摘要:

Aggregation responses of adult predators of lepidopterous pests to selected dosages of aqueous homogenates of terminal instar larvae of corn earwormHeliothis zea(Boddie) and fall armywormSpodoptera frugiperda(J. E. Smith) were measured in whorl-stage corn. The mean number ofColeomegilla maculata(De Geer) andGeocoris punctipes(Say) was significantly higher through days 1 and 6, after treatment, respectively, in plots receiving a single application of 0.1 and 1.0 larval equivalents (LE) ofH. zealarval homogenate (LH) per plant than in control plots. No consistent response to the LH was noted forHippodamia convergensGuerin Ménèville. Populations ofC. maculataandG. punctipesresponded equally well to the LH ofH. zeaandS. frugiperda. The number ofG. punctipesandC. maculataincreased significantly within 1 h of application of 1.0 LE per plant ofH. zeaLH. Populations ofG. punctipesandC. maculatapeaked at 3.8- and 11.4-fold higher, respectively, than the population of the control by 8 h after treatment. Significantly moreC. maculataegg masses were associated with the greater number of adults in plots treated with 1.0 LE ofH. zeaLH per plant. No differences were detected in rates of predation on artificially applied egg masses ofS. frugiperdaplaced in untreated plots; or in plots treated with theS. frugiperdaLH (1.0 LE per plant), despite significantly higher populations ofC. maculataadults in the treated plots. The LH competed with theS. frugiperdaegg masses as a source of food forC. maculata. However, becauseG. punctipeslikely are unable to use the LH as a food source, they apparently responded to host-seeking stimuli associated with the host larvae.

ISSN:0046-225X    

DOI:10.1093/ee/14.3.360

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

Urolepis rufipes(Ashmead), previously unreported to parasitize house flies (Musca domesticaL.), was recovered from house fly pupae at five of eight dairies surveyed in 1982 and at all eight dairies surveyed in 1983 in New York State. It was not collected from 8 dairies surveyed in 1981 nor from 10 poultry facilities surveyed in 1981 and 1982. Of the 445U. rufipescollected in 1983, 87% came from outdoors, primarily from manure pits and other accumulations of wet manure.U. rufipeswas collected from July through October, with peak numbers occurring in mid-September. It made up 20% and 15% of all parasitoids collected in 1982 and 1983, respectively. Laboratory studies at 30°C and 60% RH indicate a sex ratio of 2.65 females per male, a mean fecundity of 24.5 (range, 23 to 25) females and 9.2 (range, 3 to 15) males per female, and mean developmental times of 10.2 (range, 9 to 13) and 9.7 (range, 8 to 15) days for females and males, respectively. The short developmental time, the prevalence in wet, outdoor manure habitats, and occurrence at 43°N latitude suggest thatU. rufipesis adapted to flies at dairies in temperate climates.

ISSN:0046-225X    

DOI:10.1093/ee/14.3.365

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

In 1983 and 1984 I studied the gypsy moth,Lymantria dispar(L.), predator,Calosoma sycophantaL., in a collapsing gypsy moth infestation. Beetles caught in tree-trunk barrier traps were marked and released to assess the directions and distances they dispersed and their population sizes. In both years, about 700 to 1,000 adult beetles of each sex were in the 4-ha site; females were slightly less abundant than males. In 1983, gypsy moths were abundant, male and female beetles were active, and many beetle progeny were produced. Male beetles were more mobile than females and were trapped more often. In 1984 few gypsy moths were present and although the beetle population was substantial, very few progeny were seen and adults dispersed little. Thus, beetle behavior differs substantially at different prey abundances. By examining gypsy moth pupal remains, I found that the progeny of 1983 beetles destroyed three-fourths of the gypsy moth pupae located on tree trunks.C. sycophantamay, thus, have a substantial impact on gypsy moths.

ISSN:0046-225X    

DOI:10.1093/ee/14.3.370

出版商:Oxford University Press    

年代:1985

数据来源: OUP

ISSN:0046-225X    

DOI:10.1093/ee/14.3.378

出版商:Oxford University Press    

年代:1985

数据来源: OUP

ISSN:0046-225X    

DOI:10.1093/ee/14.3.380

出版商:Oxford University Press    

年代:1985

数据来源: OUP