Visual response of the tomato fruit fly, Neoceratitis cyanescens, to colored fruit models

To determine how mature females of the tomato fruit fly, Neoceratitis cyanescens (Bezzi) (Diptera: Tephritidae), detect host fruit after arriving in their host plant habitat, behavioral responses to colored models were observed in a laboratory flight chamber. Host‐seeking females oriented themselves preferentially towards bright orange spheres (3.7 cm in diameter), irrespective of their natal host fruit: tomato, bug weed, or black nightshade. Females oriented themselves preferentially towards the orange sphere when placed against a fluorescent yellow background as opposed to a black background, but the distribution of responses to the set of colored spheres did not vary significantly with background color. In a choice situation between bright orange spheres of various sizes (1.9, 3.7, and 7.5 cm in diameter), females landed preferentially on the bigger sphere. However, they preferred a yellow color when the latter was associated with two‐dimensional models, probably mimicking leaves. The attractiveness of orange spheres depended more on the proportion of reflected light in the spectral region around 610 nm than brightness of color in itself. Low light intensity significantly influenced the activity of the flies but not their visual preference. The strong response of females to bright orange spheres confirmed the importance of visual characteristics in short‐range mechanisms of host‐plant location in specialist insects. Responses to fruit visual stimuli are discussed relative to other Tephritidae, host‐finding strategy, and pest management.     

The effect of egg load on superparasitism by the snowberry fly

In studies conducted with fruits of the host plant, Symphoricarpus albus (L.), we examine the influence of egg load on the oviposition behaviour of Rhagoletis zephyria Snow (Diptera:Tephritidae). By altering the availability of exogenous protein, three classes of females with progressively increasing egg loads were produced, while keeping confounding factors such as age, experience, and mating status constant. Flies from all three classes were randomly presented with either a pheromone marked fruit, or with an unmarked fruit. Results indicate that increased egg load led to a greater propensity to accept, or superparasitize, the pheromone marked fruit. Upon dissection it was revealed that females which superparasitized had a mean egg load of 19.5 eggs (n=22), while females which rejected marked fruit had a mean egg load of 13.5 eggs (n=26). These results are consistent with the theory of adaptive superparasitism.     

Effects of reproductive state and host resource experience on mating decisions in a walnut fly

Prior experience with conspecifics or essential resources, aswell as physiological condition, can have important influenceson an animal's reproductive behavior. While effects of experienceand physiological state (such as reproductive condition) aregenerally treated separately in theoretical discussions, theyoften interact. No previous study has attempted to distinguisheffects of experience on physiological state from other effectsof experience in the context of mating behavior. In a studyof a walnut-infesting tephritid fly (Rhagoletis juglandis),we examined the effects of host fruit experience on mating behavior.We manipulated physiological state in terms of egg load (definedas the number of mature oocytes in a female's ovaries) independentlyof fruit experience to distinguish the effects of these variables.We found that females with high egg loads were significantlymore likely to copulate than low–egg load females; thelevel of fruit experience had no effect on propensity to copulate,except via effects on egg load. In contrast, females with priorexposure to fruit copulated for a significantly shorter durationthan control females, while egg load had no effect on copulationduration. These results suggest that female reproductive conditionand exposure to essential resources can have important, albeitdiverse effects on mating behavior. We discuss how distinguishingdifferent types of variables may provide insight into sexualconflict over mating decisions, as well as which sex controlsspecific aspects of behavior.     

