Unsaturated Cuticular Hydrocarbons Enhance Responses to Sex Pheromone in Spruce Budworm, Choristoneura fumiferana.

The primary sex pheromone components of the female spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae), are (E)- and (Z)-11-tetradecenal, produced in 95:5 ratio. However, male flight responses to calling females in a wind tunnel were faster and maintained longer than responses to any synthetic aldehyde blend. Analyses of cuticular extracts from spruce budworm adults revealed series of n-alkanes and n-monoalkenes with predominantly odd numbers of carbon atoms from C23- C29 in both sexes. (Z,Z,Z)-3,6,9-tricosatriene and (Z,Z,Z)-3,6,9-pentacosatriene were identified only in cuticular extracts from females. Pheromonally naïve males showed wing fanning and circling responses to forewing scales from females but not to scales from males. Males also exhibited the same strong responses to scales excised from pharate females, indicating that the pheromone components are produced by females prior to emergence. (Z)-11-hexadecenal and (Z)-5-tricosene enhanced male responses to the primary sex pheromone aldehydes in wind tunnel bioassays, including higher proportions of in-flight and copulatory responses by males and increased time on the source. Addition of (Z,Z,Z)-3,6,9-tricosatriene to the 95/5 blend of (E)- and (Z)-11-tetradecenal released close-range copulatory responses including abdomen curling on treated septa. We propose that the sex pheromone blend of C. fumiferana is composed of the 95/5 blend of (E)- and (Z)-11-tetradecenal as primary components, with (Z)-11-hexadecenal, (Z)-5-tricosene and (Z,Z,Z)-3,6,9-tricosatriene fulfilling secondary roles in orientation and close-range courtship.

Evidence of Male Hair Pencil Pheromone in Choristoneura fumiferana (Lepidoptera: Tortricidae).

Male Lepidoptera often possess specialized scales, called hair pencils that emit volatiles that are critical to mating success. Spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), males will display hair pencils to females before attempting copulation. The importance of volatiles on these hair pencils is, however, not clear. We compared the proportion of successful copulations in unmanipulated mating pairs to pairs where males had their hair pencils either removed or chemically washed, and to pairs where females were antennectomized. Mean proportions of successful matings were significantly lower in pairs where hair pencils had been manipulated or where females had been antennectomized compared with unmanipulated mating pairs. There was no significant difference in mating success between treatments where hair pencils had been manipulated; however, mating success was significantly lower in hair pencil treatments than in antennectomized treatments. Mean copulation proportions in hair pencil/antennectomized treatments were also significantly less than in respective sham-operated treatments. Our results suggest that volatiles are associated with hair pencils, and they may be required for mating success in C. fumiferana.

Ontogeny and stand condition influence the dispersal behavior of a defoliating specialist caterpillar.

A 4-yr field study was carried out to study the dispersal behavior of young larvae of the eastern spruce budworm (Choristoneura fumiferana Clemens) (Lepidoptera: Tortricidae) within and between crowns of balsam fir (Abies balsamea (L.) Miller), through the peak to decline of an outbreak. Newly hatched neonates, searching for overwintering sites in the fall, were frequently captured in sticky traps as they dispersed via "ballooning" (on silken threads) between and within tree crowns. A relatively small proportion of neonates were also captured on sticky tapes as they walked down the trunk toward the lower crown, where most larvae overwinter. In the spring, second-instar larvae (L2) searching for feeding sites also ballooned within and between trees, but were also frequently captured on traps on all crown levels as they walked up trunks. Over the course of our study, defoliation in our study trees increased, and current-year shoot availability decreased significantly, perhaps influencing L2 in search of food to disperse more frequently among hosts via ballooning. Results of our study suggest that the foraging priorities of neonates and L2 significantly influence larval dispersal behaviors and that spruce budworm larvae may vary behaviors in response to changing host condition during an outbreak.

DNA barcoding and the taxonomy of Microgastrinae wasps (Hymenoptera, Braconidae): impacts after 8 years and nearly 20 000 sequences.

Microgastrine wasps are among the most species-rich and numerous parasitoids of caterpillars (Lepidoptera). They are often host-specific and thus are extensively used in biological control efforts and figure prominently in trophic webs. However, their extraordinary diversity coupled with the occurrence of many cryptic species produces a significant taxonomic impediment. We present and release the results of 8 years (2004-2011) of DNA barcoding microgastrine wasps. Currently they are the best represented group of parasitoid Hymenoptera in the Barcode of Life Data System (BOLD), a massive barcode storage and analysis data management site for the International Barcoding of Life (iBOL) program. There are records from more than 20 000 specimens from 75 countries, including 50 genera (90% of the known total) and more than 1700 species (as indicated by Barcode Index Numbers and 2% MOTU). We briefly discuss the importance of this DNA data set and its collateral information for future research in: (1) discovery of cryptic species and description of new taxa; (2) estimating species numbers in biodiversity inventories; (3) clarification of generic boundaries; (4) biological control programmes; (5) molecular studies of host-parasitoid biology and ecology; (6) evaluation of shifts in species distribution and phenology; and (7) fostering collaboration at national, regional and world levels. The integration of DNA barcoding with traditional morphology-based taxonomy, host records, and other data has substantially improved the accuracy of microgastrine wasp identifications and will significantly accelerate further studies on this group of parasitoids.

Meloidogyne aquatilis n. sp (Nematoda:Meloidogynidae) from Spartina pectinata with a Key to the Canadian Species of Meloidogyne.

A new root-knot nematode, Meloidogyne aquatilis n. sp., attacking the roots of Spartina pectinata Link growing in the Ottawa River is described and illustrated. Meloidogyne aquatilis is distinguished from M. graminis by the light brown body color and by the absence of perineal lateral fields in the female. The male differs by the shorter stylet and by the hemizonid being separated by 7-9 annules from the excretory pore. The second-stage juveniles are also recognized by the 7-9-annule gap between the hemizonid and excretory pore and by the shorter tail with a disc-like subterminal tail structure, lower b ratio value, and inflated rectum. A key to the root-knot nematode species of Canada based on females, males, and juveniles is provided. The type host of Dolichodera fluvialis Mulvey and Ebsary, 1980, Spartina pectinata Link, is reported for the first time.