摘要:

Natural populations ofPlodia interpunctella(Hübner) andCadra cautella(Walker) were continuously exposed to synthetic sex pheromone for up to 99 days in 3 commercial peanut storage facilities. Mating activity, based on spermatophore counts, of females sampled at intervals from test buildings was not reduced in comparison to that of control females. It is emphasized that mating activity of wild females rather than inhibition of attraction of wild males to caged or tethered laboratory-reared females was the criterion of effectiveness employed in this study.

ISSN:0046-225X    

DOI:10.1093/ee/4.3.441

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

In laboratory studies onCadra cautella(Walker) we found that a component of the female sex pheromone (S.P.) complex,cis-9,trans-12-tetradecadien-1-ol acetate (c9,t12-14C-Ac) was slightly more effective than its isomers as a mating inhibitor. Relatively large amounts of a mixture ofc9,t12-14C-Ac and an additional component of the S.P.,c9-14C-Ac, on filter paper or topically applied to males reduced mating. However, the extent of mating inhibition was never greater than 29% of control mating. Inhibition of the stimulatory response of maleC. cautellais readily attained by previous exposure to synthetic S.P. but this inhibition is not a reliable index of its effectiveness as a mating inhibitor.

ISSN:0046-225X    

DOI:10.1093/ee/4.3.445

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Microencapsulatedcis- andtrans-11-tetradecenyl acetates (89:11) were sprayed onto apple trees at ca. 22 g/ha. This formulation disrupted (75–99%) the attraction of maleArgyrotaenia velutinana(Walker) to monitoring traps baited withcis- andtrans-11- tetradecenyl acetates (92:8) and dodecyl acetate, the natural pheromone blend of this species. Males held in smail cages and exposed to this formulation mated as frequently as a control group, indicating that the males' mating initiative was not suppressed.

ISSN:0046-225X    

DOI:10.1093/ee/4.3.448

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Virgin female clearwing moths (Sesiidae),Synanthedon pictipes(Grote and Robinson) female extracts, and isomers of 3,13-octadecadien-1-ol acetate (ODDA) were evaluated for attractancy to male clearwings.Podosesia syringae(Harris) females attracted conspecific males and males in 3 other genera in 2 subfamilies, whileS. pictipesfemales and female extracts attracted only conspecific males.(Z,Z)-ODDA attracted significant numbers of 4 sesiid species, while a mixture of 3 isomers of this compound attracted large numbers ofSanninoidea exitiosa(Say). (E,Z)-ODDA attracted onlyS. pictipesmales.Sesiids may be especially vulnerable to manipulation by these highly attractive synthetic sex attractants because these moths are relatively scarce even at pest population density, and quite host specific.

ISSN:0046-225X    

DOI:10.1093/ee/4.3.451

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Various plants containing pyrrolizidine alkaloids (PA) are visited by Lepidoptera, which congregate on dead stems, seeds, and foliage to feed. Most visitors to PA-plants belong to the nymphalid subfamilies Ithomiinae and Danainae and the moth families Ctenuchidae and Arctiidae. Ninety-six percent of ithomiines and danaines caught feeding at PA-plants are males which ingest alkaloids necessary for the production of PA-derived sex pheromones. Among Arctiidae and Ctenuchidae, however, many species show either unbiased or female-biased attraction patterns. Their visits may be linked to acquisition of PA's used for chemical defense or as yet unidentified nutritive substances. Extensive baiting with a variety of PA-plants as well as samples of etude alkaloids indicate that attraction is primarily the result of olfactory cues. Once a visitor lands on a PA-source, substances on the plant surface act as phagostimulants. Judging from attraction spectra of different PA-plant and chemical baits, at least 2 types of volatile attractants are involved: dissociated “esterifying acids” from the fused ring nucleus of the alkaloids, and substances derived from the nucleus itself. Preliminary observations of populations of Ithomiinae andDanausreveal that the presence of naturally occurring PA-sources are a major factor in determining population distribution, abundance, and reproductive behavior. The evolution of PA-attraction is discussed with respect to the various roles PA's may play in the Lepidoptera ingesting them.

