摘要:

Abstract:The biology, ecology and ethology ofPissodes piceae, taking into account phenology, life cycle, kind and state of inhabited breeding material, factors limiting the reproduction and development, and its ecological requirements (species composition and structure of the stand, soil moisture, shading conditions, age and size of infested trees, quality of their crowns and stems, needle condition, coexistence with other species of cambio‐ and xylophagous insects in ecological communities and associations, etc.) are presented in a monographic manner on the basis of the long‐term field observations (1980–1992) carried out mainly in the Krynica Experimental Forest of the Faculty of Forestry, Agricultural University of Kraków (Western Carpathians, Southern Poland), supplemented with laboratory rearings. The results obtained during this study permitted us to determine the economic importance of the fir weevil in the pure fir and mixed mountain forests as well as to work out the methods of preventing the damages, forecasting its occurrence and controlling its n

ISSN:0931-2048    

DOI:10.1111/j.1439-0418.1996.tb01569.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:The effect of host tree on the ecology of the insect natural enemy complex ofIps typographuswas investigated. Tree species was found to influence parasitoid composition and abundance, with pteromalids being more abundant inPicea jezoensisthan inP. abies. Within trees, bark texture had a significant influence on pteromalid density with higher densities occurring in smooth bark. Bark hardness was also shown to affect density of both pteromalid and braconid parasitoids. Pteromalid parasitoids were found to respond density dependently to host density. Predators showed no consistent response to host tree. Only the clerid predatorThanasimus substratusshowed a density‐dependent response to prey density. A predatory dolichopodid fly,Medeterasp., was shown to be a significant mortality factor forIps typographuslarvae. These results are compared to those of previous studies and their relevance to biological control commented upo

ISSN:0931-2048    

DOI:10.1111/j.1439-0418.1996.tb01570.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:Feeding behaviour ofHelicoverpa armigeraHbn. (Lep., Noctuidae) on tomatoes (Lycopersicon esculentumL.) in greenhouse:The feeding behaviour of larvae ofHelicoverpa armigerawas studied on tomato plants grown in a greenhouse using32P‐labelled caterpillars. When first instar larvae emerged from eggs deposited onto usual egg‐laying sites, they fed on leaves, occasionally onto inflorescence, and some burrowed into fruit when they reached the third instar. During the fourth and fifth instar, they fed alternately on leaves and fruit, and occasionally on stems. Toward the end of their development, the caterpillars went through a searching phase to look for a shelter for metamorphosis. This typical sequence could be altered and become more complex in relation with the emerging site of the caterpillars. Green fruits of tomato are usually damaged by larvae of at least 7–8 day old which made several entry holes. These entries were not usually followed by feeding, but they nevertheless damaged an average of 2 ± 0.75

ISSN:0931-2048    

DOI:10.1111/j.1439-0418.1996.tb01571.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:In forests of Pinus nigraArn. 147 egg‐batches ofT. pityocampawere collected at different locations in Bulgaria in September‐October 1991 and March and June 1992. Directly after collection all batches were put singly into test tubes with cotton stoppers and stored under laboratory conditions at 20–22°C. Oviposition always started from the base towards the top of the needle. The emergence of egg parasitoids were controlled almost daily and they were counted and identified. The eggs from which parasitoids emerged were marked for further studies. After removing the scales and opening the eggs, the impact of the parasitoid species was evaluated by their meconia and remains.Ooencyrtus pityocampae(Mercet) was observed as the most abundant egg parasitoid, followed byAnastatus bifasciatus(Fonsc.) andBaryscapus servadeii(Dom.). The hyperparasitoid,Baryscapus transversalisGraham was recorded for the first time in Bulgaria and the polyphagous speciesMacroneura vesicularis(Retzius) was collected in Bulgaria for the first time from an egg‐batch ofT. pityocampa. Trichogrammasp. was obtained in small amounts, too. Total mortality of host eggs varied from 34% to 48%; the mortality rate due to parasitism was 24.5% to 38.9%.The emergence dynamics of the egg parasitoids was studied under laboratory conditions, and the distribution of the egg parasitoids in the egg‐batches was recorded in detail. Additionally, the structure of the meconia ofA. bifasciatusandM. vesiculariswas