Influence of habitat pattern on orientation during host fruit location in the tomato fruit fly, Neoceratitis cyanescens

Fruit flies have evolved mechanisms using olfactory and visual signals to find and recognize suitable host plants. The objective of the present study was to determine how habitat patterns may assist fruit flies in locating host plants and fruit. The tomato fruit fly, Neoceratitis cyanescens (Bezzi), was chosen as an example of a specialized fruit fly, attacking plants of the Solanaceae family. A series of experiments was conducted in an outdoor field cage wherein flies were released and captured on sticky orange and yellow spheres displayed in pairs within or above potted host or non-host plants. Bright orange spheres mimicking host fruit were significantly more attractive than yellow spheres only when placed within the canopy of host plants and not when either within non-host plants or above both types of plants. Additional experiments combining sets of host and non-host plants in the same cage, or spraying leaf extract of host plant (bug weed) on non-host plants showed that volatile cues emitted by the foliage of host plants may influence the visual response of flies in attracting mature females engaged in a searching behaviour for a laying site and in assisting them to find the host fruit. Moreover, the response was specific to mature females with a high oviposition drive because starved mature females, immature females and males showed no significant preference for orange spheres. Olfactory signals emitted by the host foliage could be an indicator of an appropriate habitat, leading flies to engage in searching for a visual image.     

Host-marking behaviour as a quantitative signal of competition in the walnut fly Rhagoletis juglandis

Abstract.  1. Walnut-infesting flies in the Rhagoletis suavis species group actively re-use hosts for oviposition despite engaging in a genus-typical host-marking behaviour which, in other Rhagoletis groups, deters oviposition. In a study of the walnut fly, R. juglandis (Cresson), alternative hypotheses for the putative marking behaviour were evaluated.
2. The oviposition site attraction hypothesis proposes that the host mark guides females to oviposition sites on occupied fruit. The competition intensity signal hypothesis proposes that the host mark is an indicator of the level of competition to be incurred if fruit are re-used.
3. In a field cage, females were presented simultaneously with fruit previously exposed to 25 females that were also allowed to oviposit and engage in the putative marking behaviour, and control fruit on which females were allowed only to oviposit. The occurrence of host marking reduced a female's propensity to oviposit from 46% to just over 10%, consistent with the competition intensity signal hypothesis only.
4. In a laboratory assay, the duration of host marking was correlated positively with the size of a female's clutch. This result, also consistent with the competition intensity signal hypothesis, suggests that the amount of marking pheromone on a fruit is a reliable indicator of the number of eggs already deposited within.
5. In a second field-cage experiment, females were allowed to mark on fruit for 0, 10, 20, or 30 min and fruit were presented to test females. Whether or not females alighted on a particular host was not affected by the duration of marking; however, the frequency of both ovipositor probing and egg deposition decreased with increasing duration of marking. Consistent with the competition intensity signal hypothesis, this result suggests that the host mark permits females to assess the level of competition that a clutch will incur within re-used fruit.     

Effects of recent experience on foraging in tephritid fruit flies

In field-cage studies, we investigated how the foraging behavior of tephritid fruit flies is modified by experience immediately prior to release on host plants. We observed females of a relatively monophagous species,Rhagoletis mendax (blueberry maggot fly), an oligophagous species,Rhagoletis pomomella (apple maggot fly), and a polyphagous species,Ceratitis capitata (Mediterranean fruit fly). Just prior to release on a host plant, the following kinds of stimuli were supplied: (1) single oviposition in a host fruit, (2) contact with 20% sucrose, (3) contact with a mixture of protein food (bird feces and sucrose), (4) contact with water, and (5) a walk over a host-plant leaf. When flies foraged on host plants without resources, search was most intensive (as measured by number of leaves visited) following a single oviposition in fruit, but residence time generally was the same following exposure to sugar, protein, and fruit stimuli.Rhagoletis mendax andC. capitata females visited the fewest leaves following exposure to water or host leaves, whereasR. pomonella foraged equally intensively following exposure to food stimuli, water, or leaves. On host plants containing resources (fruit and protein food), a single oviposition dramatically increased the number of females of all three species that found fruit compared to females that received experience with food, water or foliar stimuli. We found no significant effect of recent brief experience with any of the stimuli on subsequent attraction to protein food. Overall,C. capitata exhibited a higher propensity to abandon host plants than eitherR. mendax orR. pomonella. We suggest that this may reflect adaptations to differences in distribution of host plants in nature, strategies of dispersal, and host range.     

