Females of Riptortus pedestris (Hemiptera: Alydidae) in Reproductive Diapause are More Responsive to Synthetic Aggregation Pheromone

Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) enters reproductive diapause under short-day length (< 13.5 h) conditions. As an apparent increase of field populations of R. pedestris has been observed during the fall when aggregation pheromone traps are placed in soybean fields, we tested the hypothesis that R. pedestris becomes more responsive to the aggregation pheromone during fall as it enters its reproductive diapause. The response of R. pedestris females-either ones collected seasonally from fields or reared in the laboratory under short-day length (10:14 [L:D] h) conditions-to the aggregation pheromone was examined using a Y-tube olfactometer. Riptortus pedestris collected in fall showed a higher response to the aggregation pheromone (74-80%) than those collected in July (40%). Females in which diapause was induced in the laboratory also showed a higher response to the pheromone than those not in diapause. In a wind tunnel assay, female bugs in laboratory-induced diapause also responded positively to the aggregation pheromone. In addition, we assessed the reproduction of females to verify their diapausing status. Diapausing females never mated with either short- or long-day-reared males, nor did they reproduce, but non-diapausing females mated with short-day-reared males at a rate of 13%. Females collected from fields during fall never mated. In a soybean field evaluation, the number of adult female R. pedestris was higher in the presence of an aggregation pheromone trap than in the absence of one. This is the first confirmation of higher response to the aggregation pheromone of both field-collected and laboratory-reared R. pedestris in reproductive diapause.

Preseasonal treatment with either omalizumab or an inhaled corticosteroid boost to prevent fall asthma exacerbations

BACKGROUND

Short-term targeted treatment can potentially prevent fall asthma exacerbations while limiting therapy exposure.

OBJECTIVE

We sought to compare (1) omalizumab with placebo and (2) omalizumab with an inhaled corticosteroid (ICS) boost with regard to fall exacerbation rates when initiated 4 to 6 weeks before return to school.

METHODS

A 3-arm, randomized, double-blind, double placebo-controlled, multicenter clinical trial was conducted among inner-city asthmatic children aged 6 to 17 years with 1 or more recent exacerbations (clincaltrials.gov #NCT01430403). Guidelines-based therapy was continued over a 4- to 9-month run-in phase and a 4-month intervention phase. In a subset the effects of omalizumab on IFN-α responses to rhinovirus in PBMCs were examined.

RESULTS

Before the falls of 2012 and 2013, 727 children were enrolled, 513 were randomized, and 478 were analyzed. The fall exacerbation rate was significantly lower in the omalizumab versus placebo arms (11.3% vs 21.0%; odds ratio [OR], 0.48; 95% CI, 0.25-0.92), but there was no significant difference between omalizumab and ICS boost (8.4% vs 11.1%; OR, 0.73; 95% CI, 0.33-1.64). In a prespecified subgroup analysis, among participants with an exacerbation during the run-in phase, omalizumab was significantly more efficacious than both placebo (6.4% vs 36.3%; OR, 0.12; 95% CI, 0.02-0.64) and ICS boost (2.0% vs 27.8%; OR, 0.05; 95% CI, 0.002-0.98). Omalizumab improved IFN-α responses to rhinovirus, and within the omalizumab group, greater IFN-α increases were associated with fewer exacerbations (OR, 0.14; 95% CI, 0.01-0.88). Adverse events were rare and similar among arms.

CONCLUSIONS

Adding omalizumab before return to school to ongoing guidelines-based care among inner-city youth reduces fall asthma exacerbations, particularly among those with a recent exacerbation.