摘要:

A process-oriented model was developed to simulate the phenology of the western grapeleaf skeletonizer,Harrisina brilliansBarnes&McDunnough. Processes defined in the model include spring adult emergence, moth longevity, oviposition, and immature life-stage development. Model versions including discrete or distributed delays of life-stage development were compared. Model output was compared with pheromone trap count data collected in seven individual vineyards in 1988 and in three vineyards each year from 1989 through 1991. Model predictions and pheromone trap counts at 50% of cumulative catch were within 7 d of each other in 36 of 48 generational moth flight periods. Based on the level of variation in immature life-stage development that is characteristic ofH. brillians, simulation output differed little between discrete delay versus distributed delay model versions. Results indicate that model implementation has considerable potential for predicting the seasonal occurrence of damaging immature life stages of this vineyard pest.

DOI:10.1093/ee/22.3.577

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Ants in 12 by 12 m plots in a young, regrown mixed oak-maple forest were attracted by sugar sprays or suppressed using barrier bands and poison baits. Sampling for ants using cat food baits and direct observations confirmed that ant abundance was changed by these treatments. Predation of tethered gypsy moth,Lymantria dispar(L.), larvae followed a similar pattern. Direct counts of young gypsy moth larvae were lower in plots where ants were attracted with sprays and higher in plots where ants were suppressed with baits. The implications these results have for control of gypsy moths by ants are discussed.

DOI:10.1093/ee/22.3.587

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Distribution of Japanese beetle,Popillia japonicaNewman, grubs and dispersal of an entomopathogenic nematode,Heterorhabditis bacteriophoraPoinar ‘Oswego’ strain (an isolate from New York state), were examined for 5 wk within soil-filled flats containing grass. Japanese beetle grubs uniformly dispersed to all sections of the flats not infested withH. bacteriophora‘Oswego’ strain. In flats infested withH. bacteriophora‘Oswego’ strain, however, greater proportions of Japanese beetle grubs were recovered in sections near the nematode release site or center sections of the flats.H. bacteriophora‘Oswego’ strain dispersed to all sections of the flats but dispersed more rapidly within the flats infested with Japanese beetle grubs than in flats not infested with Japanese beetle grubs.

DOI:10.1093/ee/22.3.595

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Alocasia odoraC. Koch, a hermaphroditic understory clonal herb, showed endogenous heat production during its blooming sequence. The first heat production cycle was associated with the initiation of the female phase and the third or the fourth cycle was associated with the male phase. Two flower-breeding flies,Colocasiomyia alocasiae(Okada) andC. xenalocasiae(Okada) (Diptera: Drosophilidae), were attracted by the strong odor that emanated fromA. odora. The flies carried pollen from other inflorescences thus affecting the reproductive success of the female phase of the hermaphroditic host. The flies stayed within the flowers, eating pollen during the subsequent male phase, then exited the inflorescence carrying pollen to other inflorescences, thus affecting reproductive success of the male phase. These flower-breeding flies increased the efficiency of the alternating reproductive tactics of the protogynous host plant. The special odor that emanated from the host during heat production may serve as an important stimulus for the two pollinator species to locate their host inflorescences.

DOI:10.1093/ee/22.3.601

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Young blackheaded fireworm,Rhopobota naevana(Hübner), feed on old leaves or, when available, new leaves of cranberry,Vaccinium macrocarponAiton. In laboratory choice experiments, first-instar caterpillars preferred new leaves to old leaves regardless of temperature and photoperiod or generation of larvae. In no-choice tests, more larvae died before feeding (61.4%) when exploring dormant cuttings with only old leaves than did those exploring growing cuttings (11.8%). Larvae continued to reject old leaves and climb to the top of shoots even when deprived of food. Duration of the first stadium was 65% longer on overwintered leaves compared with young leaves. Survival of larvae in commercial cranberry marshes was 4.9 times greater after new shoot growth than survival of larvae hatched before new growth.

DOI:10.1093/ee/22.3.607

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Use of hollow trees as diurnal resting shelter byLutzomyia shannoniDyar was studied on Ossabaw Island, Chatham County, GA. This species was collected in large numbers from constrictive openings (tree holes) leading into living hardwood trees that contained larger internal hollows. Laurel oak (Quercus laurifoliaMichaux) and live oak (Q. virginianaMiller) were the most commonly used species. Regression analysis demonstrated no significant correlation between mean number of sand flies trapped from individual tree holes and six environmental variables: tree species, crown class, and diameter of the trees containing the holes; and area, compass bearing, and height above ground of tree holes from which flies were collected. The mean number of sand flies captured from individual hollow trees in 1990 was similar to and significantly correlated with the mean number of sand flies collected from the same trees in 1988, indicating that the tree-hole niche is stable for sand flies over time at this site.