Trap position and fruit presence affect visual responses of apple maggot flies (Dipt., Tephritidae) to different trap types

Abstract:  We compared responses of apple maggot flies, Rhagoletis pomonella (Walsh), in a commercial apple orchard in Massachusetts with three different types of visual traps baited with synthetic fruit volatiles. The traps were red spheres, Ladd traps (a rectangular yellow panel between two red hemispheres) and rectangular yellow panels. Traps were placed either in optimal position (D rummond , F.; G roden , E.; P rokopy , R. J., 1984: Environ. Entomol. 13, 232–235.) or sub-optimal position (not surrounded by foliage and fruit from all sides). The study was performed over 3 years. Early in the fruiting season, when apples were small and green, red spheres followed by Ladd traps attracted more flies than yellow panels. Ladd traps were the most sensitive to trap positioning, losing effectiveness when placed in sub-optimal position. Late in the fruiting season, in years yielding crops of large red apples, red spheres in optimal position (surrounded by growing red fruit) lost some effectiveness relative to Ladd traps in optimal position. Red spheres in sub-optimal position were not similarly affected, perhaps because of the lack of fruit in the background. Red sphere performance relative to Ladd traps was re-established after removal of competing fruit from trees at harvest. Because Ladd traps are more expensive to purchase and more difficult to position, red spheres are a better option for commercial growers in eastern North America. Conceivably, loss of capturing power of red spheres because of visual competition from red apples towards harvest could be mitigated by adjusting trap positioning.     

Role of host fruit color in the behavior of the walnut fly Rhagoletis juglandis

Observations and sticky-trap tests were used to assess the effect of fruit color on the behavior of adult male and female Rhagoletis juglandis Cresson (Diptera: Tephritidae), a tephritid that infests husks of Arizona walnut in southeastern Arizona. In the first experiment, during which flies were observed foraging among walnut models suspended from small walnut trees, models were painted green to appear ripe and uninfested or yellow with brown patches to appear ripe and infested. Flies used for this first experiment were also of two types: prior to observations, one group of flies had access to real walnuts for 1.5 days (prior experience) while the other group of flies was held without real walnut fruits (no prior experience). Regardless of prior experience with real walnut fruits, female flies landed on green models more than yellow/brown models. Experienced males also were more likely to land on green models than on yellow/brown models. More interactions also occurred on green models, because there were more landings.In the field behavioral assay, flies from a natural population given a choice of green, yellow, and yellow/brown models landed most often on green models, and all interactions and oviposition attempts occurred on green models. Flies also distinguished models by color in field sticky trap assays.These results suggest that female response to ripeness cues is innate, while males develop a preference for green based on their encounter rate with females.     

Apple maggot fly response to red sphere traps in relation to fly age and experience

Responses of the apple maggot fly,Rhagoletis pomonella (Walsh), to 8 cm red sticky sphere traps, baited with the synthetic fruit odor butyl hexanoate, were investigated in field-caged apple trees containing green or red Gravenstein apples. Trap capture rate and the probability of oviposition in apples before capture generally increased with female age and number of mature eggs in ovaries. Two days of pre-test exposure of mature females to red hawthorns, green Red Delicious apples or green Gravenstein apples had no significant effect on the likelihood of a fly finding a red sphere. However, before capture on a sphere or departing a tree, hawthorn-exposed females found significantly fewer apples and laid significantly fewer eggs than females exposed to Gravenstein apples. Variation in duration of pre-test exposure (1–4 days) of flies to Gravenstein apples had no detectable influence on female response to apples or to a red sphere in a test tree. The relevance of these findings to effectiveness of sphere traps, forR. pomonella control in commercial orchards is discussed.     

