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280 lion of a signal. Costs associated with error in signal detection are believed to profoundly influence the evolution ol communication systems (Reeve, 1989; Wiley. 1994; Bradbury & Vehrencamp. 1998). Two kinds of errors in signal detection that are commonly considered to shape communicalion systems are errors a.ssociaied with missed detections and errors associated with false alarms. In the conie.xi of host-marking, a missed detection would occur when an insect failed to delect MP when in fact it had been deposited on or in a host. A false alarm would occur when an insect responded a.s though a MP had been deposited on or in a host when in fact it had not. Aspects of host-marking behavior in some insects seem designed to reduce signal detection errors due to mis.sed detection. For example, lephnlid lly females mark host fruit by dragging their ovipositor on the fruit surface. Females generally do not restrict hostmarking to the vicinity of the oviposition site, but rather generate a trail of MP over signiticant areas of the fruit surface. Such behavior, though costly in time and perhaps energy, seems designed to dis.seminate the •VIP over the surface and thereby decrease the chance that a female subsequently visiting the fruit might fail to detect the mark. In Anastrepha fraterculus and R. poinonella. females mark longer on larger fruit, a strategy that possibly reflects a tradeoff between the cost of MP and the cost of missed detection (Prokopy et al.. 1982b; Averill & Prokopy. 1987b). In still other in.sccts. females mark substrates around exploited host patches (Price. 1970; Waage. 1979; Sugimoto et al.. 1986). Such behavior can improve detection of a MP and reduce the time needed for host assessment (Hoffmeister Jt Roitberg. 1997). Rnally. a common strategy in communication systems for minimizing missed detections is redundancy. The propensity for certain entomophagous parasitotds to mark both the inside and the outside of the host (reviewed by van Lenteren. 1976; Hofsvang. 1990) may reflect a strategy of redundancy. Other parasitoids utilize a two-component chemical marking system; the deployment of more than one component in hostmarking has many possible explanations, of which redundancy is one (Holler et al.. 1991). Examples of errors associated with false alarms are harder to come by in host-marking systems. On its face, contact chemoreccption potentially provides such high resolution in terms of discrimination among chemical compounds that it seems unlikely that a chemical compound or set of compounds that were not a MP would be mistaken for one. However, there 29 are at least hints of the occurrcnce of false alarms in host-marking communication. Intephritid flies, for example. extracts of feces deter female oviposition into fruit or surrogate fruit. Even male feces have such activity (Prokopy et al., 1982a), causing one to wonder if fecal deposition on fruit may sometimes be misinterpreted by inspecting females. Similarly, in the bruchid beetle, C. maculatus. egg-free beans that have been 'conditioned' by males as they walked or defecated on seeds receive fewer eggs than unconditioned beans (Sakai et al., 1986) and, while there are alternative interpretations, this might again constitute an example of a false alarm in MP communication. Documented examples of false alarms in the animal communication literature are typically intenpecilic in nature as. for example, in ca.ses of aggressive mimicry in which one species mimics another species' signal and preys upon receivers that unwittingly onent to the mimic signal (Haynes& Yeargan. 1999). Examples of aggressive mimicry are well known in relation to sex pheromones and yet wholly unknown in relation to MPs, perhaps because the effect of a MP (unlike that of a sex pheromone I is usually deterrent and thus not of use to a predator. If there are any cases of aggressive mimicry involving MPs. they might occur in those situations in which a MP ha.s an aggregative, rather than a deterrent, effect.- •Marking pheromones and the value of inrormation about brood presence Evidence from strain differences Use of a signal should vary in relation to changes in the costs and benefits of information provided by that signal (Bradbury & Vehrencamp. 1998). If host-marking is costly in relation to the benefit of information about brood presence, then we would expect to observe host-marking only in species or strains for which such marking has significant value in terms of the fitness of a female's progeny. In C. maculatus beetles, avoidance of occupied hosts can lead to considerable increases in female and offspring fitness (Credland et al.. 1986) and. in these beetles, degree of avoidance varies between strains. A series of crosses and backcrosses between two strains showed that strain differences were genetically based (Messina. 1989). Differences in avoidance of occupied hosts may arise in two ways; first, signalers may change the 'strength' of marks placed on a host or; second, receivers may
