摘要:

The effect of temperature on the fertility and longevity ofAnastatus semiflavidusGahan (Hymenoptera: Eupelmidae), an egg parasitoid of the range caterpillar,Hemileuca oliviaeCockerell, was investigated. Age-specific fertility,mx, and survivorship,lx, were measured at six temperatures. The intrinsic rate of increase,rm, on a daily basis was 0.043, 0.079, 0.145, and 0.166 for 20, 25, 30, and 35°C, respectively. Generation time,T, for each of these temperatures was 80.2, 57.2, 30.2, and 22.7 d; net reproductive rate,R0, was 31.0, 90.1, 80.3, and 43.3, and the mean number of offspring produced was 50.1, 140.7, 125.5, and 67.6. The parasitoid showed no evidence of oviposition at 10 and 15°C. A honey supplement greatly enhanced offspring production. The possible effects of seasonal temperatures on the reproduction of the parasitoid and ability to control the range caterpillar are discussed.

ISSN:1754-5692    

DOI:10.1093/ee/16.5.1035

出版商:Oxford University Press    

年代:1987

数据来源: OUP

摘要:

‘Urban’ elm, a single clone (no. 314) ofUlmus wilsonianaSchneider and hybrids between ‘Urban’ elm and theU. wilsonianaclone were compared for suitability for the adult elm leaf beetle,Xanthogaleruca luteola(Müller). Measures of suitability were adult male and female longevity, preoviposition period, and fecundity. Results showed that ‘Urban’ elm was generally suitable and theU. wilsonianaclone was generally unsuitable as a host. When compared with parents, most hybrids were intermediate in suitability. Thus, it appears that hybrid offspring inherit resistance to elm leaf beetles fromU. wilsoniana.

ISSN:1754-5692    

DOI:10.1093/ee/16.5.1042

出版商:Oxford University Press    

年代:1987

数据来源: OUP

摘要:

An estimate of the energy requirements of the three species of aphids,Monellia caryella(Fitch),Monelliopsis pecanisBissell, andMelanocallis caryaefoliae(Davis), that feed on pecan,Carya illinoensis(Wangenh.) K. Koch, indicated that during a lifetime, an individual ofM. caryellaconsumes 8.4-fold more energy (301 J) than that ofM. pecanis(36.1 J) and ca. 7-fold that ofM. caryaefoliae(44.8 J). When expressed as an average-age individual typical of a season-long field population,M. caryellaextracts ca. 8-fold more energy thanM. pecanisorM. caryaefoliae. Most energy consumed by all three species was excreted as honeydew. Growth efficiency was low for all three species, but was highest forM. caryaefoliae(25%), followed byM. pecanis(19%) andM. caryella(5%). Regression models were derived to estimate the cumulative level of energy consumed by aphids of various ages for growth, respiration, excretion, and total energy removal. Determination of the season-long standing-aphid population (and aphid-days) in two different aphid management programs within a 70-yr-old ‘Stuart’ pecan orchard and influence of these populations on nut yield indicated that all three species are highly detrimental to nut production; extraction of 1 × 106J, via feeding byM. pecanisorM. caryella, reduced in-shell nut production by 58.7 g per 70-yr-old ‘Stuart’ tree. A season-long standing population of one individual ofM. pecanisper leaf of such trees reduced in-shell nut yield by 2.41 kg; 18.13 kg was lost because of the same level ofM. caryella.

ISSN:1754-5692    

DOI:10.1093/ee/16.5.1045

出版商:Oxford University Press    

年代:1987

数据来源: OUP

摘要:

Larvae and adults of the pickleworm,Diaphania nitidalisStoll, and of the melonworm,Diaphania hyalinataL., were sampled in southern and central Florida during 1983 and 1984. Pickleworm (PW) larvae on cultivated hosts were found during the winter in south Florida (0.68–1 larva per m2), and appeared during the spring in central Florida. Major cultivated hosts for the pickleworm in the overwintering sites were squash and zucchini (Cucurbita pepoL.), whereas the major host for the melonworm (MW) was the Cuban pumpkin,Cucurbita moschataDuchesne. Native hosts of the PW and MW, i.e.,Melothria pendulaandMomordica charantia, supported PW and MW larvae during the fall in central and south Florida and during the winter in southern Florida. Adult PW were trapped during the winter only in the Florida Keys and in south Florida.

ISSN:1754-5692    

DOI:10.1093/ee/16.5.1057

出版商:Oxford University Press    

年代:1987

数据来源: OUP

摘要:

The effect of larval parasites of the pickleworm,Diaphania nitidalis(Stoll), and of the melonworm,Diaphania hyalinata(L.), were determined in southern and central Florida.Apantelessp.,Hypomicrogaster diaphaniae(Muesebeck),Pristomerus spinator(Fabricius),Casinaria infesta(Cresson),Temeluchasp., andChelonussp. were collected from the pickleworm and from the melon worm larvae.Gambrus ultimus(Cresson) andAgathis texana(Cresson) accounted for a small proportion of melonworm larval parasitism. Average parasitism of the pickleworm larvae was 2.28 and 4.33% in 1983 and 1984. Average parasitism of melonworm larvae was 12.14 and 13.42% in 1983 and 1984, respectively. Relationship between abundance of parasite species and cucurbit plants is discussed.