Effects of egg load on finding and acceptance of host fruit in Ceratitis capitata flies

Abstract. In studies conducted on potted host trees in field cages and in the laboratory, we examined the influence of egg load on the finding and acceptance of high-ranking (kumquat) and lower-ranking (grapefruit) hosts for oviposition by wild-origin Mediterranean fruit fly females, Ceratitis capitata (Wiedemann). By prescribing the periods during which females had access to protein prior to testing, we generated four classes of females having progressively increasing egg loads but not differing in population origin, age, degree of protein hunger at testing, or amount of prior experience with host fruit (none). Egg load had no discernible effect on behaviour associated with finding either type of fruit but did have a significant effect on several behaviours associated with oviposition after alighting on fruit. Increasing egg load led to increasing propensity to engage in ovipositional-type behaviour on both kumquats and grapefruits. There was no evidence, however, to support a hypothesis that medflies would become less discriminating against grapefruits relative to kumquats as egg load increased. Relative to kumquats, grapefruits were accepted for oviposition by intermediate and high egg load females to a substantially greater degree in laboratory cages than on trees, suggesting that results of laboratory cage experiments on host discrimination by tephritid flies may poorly reflect differences in behavioural responses expressed under less constrained conditions.     

Attraction of adult Rhagoletis indifferens (Diptera: Tephritidae) to unbaited and odor-baited red spheres and yellow rectangles

Five sizes of red spheres (4, 6, 8, 10, and 12 cm diameter) and 2 orientations of yellow rectangles (vertical and V) were evaluated as unbaited sticky-coated traps for western cherry fruit flies, Rhagoletis indifferens Curran, in unmanaged cherry trees in Washington and Oregon. Red spheres that were 10 cm in diameter attracted more flies than red spheres that were 8 or 12 cm in diameter and significantly more flies than 4- or 6-cm spheres and yellow rectangles of either orientation. In a 2nd test, red spheres (10 cm diameter) baited with ammonium carbonate alone or ammonium carbonate plus putrescine attracted significantly more R. indifferens than similar spheres baited with ammonium acetate alone, putrescine alone, 3-methyl-1-butanol alone, or combinations of these substances. In a 3rd test, vertical yellow rectangles baited with ammonium carbonate alone attracted numerically more R. indifferens than any of the aforementioned substances alone or in combination. We discuss the potential value of 10-cm red spheres baited with ammonium carbonate for monitoring and direct control of R. indifferens.     

Evaluation of various deployment strategies of imidacloprid-treated spheres in highbush blueberries for control of Rhagoletis mendax (Diptera: Tephritidae)

Biodegradable, ammonium-baited spheres treated with the neonicotinoid insecticide Provado (imidacloprid) at 2% (AI) were evaluated for controlling blueberry maggot flies, Rhagoletis mendax Curran. Three strategies for sphere deployment in highbush blueberries, Vaccinium corymbosum L., were compared with untreated control plots in 1999 and once again compared against control plots and organophosphate insecticide sprays in 2000. The patterns of sphere deployment were as follows: (1) perimeter deployment in which spheres were hung individually and spaced equally around the perimeter of experimental plots; (2) cluster deployment in which four groups of three spheres were hung in equally spaced perimeter locations of experimental plots; and (3) uniform deployment in which spheres were placed 10 m apart (in a grid-like pattern) within experimental plots. In 1999, there were no significant differences in fruit injury levels based on observed R. mendax oviposition scars and reared larvae among plots containing imidacloprid-treated spheres in perimeter, cluster, and internal-grid patterns. However, all plots containing spheres had significantly lower fruit infestation levels (<2%), compared with unsprayed control plots with no spheres deployed, which had infestation levels (>20%). In 2000, there were no significant differences in fruit injury based on observed R. mendax oviposition scars between plots containing imidacloprid-treated spheres in the three deployment strategies tested and plots that received Guthion (Azinphosmethyl) spray applications. However, significantly fewer R. mendax larvae were reared from berries collected from plots that received two applications of Guthion compared with plots in which imidacloprid-treated spheres were deployed. Irrespective of sphere deployment strategies, all sphere-treated and sprayed plots had significantly lower injury levels (<1.5%), based on numbers of reared larvae compared with berries collected from the control plots (>4.0%). Based on captures of flies on unbaited Pherocon AM boards placed in the center of treatment plots, we observed a suppression of R. mendax in plots containing imidacloprid-treated spheres compared with control plots. The potential of using imidacloprid-treated spheres as a behavioral control integrated pest management tactic for blueberry maggot flies is discussed.     

