Effects of winter temperatures on the sex ratios ofAphytis melinus [Hym.: Aphelinidae] in the San Joaquin Valley of California

Hoffmann, Rudolf; Kennett, C. E.

doi:10.1007/bf02372245

Cited by 10 publications

(10 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar results were found in California citrus orchards by Hoffmann and Kennett (1985). As it was assessed by Abdelrahman (1974a), when cool temperatures prevail, the thelytoky of A. chrysomphali might give an advantage over the arrhenotokous A. melinus because the former produce female progeny a few hours after emergence, whereas A. melinus produces only male progeny until fertilization.…”

Section: Discussionsupporting

confidence: 84%

“…The displacement of Aphytis species by A. melinus has been related to climate adaptability and to other biological differences between species Luck 1979, Huffaker 1990). The effects of temperatures on the different natural enemies of CRS have been widely studied (Abdelrahman 1974a, b, Atkinson 1983, Kfir and Podoler 1983, Kfir and Luck 1984, Hoffmann and Kennett 1985. DeBach and Rosen (1991) experimentally demonstrated that some Aphytis parasitoids can be precluded from exerting adequate control by adverse climatic factors.…”

Section: Parasitoid Competitionmentioning

confidence: 99%

See 1 more Smart Citation

Parasitoid competitive displacement and coexistence in citrus agroecosystems: linking species distribution with climate

Sorribas¹,

Rodríguez²,

Garcia‐Marí³

2010

Ecological Applications

View full text Add to dashboard Cite

Abstract. The introduced parasitoid wasp Aphytis melinus, the most widespread natural enemy of the California red scale (Aonidiella aurantii ) and the superior competitor, has displaced the native Aphytis chrysomphali from most citrus areas of the Mediterranean basin and other citrus areas all over the world. However, our extensive survey data on the scale parasitoid populations collected in [2004][2005][2006][2007][2008] show that in large citrus areas of eastern Spain both parasitoids coexist. Using field data from 179 orchards spatially divided in five citrusproducing agroecosystems, we examined the mechanisms that could explain displacement or coexistence between both Aphytis species in relation to weather conditions. The distribution and abundance of the parasitoid species are related to the mean summer and winter temperatures and relative humidity of each ecosystem. The relative proportion of A. melinus is higher during the warm months, and the abundance of A. chrysomphali increases from south to north, being higher in the cooler northern areas. Aphytis melinus has displaced A. chrysomphali from hot and dry areas, whereas regions with mild summer temperatures and moderate relative humidity present the optimal conditions for the coexistence of the two parasitoids. The more negative effects of winter temperatures on A. melinus allow the earlier use of the available host resource in late winter and spring by A. chrysomphali and the coexistence of both parasitoids in the same orchard via temporal niche partitioning. We combine previous literature on the behavior of Aphytis species in the laboratory under different temperature and humidity conditions with our field results to confirm the role of spatiotemporal weather conditions and seasonal changes in host stages on the variation of Aphytis relative abundance and parasitoid coexistence.

show abstract

Section: Discussionsupporting

confidence: 84%

Section: Parasitoid Competitionmentioning

confidence: 99%

Parasitoid competitive displacement and coexistence in citrus agroecosystems: linking species distribution with climate

Sorribas¹,

Rodríguez²,

Garcia‐Marí³

2010

Ecological Applications

View full text Add to dashboard Cite

show abstract

“…In addition, the sex ratio of the parasitoid depends upon a number of environmental factors (Suzuki and Iwasa, 1980), including (a) postcopulatory period (Mackauer, 1976), (b) host and parasitoid density (Ashley and Chambers, 1979), (c) virility of the male that inseminates the female (Rabasse and Shalaby, 1980), (d) host size (Avilla and Albajes, 1984), (e) temperature (Hoffmann and Kennett, 1985), (f) nutrient sources (Hu e\ al., 1986), (g) parental age (Hutchinson et al, 1986), (h) host plants (Kumar and Tripathi, 1987) and (i) the presence of males with the females (Abidi et al, 1988).…”

Section: Discussionmentioning

confidence: 99%

“…Parasitoid sex ratio is important in biocontrol programmes, as it is the female parasitoid that brings about parasitism and pest mortality (Waage, 1982;Hassell et al, 1983;Kumar and Tripathi, 1987). Regulation of the sex ratio of progeny is an important aspect of arrhenotokous species (Avilla and Albajes, 1984), as mated females are able to lay both haploid and diploid eggs (Waage and Sook Ming, 1984;Hoffmann and Kennett, 1985). Selective fertilisation of the eggs in response to external stimuli, such as host cues, is the way to control the sex ratio.…”

Section: Introductionmentioning

confidence: 99%

Sex Ratio of Campoletis Chlorideae Uchida in Response to Helicoverpa Armigera (Hübner) Density

Kumar

Tripathi

2000

Int. J. Trop. Insect Sci.

View full text Add to dashboard Cite

Experiments were conducted to elucidate the effect of host density on sex ratio of parasitoid offspring, using Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) and its endoparasitoid Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae). The sex ratio of Campoletis chlorideae was female-biased showing a linear decrease with increasing parasitoid density at fixed host densities. However, with more hosts available, the number of parasitoids emerging increased, stabilising after a density of 32 hosts per parasitoid. To obtain a female-biased sex ratio, a low density of parasitoids should be released at a recommended site.

show abstract

“…Three other citrus growing regions do not face these impediments (Hoffmann and Kennett 1985;Kennett and Hoffmann 1985;Luck 1995;Yu and Luck 1988). A 2010 survey of California citrus growers asked growers about the presence of natural enemies, including A. melinus, and their pest control methods used for four major pests, including California red scale.…”

Section: Citrus Growers and California Red And Cottony Cushion Scalesmentioning

confidence: 99%

Integrated Pest Management: Fruit Production in the Western United States

Grogan

2014

Integrated Pest Management

View full text Add to dashboard Cite

Effects of winter temperatures on the sex ratios ofAphytis melinus [Hym.: Aphelinidae] in the San Joaquin Valley of California

Cited by 10 publications

References 10 publications

Parasitoid competitive displacement and coexistence in citrus agroecosystems: linking species distribution with climate

Parasitoid competitive displacement and coexistence in citrus agroecosystems: linking species distribution with climate

Sex Ratio of Campoletis Chlorideae Uchida in Response to Helicoverpa Armigera (Hübner) Density

Integrated Pest Management: Fruit Production in the Western United States

Contact Info

Product

Resources

About