摘要:

This study focused on the effects of constant- and variable-humidity and temperature regimes on the developmental periods of the spruce spider mite,Oligonychus ununguis(Jacobi), and a predator of this mite,Neoseiulus fallacis(Garman). Variable-humidity regimes, either alone or with variable-temperature regimes, had no significant effect on the developmental period of the immature stages ofO. ununguis. Survival was marginally decreased under variable-temperature regimes. Temperature was the overriding influence for development of this mite. Developmental periods ofN. fallacisimmatures, however, were markedly increased by the use of a constant-humidity regime with a constant-temperature regime. In addition, survival of the immatures was low under low constant-humidity regimes. The effects of a range of constant-humidity regimes over a range of constant-temperature regimes on the survival and developmental period ofN. fallaciseggs also were studied. Humidity was found to have a statistically significant but biologically trivial effect on the egg developmental period at the lower temperatures. However, when the vapor pressure deficit was high, there was a significant relationship between egg survival and vapor pressure deficit. The data suggest that the meteorological conditions in the field during the hot, dry summer months may not support a large population ofN. fallacisand thereby allowO. ununguispopulations to build up during these months.

ISSN:1754-5692    

DOI:10.1093/ee/18.5.743

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Aggregation pheromone production byOryzaephilus surinamensis(L.) andO. mercator(Fauvel) was measured as a function of adult age and population density. Porapak Q-captured volatiles were monitored weekly from mixed-sex adults feeding on rolled oats at two different population densities. Macrolide aggregation pheromones (cucujolides) were produced by males of both species by the end of the first week after eclosion and maximum production rates were still maintained more than 3 mo later. ForO. mercator, the previously identified cucujolides were 3(Z),11(R)-dodecen-11-olide and 3(Z),6(Z),11(R)-dodecadien-11-olide, and forO. surinamensis, 3(Z),6(Z),11(R)-dodecadien-11-olide, 3(Z),6(Z)-dodecadienolide, and 5(Z),8(Z),13(R)-tetradecadien-13-olide.O. surinamensisless than 1 mo after eclosion showed a two- to threefold increase in cucujolide production compared with adults maintained at a fivefold higher population density. In comparison, cucujolide production by youngO. mercatorwas less sensitive to the presence of conspecifics. At the lower population density, adults of both species more than 1 mo after eclosion produced almost optically pure (R)-(−)-1-octen-3-01. Laboratory bioassays in a two-choice, pitfall olfactometer indicated that l-octen-3-01 alone serves as an aggregation pheromone, and when added to mixtures of cucujolide pheromones, it extends the attractive range of the cucujolides for bothOryzaephilusspecies.

ISSN:1754-5692    

DOI:10.1093/ee/18.5.747

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

The supercooling capacity and cold tolerance ofMusca domesticaL. embryos, larvae, prepupae, pupae, and adults were examined. Two-h-old embryos had the greatest supercooling capacity (−34°C) followed by 2-d-old pupae (−24°C), adults (−16°C), 1-d-old larvae (−15°C), and prepupae (−14°C). Significant differences (P≥ 0.001) between temperatures of crystallization means were observed among and within several stages. Age within a developmental stage was critical to survival at the treatment temperatures tested. The 50% mortality levels of the five developmental stages exposed to 10, 5, 0, and −5°C were determined and compared with the supercooling capacity. At temperatures above O°C, pupae were the most cold tolerant, followed by adults, larvae and prepupae, and embryos. However, at −5°C, 10- and 12-h-old embryos were able to tolerate the longest exposure, followed by pupae, larvae, prepupae, and adults. With this insect, the temperature of crystallization is not a reliable indicator of the lowest lethal temperature.

ISSN:1754-5692    

DOI:10.1093/ee/18.5.756

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Larval feeding bioassays were done with the lesser cornstalk borer (Elasmopalpus lignosellus(Zeller)) using agar plugs containing samples from eight peanut (Arachis hypogaeaL. cv. Florunner) plant parts to determine their phagostimulative effects. Agar plugs containing residues from roots, pegs, lower stems, lower leaves, higher stems, higher leaves, young pods, or old pods were fed upon the most by larvae. Chemically pure cellulose was not an adequate substitute for these residues. The methanol and water extracts had some phagostimulative properties. When samples of different peanut plant parts were tested together, significantly more lesser cornstalk borer larvae fed on those obtained from pods and leaves.