Attracticidal spheres for controlling apple maggot flies: commercial-orchard trials

Wooden pesticide-treated red spheres and biodegradable sugar/flour pesticide-treated red spheres were compared with wooden sticky-coated red spheres and insecticide sprays for controlling apple maggot flies, Rhagoletis pomonella(Walsh) (Diptera: Tephritidae), in small blocks of apple trees in Massachusetts commercial orchards in 1997, 1998 and 1999. Pesticide-treated spheres received a coating of 70% latex paint, 20% feeding stimulant (sucrose), and 10% formulated insecticide (containing 20% imidacloprid). To replenish sucrose lost during rainfall, wooden spheres were capped with a disc comprised of hardened sucrose that seeped onto the sphere surface, whereas the surface of sugar/flour spheres received sucrose that seeped from the interior. Each year, each of the 24 perimeter trees of each non-sprayed block received a sphere baited with butyl hexanoate (an attractive component of host fruit odor), with the intent of intercepting immigrating flies. Based on captures of flies on unbaited sticky-coated red spheres placed near the center of each block and on periodic samples of fruit for injury, there was a consistent pattern of treatment performance. Each year, sticky-coated spheres were only slightly less effective than two or three sprays of organophosphate insecticide, sugar/flour pesticide-treated spheres were only slightly less effective than sticky spheres, and wooden pesticide-treated spheres were least effective. Versions of pesticide-treated spheres used in 1999 were more durable than those used in previous years, but further improvement is needed before either wooden or sugar/flour pesticide-treated spheres can be recommended for grower use.     

Revisiting within-tree trap positioning for apple maggot fly (Dipt., Tephritidae) behavioural control

Abstract:  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.     

The genetic basis for fruit odor discrimination in Rhagoletis flies and its significance for sympatric host shifts

Rhagoletis pomonella (Diptera: Tephritidae) use volatile compounds emitted from the surface of ripening fruit as important chemosensory cues for recognizing and distinguishing among alternative host plants. Host choice is of evolutionary significance in Rhagoletis because these flies mate on or near the fruit of their respective host plants. Differences in host choice based on fruit odor discrimination therefore result in differential mate choice and prezygotic reproductive isolation, facilitating sympatric speciation in the absence of geographic isolation. We test for a genetic basis for host fruit odor discrimination through an analysis of F2 and backcross hybrids constructed between apple-, hawthorn-, and flowering dogwood-infesting Rhagoletis flies. We recovered a significant proportion (30-65%) of parental apple, hawthorn, and dogwood fly response phenotypes in F2 hybrids, despite the general failure of F1 hybrids to reach odor source spheres. Segregation patterns in F2 and backcross hybrids suggest that only a modest number of allelic differences at a few loci may underlie host fruit odor discrimination. In addition, a strong bias was observed for F2 and backcross flies to orient to the natal fruit blend of their maternal grandmother, implying the existence of cytonuclear gene interactions. We explore the implications of our findings for the evolutionary dynamics of sympatric host race formation and speciation.     

Evaluation of yellow rectangle traps coated with hot melt pressure sensitive adhesive and sticky gel against Rhagoletis indifferens (Diptera: Tephritidae)

Sticky yellow rectangle traps have been used for many years to capture Rhagoletis (Diptera: Tephritidae) fruit flies. Traditional sticky yellow traps are coated with a sticky gel (SG) that can leave residues on the hands of users. An alternative to SG on traps are hot melt pressure sensitive adhesives (HMPSAs), which are less messy. The main objective here was to evaluate two rectangle traps of two yellow colors, the Alpha Scents Yellow Card coated with HMPSA (Alpha Scents, West Linn, OR), and the Pherocon AM trap coated with SG (Pherocon; Trécé, Adair, OK), for capturing western cherry fruit fly, Rhagoletis indifferens Curran. Flies captured on both traps and held in the laboratory and field did not escape their surfaces. Flies caught on HMPSA were damaged when removed from traps without citrus solvent, whereas flies caught on SG could be removed intact without solvent. In field tests, Alpha Scents traps baited with an ammonium bicarbonate lure captured 1.4-2.2 times more R. indifferens than Pherocon traps baited with the same lure. Results of an experiment that eliminated differences in surface sticky material type, overall size, and surface sticky area between Alpha Scents and Pherocon traps suggested, although did not show conclusively, that more flies were caught on the Alpha Scents than Pherocon traps because of their different yellow color and/or lower fluorescence and not the HMPSA. Overall, the Alpha Scents trap is a viable alternative to the Pherocon trap for detecting R. indifferens.     

颜色对梨小食心虫产卵选择性的影响

梨小食心虫(Grapholitha molesta Busck)是一种重要的果树害虫,早春产卵喜在桃嫩梢叶上,为探明寄主颜色在其产卵选择中的作用,利用彩色卡纸模拟寄主颜色,室内比较了红、粉红、浅粉、橙黄、深黄、浅黄、青绿、深绿、浅绿、蓝、紫、褐色等12种不同颜色基质对其成虫产卵选择性的影响。结果发现:基质颜色对梨小食心虫的产卵选择性有显著影响,其产卵偏嗜浅黄和浅绿色,白色和黑色参比时其产卵选择率分别依次为68.9%、63.8%和64.1%、65.5%,蓝和浅粉色则表现一定的拒避作用,白色和黑色参比时其产卵选择率分别依次为47.7%、40.4%和47.2%、42.7%,且参比色对其产卵选择性影响差异显著。基质颜色对其产卵量亦有显著性影响,无论黑或白色参比,黄、绿颜色上的产卵量均较多,尤其是深黄、深绿和青绿色。基质颜色对1—7日龄梨小食心虫成虫的产卵选择性均有显著影响。白色参比时,2、3日龄蛾对浅绿和浅黄色的产卵选择率显著高于其他颜色;黑色参比时,2日龄时明显偏嗜浅绿色(79.7%),6日龄时明显偏嗜浅黄色(74.8%)。表明寄主颜色在梨小食心虫产卵场所选择中具有重要作用,为其卵期监测和防控中颜色应用乃至进一步揭示其产卵寄主选择机理提供了依据和参考。     

Attraction of fruit flies of the genus Bactrocera to colored mimics of host fruit

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.     

Determinants of egg load in the soybean aphid parasitoid Binodoxys communis

We used a series of laboratory studies to investigate factors contributing to variability in egg load of the parasitoid Binodoxys communis (Gahan) (Hymenoptera: Braconidae), a biological control agent of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae). The change in egg load in newly emerged females over time was determined in response to three treatments: post‐eclosion temperature, sugar meals, and host density. Binodoxys communis females emerge with an average egg load of approximately 40 mature eggs that increases to approximately 200 eggs within 24 h of emergence. The egg maturation rate over this time period is higher when females are held at 26 °C than at 18 °C. And although the egg load of sugar‐fed females was slightly higher than that of starved females, this difference was not statistically significant. Binodoxys communis females that were held with 150 hosts for 8 h laid more eggs than those that were held with 30 hosts, and they also matured more eggs over the subsequent 16 h than those held with 30 hosts or no hosts at all. However, we detected no difference in the egg maturation pattern between B. communis females held with the low host density and that of control females held with no hosts at all. Thus, we conclude that enhanced egg maturation in the higher host‐density treatment is more likely explained by a rapid replenishing of partially depleted ovaries than a host‐induced stimulus of egg maturation per se. Taken together, these results suggest a strategy of maintaining a high egg load and thus avoiding or mitigating the negative effects of egg limitation.