Stored Product Beetle Control
There are five main species of beetle that will infest grain products:
Flour Beetle – They have hard leathery forewings, membranous hind wings, biting mouth parts, 5-6 segmented antennae. Adults reach around 2.0 – 5.0mm in length and reddish brown in colour.
Grain Beetle – Like the flour beetle they have hard leathery fore wings, membranous hindwings and biting mouth parts. Adults reach around 2.5 - 3.5mm long have eleven segmented dubbed antennae and are dark brown in colour.
Grain Weevils – Have thick leathery forewings, membranous hindwings, biting mouthparts, cylindrical bodies, pronounced snout (rostrum), dubbed and elbowed antennae. Adults reach around 3-4mm long and are a shiny dark brown, almost black in colour.
Lesser Grain Borer - Have thick leathery forewings, membranous hindwings, antennae usually less than eleven segmented with lose three segmented antennal club, biting mouthparts and cylindrical bodies. Adults are around 2.0 - 3mm long and dark reddish brown/black in colour.
Spider Beetles – Have many characteristics that give them a spider – like appearance, stout hairy body, thick leathery forewings, membranous hindwings, long eleven segmented antennae, biting mouthparts. Adults reach between 2.5 - 4mm long and are reddish/golden brown in colour.
Biscuit beetles - Can also be known as drug store beetles are part of the Anobiidae family. They have hard leathery forewings that meet across the mid line of the dorsal surface, their hindwings are membranous, and they sometimes lack biting mouthparts. They have 11 segmented antennae and 5 segmented tarsi. Adults are 2 - 5mm long and are reddish brown in colour and the body is covered in yellow hairs.
All the beetles above infest flour, grains and stored products causing loss of value, damage and even spoiling stocks.
The extent of the infestation must be assessed, there are a range of products that can be used to do this such as, pit fall traps, insect probe traps, bait bags and adhesive traps. Whatever method is used thorough records must be kept.
Hygiene is very important, all stores should be well constructed, maintained and easily cleaned. Stores should be well ventilated, insulated and damp proofed, any cracks should be sealed so that the beetles have no access and places to hide.
Commodities should be stored above floor level and neatly stacked away from the walls and should never touch the ceiling. Keeping a gap between stored commodities like this allows for proper ventilation, cleaning, easy inspection and if necessary insecticidal treatments to be applied.
The rotation of stock is important and if possible, a one-way system of transporting the commodities through the premises should be used. Put some thought into packaging as thicker packaging will help deter the beetles and always ensure packaging is tightly sealed. Any food residues should be cleaned thoroughly to prevent the beetles breeding and developing allowing them to infest new materials. Any infested materials should be destroyed or fumigated.
All stored grain must be dried to a suitable moisture content and stored at a suitable temperature for example: 15% moisture content and 15 degrees C and maintained in these conditions.
Insecticides can be used and applied to the fabrics of stores focusing on the potential harbourage for the insects. It may be advised that you use grain protectants for a more long-term solution.
For control in the home it is pretty much the same advice, find the source of the infestation. It could be any stored product such as flour, rice, biscuits, cereals, dog food. Once the source has been identified this needs to be removed and destroyed. Any other products in the vicinity need to be closely inspected and removed if insects are found. Once this has been done insecticidal treatments are needed as there may be insects in the walls, skirting boards or cupboard structures which will re-infest if they aren’t treated.
Call Manchester pest control on 0161 210 2536