▪ Abstract Many agroecosystems are unfavorable environments for natural enemies due to high levels of disturbance. Habitat management, a form of conservation biological control, is an ecologically based approach aimed at favoring natural enemies and enhancing biological control in agricultural systems. The goal of habitat management is to create a suitable ecological infrastructure within the agricultural landscape to provide resources such as food for adult natural enemies, alternative prey or hosts, and shelter from adverse conditions. These resources must be integrated into the landscape in a way that is spatially and temporally favorable to natural enemies and practical for producers to implement. The rapidly expanding literature on habitat management is reviewed with attention to practices for favoring predators and parasitoids, implementation of habitat management, and the contributions of modeling and ecological theory to this developing area of conservation biological control. The potential to int...

Habitat Management to Conserve Natural Enemies of Arthropod Pests in Agriculture

OUTPU T 29 OUTPU T 30 OUTPU T 31 OUTPU T 32 OUTPU T 25 OUTPU T 26 OUTPU T 27 OUTPU T 28 OUTPU T 21 OUTPU T 22 OUTPU T 23 OUTPU T 24 OUTPU T 17 OUTPU T 18 OUTPU T 19 OUTPU T 20 OUTPU T 13 OUTPU T 14 OUTPU T 15 OUTPU T 16 OUTPU T 9 OUTPU T 10 OUTPU T 11 OUTPU T 12 OUTPU T 5 OUTPU T 6 OUTPU T 7 OUTPU T 8 OUTPU T 1 OUTPU T 2 OUTPU T 3 OUTPU T 4 29 30 31 32 25 26 27 28 21 22 23 24 17 18 19 20 13 14 15 16 9

A User’s Guide

What is ecological speciation

▪ Abstract This review covers selected literature from 1982 to the present on some of the ecological, behavioral, and biochemical aspects of hydrocarbon use by insects and other arthropods. Major ecological and behavioral topics are species- and gender-recognition, nestmate recognition, task-specific cues, dominance and fertility cues, chemical mimicry, and primer pheromones. Major biochemical topics include chain length regulation, mechanism of hydrocarbon formation, timing of hydrocarbon synthesis and transport, and biosynthesis of volatile hydrocarbon pheromones of Lepidoptera and Coleoptera. In addition, a section is devoted to future research needs in this rapidly growing area of science.

/pdf/ecological-behavioral-and-biochemical-aspects-of-insect-4bbi7ldpkx.pdf

Ecological, behavioral, and biochemical aspects of insect hydrocarbons*

Sperm are produced in astronomical numbers compared with eggs, and there is good evidence that sperm competition is the force behind the evolution of many tiny sperm. However, sperm production inevitably has costs. Recent research shows that male ejaculate expenditure is dynamic in both time and space, and that males are sensitive to risks of sperm competition and can vary ejaculate size accordingly. We focus on studies showing that males assess mating status and relative fecundity of females, and reveal that modulation of ejaculate investment by males can sometimes result in sperm limitation for females.

Sperm competition, male prudence and sperm-limited females

Reproductive division of labor in insect societies is regulated through multiple concurrent mechanisms, primarily chemical and behavioral. Here, we examined if the Dufour’s gland secretion in the primitively eusocial bumble bee Bombus impatiens signals information about caste, social condition, and reproductive status. We chemically analyzed Dufour’s gland contents across castes, age groups, social and reproductive conditions, and examined worker behavioral and antennal responses to gland extracts. We found that workers and queens each possess caste-specific compounds in their Dufour’s glands. Queens and gynes differed from workers based on the presence of diterpene compounds which were absent in workers, whereas four esters were exclusive to workers. These esters, as well as the total amounts of hydrocarbons in the gland, were produced in larger quantities by queenless, fertile workers at specific age groups as compared to queenright, sterile workers. Olfactometer bioassays demonstrated attraction of workers to Dufour’s gland extracts that did not represent a reproductive conflict, while electroantennogram recordings showed higher overall antennal sensitivity in queenless workers. Our results demonstrate that compounds in the Dufour’s gland act as caste- and physiology-specific signals and are used by workers to discriminate between workers of different social and reproductive status.

/pdf/show-me-your-dufour-s-gland-and-i-ll-tell-you-who-you-are-ayq1iu31yo.pdf

Show me your Dufour's gland and I'll tell you who you are: caste and physiology specific signals in Bombus impatiens

/pdf/special-issues-in-honor-of-professor-dr-dr-hc-mult-wittko-317ugy90.pdf

Special Issues in Honor of Professor Dr. Dr. hc mult. Wittko Francke, 28 November 1940–27 December 2020

CLOVE BUD OIL AS A NOVEL MOLLUSCICIDAL DRENCH FOR POTTED PLANTS R. Mc Donnell, R. Hollingsworth, J. Millar, and T. Paine 1 Dept of Crop and Soil Science, Oregon State University, Corvallis OR 97331 2 USDA-ARS-PBARC, 64 Nowelo Street, Hilo, Hawaii 96720 3 Dept of Entomology, University of California, Riverside CA92521 rory.mcdonnell@oregonstate.edu, robert.hollingsworth@ars.usda.gov, jocelyn.millar@ucr.edu, timothy.paine@ucr.edu

/pdf/clove-bud-oil-as-a-novel-molluscicidal-drench-for-potted-1moqiopr4r.pdf

Clove Bud Oil As A Novel Molluscicidal Drench For Potted Plants

Firefly flashes are well-known visual signals used by these insects to find, identify, and choose mates. However, many firefly species have lost the ability to produce light as adults. These “unlighted” species generally lack developed adult light organs, are diurnal rather than nocturnal, and are believed to use volatile pheromones acting over a distance to locate mates. While cuticular hydrocarbons, which may function in mate recognition at close range, have been examined for a handful of the over 2000 extant firefly species, no volatile pheromone has ever been identified. In this study, using coupled gas chromatography - electroantennographic detection, we detected a single female-emitted compound that elicited antennal responses from wild-caught male winter fireflies, Photinus corrusca. The compound was identified as (1S)-exo-3-hydroxycamphor (hydroxycamphor). In field trials at two sites across the species’ eastern North American range, large numbers of male P. corrusca were attracted to synthesized hydroxycamphor, verifying its function as a volatile sex attractant pheromone. Males spent more time in contact with lures treated with synthesized hydroxycamphor than those treated with solvent only in laboratory two-choice assays. Further, using single sensillum recordings, we characterized a pheromone-sensitive odorant receptor neuron in a specific olfactory sensillum on male P. corrusca antennae and demonstrated its sensitivity to hydroxycamphor. Thus, this study has identified the first volatile pheromone and its corresponding sensory neuron for any firefly species, and provides a tool for monitoring P. corrusca populations for conservation, and further inquiry into the chemical and cellular bases for sexual communication among fireflies.

Jocelyn G. Millar

Papers

Show me your Dufour's gland and I'll tell you who you are: caste and physiology specific signals in Bombus impatiens

Special Issues in Honor of Professor Dr. Dr. hc mult. Wittko Francke, 28 November 1940–27 December 2020

Clove Bud Oil As A Novel Molluscicidal Drench For Potted Plants

Identification of a Female-produced Sex Attractant Pheromone of the Winter Firefly, Photinus corrusca