James L. Nation

A New Method Using Hexamethyldisilazane for Preparation of Soft Insect Tissues for Scanning Electron Microscopy

A new rapid procedure for preparing soft internal tissues from insects that allows air drying was found to compare favorably with tissues prepared by critical point drying. In the new procedure, tissues were fixed in 1% glutaraldehyde, dehydrated through a graded ethanol series, immersed in hexamethyldisilazane (HMDS) for 5 minutes, and air dried. Tissues prepared by both the HMDS treatment and by critical point drying were coated with gold for scanning electron microscopy. Tissues prepared by the HMDS treatment did not shrink or distort upon air drying and excellent surface detail was preserved. The HMDS treatment required about 5 minutes, whereas the critical point drying procedure required about 1.5 hours.

Comparison of volatiles emitted by male caribbean and mexican fruit flies

Volatiles emitted byAnastrepha suspensa andAnastrepha ludens males were trapped and compared by GC-MS. Both species emitted previously reported nine-carbon alcohols, (Z)-3-nonenol and (Z,Z)-3,6-nonadienol, and epimeric lactones, anastrephin and epianastrephin. A third isomeric lactone, the macrolide suspensolide, which was previously known only fromA. suspensa is reported here for the first time in the volatiles ofA. ludens. We also report that both species released different proportions of the same three sesquiterpene hydrocarbons:α-farnesene,β-bisabolene, andα-trans-bergamotene. Theβ-bisabolene was isolated in sufficient quantity fromA. suspensa volatiles to establish its absolute configuration as the (R)-(+)-enantiomer. Some plausible biosynthetic relationships of farnesol to the isoprenoid lactones and sesquiterpenes identified in this study are discussed. Finally, we report thatA. suspensa produces the monoterpene (Z)-β-ocimene whileA. ludens volatiles contained limonene.

Anastrephin and epianastrephin, novel lactone components isolated from the sex pheromone blend of male caribbean and mexican fruit flies

Anastrephin and epianastrephin, novel lactone components isolated from the male produced pheromone of two Anastrepha fruit fly species (Caribbean and Mexican) are assigned the structure and relative stereochemistry 1 and 2, respectively, on the basis of spectroscopic and chemical evidence including synthesis.

Biology of pheromone release by male caribbean fruit flies,Anastrepha suspensa (Diptera: Tephritidae)

Males of the Caribbean fruit fly,Anastrepha suspensa (Loew), typically form leks and attract females by releasing a multicomponent volatile pheromone. Previous reports have identified two nine-carbon alcohols, three lactones, a sesquiterpene, and a monoterpene in the volatiles. The present report is a study of the physiology of male pheromone release and of ecological and social interactions that influence pheromone release by laboratoryreared flies. Volatiles released by males were trapped on Tenax, eluted, separated, and quantitatively measured by gas chromatography. Experiments showed that the volatiles were primarily released from mouth and anus. Sealing the anal opening or the mouth with melted beeswax resulted in up to 40% or greater reduction in most components, and sealing both mouth and anus further reduced release of volatiles, but some volatiles are possibly still released directly from the cuticle. An anal pouch of everted tissue played a major role as a large evaporative surface for release of some of the volatile components. Male flies entrained to a 14∶10 light-dark cycle showed a peak release of volatiles at 11–12 hr into the photophase, but smaller quantities of the same volatiles were released over a broad period during the daylight hours. Laboratory-reared males peaked in pheromone release at 7–10 days and production and release continued through 35 days of age. Single males released significantly more of all components measured than did groups of males. The reduction by aggregations of males may be related to lekking behavior in this fruit fly. The pheromone probably serves to attract females to a lek site, but additional parameters are likely to enter into the choice of male made by the arriving female.

Caribbean fruit fly,Anastrepha suspensa (Loew), attraction to host fruit and host kairomones

Extracts of 22 fruits were tested for their attractancy toAnastrepha suspensa (Loew), the Caribbean fruit fly. Box-orange, calamondin, carambola, cattley guava, loquat, and Surinam-cherry were about equal in attractiveness to males and females. Nine synthetic chemicals, including four found in box-orange ripe seed, were attractive to females. Five synthetic chemicals, including two in box-orange ripe seed, were attractive to males. Farnesol,α-phellandrene, and 3-carene were highest in attractiveness to both males and females. Females were more attracted than males to 12 synthetic chemicals. These data suggest that host chemicals serve as attractants and that female and male specific attractants and traps could be developed from host kairomone data. These data also suggest that the volatilization of chemicals from water may play an important role in kairomone biology.

