Yes, Onslaught Insecticide can be applied in crawl spaces. Please see the product label for specific application instructions.
Onslaught Insecticide and Onslaught FastCap will both do a great job for chiggers. Onslaught FastCap would be the faster acting product due to its one of a kind formulation made of Exponent brand synergist, Esfenvalerate, and Prallethrin. This product does not kill on contact. The active ingredients release over time, allowing the pests to pick up the residual and carry it back into wall voids, cracks and crevices, and other spots where they may hide. The product label does state that this product can be highly toxic to bees and other pollinating insects exposed to direct treatment or residues left on blooming crops or weeds. The best way to reduce the chance of the product affecting the bees, butterflies and beneficial insects is to spray later in the day when they are not active and are back in their homes/nests and try to avoid blooms of flowers and plants they would use for pollination.
Yes, Onslaught Insecticide is labeled for cluster flies. It is mixed at 0.5-1 fl oz per gallon of water per 1,000 sq ft.
Onslaught is a great product for chigger control. Treatments for chiggers should begin in April/May and could need to continue through the summer as new chiggers move into the area. Treating the entire lawn is of little benefit because chiggers avoid direct sunlight and normally will not infest areas that are mowed or otherwise well maintained. Focus treatment on the unkempt areas of the lawn and lawn edge. You can also use Onslaught to do a barrier treatment around the outside of your home and in your crawl space to stop pests from moving indoors.
As long as you are only spraying in the areas specified on the product label, there should be no reason to turn off the natural gas when applying Onslaught. If applying near units with pilot lights you would need to turn those off.
<span new="" roman;="" font-size:medium"="">Both products are pretty comparable to each other, and which you choose really depends on what you are treating for, as they are both great for general pest control. Cyonara is labeled to be used as a crack and crevice treatment only when used indoors. You should use Onslaught insecticide if you would like to do a broadcast treatment over the carpeted areas, it is labeled for over 200 different pests whereas as Cyonara does not have such a broad label. They both can be used in the same areas outside, though Onslaught will hold up a little longer on outside surfaces.
Onslaught can be applied using a hose end sprayer. Be sure that the dial accomodates the mixing ratio needed for your treatment.
Onslaught is a micro-encapsulated product which means it is a time released formula and can take a little longer to kill insects than other products. The exact time it takes to kill will depend on several factors, such as the age and health of the roach and how long it spent in contact with a treated surface. It is often helpful to use a roach bait gel along with an insect growth regulator (IGR) in addition to an insecticide when treating for roaches for complete control. You may want to take a look at our article on How To Get Rid Of Roaches if you have a moment.
Onslaught Insecticide would be a good choice for you. It will control all of the pests you mentioned, in addition to many others.