摘要:

β-nitropropionic acid (BNPA) added to a pinto bean diet and fed to cabbage loopers,Trichoplusia ni(Hübner), increased the mortality of 1st instar larvae, the length of the larval and pupal periods, and the life span of male moths, but reduced pupal weights and fecundity. A mixture of glucose triesters, (coronillin and karakin) was less toxic than BNPA. A diester (cibarian) was the least toxic of the materials tested. All 3 compounds were isolated from leaves of crown vetch,Coronilla variaL., and are toxic to nonruminant animals. BNPA and its glucose esters may have adaptive significance as a feeding deterrent to insects that attempt to feed on crownvetch. Plant breeding programs designed to eliminate BNPA from crown vetch to make the forage nontoxic to nonruminants may accidentally produce an insect-susceptible cultivar.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.229

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Males and females of 3 species of flour beetles,Tribolium confusum, T. castaneumandT. brevicorniswere infected with ova ofHymenolepis diminutato determine whether the sex of the host influences the number of cysticercoids harboured by the beetles and the extent of host specificity withinTribolium. All of the species were successfully infected byH. diminutaova.InT. confusumandT. castaneuma significantly greater percentage of female beetles became infected compared to the males. Average number of cysticercoids per infected beetle was also significantly greater in the females ofT. confusumandT. castaneum. T. brevicornisshowed no significant difference between the sexes in the percentage of infected beetles or in the number of cysticercoids harboured by each beetle. Number of cysticercoids per gram of body weight was also greater in the females compared to males. A significantly higher percentage of females of all 3 species used in the experiment were infected compared to the males.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.233

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

A 50m2salt marsh study plot was used to determine relative densities of flowering plants and to directly observeAedes sollicitansnectar feeding. In addition to 190 flower-visiting mosquitoes (103 ♀, 87 ♂), 260 resting and 280 blood-seeking females were collected from the marsh and an inland woodland habitat; specimens were agegraded by the Polovodova method and analyzed for fructose by an anthrone test. There were no significant differences in nectar feeding rates between sexes. Newly-emerged and recently-oviposited mosquitoes nectar-fed fromSolidago sempervirens(seaside goldenrod),Achillea millefolium(yarrow),Hieracium pratense(king-devil hawkweed), andChrysanthemum leucanthemum(ox-eye daisy) both at times when these plant hosts were at high and very low relative densities. Mosquito avoidance of other dominant blooming plant species and their selection of plants having lighter-colored flowers suggests that there may be preferences for certain plant hosts. Females nectar fed in all phases of the gonotrophic cycle, but there was a significantly higher rate of recent nectar feeding among females in the salt marsh (avg. 60% positive) than in woodlands (avg. 11%). Greater nectar-feeding activity in salt marshes is probably indicative of the female's need for simple sugars before dispersing inland and/or that nectar sources were more plentiful.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.237

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

The effect of gossypol acetate on the growth, pupation rate and mortality of larvae ofSpodoptera littoralis(Boisd.) was investigated by incorporating the compound in a semi-synthetic diet. 0.5% and 0.25% gossypol acetate-treated diets as well as an untreated diet were offered to the larvae throughout their entire life span. On the 0.5% gossypol acetate diet, within the 1st 10 days larval mortality was nearly 70%, the average weight was very low at each observation time, and only 0.3% of the larvae pupated. On the 0.25% gossypol acetate diet 44% of the larvae died within the 1st 10 days, the average weights were intermediate between 0.5% and the control, and 26% of the larvae pupated.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.243

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

A synthetic sex pheromone for the pitch pine tip moth,Rhyacionia rigidana(trans-8,trans-10-dodecadienyl acetate) prevented males of the Nantucket pine tip moth,R. frustranafrom responding to conspecific calling females in traps.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.245

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

This paper describes patterns in the assemblages of insects associated with nearly 200 different patches of Ohio old-field vegetation. The patches were located randomly in an old-field or upon experimental islands in a nearby pond. Experimental islands were defaunated at the beginning of the experiment. Assemblages on old-field patches vary with respect to species composition but maintain a trophic structure of 12–14 herbivore species, 5–6 saprophore species, and 2–3 carnivore species with a maximum of 5–7 parasite species (95% confidence intervals) between late June and early August. The numbers of herbivore, saprophore, carnivore, or parasite species regained by defaunated islands are similar to those seen in the old-field. Evenness and population density characteristic of old-field patches is not regained by defaunated islands.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.247

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Examination of ovarian maturation in field-collected adults and observations of the reproductive development of adults reared under experimental photoperiods indicate thatNotonecta undulatahas 2 generations annually in Connecticut. Females of the 1st generation that become adults during July, when the photoperiod is greater than 14½ h, become reproductively mature and produce a second generation. Individuals that become adults after July or early August enter reproductive diapause. Diapause is terminated in most females by late October but little active vitellogenesis occurs during the autumn.Approximately 75% of the females reared at 22°C in the laboratory under a 15-h photoperiod (LD) oviposited within 4 wk after the adult molt, whereas less than 20% of the females reared under a 12-h photoperiod (SD) oviposited in the same period of time. SD females generally had terminal oocytes no longer than one-third the length of mature oocytes and their oocytes had little or no yolk. Oosorption occurred in the few SD females that developed mature oocytes. Photoperiods under which the nymphs were reared appeared to have no effect on the subsequent reproductive development of the adults. Low temperature (15°C) did not modify the effect of LD conditions in preventing diapause.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.258

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

In February 1977 issue of Environmental Entomology, paper by W. G. Wellington, pages 1–8, second line on page 7: word “exercised” should be “exorcised.”In February issue of Environmental Entomology, paper by Ellenberger and Cameron, pages 101–106, the ratio in Footnote “a”, Table 2, page 105, should read:$\frac{\tt\bar Y^2}{\tt\ S^2 - \bar Y }$

ISSN:1754-5692    

DOI:10.1093/ee/6.2.262

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Peak infestations of adultAmblyomma americanum(L.) ticks on white-tailed deer [Odocoileus virginanus(Boddaert)] occurred in late May, June and early July in 1973 and 1974. Significant nymphal tick infestations were observed from April to October. Peak larval tick infestations occurred in late July and August. The dynamics of the infestation levels were affected by climatic conditions and deer numbers.Repression of repletion of the adult and nymphal tick stages, apparently a response to photoperiod, has survival value in that the subsequent stage after molt does not become an active host-seeker at a time unfavorable for its maximum survival.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.263

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Adult males of the glassy cutworm,Crymodes devastator(Brace), were attracted to traps baited with equal-part mixtures ofZ-11-hexadecen-1-yl acetate,Z-11-hexadecenal andZ-7-dodecen-1-yl acetate. Other species were not attracted to this ternary sex attractant. Electroantennogram measurements revealed strong male antennal stimulations by each of the 3 components. Attractancy in the field was completely inhibited by the incorporation of small quantities of eitherZ-11-hexadecen-1-ol orZ-9-tetradecen-1-yl acetate in the chemical lures.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.270

出版商:Oxford University Press    

年代:1977

数据来源: OUP