ISSN:0046-225X    

DOI:10.1093/ee/4.3.455

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Certain plants containing pyrrolizidine alkaloids attract numerous Lepidoptera (Danainae, Ithomiinae, Ctenuchidae, Arctiidae) which congregate on dead shoots and inflorescences to feed. In many species, visitors are nearly all males. It is established that male Ithomiinae and Danainae ingest alkaloidal precursors for sex pheromones. Various parts of the live plantsHeliotropium indicumL. andEupatorium xestolepisRobinson are also attractive to these Lepidoptera and form the basis of an unusual relationship.H. indicumhas a number of pollinators that visit the plant primarily for the purpose of obtaining pheromone precursors, spending much of their time at ripe seeds. InE. xestolepis, the floral fragrance may contain some of the volatile compounds typical of dead plant tissue which attract male Ithomiinae and Ctenuchidae. These insects constitute nearly 100% of the pollinators. In addition, this plant shows ecological specialization for subsisting in the habitat of its pollinators.

ISSN:0046-225X    

DOI:10.1093/ee/4.3.474

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

To evaluate the importance of subterranean termites in the detritus cycle it was necessary to determine density and dispersion of termite foraging populations and the types and amounts of wood available to them. Sampling was carried out in a shrub-invaded desert grassland south of Tucson, Ariz. Fifty randomly located, circular quadrats were sampled to study the relationships between foraging termites and the abundance of wood. Standing crop biomass of superficial dead wood was 2127 kg/ha. Five plant species represent 97.6% of the biomass while 6 account for 96.4% of the 450 kg/ha of such wood produced annually. Instantaneous estimates of mean surface foraging numbers ofHeterotermes aureus(Snyder),Gnathamitermes perplexus(Banks),Paraneotermes simplicicornis(Banks),Amitermes wheeleri(Desneux), andA. minimusLight were 6.89, 0.35, 1.31, 1.51, and 0.12 termites/m2. Caste composition varied between the species and was important in determining total biomass. Neither superficial dead wood nor foraging termites were randomly dispersed; rather, they were aggregated on the site. Estimated total number of all 5 termite species was set at 1025/m2with a biomass of 0.414 g/m2, based on a literature ratio between surface and subsurface foragers ofGnathamitermes tubiformans. We have tested the hypothesis that quantity and/or quality of wood available influences termite abundance. Results indicate that the abundance of a particular oligophagous species is correlated with the quantity of a highly perferred wood, where there is no correlation between ployphagous species and the quantity of any species of wood.

ISSN:0046-225X    

DOI:10.1093/ee/4.3.480

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Early nymphal mortality in the cotton fleahopper,Pseudatomoscelis seriatus(Reuter), was increased in constant temperatures above 29.4°C or below 23.9°C. Nymphal survival in 40.6, 12.8, and 15.0°C regimens was low. No significant differences were found in length of preoviposition or oviposition periods or numbers of eggs deposited at different constant temperatures. However, fewer females deposited eggs in temperatures above 29.4°C or below 23.9°C.There was close agreement between theoretical thermal constants and observed thermal constants calculated for insects reared in constant, fluctuating, and insectary conditions where temperatures were not extreme. Predictions of developmental rates at high or low temperatures were less accurate. During the time most fleahoppers are present in the field, the thermal constant of the total life cycle (egg to egg) for fleahoppers reared on hosts as suitable as beans and potatoes is probably between 570 and 600°C-days above a developmental threshold of 7.0°C.

ISSN:0046-225X    

DOI:10.1093/ee/4.3.487

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Whole plant counts (visualin situexamination) for hooded beetles,Notoxus monodonF.; cotton fleahoppers,Pseudatomoscelis seriatus(Reuter); lady beetles,Hippodomiaspp.; and collops,Collopsspp., were made on ¼ acre of cotton to determine the best sampling-unit size. The insect counts were distributed according to the negative binomial, withkvalues increasing with sampling-unit size. The number of samples, linear row feet, and sampling time required for equal precision are illustrated for 7 sampling-unit sizes at 2 levels of precision. The single plant sampling-unit was determined as optimum for minimizing the variance.

ISSN:0046-225X    

DOI:10.1093/ee/4.3.491

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Adult emergence in the sorghum midge,Contarinia sorghicola(Coquillett), is a singlephase diel rhythm with peak eclosion 1–2 h after sunrise, Males began emerging 30–45 min earlier than females and by the time the latter reached peak numbers, male emergence was 85% complete. Males began emerging at 55–60°F (12.8–15.6°C) and females at 65–70°F (18.4–20.1°C). Emergence of both sexes ceased at 95°F (35°C). The sex ratio was near 1:1 early in the season (Aug.) but by October females outnumbered males ca. 2:1.Females dispersed to susceptible florets and oviposited until death. Males continued to swarm around head from which they emerged and were not associated with blooming heads.

ISSN:0046-225X    

DOI:10.1093/ee/4.3.495

出版商:Oxford University Press    

年代:1975

数据来源: OUP