Cuticular hydrocarbons fromVarroa jacobsoni

The cuticular hydrocarbons fromVarroa mites collected in Florida and Italy and their honeybee hosts were characterized by gas chromatography (GC) and by coupled GC-mass spectrometry (MS). AVarroa mite has a hydrocarbon pattern that is qualitatively identical to that of its honeybee host. Mites and all stages of honeybees share a characteristic pattern of prominant alkane components including heneicosane, tricosane, pentacosane, heptacosane, nonacosane and hentriacontane. Adult honey bees and mites from adult bees also have as major components the alkenes 8-nC31:1, 10-nC31:1 and 10-nC33:1, while pupae and mites from pupae have only traces of these alkenes. Coupled GC-MS analysis after addition of dimethyl disulfide (DMDS) was used to determine the location of the double bound in the three prominent alkenes above. The question as to whether the mites simply acquire the hydrocarbons from their hosts or possibly synthesize them was not resolved. No characteristic differences between the hydrocarbons of mites from Italy and from Florida were found. We speculate that the hydrocarbons help the mites avoid desiccation and may help integrate the mites into honeybee colony life.

Sex-specific glands in tephritid fruit flies of the genera Anastrepha, Ceratitis, Dacus and Rhagoletis (Diptera : Tephritidae)

Abstract The objectives of this work were to systematically examine males and females of tephritid fruit flies from the genera Anastrepha, Ceratitis, Dacus and Rhagoletis for the presence of possible sex pheromone glands, and to determine whether particular glands may be characteristic of certain genera. Flies from the 4 genera were examined from paraffin embedded histological sections. Pleural epidermal glands and sexually dimorphic, enlarged salivary glands were found in males, but not in females, of 7 species of Anastrepha and in 2 species of Ceratitis. Females of these species do not develop the pleural epidermal glands at all, and although they have salivary glands, the glands do not have the large glandular mass of tissue that is found in males. The pleural glands were similar in all the males, and consisted of a single layer of enlarged, columnar epidermal cells in the pleural region of abdominal segments 3, 4 and 5. The salivary glands of males were divided into 4 types based upon structure. Pleural glands and enlarged salivary glands were searched for, but were not found, in 2 species of Rhagoletis and in 3 species of Dacus. Anal glands, opening externally on the last segment, were confirmed in C. capitata, and were found in C. rosa. Anal glands were not found in any of the other species. A diverticulum from the rectum, the rectal pouch or gland, was confirmed in D. dorsalis, D. cucurbitae and D. tryoni as already published, but this gland was not found in species of other genera. Growth of the pleural glands and salivary glands in males of A. ludens, A. fraterculus and C. capitata was described as a function of age of flies.

Suspensolide, a new macrolide component of male caribbean fruit fly(anastrepha suspensa [loew]) volatiles

Abstract A novel macrolide was isolated from volatiles produced by male Caribbean fruit flies and identified as ( E , E )-4,8-dimethyl-3,8-decadien-10-olide, I, on the basis of spectroscopic and chemical evidence, including synthesis.

Trans-verbenol, turpentine, and ethanol as trap baits for the black turpentine beetle, Dendroctonus terebrans, and other forest Coleoptera in north Florida.

Trans-verbenol, ethanol, and gum turpentine were evaluated alone and in combinations as trap baits for the black turpentine beetle (BTB), Dendroctonus terebrans (Olivier). Traps without turpentine ...

Vitellin and vitellogenin in the soldier bug, Podisus maculiventris: Identification with monoclonal antibodies and reproductive response to diet†

A 171,000 M(r )polypeptide of Podisus maculiventris (Say) (Heteroptera: Pentatomidae) that constituted 16% of the protein in eggs also constituted up to 25% of the protein in hemolymph of fed females. It was identified as the major or sole apoprotein of vitellogenin. Eggs contained major polypeptides of 171, 106, and 51 kDa. The hemolymph polypeptide was identified with a polypeptide (vitellin) in egg extracts by comparing molecular weights, specificity of occurrence in fed females, and immunological reactivities. Females, starved for 5 days after eclosion to assure complete previtellogenic development, produced vitellogenin within a day after feeding on larval Galleria mellonella, and within 4 days after feeding on an artificial diet. Appearance of vitellogenin preceded ovarian growth by 2-3 days. Two monoclonal antibodies raised against egg proteins of P. maculiventris were selected for their strong reaction against egg extract and female hemolymph and null reaction against male hemolymph. Only one 170-kDa band in egg and hemolymph reacted with the antibodies on denaturing Western blots. These monoclonal antibodies are being used to develop an enzyme-linked immunosorbent assay (ELISA) to quantitate reproductive response of females to diets of differing quality.