ISSN:1754-5692    

DOI:10.1093/ee/16.5.1062

出版商:Oxford University Press    

年代:1987

数据来源: OUP

摘要:

Tepary beans,Phaseolus acutifoliusA. Gray, were more resistant to feeding by the bean weevil,Acanthoscelides obtectusSay (Coleoptera: Bruchidae), than common beans,Phaseolus vulgarisL. Developmental times were longer and mortality percentages were greater on all tepary accessions compared with common beans. In most cases, emergence rates and adult prereproductive dry weights were lower on tepary versus common bean accessions. The estimated number of adults present after 182 d of seed storage was low for all tepary accessions and was high for most common bean accessions. Tepary beans may provide a useful germplasm source for the improvement of bruchid resistance in common beans.

ISSN:1754-5692    

DOI:10.1093/ee/16.5.1067

出版商:Oxford University Press    

年代:1987

数据来源: OUP

摘要:

A 4-yr study (1980–83) of population levels of the European corn borer,Ostrinia nubilalis, was conducted in Woodford County, Ill. Survivorship of the first generation was determined, as well as the levels of infection byNosema pyrausta(Paillot), a protozoan pathogen, and parasitism byMacrocentrus grandii(Hymenoptera: Braconidae) for the eggs, instars 3–5, and pupae for both generations of the corn borer.M. grandiibecame increasingly important as a factor in first-generation mortality during the 4-yr period. The level ofN. pyraustaincreased annually in the second-generation corn borer population.

ISSN:1754-5692    

DOI:10.1093/ee/16.5.1071

出版商:Oxford University Press    

年代:1987

数据来源: OUP

摘要:

The overwintered population density of the tobacco budworm,Heliothis virescens(F.), was estimated during 1981–83 for an area 146.4 km2in the central delta of Mississippi. Pheromone-baited cone traps were used to trap wild and released tobacco budworm males in a mark/release/recapture experiment. Estimates of the per-capita death rate of males trapped in 1982 and 1983 indicate that males live an average of 5–7 d in the spring. The total numbers of overwintered tobacco budworm moths emerging per hectare in 1981, 1982, and 1983 were estimated at 243, 5.7, and 20.9, respectively. Similar numbers of moths trapped at different distances from the release sites indicated that released moths were not clumped around the release sites.

ISSN:1754-5692    

DOI:10.1093/ee/16.5.1076

出版商:Oxford University Press    

年代:1987

数据来源: OUP

摘要:

The larvae of the imported willow leaf beetle,Plagiodera versicolora(Laicharting), feed in coordinated groups of full and half siblings during early development. When disturbed they exude an antipredator chemical, which may be more effective in groups. Two experimental studies were conducted to test for a group advantage. Groups of initial size 2–10 or 2–14 larvae were established and sampled from days 1 to 6 after hatching. The first study showed no effect of group size on survivorship nor on average leaf area consumed, but there was a significant effect of group size on larval growth. This suggested an increase in feeding efficiency with group size. In the second study the initial average rate of cannibalism for a group had a significant effect on subsequent individual growth rates, and survivorship increased with group size.

ISSN:1754-5692    

DOI:10.1093/ee/16.5.1082

出版商:Oxford University Press    

年代:1987

数据来源: OUP

摘要:

Adults of the Wilbur Springs shore bug,Saldula usingeriPolhemus, live longer (8.5 cf. 2.0 d) than the closely relatedSaldula pexaDrake when cultured in the high salinity water ofS. usingeri's habitat (Wilbur Hot Springs, Colusa County, Calif.). However, survivorship of the two species is similar in the low salinity water ofS. pexa's habitat (Grizzly Springs, Lake County, Calif., 15 km from Wilbur Hot Springs). Tests with glycine-radiolabeled water indicate thatS. usingeriimbibes fluids from its prey, larvae of the brine flyParacoenia calidaMathis, rather than imbibing water from its habitat; in contrast,S. pexaimbibes water from its own habitat, and Wilbur Hot Springs water as well. By imbibing fluids from its prey,S. usingeriexpends less energy for osmoregulation and its intake of toxic ions from Wilbur Hot Springs water is reduced. By imbibing Wilbur Hot Springs water, the potentially coexistingS. pexalacks these advantages. Although abiotic differences may explainS. pexa's absence fromS. usingeri's habitats, susceptibility ofS. usingerito spider predation may explain the absence ofS. usingerifromS. pexa's habitats. Predatory spiders are virtually absent fromS. usingeri's habitats but are very abundant inS. pexa's habitats. In laboratory tests, the wolf spiderPardosa ramulosaMcCook (Araneae: Lycosidae) killed 8-fold as many of the sluggishS. usingeriadults as the skittishS. pexaadults. Sluggishness may be an advantage whenS. usingerioccurs along margins of lethal thermal effluents (as at Wilbur Hot Springs) but it may be a disadvantage in nonthermal habitats with mobile predators.

ISSN:1754-5692    

DOI:10.1093/ee/16.5.1087

出版商:Oxford University Press    

年代:1987

数据来源: OUP