scholarly journals Blueberry, Early Season Control of Cranberry Fruitworm and Cherry Fruitworm, 1996

1997 ◽  
Vol 22 (1) ◽  
pp. 53-53
Author(s):  
John C. Wise
Keyword(s):  
Egg Laying ◽  
Early Season ◽  
Cranberry Fruitworm ◽  
Research Complex

Abstract Insecticides were applied to mature blueberry bushes at the Trevor Nichols Research Complex in Douglas, MI at a rate of 50 GPA with a FMC 1029 airblast sprayer. Treatment plots were arranged in a CRB design of two 44 ft long rows containing a total of 22 bushes, replicated 4 times. Funginex was applied separately to all treatments. Applications of materials were made on 10 Jun (1st egg laying, Bloom), 19 Jun (Petal Fall), 25 Jun (PF + 7 days), and 2 Jul (1C). Harvest fruit evaluations were made on 12 Jul by randomly picking 25 blueberry fruit clusters per replicate, or 100 clusters per treatment, and evaluating the fruit for CBFW and CFW injury.

scholarly journals Blueberry, Early Season Control of Cranberry Fruitworm and Cherry Fruitworm, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 59-60
Author(s):  
James W. Johnson ◽  
Robert D. Kriegel ◽  
John C. Wise
Keyword(s):  
Untreated Control ◽  
Treatment Effects ◽  
Egg Laying ◽  
Multiple Comparison ◽  
Early Season ◽  
Cranberry Fruitworm ◽  
Multiple Comparison Procedure

Abstract Insecticides were applied to mature blueberry bushes near Douglas, MI at a rate of 50 gpa with a FMC 1029 airblast sprayer. Treatments plots were arranged in a CRD of two 44 foot-long rows containing a total of 22 bushes, replicated 4 times. Untreated control plots contained 3 rows of blueberries (33 bushes). Funginex was applied separately to all treatments. Applications of materials were made on 9 Jun (1st egg laying) and 15 Jun (Petal Fall) as indicated in the tables. CBFW and CFW injury was assessed by sampling fruit twice weekly from 8 Jun to 29 Jun. Data were analyzed by two way ANOVA followed by Fischer’s LSD multiple comparison procedure for sample dates with significant main treatment effects (P ≤ 0.05). Larval counts for 15, 19, 26, and 29 Jun were transformed using Log(x +1).

Benefits of Courtship-Feeding for Rifleman (Acanthisitta Chloris) Parents

Behaviour ◽  
1989 ◽  
Vol 109 (3-4) ◽  
pp. 303-318 ◽  
Author(s):  
Greg Sherley
Keyword(s):  
Egg Laying ◽  
Early Season ◽  
Food Items ◽  
Total Food Intake ◽  
Energy Demands ◽  
Pair Bonds ◽  
Courtship Feeding ◽  
Total Food ◽  
First Clutch ◽  
Maintenance Requirements

Abstract1. Courtship-feeding was studied in riflemen (Acanthisitta chloris) in a population at Kaikoura, South Island, New Zealand between 1982 and 1984. The proportion of the food males collected which was donated to his mate was calculated and what proportion of the female's diet this represented. This information revealed that males made a significant early season contribution to parental care. 2. Allied information collected during the pre-lay and egg-laying periods included the time to form eggs, laying interval and clutch size. 3. Courtship-feeding in riflemen involved no ceremony. 4. Copulation attempts did not correspond with bouts courtship-feeding or the peak of courtship-feeding. 5. Pairs spent 91.2% of daylight hours in each other's company, which facilitated coursthip-feeding. 6. Food items delivered in courtship-feeding were significantly larger than those eaten by males or females while foraging for themselves, and larger food items were consistently offered throughout the pre-laying and egg-laying periods. 7. The peak in the volume of food delivered to the female occurred about 3.5 days after the first egg was laid. 8. Overall the male contributed 42% of the food he gathered to the female and this comprised 35% of her total food intake. 9. Females fed themselves enough food to meet maintenance requirements and the extra required for oogenesis was received from the male through courtship-feeding and any reserves stored by the female. 10. Riflemen laid eggs every 48 hours which probably reduced peak energy demands during oogenesis. 11. Courtship-feeding was not associated with second clutches which were significantly smaller than the first clutch laid and reared in a season. 12. Incubation occurred after the last egg was laid but was sometimes delayed. During the delay courtship-feeding continued until incubation started. 13. Courtship-feeding represents a significant early season investment by male riflemen in their offspring which probably allows time to rear two broods thereby improving both parents' productivity. Such early season investment might influence sexual selection towards stable, monogamous pair bonds.

