Natural enemy defense, provisioning and oviposition site selection as maternal strategies to enhance offspring survival in a sub-social bug - Fig 3

<p><b>Effect of oviposition site selection (host tree vs. non-host vegetation) on (A) production of core brood and additional eggs, (B) proportion of core brood eggs parasitized, (C) production of offspring nymphs.</b> Values above columns indicate mean (A, C) or median (B) values. Values followed by identical letters did not differ significantly (P > 0.05), except for letter marked with asterisk (*) in (A) which was marginally significant (P = 0.058). Vertical bars indicate interquartile range for median values and standard error for mean values.</p

Natural enemy defense, provisioning and oviposition site selection as maternal strategies to enhance offspring survival in a sub-social bug

<div><p>The influence of maternal defense against natural enemies, maternal provisioning and oviposition site selection on offspring survival before and after hatching were examined in a semelparous pentatomid bug, <i>Ramosiana insignis</i>. Oviposition occurs on leaves of <i>Schoepfia schreberi</i>, or surrounding vegetation from which nymphs migrate to feed exclusively on <i>S</i>. <i>schreberi</i> flower buds. Oviposition is asynchronous; the mother lays additional eggs immediately prior to hatching of the core brood that rapidly consume the additional eggs. In the absence of maternal defense egg masses were more heavily parasitized, suffered ant predation and an increased prevalence of sibling cannibalism. Maternal provisioning in the form of addition eggs significantly reduced the prevalence of sibling cannibalism of core brood eggs. Migration of the core brood away from the oviposition site was also significantly higher in the absence of maternal provisioning. If not consumed, additional eggs were capable of producing viable progeny of both sexes, indicating that they were in fact marginal progeny. The average clutch size on non-host vegetation was numerically greater than clutches laid on host trees (borderline significant P = 0.058). A greater number of additional eggs were deposited with clutches laid on non-host vegetation compared to those on the host plant. Egg masses on non-host vegetation were less likely to be discovered by parasitoids, compared to those on the host tree. Overall, clutches on non-host vegetation produced one third more offspring than clutches on the host tree. We conclude that <i>R</i>. <i>insignis</i> females present a remarkable combination of maternal defense, provisioning of additional eggs and oviposition site selection as strategies to enhance offspring survival in both the egg and nymph stages.</p></div

Natural enemy defense, provisioning and oviposition site selection as maternal strategies to enhance offspring survival in a sub-social bug - Fig 4

<p><b>Nymph survival time for core brood that hatched from egg masses collected on (A) host plants or (B) non-host plants</b>. Core brood were assigned to one of four treatments, with or without additional eggs and with or without flower buds as food. Points labeled with identical letters did not differ significantly (Weibull analysis, P>0.05). Vertical bars indicate 95% confidence internal.</p

Time series of photographs of eclosion of <i>Ramosiana insignis</i> nymphs.

<p>Nymphs begin hatching from core brood (pink) eggs at 12.15 hrs on 10/13/2013 and immediately consume additional yellow-colored eggs on underside of a leaf of <i>Schoepfia schreberi</i> host plant over the following 2 hrs. Images dated 10/14/2013 and 10/20/2013 show presence of core brood at 1 day and 7 days post-hatching. Date format is mo/day/yr.</p

Parameters observed to determine the optimum incubation temperature.

<p>(A) Mean OB production (OBs/larva) and (B) Mean time to death (hours post-infection) of L₅ <i>H</i>. <i>armigera</i> larvae after inoculation with a LC₉₅ concentration of HearSP1B:LB6 OBs and incubated at 23, 26 and 30°C until death. Values followed by identical letters did not differ significantly (OB production: ANOVA, Tukey test, P>0.05; Mean time to death: Weibull analysis, P<0.05). Vertical bars indicate the standard error.</p

Graphical optimization.

<p>(a) Annual cost savings, (b) pupation, (c) duration of the larval stage, (d) pupal weight, (e) adult emergence and (f) overlay contour plot depicting the area of operability. That is, the experimental area meeting all optimization criteria, in which the predicted responses of <i>A</i>. <i>ludens</i> flies to the yeast: corn flour: corncob fractions mixtures representing the highest savings of all mixtures in the area of operability is shown. The yellow shaded area in each plot indicates the experimental space meeting optimization criteria, the gray shaded area is the space that does not fit those criteria.</p

Parameters observed to determine the optimum incubation temperature.

<p>(A) Mean OB production (OBs/larva) and (B) Mean time to death (hours post-infection) of L₅ <i>H</i>. <i>armigera</i> larvae after inoculation with a LC₉₅ concentration of HearSP1B:LB6 OBs and incubated at 23, 26 and 30°C until death. Values followed by identical letters did not differ significantly (OB production: ANOVA, Tukey test, P>0.05; Mean time to death: Weibull analysis, P<0.05). Vertical bars indicate the standard error.</p

Parameters observed to determine the optimum inoculum concentration.

<p>(A) Initial and virus-killed cadaver weight, (B) Percentage of larval mortality, (C) Production of OBs/larva, and (D) OB production per cohort of 100 inoculated larvae, in recently molted L₅ <i>H</i>. <i>armigera</i> inoculated with LC₉₅, LC₉₀ and LC₈₀ concentrations of HearSP1B:LB6 OBs. Values followed by identical letters did not differ significantly (ANOVA and Tukey test, P>0.05). Vertical bars indicate the standard error.</p

Modeling the cost-effectiveness of insect rearing on artificial diets: A test with a tephritid fly used in the sterile insect technique

<div><p>We modeled the cost-effectiveness of rearing <i>Anastrepha ludens</i>, a major fruit fly pest currently mass reared for sterilization and release in pest control programs implementing the sterile insect technique (SIT). An optimization model was generated by combining response surface models of artificial diet cost savings with models of <i>A</i>. <i>ludens</i> pupation, pupal weight, larval development time and adult emergence as a function of mixtures of yeast, a costly ingredient, with corn flour and corncob fractions in the diet. Our model revealed several yeast-reduced mixtures that could be used to prepare diets that were considerably cheaper than a standard diet used for mass rearing. Models predicted a similar production of insects (pupation and adult emergence), with statistically similar pupal weights and larval development times between yeast-reduced diets and the standard mass rearing diet formulation. Annual savings from using the modified diets could be up to 5.9% of the annual cost of yeast, corn flour and corncob fractions used in the standard diet, representing a potential saving of US $27.45 per ton of diet (US$47,496 in the case of the mean annual production of 1,730.29 tons of artificial diet in the Moscafrut mass rearing facility at Metapa, Chiapas, Mexico). Implementation of the yeast-reduced diet on an experimental scale at mass rearing facilities is still required to confirm the suitability of new mixtures of artificial diet for rearing <i>A</i>. <i>ludens</i> for use in SIT. This should include the examination of critical quality control parameters of flies such as adult flight ability, starvation resistance and male sexual competitiveness across various generations. The method used here could be useful for improving the cost-effectiveness of invertebrate or vertebrate mass rearing diets worldwide.</p></div

Lethal concentration (LC₅₀) values and relative potencies of HearSP1B:LB6 OBs produced in L₅ <i>Helicoverpa armigera</i> larvae incubated at different temperatures.

<p>OBs were bioassayed in second instar larvae.</p