ISSN:1754-5692    

DOI:10.1093/ee/18.5.763

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

The biology ofLiriomyza sativaeBlanchard on castor bean,Ricinus communisL., was studied. Host preferences ofL. sativaeandL. trifolii(Burgess) for castor bean and celery,Apium graveolensL., were determined. Total developmental times for the immature stages ofL. sativaereared on castor bean varied from 13.1 d at 30°C to 28.5 d at 20°C; pupal development lasted slightly longer than the combined egg and larval stages.L. sativaefemales produced a mean of 164.5 larval progeny at 25°C on castor bean during an average lifespan of 13.4 d. Fecundity peaked at age five days.L. sativaefemales strongly preferred castor bean over celery for oviposition; no progeny were produced on celery. In contrast,L. trifoliiproduced about four times as many progeny on celery as on castor bean.

ISSN:1754-5692    

DOI:10.1093/ee/18.5.768

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

The effect of damage by the heliozelid leafminer,Coptodisca negligensBraun, on abscission of cranberry,Vaccinium macrocarponAiton, leaves was studied in Connecticut during 1986. The abscission of second-year leaves was significantly greater and earlier on wild and potted vines with leafminer injury than on those without injury. The mean week of abscission was significantly earlier (about 1 wk) for leaves with two miners than for those with one miner. Wild plants in a bog dropped most of their mined leaves during June when fourth instars ofC. negligenswere completing their development. In the laboratory, 90% of 20 fourth instars in detached leaves survived to construct oval leaf cases for pupation.

ISSN:1754-5692    

DOI:10.1093/ee/18.5.773

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Seasonal and spatial distribution patterns ofCulicoides furens(Poey) andC. mississippiensisHoffman larvae were determined during a 19-mo study of a 5-ha salt marsh located near Yankeetown, Fla. Larvae of both species were found throughout the year in substrate samples taken from all vegetation types (includingSpartinaandDistichlis), but their relative distributions apparently changed according to annual tidal dynamics. Maximum larval production occurred when approximately equal flood index values were recorded; i.e., 0.22 (December–April) forSpartinaand 0.20 (May–September) forDistichlis. These values represent periods of least and most frequent flooding forSpartinaandDistichlis, respectively.C. mississippiensisandC. furenswere most abundant, respectively, inSpartinaandDistichlisareas.

ISSN:1754-5692    

DOI:10.1093/ee/18.5.778

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Populations ofTrichoplusia ni(Hübner) andAutographa californica(Speyer) were monitored in alfalfa, cotton, and lettuce in the Imperial Valley of California. Both species were found in all three crops withT. nipredominant in cotton and lettuce. In alfalfaT. niwas predominant during most of the year, butA. californicawas more abundant during March and April. Populations ofT. niwere highest in spring, early summer, and late fall;A. californicapopulations were highest during spring.

ISSN:1754-5692    

DOI:10.1093/ee/18.5.785

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

Reproductive behavior of the egg parasitoidTetrastichus gallerucae(Fonscolombe) is described. Males show the same distinct behavioral pattern before and after copulation. Males were aggressive toward other males on or near parasitized egg masses. No overt female courtship behavior was observed. Males mated more than once, but females were unreceptive after a successful copulation. Oviposition and associated behavior for each female was>8 h on elm leaf beetle,Xanthogaleruca(=Pyrrhalta)luteola(Müller), egg masses of 20 eggs. Females did not show any egg guarding or external marking behavior. Possible costs of female ovipositional behavior and male guarding behavior are discussed.

ISSN:1754-5692    

DOI:10.1093/ee/18.5.791

出版商:Oxford University Press    

年代:1989

数据来源: OUP

摘要:

The density of eggs laid per centimeter of gallery by laboratory-rearedIps calligraphus(Germar) females was determined following introduction into thin phloem bolts cut from 25-yr-old slash pine,pinus elliotiiEngelm. var.elliottii, that had been fertilized at the time of planting with a combination of nitrogen, phosphorus, and potassium, or phosphorus alone. Egg density was negatively correlated with female pronotal width (size) and positively correlated with the phloem phosphorus concentration. These two variables explained 64% of the variation in egg density. It is hypothesized that altering egg density in response to varying phloem nutrition represents a resource partitioning mechanism that reduces larval competition. These results also suggest that excessive phosphorus fertilization of slash pine on the Coastal Plain soils could contribute to a build-up in the beetle population without the added benefits of stand growth.

ISSN:1754-5692    

DOI:10.1093/ee/18.5.795

出版商:Oxford University Press    

年代:1989

数据来源: OUP