change the degree to which ihey respond to a mark of a given strength. Experiments conducted by Messina et al. (1991) demon.strated that both mechanisms contributed to strain differences in avoidance. Females of a strain found on relatively smaller hosts where interference competition was relatively greater responded more keenly to a mark produced by either strain. Females of the strain which experienced greater interference competition also produced a mark that acted as a greater deterrent to further egg-laying by females of either strain. .A genetic change in re.spon.se to a mark may not nece.s-sarily involve tixed changes in MP reception, processing or strength. Selection may mediate strain differences in response via effects on a female's mean egg load which, in turn, affects behavior iWaaae. 1986; Wajnberg et al.. 1989). Egg load, detined as the number of mature egg.s a female has available to lay. can affect respon.ses to host.s m many ways iMinkenbcrg et al.. 1992). of which respon.se to .MP is but one. Typically, higher egg loads increase a female's propensity to lay clutches into previously exploited hosts (van Randen & Roitberg. 1996). Selection for higher egg loads may es.sentially lead to females reducing their propensity to rejected previously marked host. Facultative partem^ in MP Jeplovment Host-marking in phytophagous in.sects is usually obligatory, with females nearly always depositing MP when eggs are laid. However, deployment of MP is occasionally facultative: presumably, facultative marking reduces the overall costs of marking by deploying a signal only when it is beneficial lo do so. For example, females of a Delia (= Hylemya) species (Family .Anthomy iidae) mark one of their host species but not the other. On developing flower buds of Polemnnium folinxsimum. female.s deposit a single egg and an a.sscK:iated MP. The MP generates an overlydispersed distribution of eggs within resource patches (Zimmerman. 1979). The same Delia sp. al.so utilizes Ipttmopsis aKgregata a.\ a larval resource but. in contrast to its first host, females often lay more than one egg on this host. Interestingly. female> do not deposit a MP when they oviposit on thi.s second host. .According to Zimmerman (1980. 1982). females fail to mark I. plants not because these hosts support relatively more offspring to maturity, but becau.se egg mortality on /. aggregata is so severe that females experience little titne.vs los.s&s if consecutive females 250 -I — 200 ' S I — ISO ] I 100 • 50 0 12 3 No. Previous Marks on Fruit Fiiiuie J. Time spent n);irkinc by lenule AnuMtrfho as .1 luncium oi ihc niinibcr ul ICIIUICN ihul prcvuHivK h«.»Nl murknl a Iruil (uciapicU from Pupa| & Alup. re-use an infested host. In P. folinssimiun. by contrast. egg monality is low and female re-use leads to relatively intense larval competition between clutches. The time spent host marking has also been found to be correlated with the sequence in which a female exploits a multiply-infested host. In the fruit fly .4. Intienx. time spent host marking increa.sed exponentially as females deposited clutches into hosts previously marked zero. one. two or three times (Papaj & .Aluja. 1993) (Figure 2). The increa.se in marking time was proposed to he functional for two rea.sons. First, by increasing the amount of mark placed on a host, females might compeasate for partial degradation of previous marks. Second, increases in marking times might reflect declines in fitness of progeny in progressively later-laid clutches. D\namtcs in iiiteniul \rate and the value nf mfonnutnm Female respon.ses to signals from occupied hosts depend on variation in internal state related to egg load, age or experience in a manner consistent with dynamical foraging theory (Mangel & Clark. 1988). •Avoidance of marked hawthorn fruit, for example, decreases for a R. pimumella female as her time since last oviposition increases (Roitberg & Prokopy. 1983i. Such a pattern is functional. When host fruit are rare and time between encounters long, females should not be ;LS choosy about u.se of infested hosts as when host fruit are common, so long as an egg laid in an infested fruit has a meaningful chance of surviving to repaxluce. Responses to .MP likewise vary with egg load. Female snowberry flies. R. zephvna. of similar age. experience and mating status but with higher egg loads were sianificantiv more likelv to re-use marked hosts
Page 1: INFORMATION TO USERS This manuscrip
Page 4 and 5: UMI Number: 3053915 Copyright 2002
Page 6 and 7: STATEMENT BY AUTHOR This dissertati
Page 8 and 9: DEDICATION This work is dedicated t
Page 10 and 11: ABSTRACT Choosing where offspring w
Page 12 and 13: An explanation of tiie problem CHAP
Page 14 and 15: euse occurs in the field, the impac
Page 16 and 17: Appendix D, "Aggregative behavior i
Page 18 and 19: offspring performance. Counter to t
Page 20 and 21: Lalonde RG, Mangel M, 1994. Seasona
Page 22 and 23: APPENDIX A HOST MARKING BEHAVIOR IN
Page 24 and 25: kluwer the language of science Dr.