ISSN:0931-2048    

DOI:10.1111/j.1439-0418.1996.tb01572.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:Significance of sexual pheromones and light for flight activity and attraction of the male spruce web‐spinning sawflyCephalcia abietisL. (Hymenoptera, Pamphiliidae):The existence of sexual pheromones inC. abietiswas shown in field experiments. The highest number of males were caught by traps baited with virgin females. Less‐attractive baits used mated females and males. In all baits without virgin females, the number of caught males correlated significantly with light intensity. The results are discussed with respect to a reaction chain with highly volatile substances as longdistance sexual pheromones and optical stimuli, or less volatile substances for close‐up attra

ISSN:0931-2048    

DOI:10.1111/j.1439-0418.1996.tb01573.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:Blooms of Hawaii's banana poka,Passiflora tripartitavar.tripartita, grown at Ipiales, Colombia were found suitable for the completion of the life cycle of the flyZapriothricasp. The tubular flowers were an ideal habitat for the mating and reproduction of this minute Andean fly. Oviposition occurred only on immature flowers 30‐20 days from bud opening. Eggs hatched 10–13 days after oviposition. Larvae averaged 1.3 × 0.3 mm at hatching, and 15 days after hatching at the end of the third larva instar averaged 5.2 × 1.0 mm. The light‐brown pupa averaged 3.6 × 1.3 mm and required 40–45 days for completion of this stage. Adult flies averaged 5.1 × 1.3 mm and their life span was 7–10 days in captivity and 5–8 days in field cages. Mating was inside the flower tube and a minimum of five pairs of adults were required for copulation. OtherPassifloraspp. of high elevation with tubular flowers were host of the insect. However, campanulate flowers, e.g.,P. edulis, P. ligularis, andP. alnifoliadid not elicit any response whatsoever for feeding, aggregation, mating or oviposition. The dropping of immature flower‐buds caused by this insect inP. tripartitav.mollissimaandP. tripartitav.tripartitawas 60–80% in Colombian and Ecuadorian curuba farms with hi

ISSN:0931-2048    

DOI:10.1111/j.1439-0418.1996.tb01574.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:Chrysoperla carnealarval diet exerts a significant effect on the rate of development, survival, cocoon weight and the fecundity of the adult females. For this predator,Pieris brassicaeL. eggs proved to be as important a prey as aphids, and, althoughDrosophila melanogasterpupae and adults were accepted as prey, they proved to be relatively inferior as a prey source.

ISSN:0931-2048    

DOI:10.1111/j.1439-0418.1996.tb01575.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:Colonies of the banana aphidPentalonia nigronervosaCoq. were heavily attended by ants in banana plantations on Tongatapu Island, Kingdom of Tonga. Ant‐attendance reduced the density of indigenous predators ofP. nigronervosaconsiderably. Most important was the reduction by ants of the parasitism ofAphis gossypiiby the aphelinid waspAphelinus gossypii. The introduced aphid parasitoidAphidius colemaniwas also heavily attacked by various ant species, and we conclude that ant‐attendance may limit the economic impact of this successfully introduced parasitoid spec

ISSN:0931-2048    

DOI:10.1111/j.1439-0418.1996.tb01576.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0931-2048    

DOI:10.1111/j.1439-0418.1996.tb01577.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:In Hokkaido (Japan), the spruce beetle (Ips typograpaus japonicus) kills standing spruce trees after selection cutting. The seasonal change in the number of beetles captured in 18–21 traps within or outside forest was analysed, with reference to a control strategy for this species in a bivoltine area. The number of beetles captured in traps had two peaks: one, which was small, in early June, and the other, which was a large peak, in July. However, the number of beetles captured in traps outside the forest had only one small peak, in June. The difference between the inside and outside of the forest was caused by the difference in the number of newly emerged beetles captured in traps. Beetles were distributed contagiously within the forest and there was no remarkable change in distribution pattern throughout seasons. Beetles were distributed at random in June when beetle activity was high outside forest. Overwintered beetles must undertake long‐range dispersal irrespective of whether they are within or outside of forest for finding suitable breeding materials. Nevertheless, the most important point is that newly emerged beetles stayed inside the forest and only a few individuals dispersed outside the forest. This study recommends that different control methods are adopted according to the seasons for the control of spruce beet

ISSN:0931-2048    

DOI:10.1111/j.1439-0418.1996.tb01578.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY