Groups of two or more consexual conspecific adults of many kinds of
nonsocial insects have been observed to form at feeding, mating, ovipositional,
or sheltering sites. Conversely, adults of these ...same insects have been
observed to avoid joining consexual conspecifics (or their progeny) and to
place themselves (or their progeny) at some distance that results in spacing.
Examples from various taxa illustrate that mechanisms underlying joining or
avoidance behavior differ among species, as do types of benefits and costs to
individuals who decide to join or avoid others. Moreover, within a given
species, the decision to join or avoid others can be affected markedly by the
physiological and informational state of the individual and by contextual
response thresholds to resource availability. Decisions that benefit the
individual may or may not affect the group in terms of total reproductive
output.
From the outset, a bottom-up, ecologically based approach to apple pest management was applied to a small commercial apple orchard in Conway, MA (USA). This approach was maintained throughout the ...first 20 years (1981–2000) of commercial production. It consisted of maximizing genetic-based resistance to pests through the planting of cultivars resistant to apple scab, designing the orchard and managing the surrounding habitat so as to be minimally conducive to influx of pests and maximally conducive to influx of natural enemies of pests, using behavioral and cultural pest management techniques where appropriate, and minimizing the use of pesticides. No insect pest caused damage to fruit that was greater in the fourth quartile of orchard operation (1996–2000) than in a preceding quartile, indicating no buildup of any damaging fruit insect pest across 20 years of essentially unvarying insect management tactics. Original management of surrounding habitat proved insufficient, however, for sustained suppression of pathogens causing summer diseases of apples. These built to unacceptable levels during the second quartile, were partially suppressed through additional habitat management during the third quartile, and were effectively suppressed using fungicide during the fourth quartile. During the fourth quartile, fruit of Conway orchard trees (which received two annual insecticide and two annual fungicide sprays) averaged 92% clean (free of any pest injury) compared with 0% clean fruit on unmanaged apple trees 200–250
m away from the orchard and 86% clean fruit on trees in large commercial apple orchards in Massachusetts that employed basic integrated pest management practices and annually received seven insecticide and nine fungicide sprays. No foliar pest of Conway orchard trees ever reached a threshold level requiring intervention with pesticide. Combined findings demonstrate long-term durability of a bottom-up, ecologically based approach to apple pest management suitable for small commercial orchards in northeastern North America.
Isolates of the bacterium Enterobacter agglomerans, obtained from the alimentary tract of the apple maggot fly, Rhagoletis pomonella, were found to be attractive or nonattractive in attraction tests. ...Polyacrylamide gel electrophoresis (PAGE) of whole bacterial cell and outer membrane preparations of bacteria revealed the presence of a protein confined to isolates attractive to the flies. This protein, with an approximate molecular weight of 106 kDa, was found to be extracellular in E. agglomerans, but absent in either whole cell or extracellular preparations of Klebsiella oxytoca or Klebsiella pneumoniae. Comparison of this protein with authentic uricase revealed that this protein has a molecular weight, a PAGE migration rate (R^sub f^ = 0.22), and behavior on a G-100 Sephadex column similar to pure uricase. This protein appears to be made by E. agglomerans in the absence of uric acid, i.e., constitutively, and its presence is positively linked to apple maggot fly response in attraction assays. The probable roles of this unique protein in purine degradation and the lives of apple maggot adults are discussed.PUBLICATION ABSTRACT
In a field study in Hawaii, color-marked protein-deprived and protein-fed female melon flies, Bactrocera cucurbitae Coquillett, were released within canopies of unsprayed sorghum plants (a nonhost of ...melon flies) outside of a border area of unsprayed or bait-sprayed sorghum plants or open space that surrounded cucumbers, a favored host of melon flies. Application of bait spray to sorghum or sugarcane surrounding host plants of melon flies is a common practice for melon fly control in Hawaii. GF-120 Fruit Fly Bait spray proved very effective in preventing protein-deprived females from alighting on cucumbers (23% of released females were observed dead on bait-sprayed sorghum; 0% were observed alive on cucumbers), but proved less effective in suppressing protein-fed females (14% of released females were observed dead on bait-sprayed sorghum; 11% were observed alive on cucumbers). No females were found dead on unsprayed sorghum. Compared with open space surrounding cucumbers, the presence of unsprayed sorghum as surrounding border area neither significantly enhanced nor significantly inhibited the ability of either type of female with respect to finding cucumbers. Greenhouse cage assays revealed that compared with droplets of water, droplets of GF-120 Fruit Fly Bait spray were highly attractive to protein-deprived females within 1 h of bait spray application to sorghum, but lost about half of their attractiveness within 5 h and all of it within 24 h under the dry greenhouse conditions used for maintaining baited-sprayed sorghum plants in these assays. Laboratory cup assays showed that bait spray droplets remained highly toxic to protein-deprived females 24 h after application, but lost nearly half of their toxicity within 4 d under laboratory exposure and nearly all of it after ≈8 mm of rainfall. Combined findings suggest that application of GF-120 Fruit Fly Bait spray to nonhost plants for melon fly control either be made often enough to overcome loss of attractiveness of bait spray droplets to females or that bait spray be applied to nonhost plants that are themselves attractive to the females.
Abstract
Studies were conducted to determine attraction and feeding propensity of Mediterranean fruit fly,
Ceratitis capitata
(Wiedemann), to different protein bait mixtures with and without the ...insecticides malathion, spinosad, and phloxine B. Protein baits were more attractive to females than to males. Protein‐starved females responded more than protein‐fed females. The type of protein (USB® yeast hydrolysate enzymatic, Mazoferm®E802, Nu‐Lure®Insect Bait, or Provesta® 621 autolyzed yeast extract) in the bait had a major influence on
C. capitata
attraction, which was strongest to fresh Provesta. Aged baits (four day‐old) were not as attractive as fresh baits. In feeding propensity studies, highest response was observed for USB protein. On the basis of attraction and feeding responses Provesta (attraction and feeding) and USB (feeding) outperformed the standard Nu‐Lure. Protein‐starved flies were much more likely to feed on protein compared to protein‐fed flies. For protein‐starved flies, a mixture of Provesta and malathion repelled fruit flies, compared to a mixture of Provesta and spinosad or phloxine B. This was not the case with protein–fed flies. The wasp
Fopius arisanus
(Sonan), one of
C. capitata
's primary natural enemies in Hawaii, would not consume protein baits. Our studies suggest that spinosad or phloxine B, with low contact toxicity, mixed with protein baits offers a more environmentally friendly choice for control of
C. capitata
and conservation of
F. arisanus
, whereby the nontarget effects of broad spectrum contact poisons such as malathion can be avoided. Presumably, due to greater selectivity with spinosad and phloxine B bait treatments, the host would be killed, but not the natural enemy.
Adults of apple maggot fly Rhagoletis pomonella (Walsh) of differing physiological states were marked and released in blocks of apple trees ringed by sticky red spheres. Spheres were either unbaited, ...baited with butyl hexanoate (synthetic host fruit odour) or baited with both butyl hexanoate and ammonium carbonate (synthetic food odour). All trap and lure treatments were compared in the presence or absence of food (bird faeces) in the blocks. Simultaneously, the response of wild immigrant flies to treatments was measured and wild females were dissected to determine state of ovary development. Large proportions (25-40%) of released mature male and female R. pomonella were recovered in blocks having traps baited with butyl hexanoate. Ammonium carbonate did not enhance trap captures and presence of food had little effect on response to synthetic odours by mature R. pomonella. Immature flies of each sex responded weakly to traps and to both types of synthetic lures and may have been arrested in blocks having food. Wild flies of both sexes exhibited a response pattern very similar to mature released flies, regardless of eggload (in the case of wild females). Results indicate that wild R. pomonella immigrating into apple orchards are primarily mature, and not hungry for protein. Behavioural control strategies are discussed in that context.
We evaluated olfactory attraction of overwintered plum curculio (PC) adults, Conotrachelus nenuphar, to 16 individual volatile components of unripe plum odor in the laboratory using a still-air ...dual-choice bioassay system and in the field using baited cotton dental wicks attached to boll-weevil traps placed on the ground beneath the canopy of unsprayed apple trees. Two compounds, ethyl isovalerate and limonene, were significantly attractive in both laboratory bioassays and field experiments. In laboratory bioassays, as concentration was decreased across five orders of magnitude, a greater number of compounds elicited responses suggestive of attractancy (except at the lowest concentration). Even so, linalool, 2-hexanone, and 3-hydroxy-2-butanone were the only other compounds showing significant attractiveness in laboratory bioassays, but none of these (nor any other compounds) were significantly attractive in field assays. We suggest that the use of ethyl isovalerate and/or limonene as odor attractants offers potential to increase the efficacy of current traps for monitoring PCs immigrating into fruit orchards during spring.
: Aiming to minimize visual competition between large red apples and red sphere traps from influencing effectiveness of traps for apple maggot fly (AMF) control, we compared AMF captures by red ...spheres in standard recommended position (no fruit within 15 cm), red spheres in similar position but with all fruit removed within a 30‐cm radius (fruitless), red spheres with additional visual competition provided by three plastic red spheres hung 15 cm from sphere traps, and yellow panels. Traps were coated with adhesive, baited with synthetic fruit odour, and hung on trees of an apple cultivar bearing red fruit (Akeene) and trees of an apple cultivar bearing pale yellow fruit (Golden Delicious). On Akeene trees, red spheres in recommended position and fruitless red spheres caught more AMF than red spheres surrounded by plastic spheres and than yellow panels. Towards harvest, effectiveness of red spheres in recommended position decreased as reflectance of the surface of Akeene apples approached that of red spheres. By contrast, effectiveness of fruitless spheres increased over time. On Golden Delicious trees, fruitless spheres were the most effective, followed by spheres surrounded by uncoated plastic spheres and red spheres in recommended position. We conclude that removing all fruit within a 30‐cm radius around red sphere traps results in similar or increased trap effectiveness relative to red spheres in recommended position.
In tests on feral populations of polyphagous Bactrocera tryoni (Froggatt) adults on host guava trees, both sexes were significantly more attracted to Tangletrap‐coated 50 mm diameter spheres colored ...blue or white than to similar spheres colored red, orange, yellow, green, or black or to Tangletrap‐coated 50 mm diameter yellow‐green guava fruit. In contrast, in tests on feral populations of oligophagous Bactrocera cacuminata (Hering) on host wild tobacco plants, both sexes were significantly more attracted to Tangletrap‐coated 15 mm diameter spheres colored orange or yellow than to other colors of spheres or to Tangletrap‐coated 15 mm diameter green wild tobacco fruit. Both sexes of both tephritid species were significantly more attracted to blue (in the case of B. tryoni) or orange (in the case of B. cacuminata) 50 mm spheres displayed singly than to blue or orange 15 mm spheres displayed in clusters, even though fruit of wild tobacco plants are borne in clusters. Finally, B. tryoni adults were significantly less attracted to non‐ultraviolet reflecting bluish fruit‐mimicking spheres than to bluish fruit‐mimicking spheres having a slightly enhanced level of ultraviolet reflectance, similar to the reflectance of possible native host fruit of B. tryoni, whose bluish skin color is overlayed with ultraviolet‐reflecting waxy bloom. Responses to fruit visual stimuli found here are discussed relative to responses found in other tephritid species.
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