Pear, Early Season Control of Pear Psylla and Pear Rust Mite, 1996

1997 ◽  
Vol 22 (1) ◽  
pp. 40-41
Author(s):  
John C. Wise
Keyword(s):  
Visual Inspection ◽  
Early Season ◽  
Sooty Mold ◽  
Pear Psylla ◽  
Stereo Microscope ◽  
Leaf Harvest ◽  
Research Complex

Abstract Mature ‘Bartlett’ trees at the Trevor Nichols Research Complex in Fennville, MI (Pear 1 Block) were sprayed at a rate of 100 gpa with an FMC 1029 airblast sprayer. Trees were arranged in a CR design of single trees replicated 4 times. All materials were applied as indicated in the table on 4 Jun (IC) and 17 Jul (4C, PP Threshold of 0.3 nymphs per leaf). Streptomycin, Benlate, Penncozeb, Rubigan, Captan, and Funginex were applied to all treatments separately. Dates of PP and PRM evaluation were 19 Jun, 2 Jul, 15 Jul, and 8 Aug. At each evaluation, 50 leaves per replicate were picked, brushed in a mite-brushing machine and then examined under a stereo microscope for PRM adults. Twenty-five leaves per replicate were also evaluated under a stereomicroscope for PP nymphs and eggs. Mean data are reported as PRM adults per leaf, and PP nymphs or eggs per leaf. Harvest fruit evaluations were made on 27 Aug by picking 25 fruit randomly from the periphery of the tree from each replicate per treatment. They were examined for sooty mold from PP and PRM russetting. Sooty mold and russetting evaluations were based on visual inspection, with the scoring criteria listed in the table.

scholarly journals Host-mediated, cross-generational intraspecific competition in a multivoltine herbivore species

2020 ◽  
Author(s):  
Bastien Castagneyrol ◽  
Inge van Halder ◽  
Yasmine Kadiri ◽  
Laura Schillé ◽  
Hervé Jactel
Keyword(s):  
Host Plant ◽  
Intraspecific Competition ◽  
Interference Competition ◽  
Growing Season ◽  
Egg Laying ◽  
Larval Performance ◽  
Insect Herbivores ◽  
Next Generation ◽  
Early Season ◽  
Buxus Sempervirens

Conspecific insect herbivores co-occurring on the same host plant interact both directly through interference competition and indirectly through exploitative competition, plant-mediated interactions and enemy-mediated interactions. However, the situation is less clear when the interactions between conspecific insect herbivores are separated in time within the same growing season, as it is the case for multivoltine species. We hypothesized that early season herbivory would result in reduced egg laying and reduced performance of the next generation of herbivore on previously attacked plants. We tested this hypothesis in a choice experiment with box tree moth females, Cydalima perspectalis Walker (Lepidoptera: Crambidae), to which box trees, Buxus sempervirens L. (Buxaceae), were proposed that had or had not been previously defoliated by BTM larvae earlier in the season. We then compared the performance of the next generation larvae on previously damaged vs undamaged plants. Previous herbivory had no effect on oviposition behaviour, but the weight of next generation larvae was significantly lower in previously damaged plants. There was a negative correlation between the number of egg clutches per plant and larval performance. Overall, our findings reveal that early season herbivory reduces the performance of conspecific individuals on the same host plant later in the growing season, and that this time-lagged intraspecific competition results from a mismatch between the oviposition preference of females and the performance of their offspring.

scholarly journals Modeling phenological reaction norms over an elevational gradient reveals contrasting strategies of Dusky Flycatchers and Mountain Chickadees in response to early-season temperatures

The Auk ◽  
2021 ◽  
Author(s):  
Sharon J Coe ◽  
Kathryn L Purcell ◽  
John T Rotenberry
Keyword(s):  
Sierra Nevada ◽  
Elevational Gradient ◽  
Reaction Norm ◽  
High Elevation ◽  
Egg Laying ◽  
Reaction Norms ◽  
Breeding Cycle ◽  
Spring Temperature ◽  
Early Season ◽  
Mountain Chickadees