DOI:10.1093/ee/22.3.613

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Anisopteromalus calandrae(Howard) was reared at constant humidities of 75,56, and 43% RH at 30°C (14.6,12.8 and 11.6% grain moisture content) and a 12:12 (L:D) h photoperiod. Hosts were medium to large larvae of maize weevil,Sitophilus zeamaisMotschulsky, reared on corn. Daily fecundity, sex ratio, adult survivorship, and development time were measured to calculate net reproductive rate (Ro), generation time (T), intrinsic rate of increase (rm), and female adult life expectancy. Development time decreased slightly, but significantly, as humidity increased (from 11.45 ± 0.03 [SE] to 11.91 ± 0.04 d for females and from 10.71 ± 0.04 to 11.13 ± 0.05 d for males). Intrinsic rate of increase tended to increase (from 0.200 ± 0.006 to 0.223 ± 0.006) with humidity (from 11.6 to 14.6% moisture content).

DOI:10.1093/ee/22.3.618

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Recent attention in ecology has focused on factors that influence the foraging behavior of herbivores. We evaluated responses to different arrays of food plants exhibited by an abundant folivore within the tabonuco forest of Puerto Rico. Previous work indicates that the walkingstickLamponius portoricensisRehn forages on a limited array of plant species and selects habitats that contain high densities ofPiper treleaseanumBritton&Wilson. We designed three separate experiments to evaluate (1) if walkingsticks of different ages or of different sex have different food preferences, (2) if previous exposure to only one food type affects subsequent diet composition, and (3) if walkingsticks distinguish among leaves of different quality from the same plant. Four plants [Dendropanax arboreus(L.) Decne&Planch,Piper hispidumSw.,P. treleaseanum, andUrera baccifera(L.) Gaud.] known to be forage for this insect were used in food choice experiments. Multivariate analyses revealed that, at different ages, males and females exhibit different patterns of consumption. Likewise, preexposure to only one food influences subsequent diet differently depending upon preexposure regime and sex. In addition, preferences are shown for different qualities of leaves within single forage species. In particular, lower (older) leaves ofP. treleaseanumare preferred, whereas leaves ofD. arboreusandU. bacciferaare eaten indiscriminately. These results are consistent with the contention that herbivores forage within nutritional constraints. In addition, walkingsticks distinguish between plant species, recognize differences in leaf quality associated with age or position, and modify their diet to reflect past experience.

DOI:10.1093/ee/22.3.625

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Lamponius portoricensisRhen is a folivorous neotropical walkingstick that is a common light-gap inhabitant of the tabonuco forest in Puerto Rico. Little is known concerning the spatial distribution of this phasmatid or the manner in which it selects habitats. Based on multiple regression analysis of a suite of taxonomic and structural characteristics of understory flora, we determined that the density of walkingsticks was associated with patches that exhibit high apparency values forPiper treleaseanumBritton&Wilson andSymplocos martinicensisJacq., and low apparency values forDryopteris deltoidea(Sw.) Kuntze. The total development of the understory regardless of taxonomic composition at 76 cm (2.5 ft) and 107 cm (3.5 ft) also contributes to high walkingstick density, based on correlative analyses. Moreover, nonparametric analysis suggests thatL. portoricensisdisproportionately occurs onP. treleaseanum(approximately twice as often as expected based on plant apparency). Despite these associations, only a third of the variation in walkingstick density is accounted for by this suite of floral characteristics. The low vagility ofL. portoricensismay result in its having incomplete information about the abundance and distribution of forage plants, whereas patch-dynamic processes involving changes in quality of forage can confound the significance of apparency alone in predicting density. The production of aromatic attractants byPipermay act as the proximate cue affecting patch selection.

DOI:10.1093/ee/22.3.634

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

The effect of tannic acid on gypsy moth,Lymantria dispar(L.), larvae was stadium-specific. First- to third-instar gypsy moth were larger and developed faster on tannin-supplemented artificial diets than on control diets. After the start of the fourth stadium, however, larvae on tannin diets grew more slowly than larvae on control diets. The longer the insect's feeding period after the fourth stadium, the greater the negative effect of the tannin diets on eventual pupal weights. Female gypsy moths were most affected by tannin content of the diet because their extra instar results in a longer feeding period. This results in a proportionally greater influence of the negative effects of tannins.

DOI:10.1093/ee/22.3.642

出版商:Oxford University Press    

年代:1993

数据来源: OUP