Page 26 and 27: 174 belter categorized as cues than
Page 28 and 29: fubfe 2. Kinds ot cvicknce used lo
Page 30 and 31: 278 defend themselves and because i
Page 34 and 35: 282 than were conspccifics with low
Page 36 and 37: 284 thai (he marker was a mutant fo
Page 38 and 39: 286 dropping on ihe MP communicatio
Page 40 and 41: 28S inac>. 3 larval partsiloiil of
Page 42 and 43: 290 Hol'svang. T. 1988. Mechanisms
Page 44 and 45: 29Z Roitbcfg. B- D it R- G- Laionde
Page 46 and 47: APPENDIX B HOST UTILIZATION BY THE
Page 48 and 49: Dispersal by Larvae of the Stem Bor
Page 50 and 51: POPULATION ECOUXTY Host Utilization
Page 52 and 53: October 2000 NUFIO ET AL.; HOST UTI
Page 54 and 55: October 2000 Nufio et au: Hoct Unuz
Page 56 and 57: October 2000 NUFIO ET AL4 HOST UIHI
Page 58 and 59: Reuse of larval hosts by the walnut
Page 60 and 61: KEYWORDS Life history" marking pher
Page 62 and 63: Alternatively, a weak correlation b
Page 64 and 65: previously attacked hosts early in
Page 66 and 67: walnut fly oviposition punctures. T
Page 68 and 69: Effects of offspring weight on adul
Page 70 and 71: she deposited over a lifetime and t
Page 72 and 73: RESULTS Levels of host reuse in the
Page 74 and 75: Survival from egg to egg hatch Of t
Page 76 and 77: significantly correlated with pupal
Page 78 and 79: DISCUSSION While the femaie-prefere
Page 80 and 81: discriminate between hosts that hav
Page 82 and 83:
will consume fewer resources and th
Page 84 and 85:
females gain not by simply reusing
Page 86 and 87:
of her offspring but also of the nu
Page 88 and 89:
ACKNOWLEDGEMENTS We thank Henar Alo
Page 90 and 91:
Bjorkman C, Larsson S, Bommarco R,
Page 92 and 93:
Fujiyama N, Katakura H, 2001. Varia
Page 94 and 95:
Mayhew PJ, 1997. Adaptive patterns
Page 96 and 97:
Robertson IC, Roitberg BD, 1998. Du
Page 98 and 99:
Wiklund C, 1981. Generalist vs. spe
Page 100 and 101:
Table 2. The influence of various f
Page 102 and 103:
Table 4. Analysis of variance compa
Page 104 and 105:
nCURE CAPTIONS - Continued Figure 5
Page 106 and 107:
Figure 1. Fruit Cohorts (Number of
Page 108 and 109:
Figure 3. A. B. A > on •m e « 50
Page 110 and 111:
Figure 5. B. es & 1 1 0.8 • 0.6 -
Page 112 and 113:
Figure 7. B. > 09 "S s e s o •Ml
Page 114 and 115:
Figure 9. 400 9t W s 1 t 300 « Of)
Page 116 and 117:
Aggregative behavior is not explain
Page 118 and 119:
that the larval aggregations that f
Page 120 and 121:
2001). The shifting benefits and co
Page 122 and 123:
spatial patterning of clutches depo
Page 124 and 125:
16-fl oz (473-ml) plastic Solo cups
Page 126 and 127:
percentage of hatchlings that emerg
Page 128 and 129:
previously created oviposition punc
Page 130 and 131:
RESULTS Experiment 1. Effect of off
Page 132 and 133:
deposited) again improved the model
Page 134 and 135:
median pupal weight in the lone two
Page 136 and 137:
survival, using two-clutch and thre
Page 138 and 139:
DISCUSSION Absence of an AUee efTec
Page 140 and 141:
simultaneously. It would seem that
Page 142 and 143:
Spatial distribution of clutches In
Page 144 and 145:
If reuse of larval hosts negatively
Page 146 and 147:
Page 148 and 149:
Hausmann SM, Miller JR, 1989. Ovipo
Page 150 and 151:
Papaj DR, Alonso-Pimentel H, 1997.
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
FIGURE CAPTIONS continued Figure 4.
Page 158 and 159:
Figure 2 MD E DC n Om 3 Qi S V DA E
Page 160 and 161:
Figure 4. B. c. -g 60 S a. a 40 - S
Page 162 and 163:
Host marking beiiavior as a quantit
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encountered either control fruit th
Page 166 and 167:
unparasitized and parasitized hosts
Page 168 and 169:
Finally, it is conceivable that the
Page 170 and 171:
Experiment 1. Relationship between
Page 172 and 173:
or 30 minutes). Fruit were then hun
Page 174 and 175:
After two replicates of the four tr
Page 176 and 177:
Experiment 3. Female responses to h
Page 178 and 179:
RESULTS Experiment 1. Effects of cl
Page 180 and 181:
Experiment 3. Female responses to f
Page 182 and 183:
example, the possibility that ovipo
Page 184 and 185:
field cage assays. What remains to
Page 186 and 187:
Page 188 and 189:
Bauer G, 1986. Life-history strateg
Page 190 and 191:
Landolt PJ, Averill AL, 1999. Fruit
Page 192 and 193:
Quiring DT, McNeil JN, 1984. Intras
Page 194 and 195:
FIGURE CAPTIONS Figure 1. The relat
Page 196 and 197:
Figure 2. w OA 8 k 98 s o a. QH s 8
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