Abstract We developed an approach to distinguish among 3 alternative strategies that birds may employ relating the timing of egg laying across elevations to annual variation in spring temperature (phenological reaction norms), which we applied to analyze the breeding phenology of 2 species over an elevational gradient in the Sierra Nevada, California. In a “simple-offset” strategy, birds at different elevations initiate breeding relative to environmental temperature in a consistent manner, in that breeding onset is triggered by a critical temperature regardless of when it occurs in the spring. Elevation-specific reaction norms based on multiple years are offset (high-elevation birds start breeding later) but parallel. In a “delay” strategy, in cooler springs, populations at higher elevations that are sensitive to early-season weather-related risks delay laying onset relative to those at lower elevations, yielding a high-elevation reaction norm that diverges from a low-elevation one at cooler temperatures. Conversely, high-elevation populations in cooler springs that are sensitive to the risk of having insufficient time to complete a breeding cycle advance laying onset relative to lower populations (“advance” strategy), yielding a high-elevation reaction norm than converges with a low-elevation one. Both delay and advance strategies imply an elevation-dependent interaction between temperature and date (photoperiod) in influencing laying onset. Examined across 3 elevation groupings, phenological reaction norms of Mountain Chickadees (Poecile gambeli) were essentially parallel, consistent with simple offset, whereas Dusky Flycatchers (Empidonax oberholseri) relationships were more complex. In cooler springs, mid-elevation flycatchers bred comparatively late relative to lowest-elevation birds (delay), implying greater sensitivity to early-season risks, but still with sufficient time to complete a breeding cycle. However, high-elevation flycatchers bred comparatively early relative to mid-elevation populations (advance); delaying at these highest elevations may not be an option. Our approach revealed differences in risk sensitivity that were consistent with other ecological differences between the 2 species.

Experimental increase in female mass during the fertile phase leads to enhanced extra-pair paternity in pied flycatchers Ficedula hypoleuca

2019 ◽  
Author(s):  
Mireia Plaza ◽  
Alejandro Cantarero ◽  
Juan Moreno
Keyword(s):  
Negative Relationship ◽  
Ficedula Hypoleuca ◽  
Egg Laying ◽  
Female Dominance ◽  
Laying Date ◽  
Control Group ◽  
Wing Loading ◽  
Potential Fecundity ◽  
Fertile Phase ◽  
Extra Pair Paternity

Female mass in most altricial birds reaches its maximum during breeding at egg-laying, which coincides temporally with the fertile phase when extra-pair paternity (EPP) is determined. Higher mass at laying may have two different effects on EPP intensity. On the one hand, it would lead to increased wing loading (body mass/wing area), which may impair flight efficiency and thereby reduce female’s capacity to resist unwanted extra-pair male approaches (sexual conflict hypothesis). On the other hand, it would enhance female condition, favouring her capacity to evade mate-guarding and to search for extra-pair mates (female choice hypothesis). In both cases, higher female mass at laying may lead to enhanced EPP. To test this prediction, we reduced nest building effort by adding a completely constructed nest in an experimental group of female pied flycatchers (Ficedula hypoleuca). Our treatment caused an increase in mass and thereby wing loading and this was translated into a significantly higher EPP in the manipulated group compared with the control group as expected. There was also a significant negative relationship between EPP and laying date and the extent of the white wing patch, an index of female dominance. More body reserves at laying mean not only a higher potential fecundity but a higher level of EPP as well. This interaction had not previously received due attention but should be considered in future studies of avian breeding strategies.

Elevated nest predation risk promotes offspring size variation in birds with prolonged parental care.

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Predation Risk ◽  
Reproductive Cycle ◽  
Perceived Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Size Variation ◽  
Egg Laying ◽  
Offspring Size ◽  
Natural Predation ◽  
Risk Spreading

Predation of offspring is the main cause of reproductive failure in many species, and the mere fear of offspring predation shapes reproductive strategies. Yet, natural predation risk is ubiquitously variable and can be unpredictable. Consequently, the perceived prospect of predation early in a reproductive cycle may not reflect the actual risk to ensuing offspring. An increased variance in investment across offspring has been linked to breeding in unpredictable environments in several taxa, but has so far been overlooked as a maternal response to temporal variation in predation risk. Here, we experimentally increased the perceived risk of nest predation prior to egg-laying in seven bird species. Species with prolonged parent-offspring associations increased their intra-brood variation in egg, and subsequently offspring, size. High risk to offspring early in a reproductive cycle can favour a risk-spreading strategy particularly in species with the greatest opportunity to even out offspring quality after fledging.

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