phytochemicals through the nectar, pollen and propolis consumed to sustain the colony. They may also encounter mycotoxins produced by Aspergillus fungi infesting pollen in beebread. Moreover, bees are exposed to agricultural pesticides, particularly in-hive acaricides used against the parasite Varroa destructor. They cope with these and other xenobiotics primarily through enzymatic detoxificative processes, but the regulation of detoxificative enzymes in honey bees remains largely unexplored. METHODOLOGY/PRINCIPAL FINDINGS: We used several approaches to ascertain effects of dietary toxins on bee susceptibility to synthetic and natural xenobiotics, including the acaricide tau-fluvalinate, the agricultural pesticide imidacloprid, and the naturally occurring mycotoxin aflatoxin. We administered potential inducers of cytochrome P450 enzymes, the principal biochemical system for Phase 1 detoxification in insects, to investigate how detoxification is regulated. The drug phenobarbital induces P450s in many insects, yet feeding bees with phenobarbital had no effect on the toxicity of tau-fluvalinate, a pesticide known to be detoxified by bee P450s. Similarly, no P450 induction, as measured by tau-fluvalinate tolerance, occurred in bees fed xanthotoxin, salicylic acid, or indole-3-carbinol, all of which induce P450s in other insects. Only quercetin, a common pollen and honey constituent, reduced tau-fluvalinate toxicity. In microarray comparisons no change in detoxificative gene expression was detected in phenobarbital-treated bees. However, northern blot analyses of guts of bees fed extracts of honey, pollen and propolis showed elevated expression of three CYP6AS P450 genes. Diet did not influence tau-fluvalinate or imidacloprid toxicity in bioassays; however, aflatoxin toxicity was higher in bees consuming sucrose or high-fructose corn syrup than in bees consuming honey. CONCLUSIONS/SIGNIFICANCE: These results suggest that regulation of honey bee P450s is tuned to chemicals occurring naturally in the hive environment and that, in terms of toxicological capacity, a diet of sugar is not equivalent to a diet of honey

Self-Medication as Adaptive Plasticity: Increased Ingestion of Plant Toxins by Parasitized Caterpillars

Self-medication is a specific therapeutic behavioral change in response to disease or parasitism. The empirical literature on self-medication has so far focused entirely on identifying cases of self-medication in which particular behaviors are linked to therapeutic outcomes. In this study, we frame self-medication in the broader realm of adaptive plasticity, which provides several testable predictions for verifying self-medication and advancing its conceptual significance. First, self-medication behavior should improve the fitness of animals infected by parasites or pathogens. Second, self-medication behavior in the absence of infection should decrease fitness. Third, infection should induce self-medication behavior. The few rigorous studies of self-medication in non-human animals have not used this theoretical framework and thus have not tested fitness costs of self-medication in the absence of disease or parasitism. Here we use manipulative experiments to test these predictions with the foraging behavior of woolly bear caterpillars (Grammia incorrupta; Lepidoptera: Arctiidae) in response to their lethal endoparasites (tachinid flies). Our experiments show that the ingestion of plant toxins called pyrrolizidine alkaloids improves the survival of parasitized caterpillars by conferring resistance against tachinid flies. Consistent with theoretical prediction, excessive ingestion of these toxins reduces the survival of unparasitized caterpillars. Parasitized caterpillars are more likely than unparasitized caterpillars to specifically ingest large amounts of pyrrolizidine alkaloids. This case challenges the conventional view that self-medication behavior is restricted to animals with advanced cognitive abilities, such as primates, and empowers the science of self-medication by placing it in the domain of adaptive plasticity theory

Laboratory rearing of Agonopterix alstroemeriana, the defoliating poison hemlock (Conium maculatum L.) moth, and effects of piperidine alkaloids on preference and performance

Conium maculatum L. (Apiaceae), or poison hemlock, is an invasive plant native to Europe that has become extensively naturalized throughout North America. This species contains piperidine alkaloids, including coniine and -coniceine, that are highly toxic to vertebrates. C. maculatum was relatively free from herbivores in North America until the accidental introduction 30 yr ago of its monophagous European associate Agonopterix alstroemeriana (Clerck) (Lepidoptera: Oecophoridae). At present, A. alstroemeriana is widespread across the United States, and in some areas, such as the Northwest, can inßict substantial damage on its host plant, leading to desiccation and death. A. alstroemeriana has been used in recent years for the biological control of C. maculatum, although its use has been limited by the availability of larvae, which are Þeld-collected from early to mid-spring, and by the lack of available information about its life history and feeding habits. Here we describe a laboratory-rearing protocol incorporating a simulated winter to induce diapause and a semideÞned artiÞcial diet that allows the production of multiple generations per year and enabled us to determine the number and duration of A. alstroemeriana developmental stages. The development of the artiÞcial diet also permitted studies of preference and performance of A. alstroemeriana in relation to hostplant chemistry. Rearing A. alstroemeriana on artiÞcial diet supplemented with 1.5% DW coniine had no adverse impact on ultimate instar growth or performance. In a feeding behavior assay, the presence of coniine in the diet increased A. alstroemeriana consumption three-fold relative to control diet. This behavioral response contrasts dramatically with that of Agonopterix clemensella, a native Apiaceae specialist that does not use C. maculatum as a host; of 30 larvae tested, 29 fed exclusively on diets lacking supplemental coniine. The rearing protocol and artiÞcial diet presented here can facilitate further studies of ecological and evolutionary responses of C. maculatum after its reassociation with a coevolved herbivore in North America

Aposematism and mimicry in caterpillars

Volume: 49Start Page: 386End Page: 39